mm: introduce include/linux/pgtable.h

[mirror_ubuntu-jammy-kernel.git] / arch / powerpc / platforms / pseries / lpar.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * pSeries_lpar.c
 * Copyright (C) 2001 Todd Inglett, IBM Corporation
 *
 * pSeries LPAR support.
 */

/* Enables debugging of low-level hash table routines - careful! */
#undef DEBUG
#define pr_fmt(fmt) "lpar: " fmt

#include <linux/kernel.h>
#include <linux/dma-mapping.h>
#include <linux/console.h>
#include <linux/export.h>
#include <linux/jump_label.h>
#include <linux/delay.h>
#include <linux/stop_machine.h>
#include <linux/spinlock.h>
#include <linux/cpuhotplug.h>
#include <linux/workqueue.h>
#include <linux/proc_fs.h>
#include <asm/processor.h>
#include <asm/mmu.h>
#include <asm/page.h>
#include <linux/pgtable.h>
#include <asm/machdep.h>
#include <asm/mmu_context.h>
#include <asm/iommu.h>
#include <asm/tlb.h>
#include <asm/prom.h>
#include <asm/cputable.h>
#include <asm/udbg.h>
#include <asm/smp.h>
#include <asm/trace.h>
#include <asm/firmware.h>
#include <asm/plpar_wrappers.h>
#include <asm/kexec.h>
#include <asm/fadump.h>
#include <asm/asm-prototypes.h>
#include <asm/debugfs.h>

#include "pseries.h"

/* Flag bits for H_BULK_REMOVE */
#define HBR_REQUEST     0x4000000000000000UL
#define HBR_RESPONSE    0x8000000000000000UL
#define HBR_END         0xc000000000000000UL
#define HBR_AVPN        0x0200000000000000UL
#define HBR_ANDCOND     0x0100000000000000UL


/* in hvCall.S */
EXPORT_SYMBOL(plpar_hcall);
EXPORT_SYMBOL(plpar_hcall9);
EXPORT_SYMBOL(plpar_hcall_norets);

/*
 * H_BLOCK_REMOVE supported block size for this page size in segment who's base
 * page size is that page size.
 *
 * The first index is the segment base page size, the second one is the actual
 * page size.
 */
static int hblkrm_size[MMU_PAGE_COUNT][MMU_PAGE_COUNT] __ro_after_init;

/*
 * Due to the involved complexity, and that the current hypervisor is only
 * returning this value or 0, we are limiting the support of the H_BLOCK_REMOVE
 * buffer size to 8 size block.
 */
#define HBLKRM_SUPPORTED_BLOCK_SIZE 8

#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
static u8 dtl_mask = DTL_LOG_PREEMPT;
#else
static u8 dtl_mask;
#endif

void alloc_dtl_buffers(unsigned long *time_limit)
{
        int cpu;
        struct paca_struct *pp;
        struct dtl_entry *dtl;

        for_each_possible_cpu(cpu) {
                pp = paca_ptrs[cpu];
                if (pp->dispatch_log)
                        continue;
                dtl = kmem_cache_alloc(dtl_cache, GFP_KERNEL);
                if (!dtl) {
                        pr_warn("Failed to allocate dispatch trace log for cpu %d\n",
                                cpu);
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
                        pr_warn("Stolen time statistics will be unreliable\n");
#endif
                        break;
                }

                pp->dtl_ridx = 0;
                pp->dispatch_log = dtl;
                pp->dispatch_log_end = dtl + N_DISPATCH_LOG;
                pp->dtl_curr = dtl;

                if (time_limit && time_after(jiffies, *time_limit)) {
                        cond_resched();
                        *time_limit = jiffies + HZ;
                }
        }
}

void register_dtl_buffer(int cpu)
{
        long ret;
        struct paca_struct *pp;
        struct dtl_entry *dtl;
        int hwcpu = get_hard_smp_processor_id(cpu);

        pp = paca_ptrs[cpu];
        dtl = pp->dispatch_log;
        if (dtl && dtl_mask) {
                pp->dtl_ridx = 0;
                pp->dtl_curr = dtl;
                lppaca_of(cpu).dtl_idx = 0;

                /* hypervisor reads buffer length from this field */
                dtl->enqueue_to_dispatch_time = cpu_to_be32(DISPATCH_LOG_BYTES);
                ret = register_dtl(hwcpu, __pa(dtl));
                if (ret)
                        pr_err("WARNING: DTL registration of cpu %d (hw %d) failed with %ld\n",
                               cpu, hwcpu, ret);

                lppaca_of(cpu).dtl_enable_mask = dtl_mask;
        }
}

#ifdef CONFIG_PPC_SPLPAR
struct dtl_worker {
        struct delayed_work work;
        int cpu;
};

struct vcpu_dispatch_data {
        int last_disp_cpu;

        int total_disp;

        int same_cpu_disp;
        int same_chip_disp;
        int diff_chip_disp;
        int far_chip_disp;

        int numa_home_disp;
        int numa_remote_disp;
        int numa_far_disp;
};

/*
 * This represents the number of cpus in the hypervisor. Since there is no
 * architected way to discover the number of processors in the host, we
 * provision for dealing with NR_CPUS. This is currently 2048 by default, and
 * is sufficient for our purposes. This will need to be tweaked if
 * CONFIG_NR_CPUS is changed.
 */
#define NR_CPUS_H       NR_CPUS

DEFINE_RWLOCK(dtl_access_lock);
static DEFINE_PER_CPU(struct vcpu_dispatch_data, vcpu_disp_data);
static DEFINE_PER_CPU(u64, dtl_entry_ridx);
static DEFINE_PER_CPU(struct dtl_worker, dtl_workers);
static enum cpuhp_state dtl_worker_state;
static DEFINE_MUTEX(dtl_enable_mutex);
static int vcpudispatch_stats_on __read_mostly;
static int vcpudispatch_stats_freq = 50;
static __be32 *vcpu_associativity, *pcpu_associativity;


static void free_dtl_buffers(unsigned long *time_limit)
{
#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
        int cpu;
        struct paca_struct *pp;

        for_each_possible_cpu(cpu) {
                pp = paca_ptrs[cpu];
                if (!pp->dispatch_log)
                        continue;
                kmem_cache_free(dtl_cache, pp->dispatch_log);
                pp->dtl_ridx = 0;
                pp->dispatch_log = 0;
                pp->dispatch_log_end = 0;
                pp->dtl_curr = 0;

                if (time_limit && time_after(jiffies, *time_limit)) {
                        cond_resched();
                        *time_limit = jiffies + HZ;
                }
        }
#endif
}

static int init_cpu_associativity(void)
{
        vcpu_associativity = kcalloc(num_possible_cpus() / threads_per_core,
                        VPHN_ASSOC_BUFSIZE * sizeof(__be32), GFP_KERNEL);
        pcpu_associativity = kcalloc(NR_CPUS_H / threads_per_core,
                        VPHN_ASSOC_BUFSIZE * sizeof(__be32), GFP_KERNEL);

        if (!vcpu_associativity || !pcpu_associativity) {
                pr_err("error allocating memory for associativity information\n");
                return -ENOMEM;
        }

        return 0;
}

static void destroy_cpu_associativity(void)
{
        kfree(vcpu_associativity);
        kfree(pcpu_associativity);
        vcpu_associativity = pcpu_associativity = 0;
}

static __be32 *__get_cpu_associativity(int cpu, __be32 *cpu_assoc, int flag)
{
        __be32 *assoc;
        int rc = 0;

        assoc = &cpu_assoc[(int)(cpu / threads_per_core) * VPHN_ASSOC_BUFSIZE];
        if (!assoc[0]) {
                rc = hcall_vphn(cpu, flag, &assoc[0]);
                if (rc)
                        return NULL;
        }

        return assoc;
}

static __be32 *get_pcpu_associativity(int cpu)
{
        return __get_cpu_associativity(cpu, pcpu_associativity, VPHN_FLAG_PCPU);
}

static __be32 *get_vcpu_associativity(int cpu)
{
        return __get_cpu_associativity(cpu, vcpu_associativity, VPHN_FLAG_VCPU);
}

static int cpu_relative_dispatch_distance(int last_disp_cpu, int cur_disp_cpu)
{
        __be32 *last_disp_cpu_assoc, *cur_disp_cpu_assoc;

        if (last_disp_cpu >= NR_CPUS_H || cur_disp_cpu >= NR_CPUS_H)
                return -EINVAL;

        last_disp_cpu_assoc = get_pcpu_associativity(last_disp_cpu);
        cur_disp_cpu_assoc = get_pcpu_associativity(cur_disp_cpu);

        if (!last_disp_cpu_assoc || !cur_disp_cpu_assoc)
                return -EIO;

        return cpu_distance(last_disp_cpu_assoc, cur_disp_cpu_assoc);
}

static int cpu_home_node_dispatch_distance(int disp_cpu)
{
        __be32 *disp_cpu_assoc, *vcpu_assoc;
        int vcpu_id = smp_processor_id();

        if (disp_cpu >= NR_CPUS_H) {
                pr_debug_ratelimited("vcpu dispatch cpu %d > %d\n",
                                                disp_cpu, NR_CPUS_H);
                return -EINVAL;
        }

        disp_cpu_assoc = get_pcpu_associativity(disp_cpu);
        vcpu_assoc = get_vcpu_associativity(vcpu_id);

        if (!disp_cpu_assoc || !vcpu_assoc)
                return -EIO;

        return cpu_distance(disp_cpu_assoc, vcpu_assoc);
}

static void update_vcpu_disp_stat(int disp_cpu)
{
        struct vcpu_dispatch_data *disp;
        int distance;

        disp = this_cpu_ptr(&vcpu_disp_data);
        if (disp->last_disp_cpu == -1) {
                disp->last_disp_cpu = disp_cpu;
                return;
        }

        disp->total_disp++;

        if (disp->last_disp_cpu == disp_cpu ||
                (cpu_first_thread_sibling(disp->last_disp_cpu) ==
                                        cpu_first_thread_sibling(disp_cpu)))
                disp->same_cpu_disp++;
        else {
                distance = cpu_relative_dispatch_distance(disp->last_disp_cpu,
                                                                disp_cpu);
                if (distance < 0)
                        pr_debug_ratelimited("vcpudispatch_stats: cpu %d: error determining associativity\n",
                                        smp_processor_id());
                else {
                        switch (distance) {
                        case 0:
                                disp->same_chip_disp++;
                                break;
                        case 1:
                                disp->diff_chip_disp++;
                                break;
                        case 2:
                                disp->far_chip_disp++;
                                break;
                        default:
                                pr_debug_ratelimited("vcpudispatch_stats: cpu %d (%d -> %d): unexpected relative dispatch distance %d\n",
                                                 smp_processor_id(),
                                                 disp->last_disp_cpu,
                                                 disp_cpu,
                                                 distance);
                        }
                }
        }

        distance = cpu_home_node_dispatch_distance(disp_cpu);
        if (distance < 0)
                pr_debug_ratelimited("vcpudispatch_stats: cpu %d: error determining associativity\n",
                                smp_processor_id());
        else {
                switch (distance) {
                case 0:
                        disp->numa_home_disp++;
                        break;
                case 1:
                        disp->numa_remote_disp++;
                        break;
                case 2:
                        disp->numa_far_disp++;
                        break;
                default:
                        pr_debug_ratelimited("vcpudispatch_stats: cpu %d on %d: unexpected numa dispatch distance %d\n",
                                                 smp_processor_id(),
                                                 disp_cpu,
                                                 distance);
                }
        }

        disp->last_disp_cpu = disp_cpu;
}

static void process_dtl_buffer(struct work_struct *work)
{
        struct dtl_entry dtle;
        u64 i = __this_cpu_read(dtl_entry_ridx);
        struct dtl_entry *dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG);
        struct dtl_entry *dtl_end = local_paca->dispatch_log_end;
        struct lppaca *vpa = local_paca->lppaca_ptr;
        struct dtl_worker *d = container_of(work, struct dtl_worker, work.work);

        if (!local_paca->dispatch_log)
                return;

        /* if we have been migrated away, we cancel ourself */
        if (d->cpu != smp_processor_id()) {
                pr_debug("vcpudispatch_stats: cpu %d worker migrated -- canceling worker\n",
                                                smp_processor_id());
                return;
        }

        if (i == be64_to_cpu(vpa->dtl_idx))
                goto out;

        while (i < be64_to_cpu(vpa->dtl_idx)) {
                dtle = *dtl;
                barrier();
                if (i + N_DISPATCH_LOG < be64_to_cpu(vpa->dtl_idx)) {
                        /* buffer has overflowed */
                        pr_debug_ratelimited("vcpudispatch_stats: cpu %d lost %lld DTL samples\n",
                                d->cpu,
                                be64_to_cpu(vpa->dtl_idx) - N_DISPATCH_LOG - i);
                        i = be64_to_cpu(vpa->dtl_idx) - N_DISPATCH_LOG;
                        dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG);
                        continue;
                }
                update_vcpu_disp_stat(be16_to_cpu(dtle.processor_id));
                ++i;
                ++dtl;
                if (dtl == dtl_end)
                        dtl = local_paca->dispatch_log;
        }

        __this_cpu_write(dtl_entry_ridx, i);

out:
        schedule_delayed_work_on(d->cpu, to_delayed_work(work),
                                        HZ / vcpudispatch_stats_freq);
}

static int dtl_worker_online(unsigned int cpu)
{
        struct dtl_worker *d = &per_cpu(dtl_workers, cpu);

        memset(d, 0, sizeof(*d));
        INIT_DELAYED_WORK(&d->work, process_dtl_buffer);
        d->cpu = cpu;

#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
        per_cpu(dtl_entry_ridx, cpu) = 0;
        register_dtl_buffer(cpu);
#else
        per_cpu(dtl_entry_ridx, cpu) = be64_to_cpu(lppaca_of(cpu).dtl_idx);
#endif

        schedule_delayed_work_on(cpu, &d->work, HZ / vcpudispatch_stats_freq);
        return 0;
}

static int dtl_worker_offline(unsigned int cpu)
{
        struct dtl_worker *d = &per_cpu(dtl_workers, cpu);

        cancel_delayed_work_sync(&d->work);

#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
        unregister_dtl(get_hard_smp_processor_id(cpu));
#endif

        return 0;
}

static void set_global_dtl_mask(u8 mask)
{
        int cpu;

        dtl_mask = mask;
        for_each_present_cpu(cpu)
                lppaca_of(cpu).dtl_enable_mask = dtl_mask;
}

static void reset_global_dtl_mask(void)
{
        int cpu;

#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
        dtl_mask = DTL_LOG_PREEMPT;
#else
        dtl_mask = 0;
#endif
        for_each_present_cpu(cpu)
                lppaca_of(cpu).dtl_enable_mask = dtl_mask;
}

static int dtl_worker_enable(unsigned long *time_limit)
{
        int rc = 0, state;

        if (!write_trylock(&dtl_access_lock)) {
                rc = -EBUSY;
                goto out;
        }

        set_global_dtl_mask(DTL_LOG_ALL);

        /* Setup dtl buffers and register those */
        alloc_dtl_buffers(time_limit);

        state = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "powerpc/dtl:online",
                                        dtl_worker_online, dtl_worker_offline);
        if (state < 0) {
                pr_err("vcpudispatch_stats: unable to setup workqueue for DTL processing\n");
                free_dtl_buffers(time_limit);
                reset_global_dtl_mask();
                write_unlock(&dtl_access_lock);
                rc = -EINVAL;
                goto out;
        }
        dtl_worker_state = state;

out:
        return rc;
}

static void dtl_worker_disable(unsigned long *time_limit)
{
        cpuhp_remove_state(dtl_worker_state);
        free_dtl_buffers(time_limit);
        reset_global_dtl_mask();
        write_unlock(&dtl_access_lock);
}

static ssize_t vcpudispatch_stats_write(struct file *file, const char __user *p,
                size_t count, loff_t *ppos)
{
        unsigned long time_limit = jiffies + HZ;
        struct vcpu_dispatch_data *disp;
        int rc, cmd, cpu;
        char buf[16];

        if (count > 15)
                return -EINVAL;

        if (copy_from_user(buf, p, count))
                return -EFAULT;

        buf[count] = 0;
        rc = kstrtoint(buf, 0, &cmd);
        if (rc || cmd < 0 || cmd > 1) {
                pr_err("vcpudispatch_stats: please use 0 to disable or 1 to enable dispatch statistics\n");
                return rc ? rc : -EINVAL;
        }

        mutex_lock(&dtl_enable_mutex);

        if ((cmd == 0 && !vcpudispatch_stats_on) ||
                        (cmd == 1 && vcpudispatch_stats_on))
                goto out;

        if (cmd) {
                rc = init_cpu_associativity();
                if (rc)
                        goto out;

                for_each_possible_cpu(cpu) {
                        disp = per_cpu_ptr(&vcpu_disp_data, cpu);
                        memset(disp, 0, sizeof(*disp));
                        disp->last_disp_cpu = -1;
                }

                rc = dtl_worker_enable(&time_limit);
                if (rc) {
                        destroy_cpu_associativity();
                        goto out;
                }
        } else {
                dtl_worker_disable(&time_limit);
                destroy_cpu_associativity();
        }

        vcpudispatch_stats_on = cmd;

out:
        mutex_unlock(&dtl_enable_mutex);
        if (rc)
                return rc;
        return count;
}

static int vcpudispatch_stats_display(struct seq_file *p, void *v)
{
        int cpu;
        struct vcpu_dispatch_data *disp;

        if (!vcpudispatch_stats_on) {
                seq_puts(p, "off\n");
                return 0;
        }

        for_each_online_cpu(cpu) {
                disp = per_cpu_ptr(&vcpu_disp_data, cpu);
                seq_printf(p, "cpu%d", cpu);
                seq_put_decimal_ull(p, " ", disp->total_disp);
                seq_put_decimal_ull(p, " ", disp->same_cpu_disp);
                seq_put_decimal_ull(p, " ", disp->same_chip_disp);
                seq_put_decimal_ull(p, " ", disp->diff_chip_disp);
                seq_put_decimal_ull(p, " ", disp->far_chip_disp);
                seq_put_decimal_ull(p, " ", disp->numa_home_disp);
                seq_put_decimal_ull(p, " ", disp->numa_remote_disp);
                seq_put_decimal_ull(p, " ", disp->numa_far_disp);
                seq_puts(p, "\n");
        }

        return 0;
}

static int vcpudispatch_stats_open(struct inode *inode, struct file *file)
{
        return single_open(file, vcpudispatch_stats_display, NULL);
}

static const struct proc_ops vcpudispatch_stats_proc_ops = {
        .proc_open      = vcpudispatch_stats_open,
        .proc_read      = seq_read,
        .proc_write     = vcpudispatch_stats_write,
        .proc_lseek     = seq_lseek,
        .proc_release   = single_release,
};

static ssize_t vcpudispatch_stats_freq_write(struct file *file,
                const char __user *p, size_t count, loff_t *ppos)
{
        int rc, freq;
        char buf[16];

        if (count > 15)
                return -EINVAL;

        if (copy_from_user(buf, p, count))
                return -EFAULT;

        buf[count] = 0;
        rc = kstrtoint(buf, 0, &freq);
        if (rc || freq < 1 || freq > HZ) {
                pr_err("vcpudispatch_stats_freq: please specify a frequency between 1 and %d\n",
                                HZ);
                return rc ? rc : -EINVAL;
        }

        vcpudispatch_stats_freq = freq;

        return count;
}

static int vcpudispatch_stats_freq_display(struct seq_file *p, void *v)
{
        seq_printf(p, "%d\n", vcpudispatch_stats_freq);
        return 0;
}

static int vcpudispatch_stats_freq_open(struct inode *inode, struct file *file)
{
        return single_open(file, vcpudispatch_stats_freq_display, NULL);
}

static const struct proc_ops vcpudispatch_stats_freq_proc_ops = {
        .proc_open      = vcpudispatch_stats_freq_open,
        .proc_read      = seq_read,
        .proc_write     = vcpudispatch_stats_freq_write,
        .proc_lseek     = seq_lseek,
        .proc_release   = single_release,
};

static int __init vcpudispatch_stats_procfs_init(void)
{
        /*
         * Avoid smp_processor_id while preemptible. All CPUs should have
         * the same value for lppaca_shared_proc.
         */
        preempt_disable();
        if (!lppaca_shared_proc(get_lppaca())) {
                preempt_enable();
                return 0;
        }
        preempt_enable();

        if (!proc_create("powerpc/vcpudispatch_stats", 0600, NULL,
                                        &vcpudispatch_stats_proc_ops))
                pr_err("vcpudispatch_stats: error creating procfs file\n");
        else if (!proc_create("powerpc/vcpudispatch_stats_freq", 0600, NULL,
                                        &vcpudispatch_stats_freq_proc_ops))
                pr_err("vcpudispatch_stats_freq: error creating procfs file\n");

        return 0;
}

machine_device_initcall(pseries, vcpudispatch_stats_procfs_init);
#endif /* CONFIG_PPC_SPLPAR */

void vpa_init(int cpu)
{
        int hwcpu = get_hard_smp_processor_id(cpu);
        unsigned long addr;
        long ret;

        /*
         * The spec says it "may be problematic" if CPU x registers the VPA of
         * CPU y. We should never do that, but wail if we ever do.
         */
        WARN_ON(cpu != smp_processor_id());

        if (cpu_has_feature(CPU_FTR_ALTIVEC))
                lppaca_of(cpu).vmxregs_in_use = 1;

        if (cpu_has_feature(CPU_FTR_ARCH_207S))
                lppaca_of(cpu).ebb_regs_in_use = 1;

        addr = __pa(&lppaca_of(cpu));
        ret = register_vpa(hwcpu, addr);

        if (ret) {
                pr_err("WARNING: VPA registration for cpu %d (hw %d) of area "
                       "%lx failed with %ld\n", cpu, hwcpu, addr, ret);
                return;
        }

#ifdef CONFIG_PPC_BOOK3S_64
        /*
         * PAPR says this feature is SLB-Buffer but firmware never
         * reports that.  All SPLPAR support SLB shadow buffer.
         */
        if (!radix_enabled() && firmware_has_feature(FW_FEATURE_SPLPAR)) {
                addr = __pa(paca_ptrs[cpu]->slb_shadow_ptr);
                ret = register_slb_shadow(hwcpu, addr);
                if (ret)
                        pr_err("WARNING: SLB shadow buffer registration for "
                               "cpu %d (hw %d) of area %lx failed with %ld\n",
                               cpu, hwcpu, addr, ret);
        }
#endif /* CONFIG_PPC_BOOK3S_64 */

        /*
         * Register dispatch trace log, if one has been allocated.
         */
        register_dtl_buffer(cpu);
}

#ifdef CONFIG_PPC_BOOK3S_64

static long pSeries_lpar_hpte_insert(unsigned long hpte_group,
                                     unsigned long vpn, unsigned long pa,
                                     unsigned long rflags, unsigned long vflags,
                                     int psize, int apsize, int ssize)
{
        unsigned long lpar_rc;
        unsigned long flags;
        unsigned long slot;
        unsigned long hpte_v, hpte_r;

        if (!(vflags & HPTE_V_BOLTED))
                pr_devel("hpte_insert(group=%lx, vpn=%016lx, "
                         "pa=%016lx, rflags=%lx, vflags=%lx, psize=%d)\n",
                         hpte_group, vpn,  pa, rflags, vflags, psize);

        hpte_v = hpte_encode_v(vpn, psize, apsize, ssize) | vflags | HPTE_V_VALID;
        hpte_r = hpte_encode_r(pa, psize, apsize) | rflags;

        if (!(vflags & HPTE_V_BOLTED))
                pr_devel(" hpte_v=%016lx, hpte_r=%016lx\n", hpte_v, hpte_r);

        /* Now fill in the actual HPTE */
        /* Set CEC cookie to 0         */
        /* Zero page = 0               */
        /* I-cache Invalidate = 0      */
        /* I-cache synchronize = 0     */
        /* Exact = 0                   */
        flags = 0;

        if (firmware_has_feature(FW_FEATURE_XCMO) && !(hpte_r & HPTE_R_N))
                flags |= H_COALESCE_CAND;

        lpar_rc = plpar_pte_enter(flags, hpte_group, hpte_v, hpte_r, &slot);
        if (unlikely(lpar_rc == H_PTEG_FULL)) {
                pr_devel("Hash table group is full\n");
                return -1;
        }

        /*
         * Since we try and ioremap PHBs we don't own, the pte insert
         * will fail. However we must catch the failure in hash_page
         * or we will loop forever, so return -2 in this case.
         */
        if (unlikely(lpar_rc != H_SUCCESS)) {
                pr_err("Failed hash pte insert with error %ld\n", lpar_rc);
                return -2;
        }
        if (!(vflags & HPTE_V_BOLTED))
                pr_devel(" -> slot: %lu\n", slot & 7);

        /* Because of iSeries, we have to pass down the secondary
         * bucket bit here as well
         */
        return (slot & 7) | (!!(vflags & HPTE_V_SECONDARY) << 3);
}

static DEFINE_SPINLOCK(pSeries_lpar_tlbie_lock);

static long pSeries_lpar_hpte_remove(unsigned long hpte_group)
{
        unsigned long slot_offset;
        unsigned long lpar_rc;
        int i;
        unsigned long dummy1, dummy2;

        /* pick a random slot to start at */
        slot_offset = mftb() & 0x7;

        for (i = 0; i < HPTES_PER_GROUP; i++) {

                /* don't remove a bolted entry */
                lpar_rc = plpar_pte_remove(H_ANDCOND, hpte_group + slot_offset,
                                           HPTE_V_BOLTED, &dummy1, &dummy2);
                if (lpar_rc == H_SUCCESS)
                        return i;

                /*
                 * The test for adjunct partition is performed before the
                 * ANDCOND test.  H_RESOURCE may be returned, so we need to
                 * check for that as well.
                 */
                BUG_ON(lpar_rc != H_NOT_FOUND && lpar_rc != H_RESOURCE);

                slot_offset++;
                slot_offset &= 0x7;
        }

        return -1;
}

static void manual_hpte_clear_all(void)
{
        unsigned long size_bytes = 1UL << ppc64_pft_size;
        unsigned long hpte_count = size_bytes >> 4;
        struct {
                unsigned long pteh;
                unsigned long ptel;
        } ptes[4];
        long lpar_rc;
        unsigned long i, j;

        /* Read in batches of 4,
         * invalidate only valid entries not in the VRMA
         * hpte_count will be a multiple of 4
         */
        for (i = 0; i < hpte_count; i += 4) {
                lpar_rc = plpar_pte_read_4_raw(0, i, (void *)ptes);
                if (lpar_rc != H_SUCCESS) {
                        pr_info("Failed to read hash page table at %ld err %ld\n",
                                i, lpar_rc);
                        continue;
                }
                for (j = 0; j < 4; j++){
                        if ((ptes[j].pteh & HPTE_V_VRMA_MASK) ==
                                HPTE_V_VRMA_MASK)
                                continue;
                        if (ptes[j].pteh & HPTE_V_VALID)
                                plpar_pte_remove_raw(0, i + j, 0,
                                        &(ptes[j].pteh), &(ptes[j].ptel));
                }
        }
}

static int hcall_hpte_clear_all(void)
{
        int rc;

        do {
                rc = plpar_hcall_norets(H_CLEAR_HPT);
        } while (rc == H_CONTINUE);

        return rc;
}

static void pseries_hpte_clear_all(void)
{
        int rc;

        rc = hcall_hpte_clear_all();
        if (rc != H_SUCCESS)
                manual_hpte_clear_all();

#ifdef __LITTLE_ENDIAN__
        /*
         * Reset exceptions to big endian.
         *
         * FIXME this is a hack for kexec, we need to reset the exception
         * endian before starting the new kernel and this is a convenient place
         * to do it.
         *
         * This is also called on boot when a fadump happens. In that case we
         * must not change the exception endian mode.
         */
        if (firmware_has_feature(FW_FEATURE_SET_MODE) && !is_fadump_active())
                pseries_big_endian_exceptions();
#endif
}

/*
 * NOTE: for updatepp ops we are fortunate that the linux "newpp" bits and
 * the low 3 bits of flags happen to line up.  So no transform is needed.
 * We can probably optimize here and assume the high bits of newpp are
 * already zero.  For now I am paranoid.
 */
static long pSeries_lpar_hpte_updatepp(unsigned long slot,
                                       unsigned long newpp,
                                       unsigned long vpn,
                                       int psize, int apsize,
                                       int ssize, unsigned long inv_flags)
{
        unsigned long lpar_rc;
        unsigned long flags;
        unsigned long want_v;

        want_v = hpte_encode_avpn(vpn, psize, ssize);

        flags = (newpp & 7) | H_AVPN;
        if (mmu_has_feature(MMU_FTR_KERNEL_RO))
                /* Move pp0 into bit 8 (IBM 55) */
                flags |= (newpp & HPTE_R_PP0) >> 55;

        pr_devel("    update: avpnv=%016lx, hash=%016lx, f=%lx, psize: %d ...",
                 want_v, slot, flags, psize);

        lpar_rc = plpar_pte_protect(flags, slot, want_v);

        if (lpar_rc == H_NOT_FOUND) {
                pr_devel("not found !\n");
                return -1;
        }

        pr_devel("ok\n");

        BUG_ON(lpar_rc != H_SUCCESS);

        return 0;
}

static long __pSeries_lpar_hpte_find(unsigned long want_v, unsigned long hpte_group)
{
        long lpar_rc;
        unsigned long i, j;
        struct {
                unsigned long pteh;
                unsigned long ptel;
        } ptes[4];

        for (i = 0; i < HPTES_PER_GROUP; i += 4, hpte_group += 4) {

                lpar_rc = plpar_pte_read_4(0, hpte_group, (void *)ptes);
                if (lpar_rc != H_SUCCESS) {
                        pr_info("Failed to read hash page table at %ld err %ld\n",
                                hpte_group, lpar_rc);
                        continue;
                }

                for (j = 0; j < 4; j++) {
                        if (HPTE_V_COMPARE(ptes[j].pteh, want_v) &&
                            (ptes[j].pteh & HPTE_V_VALID))
                                return i + j;
                }
        }

        return -1;
}

static long pSeries_lpar_hpte_find(unsigned long vpn, int psize, int ssize)
{
        long slot;
        unsigned long hash;
        unsigned long want_v;
        unsigned long hpte_group;

        hash = hpt_hash(vpn, mmu_psize_defs[psize].shift, ssize);
        want_v = hpte_encode_avpn(vpn, psize, ssize);

        /*
         * We try to keep bolted entries always in primary hash
         * But in some case we can find them in secondary too.
         */
        hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
        slot = __pSeries_lpar_hpte_find(want_v, hpte_group);
        if (slot < 0) {
                /* Try in secondary */
                hpte_group = (~hash & htab_hash_mask) * HPTES_PER_GROUP;
                slot = __pSeries_lpar_hpte_find(want_v, hpte_group);
                if (slot < 0)
                        return -1;
        }
        return hpte_group + slot;
}

static void pSeries_lpar_hpte_updateboltedpp(unsigned long newpp,
                                             unsigned long ea,
                                             int psize, int ssize)
{
        unsigned long vpn;
        unsigned long lpar_rc, slot, vsid, flags;

        vsid = get_kernel_vsid(ea, ssize);
        vpn = hpt_vpn(ea, vsid, ssize);

        slot = pSeries_lpar_hpte_find(vpn, psize, ssize);
        BUG_ON(slot == -1);

        flags = newpp & 7;
        if (mmu_has_feature(MMU_FTR_KERNEL_RO))
                /* Move pp0 into bit 8 (IBM 55) */
                flags |= (newpp & HPTE_R_PP0) >> 55;

        lpar_rc = plpar_pte_protect(flags, slot, 0);

        BUG_ON(lpar_rc != H_SUCCESS);
}

static void pSeries_lpar_hpte_invalidate(unsigned long slot, unsigned long vpn,
                                         int psize, int apsize,
                                         int ssize, int local)
{
        unsigned long want_v;
        unsigned long lpar_rc;
        unsigned long dummy1, dummy2;

        pr_devel("    inval : slot=%lx, vpn=%016lx, psize: %d, local: %d\n",
                 slot, vpn, psize, local);

        want_v = hpte_encode_avpn(vpn, psize, ssize);
        lpar_rc = plpar_pte_remove(H_AVPN, slot, want_v, &dummy1, &dummy2);
        if (lpar_rc == H_NOT_FOUND)
                return;

        BUG_ON(lpar_rc != H_SUCCESS);
}


/*
 * As defined in the PAPR's section 14.5.4.1.8
 * The control mask doesn't include the returned reference and change bit from
 * the processed PTE.
 */
#define HBLKR_AVPN              0x0100000000000000UL
#define HBLKR_CTRL_MASK         0xf800000000000000UL
#define HBLKR_CTRL_SUCCESS      0x8000000000000000UL
#define HBLKR_CTRL_ERRNOTFOUND  0x8800000000000000UL
#define HBLKR_CTRL_ERRBUSY      0xa000000000000000UL

/*
 * Returned true if we are supporting this block size for the specified segment
 * base page size and actual page size.
 *
 * Currently, we only support 8 size block.
 */
static inline bool is_supported_hlbkrm(int bpsize, int psize)
{
        return (hblkrm_size[bpsize][psize] == HBLKRM_SUPPORTED_BLOCK_SIZE);
}

/**
 * H_BLOCK_REMOVE caller.
 * @idx should point to the latest @param entry set with a PTEX.
 * If PTE cannot be processed because another CPUs has already locked that
 * group, those entries are put back in @param starting at index 1.
 * If entries has to be retried and @retry_busy is set to true, these entries
 * are retried until success. If @retry_busy is set to false, the returned
 * is the number of entries yet to process.
 */
static unsigned long call_block_remove(unsigned long idx, unsigned long *param,
                                       bool retry_busy)
{
        unsigned long i, rc, new_idx;
        unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];

        if (idx < 2) {
                pr_warn("Unexpected empty call to H_BLOCK_REMOVE");
                return 0;
        }
again:
        new_idx = 0;
        if (idx > PLPAR_HCALL9_BUFSIZE) {
                pr_err("Too many PTEs (%lu) for H_BLOCK_REMOVE", idx);
                idx = PLPAR_HCALL9_BUFSIZE;
        } else if (idx < PLPAR_HCALL9_BUFSIZE)
                param[idx] = HBR_END;

        rc = plpar_hcall9(H_BLOCK_REMOVE, retbuf,
                          param[0], /* AVA */
                          param[1],  param[2],  param[3],  param[4], /* TS0-7 */
                          param[5],  param[6],  param[7],  param[8]);
        if (rc == H_SUCCESS)
                return 0;

        BUG_ON(rc != H_PARTIAL);

        /* Check that the unprocessed entries were 'not found' or 'busy' */
        for (i = 0; i < idx-1; i++) {
                unsigned long ctrl = retbuf[i] & HBLKR_CTRL_MASK;

                if (ctrl == HBLKR_CTRL_ERRBUSY) {
                        param[++new_idx] = param[i+1];
                        continue;
                }

                BUG_ON(ctrl != HBLKR_CTRL_SUCCESS
                       && ctrl != HBLKR_CTRL_ERRNOTFOUND);
        }

        /*
         * If there were entries found busy, retry these entries if requested,
         * of if all the entries have to be retried.
         */
        if (new_idx && (retry_busy || new_idx == (PLPAR_HCALL9_BUFSIZE-1))) {
                idx = new_idx + 1;
                goto again;
        }

        return new_idx;
}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/*
 * Limit iterations holding pSeries_lpar_tlbie_lock to 3. We also need
 * to make sure that we avoid bouncing the hypervisor tlbie lock.
 */
#define PPC64_HUGE_HPTE_BATCH 12

static void hugepage_block_invalidate(unsigned long *slot, unsigned long *vpn,
                                      int count, int psize, int ssize)
{
        unsigned long param[PLPAR_HCALL9_BUFSIZE];
        unsigned long shift, current_vpgb, vpgb;
        int i, pix = 0;

        shift = mmu_psize_defs[psize].shift;

        for (i = 0; i < count; i++) {
                /*
                 * Shifting 3 bits more on the right to get a
                 * 8 pages aligned virtual addresse.
                 */
                vpgb = (vpn[i] >> (shift - VPN_SHIFT + 3));
                if (!pix || vpgb != current_vpgb) {
                        /*
                         * Need to start a new 8 pages block, flush
                         * the current one if needed.
                         */
                        if (pix)
                                (void)call_block_remove(pix, param, true);
                        current_vpgb = vpgb;
                        param[0] = hpte_encode_avpn(vpn[i], psize, ssize);
                        pix = 1;
                }

                param[pix++] = HBR_REQUEST | HBLKR_AVPN | slot[i];
                if (pix == PLPAR_HCALL9_BUFSIZE) {
                        pix = call_block_remove(pix, param, false);
                        /*
                         * pix = 0 means that all the entries were
                         * removed, we can start a new block.
                         * Otherwise, this means that there are entries
                         * to retry, and pix points to latest one, so
                         * we should increment it and try to continue
                         * the same block.
                         */
                        if (pix)
                                pix++;
                }
        }
        if (pix)
                (void)call_block_remove(pix, param, true);
}

static void hugepage_bulk_invalidate(unsigned long *slot, unsigned long *vpn,
                                     int count, int psize, int ssize)
{
        unsigned long param[PLPAR_HCALL9_BUFSIZE];
        int i = 0, pix = 0, rc;

        for (i = 0; i < count; i++) {

                if (!firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
                        pSeries_lpar_hpte_invalidate(slot[i], vpn[i], psize, 0,
                                                     ssize, 0);
                } else {
                        param[pix] = HBR_REQUEST | HBR_AVPN | slot[i];
                        param[pix+1] = hpte_encode_avpn(vpn[i], psize, ssize);
                        pix += 2;
                        if (pix == 8) {
                                rc = plpar_hcall9(H_BULK_REMOVE, param,
                                                  param[0], param[1], param[2],
                                                  param[3], param[4], param[5],
                                                  param[6], param[7]);
                                BUG_ON(rc != H_SUCCESS);
                                pix = 0;
                        }
                }
        }
        if (pix) {
                param[pix] = HBR_END;
                rc = plpar_hcall9(H_BULK_REMOVE, param, param[0], param[1],
                                  param[2], param[3], param[4], param[5],
                                  param[6], param[7]);
                BUG_ON(rc != H_SUCCESS);
        }
}

static inline void __pSeries_lpar_hugepage_invalidate(unsigned long *slot,
                                                      unsigned long *vpn,
                                                      int count, int psize,
                                                      int ssize)
{
        unsigned long flags = 0;
        int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);

        if (lock_tlbie)
                spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);

        /* Assuming THP size is 16M */
        if (is_supported_hlbkrm(psize, MMU_PAGE_16M))
                hugepage_block_invalidate(slot, vpn, count, psize, ssize);
        else
                hugepage_bulk_invalidate(slot, vpn, count, psize, ssize);

        if (lock_tlbie)
                spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);
}

static void pSeries_lpar_hugepage_invalidate(unsigned long vsid,
                                             unsigned long addr,
                                             unsigned char *hpte_slot_array,
                                             int psize, int ssize, int local)
{
        int i, index = 0;
        unsigned long s_addr = addr;
        unsigned int max_hpte_count, valid;
        unsigned long vpn_array[PPC64_HUGE_HPTE_BATCH];
        unsigned long slot_array[PPC64_HUGE_HPTE_BATCH];
        unsigned long shift, hidx, vpn = 0, hash, slot;

        shift = mmu_psize_defs[psize].shift;
        max_hpte_count = 1U << (PMD_SHIFT - shift);

        for (i = 0; i < max_hpte_count; i++) {
                valid = hpte_valid(hpte_slot_array, i);
                if (!valid)
                        continue;
                hidx =  hpte_hash_index(hpte_slot_array, i);

                /* get the vpn */
                addr = s_addr + (i * (1ul << shift));
                vpn = hpt_vpn(addr, vsid, ssize);
                hash = hpt_hash(vpn, shift, ssize);
                if (hidx & _PTEIDX_SECONDARY)
                        hash = ~hash;

                slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
                slot += hidx & _PTEIDX_GROUP_IX;

                slot_array[index] = slot;
                vpn_array[index] = vpn;
                if (index == PPC64_HUGE_HPTE_BATCH - 1) {
                        /*
                         * Now do a bluk invalidate
                         */
                        __pSeries_lpar_hugepage_invalidate(slot_array,
                                                           vpn_array,
                                                           PPC64_HUGE_HPTE_BATCH,
                                                           psize, ssize);
                        index = 0;
                } else
                        index++;
        }
        if (index)
                __pSeries_lpar_hugepage_invalidate(slot_array, vpn_array,
                                                   index, psize, ssize);
}
#else
static void pSeries_lpar_hugepage_invalidate(unsigned long vsid,
                                             unsigned long addr,
                                             unsigned char *hpte_slot_array,
                                             int psize, int ssize, int local)
{
        WARN(1, "%s called without THP support\n", __func__);
}
#endif

static int pSeries_lpar_hpte_removebolted(unsigned long ea,
                                          int psize, int ssize)
{
        unsigned long vpn;
        unsigned long slot, vsid;

        vsid = get_kernel_vsid(ea, ssize);
        vpn = hpt_vpn(ea, vsid, ssize);

        slot = pSeries_lpar_hpte_find(vpn, psize, ssize);
        if (slot == -1)
                return -ENOENT;

        /*
         * lpar doesn't use the passed actual page size
         */
        pSeries_lpar_hpte_invalidate(slot, vpn, psize, 0, ssize, 0);
        return 0;
}


static inline unsigned long compute_slot(real_pte_t pte,
                                         unsigned long vpn,
                                         unsigned long index,
                                         unsigned long shift,
                                         int ssize)
{
        unsigned long slot, hash, hidx;

        hash = hpt_hash(vpn, shift, ssize);
        hidx = __rpte_to_hidx(pte, index);
        if (hidx & _PTEIDX_SECONDARY)
                hash = ~hash;
        slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
        slot += hidx & _PTEIDX_GROUP_IX;
        return slot;
}

/**
 * The hcall H_BLOCK_REMOVE implies that the virtual pages to processed are
 * "all within the same naturally aligned 8 page virtual address block".
 */
static void do_block_remove(unsigned long number, struct ppc64_tlb_batch *batch,
                            unsigned long *param)
{
        unsigned long vpn;
        unsigned long i, pix = 0;
        unsigned long index, shift, slot, current_vpgb, vpgb;
        real_pte_t pte;
        int psize, ssize;

        psize = batch->psize;
        ssize = batch->ssize;

        for (i = 0; i < number; i++) {
                vpn = batch->vpn[i];
                pte = batch->pte[i];
                pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
                        /*
                         * Shifting 3 bits more on the right to get a
                         * 8 pages aligned virtual addresse.
                         */
                        vpgb = (vpn >> (shift - VPN_SHIFT + 3));
                        if (!pix || vpgb != current_vpgb) {
                                /*
                                 * Need to start a new 8 pages block, flush
                                 * the current one if needed.
                                 */
                                if (pix)
                                        (void)call_block_remove(pix, param,
                                                                true);
                                current_vpgb = vpgb;
                                param[0] = hpte_encode_avpn(vpn, psize,
                                                            ssize);
                                pix = 1;
                        }

                        slot = compute_slot(pte, vpn, index, shift, ssize);
                        param[pix++] = HBR_REQUEST | HBLKR_AVPN | slot;

                        if (pix == PLPAR_HCALL9_BUFSIZE) {
                                pix = call_block_remove(pix, param, false);
                                /*
                                 * pix = 0 means that all the entries were
                                 * removed, we can start a new block.
                                 * Otherwise, this means that there are entries
                                 * to retry, and pix points to latest one, so
                                 * we should increment it and try to continue
                                 * the same block.
                                 */
                                if (pix)
                                        pix++;
                        }
                } pte_iterate_hashed_end();
        }

        if (pix)
                (void)call_block_remove(pix, param, true);
}

/*
 * TLB Block Invalidate Characteristics
 *
 * These characteristics define the size of the block the hcall H_BLOCK_REMOVE
 * is able to process for each couple segment base page size, actual page size.
 *
 * The ibm,get-system-parameter properties is returning a buffer with the
 * following layout:
 *
 * [ 2 bytes size of the RTAS buffer (excluding these 2 bytes) ]
 * -----------------
 * TLB Block Invalidate Specifiers:
 * [ 1 byte LOG base 2 of the TLB invalidate block size being specified ]
 * [ 1 byte Number of page sizes (N) that are supported for the specified
 *          TLB invalidate block size ]
 * [ 1 byte Encoded segment base page size and actual page size
 *          MSB=0 means 4k segment base page size and actual page size
 *          MSB=1 the penc value in mmu_psize_def ]
 * ...
 * -----------------
 * Next TLB Block Invalidate Specifiers...
 * -----------------
 * [ 0 ]
 */
static inline void set_hblkrm_bloc_size(int bpsize, int psize,
                                        unsigned int block_size)
{
        if (block_size > hblkrm_size[bpsize][psize])
                hblkrm_size[bpsize][psize] = block_size;
}

/*
 * Decode the Encoded segment base page size and actual page size.
 * PAPR specifies:
 *   - bit 7 is the L bit
 *   - bits 0-5 are the penc value
 * If the L bit is 0, this means 4K segment base page size and actual page size
 * otherwise the penc value should be read.
 */
#define HBLKRM_L_MASK           0x80
#define HBLKRM_PENC_MASK        0x3f
static inline void __init check_lp_set_hblkrm(unsigned int lp,
                                              unsigned int block_size)
{
        unsigned int bpsize, psize;

        /* First, check the L bit, if not set, this means 4K */
        if ((lp & HBLKRM_L_MASK) == 0) {
                set_hblkrm_bloc_size(MMU_PAGE_4K, MMU_PAGE_4K, block_size);
                return;
        }

        lp &= HBLKRM_PENC_MASK;
        for (bpsize = 0; bpsize < MMU_PAGE_COUNT; bpsize++) {
                struct mmu_psize_def *def = &mmu_psize_defs[bpsize];

                for (psize = 0; psize < MMU_PAGE_COUNT; psize++) {
                        if (def->penc[psize] == lp) {
                                set_hblkrm_bloc_size(bpsize, psize, block_size);
                                return;
                        }
                }
        }
}

#define SPLPAR_TLB_BIC_TOKEN            50

/*
 * The size of the TLB Block Invalidate Characteristics is variable. But at the
 * maximum it will be the number of possible page sizes *2 + 10 bytes.
 * Currently MMU_PAGE_COUNT is 16, which means 42 bytes. Use a cache line size
 * (128 bytes) for the buffer to get plenty of space.
 */
#define SPLPAR_TLB_BIC_MAXLENGTH        128

void __init pseries_lpar_read_hblkrm_characteristics(void)
{
        unsigned char local_buffer[SPLPAR_TLB_BIC_MAXLENGTH];
        int call_status, len, idx, bpsize;

        if (!firmware_has_feature(FW_FEATURE_BLOCK_REMOVE))
                return;

        spin_lock(&rtas_data_buf_lock);
        memset(rtas_data_buf, 0, RTAS_DATA_BUF_SIZE);
        call_status = rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1,
                                NULL,
                                SPLPAR_TLB_BIC_TOKEN,
                                __pa(rtas_data_buf),
                                RTAS_DATA_BUF_SIZE);
        memcpy(local_buffer, rtas_data_buf, SPLPAR_TLB_BIC_MAXLENGTH);
        local_buffer[SPLPAR_TLB_BIC_MAXLENGTH - 1] = '\0';
        spin_unlock(&rtas_data_buf_lock);

        if (call_status != 0) {
                pr_warn("%s %s Error calling get-system-parameter (0x%x)\n",
                        __FILE__, __func__, call_status);
                return;
        }

        /*
         * The first two (2) bytes of the data in the buffer are the length of
         * the returned data, not counting these first two (2) bytes.
         */
        len = be16_to_cpu(*((u16 *)local_buffer)) + 2;
        if (len > SPLPAR_TLB_BIC_MAXLENGTH) {
                pr_warn("%s too large returned buffer %d", __func__, len);
                return;
        }

        idx = 2;
        while (idx < len) {
                u8 block_shift = local_buffer[idx++];
                u32 block_size;
                unsigned int npsize;

                if (!block_shift)
                        break;

                block_size = 1 << block_shift;

                for (npsize = local_buffer[idx++];
                     npsize > 0 && idx < len; npsize--)
                        check_lp_set_hblkrm((unsigned int) local_buffer[idx++],
                                            block_size);
        }

        for (bpsize = 0; bpsize < MMU_PAGE_COUNT; bpsize++)
                for (idx = 0; idx < MMU_PAGE_COUNT; idx++)
                        if (hblkrm_size[bpsize][idx])
                                pr_info("H_BLOCK_REMOVE supports base psize:%d psize:%d block size:%d",
                                        bpsize, idx, hblkrm_size[bpsize][idx]);
}

/*
 * Take a spinlock around flushes to avoid bouncing the hypervisor tlbie
 * lock.
 */
static void pSeries_lpar_flush_hash_range(unsigned long number, int local)
{
        unsigned long vpn;
        unsigned long i, pix, rc;
        unsigned long flags = 0;
        struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
        int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
        unsigned long param[PLPAR_HCALL9_BUFSIZE];
        unsigned long index, shift, slot;
        real_pte_t pte;
        int psize, ssize;

        if (lock_tlbie)
                spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);

        if (is_supported_hlbkrm(batch->psize, batch->psize)) {
                do_block_remove(number, batch, param);
                goto out;
        }

        psize = batch->psize;
        ssize = batch->ssize;
        pix = 0;
        for (i = 0; i < number; i++) {
                vpn = batch->vpn[i];
                pte = batch->pte[i];
                pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
                        slot = compute_slot(pte, vpn, index, shift, ssize);
                        if (!firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
                                /*
                                 * lpar doesn't use the passed actual page size
                                 */
                                pSeries_lpar_hpte_invalidate(slot, vpn, psize,
                                                             0, ssize, local);
                        } else {
                                param[pix] = HBR_REQUEST | HBR_AVPN | slot;
                                param[pix+1] = hpte_encode_avpn(vpn, psize,
                                                                ssize);
                                pix += 2;
                                if (pix == 8) {
                                        rc = plpar_hcall9(H_BULK_REMOVE, param,
                                                param[0], param[1], param[2],
                                                param[3], param[4], param[5],
                                                param[6], param[7]);
                                        BUG_ON(rc != H_SUCCESS);
                                        pix = 0;
                                }
                        }
                } pte_iterate_hashed_end();
        }
        if (pix) {
                param[pix] = HBR_END;
                rc = plpar_hcall9(H_BULK_REMOVE, param, param[0], param[1],
                                  param[2], param[3], param[4], param[5],
                                  param[6], param[7]);
                BUG_ON(rc != H_SUCCESS);
        }

out:
        if (lock_tlbie)
                spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);
}

static int __init disable_bulk_remove(char *str)
{
        if (strcmp(str, "off") == 0 &&
            firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
                pr_info("Disabling BULK_REMOVE firmware feature");
                powerpc_firmware_features &= ~FW_FEATURE_BULK_REMOVE;
        }
        return 1;
}

__setup("bulk_remove=", disable_bulk_remove);

#define HPT_RESIZE_TIMEOUT      10000 /* ms */

struct hpt_resize_state {
        unsigned long shift;
        int commit_rc;
};

static int pseries_lpar_resize_hpt_commit(void *data)
{
        struct hpt_resize_state *state = data;

        state->commit_rc = plpar_resize_hpt_commit(0, state->shift);
        if (state->commit_rc != H_SUCCESS)
                return -EIO;

        /* Hypervisor has transitioned the HTAB, update our globals */
        ppc64_pft_size = state->shift;
        htab_size_bytes = 1UL << ppc64_pft_size;
        htab_hash_mask = (htab_size_bytes >> 7) - 1;

        return 0;
}

/*
 * Must be called in process context. The caller must hold the
 * cpus_lock.
 */
static int pseries_lpar_resize_hpt(unsigned long shift)
{
        struct hpt_resize_state state = {
                .shift = shift,
                .commit_rc = H_FUNCTION,
        };
        unsigned int delay, total_delay = 0;
        int rc;
        ktime_t t0, t1, t2;

        might_sleep();

        if (!firmware_has_feature(FW_FEATURE_HPT_RESIZE))
                return -ENODEV;

        pr_info("Attempting to resize HPT to shift %lu\n", shift);

        t0 = ktime_get();

        rc = plpar_resize_hpt_prepare(0, shift);
        while (H_IS_LONG_BUSY(rc)) {
                delay = get_longbusy_msecs(rc);
                total_delay += delay;
                if (total_delay > HPT_RESIZE_TIMEOUT) {
                        /* prepare with shift==0 cancels an in-progress resize */
                        rc = plpar_resize_hpt_prepare(0, 0);
                        if (rc != H_SUCCESS)
                                pr_warn("Unexpected error %d cancelling timed out HPT resize\n",
                                       rc);
                        return -ETIMEDOUT;
                }
                msleep(delay);
                rc = plpar_resize_hpt_prepare(0, shift);
        };

        switch (rc) {
        case H_SUCCESS:
                /* Continue on */
                break;

        case H_PARAMETER:
                pr_warn("Invalid argument from H_RESIZE_HPT_PREPARE\n");
                return -EINVAL;
        case H_RESOURCE:
                pr_warn("Operation not permitted from H_RESIZE_HPT_PREPARE\n");
                return -EPERM;
        default:
                pr_warn("Unexpected error %d from H_RESIZE_HPT_PREPARE\n", rc);
                return -EIO;
        }

        t1 = ktime_get();

        rc = stop_machine_cpuslocked(pseries_lpar_resize_hpt_commit,
                                     &state, NULL);

        t2 = ktime_get();

        if (rc != 0) {
                switch (state.commit_rc) {
                case H_PTEG_FULL:
                        return -ENOSPC;

                default:
                        pr_warn("Unexpected error %d from H_RESIZE_HPT_COMMIT\n",
                                state.commit_rc);
                        return -EIO;
                };
        }

        pr_info("HPT resize to shift %lu complete (%lld ms / %lld ms)\n",
                shift, (long long) ktime_ms_delta(t1, t0),
                (long long) ktime_ms_delta(t2, t1));

        return 0;
}

static int pseries_lpar_register_process_table(unsigned long base,
                        unsigned long page_size, unsigned long table_size)
{
        long rc;
        unsigned long flags = 0;

        if (table_size)
                flags |= PROC_TABLE_NEW;
        if (radix_enabled())
                flags |= PROC_TABLE_RADIX | PROC_TABLE_GTSE;
        else
                flags |= PROC_TABLE_HPT_SLB;
        for (;;) {
                rc = plpar_hcall_norets(H_REGISTER_PROC_TBL, flags, base,
                                        page_size, table_size);
                if (!H_IS_LONG_BUSY(rc))
                        break;
                mdelay(get_longbusy_msecs(rc));
        }
        if (rc != H_SUCCESS) {
                pr_err("Failed to register process table (rc=%ld)\n", rc);
                BUG();
        }
        return rc;
}

void __init hpte_init_pseries(void)
{
        mmu_hash_ops.hpte_invalidate     = pSeries_lpar_hpte_invalidate;
        mmu_hash_ops.hpte_updatepp       = pSeries_lpar_hpte_updatepp;
        mmu_hash_ops.hpte_updateboltedpp = pSeries_lpar_hpte_updateboltedpp;
        mmu_hash_ops.hpte_insert         = pSeries_lpar_hpte_insert;
        mmu_hash_ops.hpte_remove         = pSeries_lpar_hpte_remove;
        mmu_hash_ops.hpte_removebolted   = pSeries_lpar_hpte_removebolted;
        mmu_hash_ops.flush_hash_range    = pSeries_lpar_flush_hash_range;
        mmu_hash_ops.hpte_clear_all      = pseries_hpte_clear_all;
        mmu_hash_ops.hugepage_invalidate = pSeries_lpar_hugepage_invalidate;

        if (firmware_has_feature(FW_FEATURE_HPT_RESIZE))
                mmu_hash_ops.resize_hpt = pseries_lpar_resize_hpt;

        /*
         * On POWER9, we need to do a H_REGISTER_PROC_TBL hcall
         * to inform the hypervisor that we wish to use the HPT.
         */
        if (cpu_has_feature(CPU_FTR_ARCH_300))
                pseries_lpar_register_process_table(0, 0, 0);
}

void radix_init_pseries(void)
{
        pr_info("Using radix MMU under hypervisor\n");

        pseries_lpar_register_process_table(__pa(process_tb),
                                                0, PRTB_SIZE_SHIFT - 12);
}

#ifdef CONFIG_PPC_SMLPAR
#define CMO_FREE_HINT_DEFAULT 1
static int cmo_free_hint_flag = CMO_FREE_HINT_DEFAULT;

static int __init cmo_free_hint(char *str)
{
        char *parm;
        parm = strstrip(str);

        if (strcasecmp(parm, "no") == 0 || strcasecmp(parm, "off") == 0) {
                pr_info("%s: CMO free page hinting is not active.\n", __func__);
                cmo_free_hint_flag = 0;
                return 1;
        }

        cmo_free_hint_flag = 1;
        pr_info("%s: CMO free page hinting is active.\n", __func__);

        if (strcasecmp(parm, "yes") == 0 || strcasecmp(parm, "on") == 0)
                return 1;

        return 0;
}

__setup("cmo_free_hint=", cmo_free_hint);

static void pSeries_set_page_state(struct page *page, int order,
                                   unsigned long state)
{
        int i, j;
        unsigned long cmo_page_sz, addr;

        cmo_page_sz = cmo_get_page_size();
        addr = __pa((unsigned long)page_address(page));

        for (i = 0; i < (1 << order); i++, addr += PAGE_SIZE) {
                for (j = 0; j < PAGE_SIZE; j += cmo_page_sz)
                        plpar_hcall_norets(H_PAGE_INIT, state, addr + j, 0);
        }
}

void arch_free_page(struct page *page, int order)
{
        if (radix_enabled())
                return;
        if (!cmo_free_hint_flag || !firmware_has_feature(FW_FEATURE_CMO))
                return;

        pSeries_set_page_state(page, order, H_PAGE_SET_UNUSED);
}
EXPORT_SYMBOL(arch_free_page);

#endif /* CONFIG_PPC_SMLPAR */
#endif /* CONFIG_PPC_BOOK3S_64 */

#ifdef CONFIG_TRACEPOINTS
#ifdef CONFIG_JUMP_LABEL
struct static_key hcall_tracepoint_key = STATIC_KEY_INIT;

int hcall_tracepoint_regfunc(void)
{
        static_key_slow_inc(&hcall_tracepoint_key);
        return 0;
}

void hcall_tracepoint_unregfunc(void)
{
        static_key_slow_dec(&hcall_tracepoint_key);
}
#else
/*
 * We optimise our hcall path by placing hcall_tracepoint_refcount
 * directly in the TOC so we can check if the hcall tracepoints are
 * enabled via a single load.
 */

/* NB: reg/unreg are called while guarded with the tracepoints_mutex */
extern long hcall_tracepoint_refcount;

int hcall_tracepoint_regfunc(void)
{
        hcall_tracepoint_refcount++;
        return 0;
}

void hcall_tracepoint_unregfunc(void)
{
        hcall_tracepoint_refcount--;
}
#endif

/*
 * Since the tracing code might execute hcalls we need to guard against
 * recursion. One example of this are spinlocks calling H_YIELD on
 * shared processor partitions.
 */
static DEFINE_PER_CPU(unsigned int, hcall_trace_depth);


void __trace_hcall_entry(unsigned long opcode, unsigned long *args)
{
        unsigned long flags;
        unsigned int *depth;

        /*
         * We cannot call tracepoints inside RCU idle regions which
         * means we must not trace H_CEDE.
         */
        if (opcode == H_CEDE)
                return;

        local_irq_save(flags);

        depth = this_cpu_ptr(&hcall_trace_depth);

        if (*depth)
                goto out;

        (*depth)++;
        preempt_disable();
        trace_hcall_entry(opcode, args);
        (*depth)--;

out:
        local_irq_restore(flags);
}

void __trace_hcall_exit(long opcode, long retval, unsigned long *retbuf)
{
        unsigned long flags;
        unsigned int *depth;

        if (opcode == H_CEDE)
                return;

        local_irq_save(flags);

        depth = this_cpu_ptr(&hcall_trace_depth);

        if (*depth)
                goto out;

        (*depth)++;
        trace_hcall_exit(opcode, retval, retbuf);
        preempt_enable();
        (*depth)--;

out:
        local_irq_restore(flags);
}
#endif

/**
 * h_get_mpp
 * H_GET_MPP hcall returns info in 7 parms
 */
int h_get_mpp(struct hvcall_mpp_data *mpp_data)
{
        int rc;
        unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];

        rc = plpar_hcall9(H_GET_MPP, retbuf);

        mpp_data->entitled_mem = retbuf[0];
        mpp_data->mapped_mem = retbuf[1];

        mpp_data->group_num = (retbuf[2] >> 2 * 8) & 0xffff;
        mpp_data->pool_num = retbuf[2] & 0xffff;

        mpp_data->mem_weight = (retbuf[3] >> 7 * 8) & 0xff;
        mpp_data->unallocated_mem_weight = (retbuf[3] >> 6 * 8) & 0xff;
        mpp_data->unallocated_entitlement = retbuf[3] & 0xffffffffffffUL;

        mpp_data->pool_size = retbuf[4];
        mpp_data->loan_request = retbuf[5];
        mpp_data->backing_mem = retbuf[6];

        return rc;
}
EXPORT_SYMBOL(h_get_mpp);

int h_get_mpp_x(struct hvcall_mpp_x_data *mpp_x_data)
{
        int rc;
        unsigned long retbuf[PLPAR_HCALL9_BUFSIZE] = { 0 };

        rc = plpar_hcall9(H_GET_MPP_X, retbuf);

        mpp_x_data->coalesced_bytes = retbuf[0];
        mpp_x_data->pool_coalesced_bytes = retbuf[1];
        mpp_x_data->pool_purr_cycles = retbuf[2];
        mpp_x_data->pool_spurr_cycles = retbuf[3];

        return rc;
}

static unsigned long vsid_unscramble(unsigned long vsid, int ssize)
{
        unsigned long protovsid;
        unsigned long va_bits = VA_BITS;
        unsigned long modinv, vsid_modulus;
        unsigned long max_mod_inv, tmp_modinv;

        if (!mmu_has_feature(MMU_FTR_68_BIT_VA))
                va_bits = 65;

        if (ssize == MMU_SEGSIZE_256M) {
                modinv = VSID_MULINV_256M;
                vsid_modulus = ((1UL << (va_bits - SID_SHIFT)) - 1);
        } else {
                modinv = VSID_MULINV_1T;
                vsid_modulus = ((1UL << (va_bits - SID_SHIFT_1T)) - 1);
        }

        /*
         * vsid outside our range.
         */
        if (vsid >= vsid_modulus)
                return 0;

        /*
         * If modinv is the modular multiplicate inverse of (x % vsid_modulus)
         * and vsid = (protovsid * x) % vsid_modulus, then we say:
         *   protovsid = (vsid * modinv) % vsid_modulus
         */

        /* Check if (vsid * modinv) overflow (63 bits) */
        max_mod_inv = 0x7fffffffffffffffull / vsid;
        if (modinv < max_mod_inv)
                return (vsid * modinv) % vsid_modulus;

        tmp_modinv = modinv/max_mod_inv;
        modinv %= max_mod_inv;

        protovsid = (((vsid * max_mod_inv) % vsid_modulus) * tmp_modinv) % vsid_modulus;
        protovsid = (protovsid + vsid * modinv) % vsid_modulus;

        return protovsid;
}

static int __init reserve_vrma_context_id(void)
{
        unsigned long protovsid;

        /*
         * Reserve context ids which map to reserved virtual addresses. For now
         * we only reserve the context id which maps to the VRMA VSID. We ignore
         * the addresses in "ibm,adjunct-virtual-addresses" because we don't
         * enable adjunct support via the "ibm,client-architecture-support"
         * interface.
         */
        protovsid = vsid_unscramble(VRMA_VSID, MMU_SEGSIZE_1T);
        hash__reserve_context_id(protovsid >> ESID_BITS_1T);
        return 0;
}
machine_device_initcall(pseries, reserve_vrma_context_id);

#ifdef CONFIG_DEBUG_FS
/* debugfs file interface for vpa data */
static ssize_t vpa_file_read(struct file *filp, char __user *buf, size_t len,
                              loff_t *pos)
{
        int cpu = (long)filp->private_data;
        struct lppaca *lppaca = &lppaca_of(cpu);

        return simple_read_from_buffer(buf, len, pos, lppaca,
                                sizeof(struct lppaca));
}

static const struct file_operations vpa_fops = {
        .open           = simple_open,
        .read           = vpa_file_read,
        .llseek         = default_llseek,
};

static int __init vpa_debugfs_init(void)
{
        char name[16];
        long i;
        struct dentry *vpa_dir;

        if (!firmware_has_feature(FW_FEATURE_SPLPAR))
                return 0;

        vpa_dir = debugfs_create_dir("vpa", powerpc_debugfs_root);

        /* set up the per-cpu vpa file*/
        for_each_possible_cpu(i) {
                sprintf(name, "cpu-%ld", i);
                debugfs_create_file(name, 0400, vpa_dir, (void *)i, &vpa_fops);
        }

        return 0;
}
machine_arch_initcall(pseries, vpa_debugfs_init);
#endif /* CONFIG_DEBUG_FS */