Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux

[mirror_ubuntu-eoan-kernel.git] / arch / powerpc / mm / tlb-radix.c

/*
 * TLB flush routines for radix kernels.
 *
 * Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/memblock.h>

#include <asm/ppc-opcode.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/trace.h>
#include <asm/cputhreads.h>

#define RIC_FLUSH_TLB 0
#define RIC_FLUSH_PWC 1
#define RIC_FLUSH_ALL 2

/*
 * tlbiel instruction for radix, set invalidation
 * i.e., r=1 and is=01 or is=10 or is=11
 */
static inline void tlbiel_radix_set_isa300(unsigned int set, unsigned int is,
                                        unsigned int pid,
                                        unsigned int ric, unsigned int prs)
{
        unsigned long rb;
        unsigned long rs;
        unsigned int r = 1; /* radix format */

        rb = (set << PPC_BITLSHIFT(51)) | (is << PPC_BITLSHIFT(53));
        rs = ((unsigned long)pid << PPC_BITLSHIFT(31));

        asm volatile(PPC_TLBIEL(%0, %1, %2, %3, %4)
                     : : "r"(rb), "r"(rs), "i"(ric), "i"(prs), "r"(r)
                     : "memory");
}

static void tlbiel_all_isa300(unsigned int num_sets, unsigned int is)
{
        unsigned int set;

        asm volatile("ptesync": : :"memory");

        /*
         * Flush the first set of the TLB, and the entire Page Walk Cache
         * and partition table entries. Then flush the remaining sets of the
         * TLB.
         */
        tlbiel_radix_set_isa300(0, is, 0, RIC_FLUSH_ALL, 0);
        for (set = 1; set < num_sets; set++)
                tlbiel_radix_set_isa300(set, is, 0, RIC_FLUSH_TLB, 0);

        /* Do the same for process scoped entries. */
        tlbiel_radix_set_isa300(0, is, 0, RIC_FLUSH_ALL, 1);
        for (set = 1; set < num_sets; set++)
                tlbiel_radix_set_isa300(set, is, 0, RIC_FLUSH_TLB, 1);

        asm volatile("ptesync": : :"memory");
}

void radix__tlbiel_all(unsigned int action)
{
        unsigned int is;

        switch (action) {
        case TLB_INVAL_SCOPE_GLOBAL:
                is = 3;
                break;
        case TLB_INVAL_SCOPE_LPID:
                is = 2;
                break;
        default:
                BUG();
        }

        if (early_cpu_has_feature(CPU_FTR_ARCH_300))
                tlbiel_all_isa300(POWER9_TLB_SETS_RADIX, is);
        else
                WARN(1, "%s called on pre-POWER9 CPU\n", __func__);

        asm volatile(PPC_INVALIDATE_ERAT "; isync" : : :"memory");
}

static inline void __tlbiel_pid(unsigned long pid, int set,
                                unsigned long ric)
{
        unsigned long rb,rs,prs,r;

        rb = PPC_BIT(53); /* IS = 1 */
        rb |= set << PPC_BITLSHIFT(51);
        rs = ((unsigned long)pid) << PPC_BITLSHIFT(31);
        prs = 1; /* process scoped */
        r = 1;   /* raidx format */

        asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
                     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory");
        trace_tlbie(0, 1, rb, rs, ric, prs, r);
}

static inline void __tlbie_pid(unsigned long pid, unsigned long ric)
{
        unsigned long rb,rs,prs,r;

        rb = PPC_BIT(53); /* IS = 1 */
        rs = pid << PPC_BITLSHIFT(31);
        prs = 1; /* process scoped */
        r = 1;   /* raidx format */

        asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
                     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory");
        trace_tlbie(0, 0, rb, rs, ric, prs, r);
}

/*
 * We use 128 set in radix mode and 256 set in hpt mode.
 */
static inline void _tlbiel_pid(unsigned long pid, unsigned long ric)
{
        int set;

        asm volatile("ptesync": : :"memory");

        /*
         * Flush the first set of the TLB, and if we're doing a RIC_FLUSH_ALL,
         * also flush the entire Page Walk Cache.
         */
        __tlbiel_pid(pid, 0, ric);

        /* For PWC, only one flush is needed */
        if (ric == RIC_FLUSH_PWC) {
                asm volatile("ptesync": : :"memory");
                return;
        }

        /* For the remaining sets, just flush the TLB */
        for (set = 1; set < POWER9_TLB_SETS_RADIX ; set++)
                __tlbiel_pid(pid, set, RIC_FLUSH_TLB);

        asm volatile("ptesync": : :"memory");
        asm volatile(PPC_INVALIDATE_ERAT "; isync" : : :"memory");
}

static inline void _tlbie_pid(unsigned long pid, unsigned long ric)
{
        asm volatile("ptesync": : :"memory");
        __tlbie_pid(pid, ric);
        asm volatile("eieio; tlbsync; ptesync": : :"memory");
}

static inline void __tlbiel_va(unsigned long va, unsigned long pid,
                               unsigned long ap, unsigned long ric)
{
        unsigned long rb,rs,prs,r;

        rb = va & ~(PPC_BITMASK(52, 63));
        rb |= ap << PPC_BITLSHIFT(58);
        rs = pid << PPC_BITLSHIFT(31);
        prs = 1; /* process scoped */
        r = 1;   /* raidx format */

        asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
                     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory");
        trace_tlbie(0, 1, rb, rs, ric, prs, r);
}

static inline void __tlbiel_va_range(unsigned long start, unsigned long end,
                                    unsigned long pid, unsigned long page_size,
                                    unsigned long psize)
{
        unsigned long addr;
        unsigned long ap = mmu_get_ap(psize);

        for (addr = start; addr < end; addr += page_size)
                __tlbiel_va(addr, pid, ap, RIC_FLUSH_TLB);
}

static inline void _tlbiel_va(unsigned long va, unsigned long pid,
                              unsigned long psize, unsigned long ric)
{
        unsigned long ap = mmu_get_ap(psize);

        asm volatile("ptesync": : :"memory");
        __tlbiel_va(va, pid, ap, ric);
        asm volatile("ptesync": : :"memory");
}

static inline void _tlbiel_va_range(unsigned long start, unsigned long end,
                                    unsigned long pid, unsigned long page_size,
                                    unsigned long psize, bool also_pwc)
{
        asm volatile("ptesync": : :"memory");
        if (also_pwc)
                __tlbiel_pid(pid, 0, RIC_FLUSH_PWC);
        __tlbiel_va_range(start, end, pid, page_size, psize);
        asm volatile("ptesync": : :"memory");
}

static inline void __tlbie_va(unsigned long va, unsigned long pid,
                             unsigned long ap, unsigned long ric)
{
        unsigned long rb,rs,prs,r;

        rb = va & ~(PPC_BITMASK(52, 63));
        rb |= ap << PPC_BITLSHIFT(58);
        rs = pid << PPC_BITLSHIFT(31);
        prs = 1; /* process scoped */
        r = 1;   /* raidx format */

        asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
                     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory");
        trace_tlbie(0, 0, rb, rs, ric, prs, r);
}

static inline void __tlbie_va_range(unsigned long start, unsigned long end,
                                    unsigned long pid, unsigned long page_size,
                                    unsigned long psize)
{
        unsigned long addr;
        unsigned long ap = mmu_get_ap(psize);

        for (addr = start; addr < end; addr += page_size)
                __tlbie_va(addr, pid, ap, RIC_FLUSH_TLB);
}

static inline void _tlbie_va(unsigned long va, unsigned long pid,
                              unsigned long psize, unsigned long ric)
{
        unsigned long ap = mmu_get_ap(psize);

        asm volatile("ptesync": : :"memory");
        __tlbie_va(va, pid, ap, ric);
        asm volatile("eieio; tlbsync; ptesync": : :"memory");
}

static inline void _tlbie_va_range(unsigned long start, unsigned long end,
                                    unsigned long pid, unsigned long page_size,
                                    unsigned long psize, bool also_pwc)
{
        asm volatile("ptesync": : :"memory");
        if (also_pwc)
                __tlbie_pid(pid, RIC_FLUSH_PWC);
        __tlbie_va_range(start, end, pid, page_size, psize);
        asm volatile("eieio; tlbsync; ptesync": : :"memory");
}

/*
 * Base TLB flushing operations:
 *
 *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
 *  - flush_tlb_page(vma, vmaddr) flushes one page
 *  - flush_tlb_range(vma, start, end) flushes a range of pages
 *  - flush_tlb_kernel_range(start, end) flushes kernel pages
 *
 *  - local_* variants of page and mm only apply to the current
 *    processor
 */
void radix__local_flush_tlb_mm(struct mm_struct *mm)
{
        unsigned long pid;

        preempt_disable();
        pid = mm->context.id;
        if (pid != MMU_NO_CONTEXT)
                _tlbiel_pid(pid, RIC_FLUSH_TLB);
        preempt_enable();
}
EXPORT_SYMBOL(radix__local_flush_tlb_mm);

#ifndef CONFIG_SMP
void radix__local_flush_all_mm(struct mm_struct *mm)
{
        unsigned long pid;

        preempt_disable();
        pid = mm->context.id;
        if (pid != MMU_NO_CONTEXT)
                _tlbiel_pid(pid, RIC_FLUSH_ALL);
        preempt_enable();
}
EXPORT_SYMBOL(radix__local_flush_all_mm);
#endif /* CONFIG_SMP */

void radix__local_flush_tlb_page_psize(struct mm_struct *mm, unsigned long vmaddr,
                                       int psize)
{
        unsigned long pid;

        preempt_disable();
        pid = mm->context.id;
        if (pid != MMU_NO_CONTEXT)
                _tlbiel_va(vmaddr, pid, psize, RIC_FLUSH_TLB);
        preempt_enable();
}

void radix__local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
{
#ifdef CONFIG_HUGETLB_PAGE
        /* need the return fix for nohash.c */
        if (is_vm_hugetlb_page(vma))
                return radix__local_flush_hugetlb_page(vma, vmaddr);
#endif
        radix__local_flush_tlb_page_psize(vma->vm_mm, vmaddr, mmu_virtual_psize);
}
EXPORT_SYMBOL(radix__local_flush_tlb_page);

#ifdef CONFIG_SMP
void radix__flush_tlb_mm(struct mm_struct *mm)
{
        unsigned long pid;

        pid = mm->context.id;
        if (unlikely(pid == MMU_NO_CONTEXT))
                return;

        preempt_disable();
        if (!mm_is_thread_local(mm))
                _tlbie_pid(pid, RIC_FLUSH_TLB);
        else
                _tlbiel_pid(pid, RIC_FLUSH_TLB);
        preempt_enable();
}
EXPORT_SYMBOL(radix__flush_tlb_mm);

void radix__flush_all_mm(struct mm_struct *mm)
{
        unsigned long pid;

        pid = mm->context.id;
        if (unlikely(pid == MMU_NO_CONTEXT))
                return;

        preempt_disable();
        if (!mm_is_thread_local(mm))
                _tlbie_pid(pid, RIC_FLUSH_ALL);
        else
                _tlbiel_pid(pid, RIC_FLUSH_ALL);
        preempt_enable();
}
EXPORT_SYMBOL(radix__flush_all_mm);

void radix__flush_tlb_pwc(struct mmu_gather *tlb, unsigned long addr)
{
        tlb->need_flush_all = 1;
}
EXPORT_SYMBOL(radix__flush_tlb_pwc);

void radix__flush_tlb_page_psize(struct mm_struct *mm, unsigned long vmaddr,
                                 int psize)
{
        unsigned long pid;

        pid = mm->context.id;
        if (unlikely(pid == MMU_NO_CONTEXT))
                return;

        preempt_disable();
        if (!mm_is_thread_local(mm))
                _tlbie_va(vmaddr, pid, psize, RIC_FLUSH_TLB);
        else
                _tlbiel_va(vmaddr, pid, psize, RIC_FLUSH_TLB);
        preempt_enable();
}

void radix__flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
{
#ifdef CONFIG_HUGETLB_PAGE
        if (is_vm_hugetlb_page(vma))
                return radix__flush_hugetlb_page(vma, vmaddr);
#endif
        radix__flush_tlb_page_psize(vma->vm_mm, vmaddr, mmu_virtual_psize);
}
EXPORT_SYMBOL(radix__flush_tlb_page);

#else /* CONFIG_SMP */
#define radix__flush_all_mm radix__local_flush_all_mm
#endif /* CONFIG_SMP */

void radix__flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
        _tlbie_pid(0, RIC_FLUSH_ALL);
}
EXPORT_SYMBOL(radix__flush_tlb_kernel_range);

#define TLB_FLUSH_ALL -1UL

/*
 * Number of pages above which we invalidate the entire PID rather than
 * flush individual pages, for local and global flushes respectively.
 *
 * tlbie goes out to the interconnect and individual ops are more costly.
 * It also does not iterate over sets like the local tlbiel variant when
 * invalidating a full PID, so it has a far lower threshold to change from
 * individual page flushes to full-pid flushes.
 */
static unsigned long tlb_single_page_flush_ceiling __read_mostly = 33;
static unsigned long tlb_local_single_page_flush_ceiling __read_mostly = POWER9_TLB_SETS_RADIX * 2;

void radix__flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
                     unsigned long end)

{
        struct mm_struct *mm = vma->vm_mm;
        unsigned long pid;
        unsigned int page_shift = mmu_psize_defs[mmu_virtual_psize].shift;
        unsigned long page_size = 1UL << page_shift;
        unsigned long nr_pages = (end - start) >> page_shift;
        bool local, full;

#ifdef CONFIG_HUGETLB_PAGE
        if (is_vm_hugetlb_page(vma))
                return radix__flush_hugetlb_tlb_range(vma, start, end);
#endif

        pid = mm->context.id;
        if (unlikely(pid == MMU_NO_CONTEXT))
                return;

        preempt_disable();
        if (mm_is_thread_local(mm)) {
                local = true;
                full = (end == TLB_FLUSH_ALL ||
                                nr_pages > tlb_local_single_page_flush_ceiling);
        } else {
                local = false;
                full = (end == TLB_FLUSH_ALL ||
                                nr_pages > tlb_single_page_flush_ceiling);
        }

        if (full) {
                if (local)
                        _tlbiel_pid(pid, RIC_FLUSH_TLB);
                else
                        _tlbie_pid(pid, RIC_FLUSH_TLB);
        } else {
                bool hflush = false;
                unsigned long hstart, hend;

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
                hstart = (start + HPAGE_PMD_SIZE - 1) >> HPAGE_PMD_SHIFT;
                hend = end >> HPAGE_PMD_SHIFT;
                if (hstart < hend) {
                        hstart <<= HPAGE_PMD_SHIFT;
                        hend <<= HPAGE_PMD_SHIFT;
                        hflush = true;
                }
#endif

                asm volatile("ptesync": : :"memory");
                if (local) {
                        __tlbiel_va_range(start, end, pid, page_size, mmu_virtual_psize);
                        if (hflush)
                                __tlbiel_va_range(hstart, hend, pid,
                                                HPAGE_PMD_SIZE, MMU_PAGE_2M);
                        asm volatile("ptesync": : :"memory");
                } else {
                        __tlbie_va_range(start, end, pid, page_size, mmu_virtual_psize);
                        if (hflush)
                                __tlbie_va_range(hstart, hend, pid,
                                                HPAGE_PMD_SIZE, MMU_PAGE_2M);
                        asm volatile("eieio; tlbsync; ptesync": : :"memory");
                }
        }
        preempt_enable();
}
EXPORT_SYMBOL(radix__flush_tlb_range);

static int radix_get_mmu_psize(int page_size)
{
        int psize;

        if (page_size == (1UL << mmu_psize_defs[mmu_virtual_psize].shift))
                psize = mmu_virtual_psize;
        else if (page_size == (1UL << mmu_psize_defs[MMU_PAGE_2M].shift))
                psize = MMU_PAGE_2M;
        else if (page_size == (1UL << mmu_psize_defs[MMU_PAGE_1G].shift))
                psize = MMU_PAGE_1G;
        else
                return -1;
        return psize;
}

static void radix__flush_tlb_pwc_range_psize(struct mm_struct *mm, unsigned long start,
                                  unsigned long end, int psize);

void radix__tlb_flush(struct mmu_gather *tlb)
{
        int psize = 0;
        struct mm_struct *mm = tlb->mm;
        int page_size = tlb->page_size;

        /*
         * if page size is not something we understand, do a full mm flush
         *
         * A "fullmm" flush must always do a flush_all_mm (RIC=2) flush
         * that flushes the process table entry cache upon process teardown.
         * See the comment for radix in arch_exit_mmap().
         */
        if (tlb->fullmm) {
                radix__flush_all_mm(mm);
        } else if ( (psize = radix_get_mmu_psize(page_size)) == -1) {
                if (!tlb->need_flush_all)
                        radix__flush_tlb_mm(mm);
                else
                        radix__flush_all_mm(mm);
        } else {
                unsigned long start = tlb->start;
                unsigned long end = tlb->end;

                if (!tlb->need_flush_all)
                        radix__flush_tlb_range_psize(mm, start, end, psize);
                else
                        radix__flush_tlb_pwc_range_psize(mm, start, end, psize);
        }
        tlb->need_flush_all = 0;
}

static inline void __radix__flush_tlb_range_psize(struct mm_struct *mm,
                                unsigned long start, unsigned long end,
                                int psize, bool also_pwc)
{
        unsigned long pid;
        unsigned int page_shift = mmu_psize_defs[psize].shift;
        unsigned long page_size = 1UL << page_shift;
        unsigned long nr_pages = (end - start) >> page_shift;
        bool local, full;

        pid = mm->context.id;
        if (unlikely(pid == MMU_NO_CONTEXT))
                return;

        preempt_disable();
        if (mm_is_thread_local(mm)) {
                local = true;
                full = (end == TLB_FLUSH_ALL ||
                                nr_pages > tlb_local_single_page_flush_ceiling);
        } else {
                local = false;
                full = (end == TLB_FLUSH_ALL ||
                                nr_pages > tlb_single_page_flush_ceiling);
        }

        if (full) {
                if (local)
                        _tlbiel_pid(pid, also_pwc ? RIC_FLUSH_ALL : RIC_FLUSH_TLB);
                else
                        _tlbie_pid(pid, also_pwc ? RIC_FLUSH_ALL: RIC_FLUSH_TLB);
        } else {
                if (local)
                        _tlbiel_va_range(start, end, pid, page_size, psize, also_pwc);
                else
                        _tlbie_va_range(start, end, pid, page_size, psize, also_pwc);
        }
        preempt_enable();
}

void radix__flush_tlb_range_psize(struct mm_struct *mm, unsigned long start,
                                  unsigned long end, int psize)
{
        return __radix__flush_tlb_range_psize(mm, start, end, psize, false);
}

static void radix__flush_tlb_pwc_range_psize(struct mm_struct *mm, unsigned long start,
                                  unsigned long end, int psize)
{
        __radix__flush_tlb_range_psize(mm, start, end, psize, true);
}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
void radix__flush_tlb_collapsed_pmd(struct mm_struct *mm, unsigned long addr)
{
        unsigned long pid, end;

        pid = mm->context.id;
        if (unlikely(pid == MMU_NO_CONTEXT))
                return;

        /* 4k page size, just blow the world */
        if (PAGE_SIZE == 0x1000) {
                radix__flush_all_mm(mm);
                return;
        }

        end = addr + HPAGE_PMD_SIZE;

        /* Otherwise first do the PWC, then iterate the pages. */
        preempt_disable();

        if (mm_is_thread_local(mm)) {
                _tlbiel_va_range(addr, end, pid, PAGE_SIZE, mmu_virtual_psize, true);
        } else {
                _tlbie_va_range(addr, end, pid, PAGE_SIZE, mmu_virtual_psize, true);
        }

        preempt_enable();
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

void radix__flush_tlb_lpid_va(unsigned long lpid, unsigned long gpa,
                              unsigned long page_size)
{
        unsigned long rb,rs,prs,r;
        unsigned long ap;
        unsigned long ric = RIC_FLUSH_TLB;

        ap = mmu_get_ap(radix_get_mmu_psize(page_size));
        rb = gpa & ~(PPC_BITMASK(52, 63));
        rb |= ap << PPC_BITLSHIFT(58);
        rs = lpid & ((1UL << 32) - 1);
        prs = 0; /* process scoped */
        r = 1;   /* raidx format */

        asm volatile("ptesync": : :"memory");
        asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
                     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory");
        asm volatile("eieio; tlbsync; ptesync": : :"memory");
        trace_tlbie(lpid, 0, rb, rs, ric, prs, r);
}
EXPORT_SYMBOL(radix__flush_tlb_lpid_va);

void radix__flush_tlb_lpid(unsigned long lpid)
{
        unsigned long rb,rs,prs,r;
        unsigned long ric = RIC_FLUSH_ALL;

        rb = 0x2 << PPC_BITLSHIFT(53); /* IS = 2 */
        rs = lpid & ((1UL << 32) - 1);
        prs = 0; /* partition scoped */
        r = 1;   /* raidx format */

        asm volatile("ptesync": : :"memory");
        asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
                     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory");
        asm volatile("eieio; tlbsync; ptesync": : :"memory");
        trace_tlbie(lpid, 0, rb, rs, ric, prs, r);
}
EXPORT_SYMBOL(radix__flush_tlb_lpid);

void radix__flush_pmd_tlb_range(struct vm_area_struct *vma,
                                unsigned long start, unsigned long end)
{
        radix__flush_tlb_range_psize(vma->vm_mm, start, end, MMU_PAGE_2M);
}
EXPORT_SYMBOL(radix__flush_pmd_tlb_range);

void radix__flush_tlb_all(void)
{
        unsigned long rb,prs,r,rs;
        unsigned long ric = RIC_FLUSH_ALL;

        rb = 0x3 << PPC_BITLSHIFT(53); /* IS = 3 */
        prs = 0; /* partition scoped */
        r = 1;   /* raidx format */
        rs = 1 & ((1UL << 32) - 1); /* any LPID value to flush guest mappings */

        asm volatile("ptesync": : :"memory");
        /*
         * now flush guest entries by passing PRS = 1 and LPID != 0
         */
        asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
                     : : "r"(rb), "i"(r), "i"(1), "i"(ric), "r"(rs) : "memory");
        /*
         * now flush host entires by passing PRS = 0 and LPID == 0
         */
        asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
                     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(0) : "memory");
        asm volatile("eieio; tlbsync; ptesync": : :"memory");
}

void radix__flush_tlb_pte_p9_dd1(unsigned long old_pte, struct mm_struct *mm,
                                 unsigned long address)
{
        /*
         * We track page size in pte only for DD1, So we can
         * call this only on DD1.
         */
        if (!cpu_has_feature(CPU_FTR_POWER9_DD1)) {
                VM_WARN_ON(1);
                return;
        }

        if (old_pte & R_PAGE_LARGE)
                radix__flush_tlb_page_psize(mm, address, MMU_PAGE_2M);
        else
                radix__flush_tlb_page_psize(mm, address, mmu_virtual_psize);
}

#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
extern void radix_kvm_prefetch_workaround(struct mm_struct *mm)
{
        unsigned int pid = mm->context.id;

        if (unlikely(pid == MMU_NO_CONTEXT))
                return;

        /*
         * If this context hasn't run on that CPU before and KVM is
         * around, there's a slim chance that the guest on another
         * CPU just brought in obsolete translation into the TLB of
         * this CPU due to a bad prefetch using the guest PID on
         * the way into the hypervisor.
         *
         * We work around this here. If KVM is possible, we check if
         * any sibling thread is in KVM. If it is, the window may exist
         * and thus we flush that PID from the core.
         *
         * A potential future improvement would be to mark which PIDs
         * have never been used on the system and avoid it if the PID
         * is new and the process has no other cpumask bit set.
         */
        if (cpu_has_feature(CPU_FTR_HVMODE) && radix_enabled()) {
                int cpu = smp_processor_id();
                int sib = cpu_first_thread_sibling(cpu);
                bool flush = false;

                for (; sib <= cpu_last_thread_sibling(cpu) && !flush; sib++) {
                        if (sib == cpu)
                                continue;
                        if (paca[sib].kvm_hstate.kvm_vcpu)
                                flush = true;
                }
                if (flush)
                        _tlbiel_pid(pid, RIC_FLUSH_ALL);
        }
}
EXPORT_SYMBOL_GPL(radix_kvm_prefetch_workaround);
#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */