OpenCloudOS-Kernel/arch/powerpc/include/asm/pgalloc-64.h

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#ifndef _ASM_POWERPC_PGALLOC_64_H
#define _ASM_POWERPC_PGALLOC_64_H
/*
* 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/slab.h>
#include <linux/cpumask.h>
#include <linux/percpu.h>
struct vmemmap_backing {
struct vmemmap_backing *list;
unsigned long phys;
unsigned long virt_addr;
};
extern struct vmemmap_backing *vmemmap_list;
/*
* Functions that deal with pagetables that could be at any level of
* the table need to be passed an "index_size" so they know how to
* handle allocation. For PTE pages (which are linked to a struct
* page for now, and drawn from the main get_free_pages() pool), the
* allocation size will be (2^index_size * sizeof(pointer)) and
* allocations are drawn from the kmem_cache in PGT_CACHE(index_size).
*
* The maximum index size needs to be big enough to allow any
* pagetable sizes we need, but small enough to fit in the low bits of
* any page table pointer. In other words all pagetables, even tiny
* ones, must be aligned to allow at least enough low 0 bits to
* contain this value. This value is also used as a mask, so it must
* be one less than a power of two.
*/
#define MAX_PGTABLE_INDEX_SIZE 0xf
extern struct kmem_cache *pgtable_cache[];
#define PGT_CACHE(shift) ({ \
BUG_ON(!(shift)); \
pgtable_cache[(shift) - 1]; \
})
static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
return kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE), GFP_KERNEL);
}
static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
kmem_cache_free(PGT_CACHE(PGD_INDEX_SIZE), pgd);
}
#ifndef CONFIG_PPC_64K_PAGES
#define pgd_populate(MM, PGD, PUD) pgd_set(PGD, (unsigned long)PUD)
static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
{
return kmem_cache_alloc(PGT_CACHE(PUD_INDEX_SIZE),
GFP_KERNEL|__GFP_REPEAT);
}
static inline void pud_free(struct mm_struct *mm, pud_t *pud)
{
kmem_cache_free(PGT_CACHE(PUD_INDEX_SIZE), pud);
}
static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
{
pud_set(pud, (unsigned long)pmd);
}
static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
pte_t *pte)
{
pmd_set(pmd, (unsigned long)pte);
}
static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
pgtable_t pte_page)
{
pmd_set(pmd, (unsigned long)page_address(pte_page));
}
CONFIG_HIGHPTE vs. sub-page page tables. Background: I've implemented 1K/2K page tables for s390. These sub-page page tables are required to properly support the s390 virtualization instruction with KVM. The SIE instruction requires that the page tables have 256 page table entries (pte) followed by 256 page status table entries (pgste). The pgstes are only required if the process is using the SIE instruction. The pgstes are updated by the hardware and by the hypervisor for a number of reasons, one of them is dirty and reference bit tracking. To avoid wasting memory the standard pte table allocation should return 1K/2K (31/64 bit) and 2K/4K if the process is using SIE. Problem: Page size on s390 is 4K, page table size is 1K or 2K. That means the s390 version for pte_alloc_one cannot return a pointer to a struct page. Trouble is that with the CONFIG_HIGHPTE feature on x86 pte_alloc_one cannot return a pointer to a pte either, since that would require more than 32 bit for the return value of pte_alloc_one (and the pte * would not be accessible since its not kmapped). Solution: The only solution I found to this dilemma is a new typedef: a pgtable_t. For s390 pgtable_t will be a (pte *) - to be introduced with a later patch. For everybody else it will be a (struct page *). The additional problem with the initialization of the ptl lock and the NR_PAGETABLE accounting is solved with a constructor pgtable_page_ctor and a destructor pgtable_page_dtor. The page table allocation and free functions need to call these two whenever a page table page is allocated or freed. pmd_populate will get a pgtable_t instead of a struct page pointer. To get the pgtable_t back from a pmd entry that has been installed with pmd_populate a new function pmd_pgtable is added. It replaces the pmd_page call in free_pte_range and apply_to_pte_range. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 20:22:04 +08:00
#define pmd_pgtable(pmd) pmd_page(pmd)
static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
unsigned long address)
{
return (pte_t *)__get_free_page(GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO);
}
static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
unsigned long address)
{
struct page *page;
pte_t *pte;
pte = pte_alloc_one_kernel(mm, address);
if (!pte)
return NULL;
page = virt_to_page(pte);
if (!pgtable_page_ctor(page)) {
__free_page(page);
return NULL;
}
return page;
}
static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
{
free_page((unsigned long)pte);
}
static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
{
pgtable_page_dtor(ptepage);
__free_page(ptepage);
}
static inline void pgtable_free(void *table, unsigned index_size)
{
if (!index_size)
free_page((unsigned long)table);
else {
BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE);
kmem_cache_free(PGT_CACHE(index_size), table);
}
}
#ifdef CONFIG_SMP
static inline 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);
}
static inline 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;
pgtable_free(table, shift);
}
#else /* !CONFIG_SMP */
static inline void pgtable_free_tlb(struct mmu_gather *tlb,
void *table, int shift)
{
pgtable_free(table, shift);
}
#endif /* CONFIG_SMP */
static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
unsigned long address)
{
tlb_flush_pgtable(tlb, address);
powerpc: Fix PTE page address mismatch in pgtable ctor/dtor In pte_alloc_one(), pgtable_page_ctor() is passed an address that has not been converted by page_address() to the newly allocated PTE page. When the PTE is freed, __pte_free_tlb() calls pgtable_page_dtor() with an address to the PTE page that has been converted by page_address(). The mismatch in the PTE's page address causes pgtable_page_dtor() to access invalid memory, so resources for that PTE (such as the page lock) is not properly cleaned up. On PPC32, only SMP kernels are affected. On PPC64, only SMP kernels with 4K page size are affected. This bug was introduced by commit d614bb041209fd7cb5e4b35e11a7b2f6ee8f62b8 "powerpc: Move the pte free routines from common header". On a preempt-rt kernel, a spinlock is dynamically allocated for each PTE in pgtable_page_ctor(). When the PTE is freed, calling pgtable_page_dtor() with a mismatched page address causes a memory leak, as the pointer to the PTE's spinlock is bogus. On mainline, there isn't any immediately obvious symptoms, but the problem still exists here. Fixes: d614bb041209fd7c "powerpc: Move the pte free routes from common header" Cc: Paul Mackerras <paulus@samba.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: linux-stable <stable@vger.kernel.org> # v3.10+ Signed-off-by: Hong H. Pham <hong.pham@windriver.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-07 22:06:33 +08:00
pgtable_page_dtor(table);
pgtable_free_tlb(tlb, page_address(table), 0);
}
#else /* if CONFIG_PPC_64K_PAGES */
extern pte_t *page_table_alloc(struct mm_struct *, unsigned long, int);
extern void page_table_free(struct mm_struct *, unsigned long *, int);
extern void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift);
#ifdef CONFIG_SMP
extern void __tlb_remove_table(void *_table);
#endif
#define pud_populate(mm, pud, pmd) pud_set(pud, (unsigned long)pmd)
static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
pte_t *pte)
{
pmd_set(pmd, (unsigned long)pte);
}
static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
pgtable_t pte_page)
{
pmd_set(pmd, (unsigned long)pte_page);
}
static inline pgtable_t pmd_pgtable(pmd_t pmd)
{
return (pgtable_t)(pmd_val(pmd) & ~PMD_MASKED_BITS);
}
static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
unsigned long address)
{
return (pte_t *)page_table_alloc(mm, address, 1);
}
CONFIG_HIGHPTE vs. sub-page page tables. Background: I've implemented 1K/2K page tables for s390. These sub-page page tables are required to properly support the s390 virtualization instruction with KVM. The SIE instruction requires that the page tables have 256 page table entries (pte) followed by 256 page status table entries (pgste). The pgstes are only required if the process is using the SIE instruction. The pgstes are updated by the hardware and by the hypervisor for a number of reasons, one of them is dirty and reference bit tracking. To avoid wasting memory the standard pte table allocation should return 1K/2K (31/64 bit) and 2K/4K if the process is using SIE. Problem: Page size on s390 is 4K, page table size is 1K or 2K. That means the s390 version for pte_alloc_one cannot return a pointer to a struct page. Trouble is that with the CONFIG_HIGHPTE feature on x86 pte_alloc_one cannot return a pointer to a pte either, since that would require more than 32 bit for the return value of pte_alloc_one (and the pte * would not be accessible since its not kmapped). Solution: The only solution I found to this dilemma is a new typedef: a pgtable_t. For s390 pgtable_t will be a (pte *) - to be introduced with a later patch. For everybody else it will be a (struct page *). The additional problem with the initialization of the ptl lock and the NR_PAGETABLE accounting is solved with a constructor pgtable_page_ctor and a destructor pgtable_page_dtor. The page table allocation and free functions need to call these two whenever a page table page is allocated or freed. pmd_populate will get a pgtable_t instead of a struct page pointer. To get the pgtable_t back from a pmd entry that has been installed with pmd_populate a new function pmd_pgtable is added. It replaces the pmd_page call in free_pte_range and apply_to_pte_range. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 20:22:04 +08:00
static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
unsigned long address)
{
return (pgtable_t)page_table_alloc(mm, address, 0);
}
static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
{
page_table_free(mm, (unsigned long *)pte, 1);
}
static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
{
page_table_free(mm, (unsigned long *)ptepage, 0);
}
static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table,
unsigned long address)
{
tlb_flush_pgtable(tlb, address);
pgtable_free_tlb(tlb, table, 0);
}
#endif /* CONFIG_PPC_64K_PAGES */
static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
{
return kmem_cache_alloc(PGT_CACHE(PMD_CACHE_INDEX),
GFP_KERNEL|__GFP_REPEAT);
}
static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
{
kmem_cache_free(PGT_CACHE(PMD_CACHE_INDEX), pmd);
}
#define __pmd_free_tlb(tlb, pmd, addr) \
pgtable_free_tlb(tlb, pmd, PMD_CACHE_INDEX)
#ifndef CONFIG_PPC_64K_PAGES
#define __pud_free_tlb(tlb, pud, addr) \
pgtable_free_tlb(tlb, pud, PUD_INDEX_SIZE)
#endif /* CONFIG_PPC_64K_PAGES */
#define check_pgt_cache() do { } while (0)
#endif /* _ASM_POWERPC_PGALLOC_64_H */