Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

[mirror_ubuntu-artful-kernel.git] / arch / powerpc / mm / pgtable_64.c

/*
 *  This file contains ioremap and related functions for 64-bit machines.
 *
 *  Derived from arch/ppc64/mm/init.c
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Modifications by Paul Mackerras (PowerMac) (paulus@samba.org)
 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
 *    Copyright (C) 1996 Paul Mackerras
 *
 *  Derived from "arch/i386/mm/init.c"
 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *
 *  Dave Engebretsen <engebret@us.ibm.com>
 *      Rework for PPC64 port.
 *
 *  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/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/export.h>
#include <linux/types.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/stddef.h>
#include <linux/vmalloc.h>
#include <linux/memblock.h>
#include <linux/slab.h>
#include <linux/hugetlb.h>

#include <asm/pgalloc.h>
#include <asm/page.h>
#include <asm/prom.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/tlb.h>
#include <asm/trace.h>
#include <asm/processor.h>
#include <asm/cputable.h>
#include <asm/sections.h>
#include <asm/firmware.h>
#include <asm/dma.h>
#include <asm/powernv.h>

#include "mmu_decl.h"

#ifdef CONFIG_PPC_STD_MMU_64
#if TASK_SIZE_USER64 > (1UL << (ESID_BITS + SID_SHIFT))
#error TASK_SIZE_USER64 exceeds user VSID range
#endif
#endif

#ifdef CONFIG_PPC_BOOK3S_64
/*
 * partition table and process table for ISA 3.0
 */
struct prtb_entry *process_tb;
struct patb_entry *partition_tb;
/*
 * page table size
 */
unsigned long __pte_index_size;
EXPORT_SYMBOL(__pte_index_size);
unsigned long __pmd_index_size;
EXPORT_SYMBOL(__pmd_index_size);
unsigned long __pud_index_size;
EXPORT_SYMBOL(__pud_index_size);
unsigned long __pgd_index_size;
EXPORT_SYMBOL(__pgd_index_size);
unsigned long __pmd_cache_index;
EXPORT_SYMBOL(__pmd_cache_index);
unsigned long __pte_table_size;
EXPORT_SYMBOL(__pte_table_size);
unsigned long __pmd_table_size;
EXPORT_SYMBOL(__pmd_table_size);
unsigned long __pud_table_size;
EXPORT_SYMBOL(__pud_table_size);
unsigned long __pgd_table_size;
EXPORT_SYMBOL(__pgd_table_size);
unsigned long __pmd_val_bits;
EXPORT_SYMBOL(__pmd_val_bits);
unsigned long __pud_val_bits;
EXPORT_SYMBOL(__pud_val_bits);
unsigned long __pgd_val_bits;
EXPORT_SYMBOL(__pgd_val_bits);
unsigned long __kernel_virt_start;
EXPORT_SYMBOL(__kernel_virt_start);
unsigned long __kernel_virt_size;
EXPORT_SYMBOL(__kernel_virt_size);
unsigned long __vmalloc_start;
EXPORT_SYMBOL(__vmalloc_start);
unsigned long __vmalloc_end;
EXPORT_SYMBOL(__vmalloc_end);
struct page *vmemmap;
EXPORT_SYMBOL(vmemmap);
unsigned long __pte_frag_nr;
EXPORT_SYMBOL(__pte_frag_nr);
unsigned long __pte_frag_size_shift;
EXPORT_SYMBOL(__pte_frag_size_shift);
unsigned long ioremap_bot;
#else /* !CONFIG_PPC_BOOK3S_64 */
unsigned long ioremap_bot = IOREMAP_BASE;
#endif

/**
 * __ioremap_at - Low level function to establish the page tables
 *                for an IO mapping
 */
void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size,
                            unsigned long flags)
{
        unsigned long i;

        /* Make sure we have the base flags */
        if ((flags & _PAGE_PRESENT) == 0)
                flags |= pgprot_val(PAGE_KERNEL);

        /* We don't support the 4K PFN hack with ioremap */
        if (flags & H_PAGE_4K_PFN)
                return NULL;

        WARN_ON(pa & ~PAGE_MASK);
        WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
        WARN_ON(size & ~PAGE_MASK);

        for (i = 0; i < size; i += PAGE_SIZE)
                if (map_kernel_page((unsigned long)ea+i, pa+i, flags))
                        return NULL;

        return (void __iomem *)ea;
}

/**
 * __iounmap_from - Low level function to tear down the page tables
 *                  for an IO mapping. This is used for mappings that
 *                  are manipulated manually, like partial unmapping of
 *                  PCI IOs or ISA space.
 */
void __iounmap_at(void *ea, unsigned long size)
{
        WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
        WARN_ON(size & ~PAGE_MASK);

        unmap_kernel_range((unsigned long)ea, size);
}

void __iomem * __ioremap_caller(phys_addr_t addr, unsigned long size,
                                unsigned long flags, void *caller)
{
        phys_addr_t paligned;
        void __iomem *ret;

        /*
         * Choose an address to map it to.
         * Once the imalloc system is running, we use it.
         * Before that, we map using addresses going
         * up from ioremap_bot.  imalloc will use
         * the addresses from ioremap_bot through
         * IMALLOC_END
         * 
         */
        paligned = addr & PAGE_MASK;
        size = PAGE_ALIGN(addr + size) - paligned;

        if ((size == 0) || (paligned == 0))
                return NULL;

        if (slab_is_available()) {
                struct vm_struct *area;

                area = __get_vm_area_caller(size, VM_IOREMAP,
                                            ioremap_bot, IOREMAP_END,
                                            caller);
                if (area == NULL)
                        return NULL;

                area->phys_addr = paligned;
                ret = __ioremap_at(paligned, area->addr, size, flags);
                if (!ret)
                        vunmap(area->addr);
        } else {
                ret = __ioremap_at(paligned, (void *)ioremap_bot, size, flags);
                if (ret)
                        ioremap_bot += size;
        }

        if (ret)
                ret += addr & ~PAGE_MASK;
        return ret;
}

void __iomem * __ioremap(phys_addr_t addr, unsigned long size,
                         unsigned long flags)
{
        return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
}

void __iomem * ioremap(phys_addr_t addr, unsigned long size)
{
        unsigned long flags = pgprot_val(pgprot_noncached(__pgprot(0)));
        void *caller = __builtin_return_address(0);

        if (ppc_md.ioremap)
                return ppc_md.ioremap(addr, size, flags, caller);
        return __ioremap_caller(addr, size, flags, caller);
}

void __iomem * ioremap_wc(phys_addr_t addr, unsigned long size)
{
        unsigned long flags = pgprot_val(pgprot_noncached_wc(__pgprot(0)));
        void *caller = __builtin_return_address(0);

        if (ppc_md.ioremap)
                return ppc_md.ioremap(addr, size, flags, caller);
        return __ioremap_caller(addr, size, flags, caller);
}

void __iomem * ioremap_prot(phys_addr_t addr, unsigned long size,
                             unsigned long flags)
{
        void *caller = __builtin_return_address(0);

        /* writeable implies dirty for kernel addresses */
        if (flags & _PAGE_WRITE)
                flags |= _PAGE_DIRTY;

        /* we don't want to let _PAGE_EXEC leak out */
        flags &= ~_PAGE_EXEC;
        /*
         * Force kernel mapping.
         */
#if defined(CONFIG_PPC_BOOK3S_64)
        flags |= _PAGE_PRIVILEGED;
#else
        flags &= ~_PAGE_USER;
#endif


#ifdef _PAGE_BAP_SR
        /* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format
         * which means that we just cleared supervisor access... oops ;-) This
         * restores it
         */
        flags |= _PAGE_BAP_SR;
#endif

        if (ppc_md.ioremap)
                return ppc_md.ioremap(addr, size, flags, caller);
        return __ioremap_caller(addr, size, flags, caller);
}


/*  
 * Unmap an IO region and remove it from imalloc'd list.
 * Access to IO memory should be serialized by driver.
 */
void __iounmap(volatile void __iomem *token)
{
        void *addr;

        if (!slab_is_available())
                return;
        
        addr = (void *) ((unsigned long __force)
                         PCI_FIX_ADDR(token) & PAGE_MASK);
        if ((unsigned long)addr < ioremap_bot) {
                printk(KERN_WARNING "Attempt to iounmap early bolted mapping"
                       " at 0x%p\n", addr);
                return;
        }
        vunmap(addr);
}

void iounmap(volatile void __iomem *token)
{
        if (ppc_md.iounmap)
                ppc_md.iounmap(token);
        else
                __iounmap(token);
}

EXPORT_SYMBOL(ioremap);
EXPORT_SYMBOL(ioremap_wc);
EXPORT_SYMBOL(ioremap_prot);
EXPORT_SYMBOL(__ioremap);
EXPORT_SYMBOL(__ioremap_at);
EXPORT_SYMBOL(iounmap);
EXPORT_SYMBOL(__iounmap);
EXPORT_SYMBOL(__iounmap_at);

#ifndef __PAGETABLE_PUD_FOLDED
/* 4 level page table */
struct page *pgd_page(pgd_t pgd)
{
        if (pgd_huge(pgd))
                return pte_page(pgd_pte(pgd));
        return virt_to_page(pgd_page_vaddr(pgd));
}
#endif

struct page *pud_page(pud_t pud)
{
        if (pud_huge(pud))
                return pte_page(pud_pte(pud));
        return virt_to_page(pud_page_vaddr(pud));
}

/*
 * For hugepage we have pfn in the pmd, we use PTE_RPN_SHIFT bits for flags
 * For PTE page, we have a PTE_FRAG_SIZE (4K) aligned virtual address.
 */
struct page *pmd_page(pmd_t pmd)
{
        if (pmd_trans_huge(pmd) || pmd_huge(pmd) || pmd_devmap(pmd))
                return pte_page(pmd_pte(pmd));
        return virt_to_page(pmd_page_vaddr(pmd));
}

#ifdef CONFIG_PPC_64K_PAGES
static pte_t *get_from_cache(struct mm_struct *mm)
{
        void *pte_frag, *ret;

        spin_lock(&mm->page_table_lock);
        ret = mm->context.pte_frag;
        if (ret) {
                pte_frag = ret + PTE_FRAG_SIZE;
                /*
                 * If we have taken up all the fragments mark PTE page NULL
                 */
                if (((unsigned long)pte_frag & ~PAGE_MASK) == 0)
                        pte_frag = NULL;
                mm->context.pte_frag = pte_frag;
        }
        spin_unlock(&mm->page_table_lock);
        return (pte_t *)ret;
}

static pte_t *__alloc_for_cache(struct mm_struct *mm, int kernel)
{
        void *ret = NULL;
        struct page *page;

        if (!kernel) {
                page = alloc_page(PGALLOC_GFP | __GFP_ACCOUNT);
                if (!page)
                        return NULL;
                if (!pgtable_page_ctor(page)) {
                        __free_page(page);
                        return NULL;
                }
        } else {
                page = alloc_page(PGALLOC_GFP);
                if (!page)
                        return NULL;
        }

        ret = page_address(page);
        spin_lock(&mm->page_table_lock);
        /*
         * If we find pgtable_page set, we return
         * the allocated page with single fragement
         * count.
         */
        if (likely(!mm->context.pte_frag)) {
                set_page_count(page, PTE_FRAG_NR);
                mm->context.pte_frag = ret + PTE_FRAG_SIZE;
        }
        spin_unlock(&mm->page_table_lock);

        return (pte_t *)ret;
}

pte_t *pte_fragment_alloc(struct mm_struct *mm, unsigned long vmaddr, int kernel)
{
        pte_t *pte;

        pte = get_from_cache(mm);
        if (pte)
                return pte;

        return __alloc_for_cache(mm, kernel);
}
#endif /* CONFIG_PPC_64K_PAGES */

void pte_fragment_free(unsigned long *table, int kernel)
{
        struct page *page = virt_to_page(table);
        if (put_page_testzero(page)) {
                if (!kernel)
                        pgtable_page_dtor(page);
                free_hot_cold_page(page, 0);
        }
}

#ifdef CONFIG_SMP
void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
{
        unsigned long pgf = (unsigned long)table;

        BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
        pgf |= shift;
        tlb_remove_table(tlb, (void *)pgf);
}

void __tlb_remove_table(void *_table)
{
        void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
        unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;

        if (!shift)
                /* PTE page needs special handling */
                pte_fragment_free(table, 0);
        else {
                BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
                kmem_cache_free(PGT_CACHE(shift), table);
        }
}
#else
void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
{
        if (!shift) {
                /* PTE page needs special handling */
                pte_fragment_free(table, 0);
        } else {
                BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
                kmem_cache_free(PGT_CACHE(shift), table);
        }
}
#endif

#ifdef CONFIG_PPC_BOOK3S_64
void __init mmu_partition_table_init(void)
{
        unsigned long patb_size = 1UL << PATB_SIZE_SHIFT;
        unsigned long ptcr;

        BUILD_BUG_ON_MSG((PATB_SIZE_SHIFT > 36), "Partition table size too large.");
        partition_tb = __va(memblock_alloc_base(patb_size, patb_size,
                                                MEMBLOCK_ALLOC_ANYWHERE));

        /* Initialize the Partition Table with no entries */
        memset((void *)partition_tb, 0, patb_size);

        /*
         * update partition table control register,
         * 64 K size.
         */
        ptcr = __pa(partition_tb) | (PATB_SIZE_SHIFT - 12);
        mtspr(SPRN_PTCR, ptcr);
        powernv_set_nmmu_ptcr(ptcr);
}

void mmu_partition_table_set_entry(unsigned int lpid, unsigned long dw0,
                                   unsigned long dw1)
{
        unsigned long old = be64_to_cpu(partition_tb[lpid].patb0);

        partition_tb[lpid].patb0 = cpu_to_be64(dw0);
        partition_tb[lpid].patb1 = cpu_to_be64(dw1);

        /*
         * Global flush of TLBs and partition table caches for this lpid.
         * The type of flush (hash or radix) depends on what the previous
         * use of this partition ID was, not the new use.
         */
        asm volatile("ptesync" : : : "memory");
        if (old & PATB_HR) {
                asm volatile(PPC_TLBIE_5(%0,%1,2,0,1) : :
                             "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
                trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 1);
        } else {
                asm volatile(PPC_TLBIE_5(%0,%1,2,0,0) : :
                             "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
                trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 0);
        }
        asm volatile("eieio; tlbsync; ptesync" : : : "memory");
}
EXPORT_SYMBOL_GPL(mmu_partition_table_set_entry);
#endif /* CONFIG_PPC_BOOK3S_64 */

#ifdef CONFIG_STRICT_KERNEL_RWX
void mark_rodata_ro(void)
{
        if (!mmu_has_feature(MMU_FTR_KERNEL_RO)) {
                pr_warn("Warning: Unable to mark rodata read only on this CPU.\n");
                return;
        }

        if (radix_enabled())
                radix__mark_rodata_ro();
        else
                hash__mark_rodata_ro();
}

void mark_initmem_nx(void)
{
        if (radix_enabled())
                radix__mark_initmem_nx();
        else
                hash__mark_initmem_nx();
}
#endif