mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 10:40:15 +02:00
c766ee7223
In order to avoid multiple conversions, handover directly a pgprot_t to map_kernel_page() as already done for radix. Do the same for __ioremap_caller() and __ioremap_at(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
456 lines
14 KiB
C
456 lines
14 KiB
C
/*
|
|
* Copyright 2005, Paul Mackerras, IBM Corporation.
|
|
* Copyright 2009, Benjamin Herrenschmidt, IBM Corporation.
|
|
* 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/sched.h>
|
|
#include <linux/mm_types.h>
|
|
#include <linux/mm.h>
|
|
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/sections.h>
|
|
#include <asm/mmu.h>
|
|
#include <asm/tlb.h>
|
|
|
|
#include "mmu_decl.h"
|
|
|
|
#define CREATE_TRACE_POINTS
|
|
#include <trace/events/thp.h>
|
|
|
|
#if H_PGTABLE_RANGE > (USER_VSID_RANGE * (TASK_SIZE_USER64 / TASK_CONTEXT_SIZE))
|
|
#warning Limited user VSID range means pagetable space is wasted
|
|
#endif
|
|
|
|
#ifdef CONFIG_SPARSEMEM_VMEMMAP
|
|
/*
|
|
* vmemmap is the starting address of the virtual address space where
|
|
* struct pages are allocated for all possible PFNs present on the system
|
|
* including holes and bad memory (hence sparse). These virtual struct
|
|
* pages are stored in sequence in this virtual address space irrespective
|
|
* of the fact whether the corresponding PFN is valid or not. This achieves
|
|
* constant relationship between address of struct page and its PFN.
|
|
*
|
|
* During boot or memory hotplug operation when a new memory section is
|
|
* added, physical memory allocation (including hash table bolting) will
|
|
* be performed for the set of struct pages which are part of the memory
|
|
* section. This saves memory by not allocating struct pages for PFNs
|
|
* which are not valid.
|
|
*
|
|
* ----------------------------------------------
|
|
* | PHYSICAL ALLOCATION OF VIRTUAL STRUCT PAGES|
|
|
* ----------------------------------------------
|
|
*
|
|
* f000000000000000 c000000000000000
|
|
* vmemmap +--------------+ +--------------+
|
|
* + | page struct | +--------------> | page struct |
|
|
* | +--------------+ +--------------+
|
|
* | | page struct | +--------------> | page struct |
|
|
* | +--------------+ | +--------------+
|
|
* | | page struct | + +------> | page struct |
|
|
* | +--------------+ | +--------------+
|
|
* | | page struct | | +--> | page struct |
|
|
* | +--------------+ | | +--------------+
|
|
* | | page struct | | |
|
|
* | +--------------+ | |
|
|
* | | page struct | | |
|
|
* | +--------------+ | |
|
|
* | | page struct | | |
|
|
* | +--------------+ | |
|
|
* | | page struct | | |
|
|
* | +--------------+ | |
|
|
* | | page struct | +-------+ |
|
|
* | +--------------+ |
|
|
* | | page struct | +-----------+
|
|
* | +--------------+
|
|
* | | page struct | No mapping
|
|
* | +--------------+
|
|
* | | page struct | No mapping
|
|
* v +--------------+
|
|
*
|
|
* -----------------------------------------
|
|
* | RELATION BETWEEN STRUCT PAGES AND PFNS|
|
|
* -----------------------------------------
|
|
*
|
|
* vmemmap +--------------+ +---------------+
|
|
* + | page struct | +-------------> | PFN |
|
|
* | +--------------+ +---------------+
|
|
* | | page struct | +-------------> | PFN |
|
|
* | +--------------+ +---------------+
|
|
* | | page struct | +-------------> | PFN |
|
|
* | +--------------+ +---------------+
|
|
* | | page struct | +-------------> | PFN |
|
|
* | +--------------+ +---------------+
|
|
* | | |
|
|
* | +--------------+
|
|
* | | |
|
|
* | +--------------+
|
|
* | | |
|
|
* | +--------------+ +---------------+
|
|
* | | page struct | +-------------> | PFN |
|
|
* | +--------------+ +---------------+
|
|
* | | |
|
|
* | +--------------+
|
|
* | | |
|
|
* | +--------------+ +---------------+
|
|
* | | page struct | +-------------> | PFN |
|
|
* | +--------------+ +---------------+
|
|
* | | page struct | +-------------> | PFN |
|
|
* v +--------------+ +---------------+
|
|
*/
|
|
/*
|
|
* On hash-based CPUs, the vmemmap is bolted in the hash table.
|
|
*
|
|
*/
|
|
int __meminit hash__vmemmap_create_mapping(unsigned long start,
|
|
unsigned long page_size,
|
|
unsigned long phys)
|
|
{
|
|
int rc = htab_bolt_mapping(start, start + page_size, phys,
|
|
pgprot_val(PAGE_KERNEL),
|
|
mmu_vmemmap_psize, mmu_kernel_ssize);
|
|
if (rc < 0) {
|
|
int rc2 = htab_remove_mapping(start, start + page_size,
|
|
mmu_vmemmap_psize,
|
|
mmu_kernel_ssize);
|
|
BUG_ON(rc2 && (rc2 != -ENOENT));
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
#ifdef CONFIG_MEMORY_HOTPLUG
|
|
void hash__vmemmap_remove_mapping(unsigned long start,
|
|
unsigned long page_size)
|
|
{
|
|
int rc = htab_remove_mapping(start, start + page_size,
|
|
mmu_vmemmap_psize,
|
|
mmu_kernel_ssize);
|
|
BUG_ON((rc < 0) && (rc != -ENOENT));
|
|
WARN_ON(rc == -ENOENT);
|
|
}
|
|
#endif
|
|
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
|
|
|
|
/*
|
|
* map_kernel_page currently only called by __ioremap
|
|
* map_kernel_page adds an entry to the ioremap page table
|
|
* and adds an entry to the HPT, possibly bolting it
|
|
*/
|
|
int hash__map_kernel_page(unsigned long ea, unsigned long pa, pgprot_t prot)
|
|
{
|
|
pgd_t *pgdp;
|
|
pud_t *pudp;
|
|
pmd_t *pmdp;
|
|
pte_t *ptep;
|
|
|
|
BUILD_BUG_ON(TASK_SIZE_USER64 > H_PGTABLE_RANGE);
|
|
if (slab_is_available()) {
|
|
pgdp = pgd_offset_k(ea);
|
|
pudp = pud_alloc(&init_mm, pgdp, ea);
|
|
if (!pudp)
|
|
return -ENOMEM;
|
|
pmdp = pmd_alloc(&init_mm, pudp, ea);
|
|
if (!pmdp)
|
|
return -ENOMEM;
|
|
ptep = pte_alloc_kernel(pmdp, ea);
|
|
if (!ptep)
|
|
return -ENOMEM;
|
|
set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, prot));
|
|
} else {
|
|
/*
|
|
* If the mm subsystem is not fully up, we cannot create a
|
|
* linux page table entry for this mapping. Simply bolt an
|
|
* entry in the hardware page table.
|
|
*
|
|
*/
|
|
if (htab_bolt_mapping(ea, ea + PAGE_SIZE, pa, pgprot_val(prot),
|
|
mmu_io_psize, mmu_kernel_ssize)) {
|
|
printk(KERN_ERR "Failed to do bolted mapping IO "
|
|
"memory at %016lx !\n", pa);
|
|
return -ENOMEM;
|
|
}
|
|
}
|
|
|
|
smp_wmb();
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
|
|
unsigned long hash__pmd_hugepage_update(struct mm_struct *mm, unsigned long addr,
|
|
pmd_t *pmdp, unsigned long clr,
|
|
unsigned long set)
|
|
{
|
|
__be64 old_be, tmp;
|
|
unsigned long old;
|
|
|
|
#ifdef CONFIG_DEBUG_VM
|
|
WARN_ON(!hash__pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp));
|
|
assert_spin_locked(pmd_lockptr(mm, pmdp));
|
|
#endif
|
|
|
|
__asm__ __volatile__(
|
|
"1: ldarx %0,0,%3\n\
|
|
and. %1,%0,%6\n\
|
|
bne- 1b \n\
|
|
andc %1,%0,%4 \n\
|
|
or %1,%1,%7\n\
|
|
stdcx. %1,0,%3 \n\
|
|
bne- 1b"
|
|
: "=&r" (old_be), "=&r" (tmp), "=m" (*pmdp)
|
|
: "r" (pmdp), "r" (cpu_to_be64(clr)), "m" (*pmdp),
|
|
"r" (cpu_to_be64(H_PAGE_BUSY)), "r" (cpu_to_be64(set))
|
|
: "cc" );
|
|
|
|
old = be64_to_cpu(old_be);
|
|
|
|
trace_hugepage_update(addr, old, clr, set);
|
|
if (old & H_PAGE_HASHPTE)
|
|
hpte_do_hugepage_flush(mm, addr, pmdp, old);
|
|
return old;
|
|
}
|
|
|
|
pmd_t hash__pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,
|
|
pmd_t *pmdp)
|
|
{
|
|
pmd_t pmd;
|
|
|
|
VM_BUG_ON(address & ~HPAGE_PMD_MASK);
|
|
VM_BUG_ON(pmd_trans_huge(*pmdp));
|
|
VM_BUG_ON(pmd_devmap(*pmdp));
|
|
|
|
pmd = *pmdp;
|
|
pmd_clear(pmdp);
|
|
/*
|
|
* Wait for all pending hash_page to finish. This is needed
|
|
* in case of subpage collapse. When we collapse normal pages
|
|
* to hugepage, we first clear the pmd, then invalidate all
|
|
* the PTE entries. The assumption here is that any low level
|
|
* page fault will see a none pmd and take the slow path that
|
|
* will wait on mmap_sem. But we could very well be in a
|
|
* hash_page with local ptep pointer value. Such a hash page
|
|
* can result in adding new HPTE entries for normal subpages.
|
|
* That means we could be modifying the page content as we
|
|
* copy them to a huge page. So wait for parallel hash_page
|
|
* to finish before invalidating HPTE entries. We can do this
|
|
* by sending an IPI to all the cpus and executing a dummy
|
|
* function there.
|
|
*/
|
|
serialize_against_pte_lookup(vma->vm_mm);
|
|
/*
|
|
* Now invalidate the hpte entries in the range
|
|
* covered by pmd. This make sure we take a
|
|
* fault and will find the pmd as none, which will
|
|
* result in a major fault which takes mmap_sem and
|
|
* hence wait for collapse to complete. Without this
|
|
* the __collapse_huge_page_copy can result in copying
|
|
* the old content.
|
|
*/
|
|
flush_tlb_pmd_range(vma->vm_mm, &pmd, address);
|
|
return pmd;
|
|
}
|
|
|
|
/*
|
|
* We want to put the pgtable in pmd and use pgtable for tracking
|
|
* the base page size hptes
|
|
*/
|
|
void hash__pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
|
|
pgtable_t pgtable)
|
|
{
|
|
pgtable_t *pgtable_slot;
|
|
|
|
assert_spin_locked(pmd_lockptr(mm, pmdp));
|
|
/*
|
|
* we store the pgtable in the second half of PMD
|
|
*/
|
|
pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
|
|
*pgtable_slot = pgtable;
|
|
/*
|
|
* expose the deposited pgtable to other cpus.
|
|
* before we set the hugepage PTE at pmd level
|
|
* hash fault code looks at the deposted pgtable
|
|
* to store hash index values.
|
|
*/
|
|
smp_wmb();
|
|
}
|
|
|
|
pgtable_t hash__pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
|
|
{
|
|
pgtable_t pgtable;
|
|
pgtable_t *pgtable_slot;
|
|
|
|
assert_spin_locked(pmd_lockptr(mm, pmdp));
|
|
|
|
pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
|
|
pgtable = *pgtable_slot;
|
|
/*
|
|
* Once we withdraw, mark the entry NULL.
|
|
*/
|
|
*pgtable_slot = NULL;
|
|
/*
|
|
* We store HPTE information in the deposited PTE fragment.
|
|
* zero out the content on withdraw.
|
|
*/
|
|
memset(pgtable, 0, PTE_FRAG_SIZE);
|
|
return pgtable;
|
|
}
|
|
|
|
/*
|
|
* A linux hugepage PMD was changed and the corresponding hash table entries
|
|
* neesd to be flushed.
|
|
*/
|
|
void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr,
|
|
pmd_t *pmdp, unsigned long old_pmd)
|
|
{
|
|
int ssize;
|
|
unsigned int psize;
|
|
unsigned long vsid;
|
|
unsigned long flags = 0;
|
|
|
|
/* get the base page size,vsid and segment size */
|
|
#ifdef CONFIG_DEBUG_VM
|
|
psize = get_slice_psize(mm, addr);
|
|
BUG_ON(psize == MMU_PAGE_16M);
|
|
#endif
|
|
if (old_pmd & H_PAGE_COMBO)
|
|
psize = MMU_PAGE_4K;
|
|
else
|
|
psize = MMU_PAGE_64K;
|
|
|
|
if (!is_kernel_addr(addr)) {
|
|
ssize = user_segment_size(addr);
|
|
vsid = get_user_vsid(&mm->context, addr, ssize);
|
|
WARN_ON(vsid == 0);
|
|
} else {
|
|
vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
|
|
ssize = mmu_kernel_ssize;
|
|
}
|
|
|
|
if (mm_is_thread_local(mm))
|
|
flags |= HPTE_LOCAL_UPDATE;
|
|
|
|
return flush_hash_hugepage(vsid, addr, pmdp, psize, ssize, flags);
|
|
}
|
|
|
|
pmd_t hash__pmdp_huge_get_and_clear(struct mm_struct *mm,
|
|
unsigned long addr, pmd_t *pmdp)
|
|
{
|
|
pmd_t old_pmd;
|
|
pgtable_t pgtable;
|
|
unsigned long old;
|
|
pgtable_t *pgtable_slot;
|
|
|
|
old = pmd_hugepage_update(mm, addr, pmdp, ~0UL, 0);
|
|
old_pmd = __pmd(old);
|
|
/*
|
|
* We have pmd == none and we are holding page_table_lock.
|
|
* So we can safely go and clear the pgtable hash
|
|
* index info.
|
|
*/
|
|
pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
|
|
pgtable = *pgtable_slot;
|
|
/*
|
|
* Let's zero out old valid and hash index details
|
|
* hash fault look at them.
|
|
*/
|
|
memset(pgtable, 0, PTE_FRAG_SIZE);
|
|
/*
|
|
* Serialize against find_current_mm_pte variants which does lock-less
|
|
* lookup in page tables with local interrupts disabled. For huge pages
|
|
* it casts pmd_t to pte_t. Since format of pte_t is different from
|
|
* pmd_t we want to prevent transit from pmd pointing to page table
|
|
* to pmd pointing to huge page (and back) while interrupts are disabled.
|
|
* We clear pmd to possibly replace it with page table pointer in
|
|
* different code paths. So make sure we wait for the parallel
|
|
* find_curren_mm_pte to finish.
|
|
*/
|
|
serialize_against_pte_lookup(mm);
|
|
return old_pmd;
|
|
}
|
|
|
|
int hash__has_transparent_hugepage(void)
|
|
{
|
|
|
|
if (!mmu_has_feature(MMU_FTR_16M_PAGE))
|
|
return 0;
|
|
/*
|
|
* We support THP only if PMD_SIZE is 16MB.
|
|
*/
|
|
if (mmu_psize_defs[MMU_PAGE_16M].shift != PMD_SHIFT)
|
|
return 0;
|
|
/*
|
|
* We need to make sure that we support 16MB hugepage in a segement
|
|
* with base page size 64K or 4K. We only enable THP with a PAGE_SIZE
|
|
* of 64K.
|
|
*/
|
|
/*
|
|
* If we have 64K HPTE, we will be using that by default
|
|
*/
|
|
if (mmu_psize_defs[MMU_PAGE_64K].shift &&
|
|
(mmu_psize_defs[MMU_PAGE_64K].penc[MMU_PAGE_16M] == -1))
|
|
return 0;
|
|
/*
|
|
* Ok we only have 4K HPTE
|
|
*/
|
|
if (mmu_psize_defs[MMU_PAGE_4K].penc[MMU_PAGE_16M] == -1)
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|
|
|
|
#ifdef CONFIG_STRICT_KERNEL_RWX
|
|
static bool hash__change_memory_range(unsigned long start, unsigned long end,
|
|
unsigned long newpp)
|
|
{
|
|
unsigned long idx;
|
|
unsigned int step, shift;
|
|
|
|
shift = mmu_psize_defs[mmu_linear_psize].shift;
|
|
step = 1 << shift;
|
|
|
|
start = ALIGN_DOWN(start, step);
|
|
end = ALIGN(end, step); // aligns up
|
|
|
|
if (start >= end)
|
|
return false;
|
|
|
|
pr_debug("Changing page protection on range 0x%lx-0x%lx, to 0x%lx, step 0x%x\n",
|
|
start, end, newpp, step);
|
|
|
|
for (idx = start; idx < end; idx += step)
|
|
/* Not sure if we can do much with the return value */
|
|
mmu_hash_ops.hpte_updateboltedpp(newpp, idx, mmu_linear_psize,
|
|
mmu_kernel_ssize);
|
|
|
|
return true;
|
|
}
|
|
|
|
void hash__mark_rodata_ro(void)
|
|
{
|
|
unsigned long start, end;
|
|
|
|
start = (unsigned long)_stext;
|
|
end = (unsigned long)__init_begin;
|
|
|
|
WARN_ON(!hash__change_memory_range(start, end, PP_RXXX));
|
|
}
|
|
|
|
void hash__mark_initmem_nx(void)
|
|
{
|
|
unsigned long start, end, pp;
|
|
|
|
start = (unsigned long)__init_begin;
|
|
end = (unsigned long)__init_end;
|
|
|
|
pp = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL));
|
|
|
|
WARN_ON(!hash__change_memory_range(start, end, pp));
|
|
}
|
|
#endif
|