linux/arch/powerpc/include/asm/pgtable-ppc64.h

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#ifndef _ASM_POWERPC_PGTABLE_PPC64_H_
#define _ASM_POWERPC_PGTABLE_PPC64_H_
/*
* This file contains the functions and defines necessary to modify and use
* the ppc64 hashed page table.
*/
#ifdef CONFIG_PPC_64K_PAGES
#include <asm/pgtable-ppc64-64k.h>
#else
#include <asm/pgtable-ppc64-4k.h>
#endif
#define FIRST_USER_ADDRESS 0
/*
* Size of EA range mapped by our pagetables.
*/
#define PGTABLE_EADDR_SIZE (PTE_INDEX_SIZE + PMD_INDEX_SIZE + \
PUD_INDEX_SIZE + PGD_INDEX_SIZE + PAGE_SHIFT)
[POWERPC] Rewrite IO allocation & mapping on powerpc64 This rewrites pretty much from scratch the handling of MMIO and PIO space allocations on powerpc64. The main goals are: - Get rid of imalloc and use more common code where possible - Simplify the current mess so that PIO space is allocated and mapped in a single place for PCI bridges - Handle allocation constraints of PIO for all bridges including hot plugged ones within the 2GB space reserved for IO ports, so that devices on hotplugged busses will now work with drivers that assume IO ports fit in an int. - Cleanup and separate tracking of the ISA space in the reserved low 64K of IO space. No ISA -> Nothing mapped there. I booted a cell blade with IDE on PIO and MMIO and a dual G5 so far, that's it :-) With this patch, all allocations are done using the code in mm/vmalloc.c, though we use the low level __get_vm_area with explicit start/stop constraints in order to manage separate areas for vmalloc/vmap, ioremap, and PCI IOs. This greatly simplifies a lot of things, as you can see in the diffstat of that patch :-) A new pair of functions pcibios_map/unmap_io_space() now replace all of the previous code that used to manipulate PCI IOs space. The allocation is done at mapping time, which is now called from scan_phb's, just before the devices are probed (instead of after, which is by itself a bug fix). The only other caller is the PCI hotplug code for hot adding PCI-PCI bridges (slots). imalloc is gone, as is the "sub-allocation" thing, but I do beleive that hotplug should still work in the sense that the space allocation is always done by the PHB, but if you unmap a child bus of this PHB (which seems to be possible), then the code should properly tear down all the HPTE mappings for that area of the PHB allocated IO space. I now always reserve the first 64K of IO space for the bridge with the ISA bus on it. I have moved the code for tracking ISA in a separate file which should also make it smarter if we ever are capable of hot unplugging or re-plugging an ISA bridge. This should have a side effect on platforms like powermac where VGA IOs will no longer work. This is done on purpose though as they would have worked semi-randomly before. The idea at this point is to isolate drivers that might need to access those and fix them by providing a proper function to obtain an offset to the legacy IOs of a given bus. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-04 07:15:36 +02:00
#define PGTABLE_RANGE (ASM_CONST(1) << PGTABLE_EADDR_SIZE)
/* Some sanity checking */
#if TASK_SIZE_USER64 > PGTABLE_RANGE
#error TASK_SIZE_USER64 exceeds pagetable range
#endif
#ifdef CONFIG_PPC_STD_MMU_64
#if TASK_SIZE_USER64 > (1UL << (USER_ESID_BITS + SID_SHIFT))
#error TASK_SIZE_USER64 exceeds user VSID range
#endif
#endif
/*
* Define the address range of the kernel non-linear virtual area
*/
#ifdef CONFIG_PPC_BOOK3E
#define KERN_VIRT_START ASM_CONST(0x8000000000000000)
#else
#define KERN_VIRT_START ASM_CONST(0xD000000000000000)
#endif
#define KERN_VIRT_SIZE PGTABLE_RANGE
/*
* The vmalloc space starts at the beginning of that region, and
* occupies half of it on hash CPUs and a quarter of it on Book3E
*/
#define VMALLOC_START KERN_VIRT_START
#ifdef CONFIG_PPC_BOOK3E
#define VMALLOC_SIZE (KERN_VIRT_SIZE >> 2)
#else
#define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1)
#endif
#define VMALLOC_END (VMALLOC_START + VMALLOC_SIZE)
/*
* The second half of the kernel virtual space is used for IO mappings,
* it's itself carved into the PIO region (ISA and PHB IO space) and
* the ioremap space
[POWERPC] Rewrite IO allocation & mapping on powerpc64 This rewrites pretty much from scratch the handling of MMIO and PIO space allocations on powerpc64. The main goals are: - Get rid of imalloc and use more common code where possible - Simplify the current mess so that PIO space is allocated and mapped in a single place for PCI bridges - Handle allocation constraints of PIO for all bridges including hot plugged ones within the 2GB space reserved for IO ports, so that devices on hotplugged busses will now work with drivers that assume IO ports fit in an int. - Cleanup and separate tracking of the ISA space in the reserved low 64K of IO space. No ISA -> Nothing mapped there. I booted a cell blade with IDE on PIO and MMIO and a dual G5 so far, that's it :-) With this patch, all allocations are done using the code in mm/vmalloc.c, though we use the low level __get_vm_area with explicit start/stop constraints in order to manage separate areas for vmalloc/vmap, ioremap, and PCI IOs. This greatly simplifies a lot of things, as you can see in the diffstat of that patch :-) A new pair of functions pcibios_map/unmap_io_space() now replace all of the previous code that used to manipulate PCI IOs space. The allocation is done at mapping time, which is now called from scan_phb's, just before the devices are probed (instead of after, which is by itself a bug fix). The only other caller is the PCI hotplug code for hot adding PCI-PCI bridges (slots). imalloc is gone, as is the "sub-allocation" thing, but I do beleive that hotplug should still work in the sense that the space allocation is always done by the PHB, but if you unmap a child bus of this PHB (which seems to be possible), then the code should properly tear down all the HPTE mappings for that area of the PHB allocated IO space. I now always reserve the first 64K of IO space for the bridge with the ISA bus on it. I have moved the code for tracking ISA in a separate file which should also make it smarter if we ever are capable of hot unplugging or re-plugging an ISA bridge. This should have a side effect on platforms like powermac where VGA IOs will no longer work. This is done on purpose though as they would have worked semi-randomly before. The idea at this point is to isolate drivers that might need to access those and fix them by providing a proper function to obtain an offset to the legacy IOs of a given bus. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-04 07:15:36 +02:00
*
* ISA_IO_BASE = KERN_IO_START, 64K reserved area
[POWERPC] Rewrite IO allocation & mapping on powerpc64 This rewrites pretty much from scratch the handling of MMIO and PIO space allocations on powerpc64. The main goals are: - Get rid of imalloc and use more common code where possible - Simplify the current mess so that PIO space is allocated and mapped in a single place for PCI bridges - Handle allocation constraints of PIO for all bridges including hot plugged ones within the 2GB space reserved for IO ports, so that devices on hotplugged busses will now work with drivers that assume IO ports fit in an int. - Cleanup and separate tracking of the ISA space in the reserved low 64K of IO space. No ISA -> Nothing mapped there. I booted a cell blade with IDE on PIO and MMIO and a dual G5 so far, that's it :-) With this patch, all allocations are done using the code in mm/vmalloc.c, though we use the low level __get_vm_area with explicit start/stop constraints in order to manage separate areas for vmalloc/vmap, ioremap, and PCI IOs. This greatly simplifies a lot of things, as you can see in the diffstat of that patch :-) A new pair of functions pcibios_map/unmap_io_space() now replace all of the previous code that used to manipulate PCI IOs space. The allocation is done at mapping time, which is now called from scan_phb's, just before the devices are probed (instead of after, which is by itself a bug fix). The only other caller is the PCI hotplug code for hot adding PCI-PCI bridges (slots). imalloc is gone, as is the "sub-allocation" thing, but I do beleive that hotplug should still work in the sense that the space allocation is always done by the PHB, but if you unmap a child bus of this PHB (which seems to be possible), then the code should properly tear down all the HPTE mappings for that area of the PHB allocated IO space. I now always reserve the first 64K of IO space for the bridge with the ISA bus on it. I have moved the code for tracking ISA in a separate file which should also make it smarter if we ever are capable of hot unplugging or re-plugging an ISA bridge. This should have a side effect on platforms like powermac where VGA IOs will no longer work. This is done on purpose though as they would have worked semi-randomly before. The idea at this point is to isolate drivers that might need to access those and fix them by providing a proper function to obtain an offset to the legacy IOs of a given bus. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-04 07:15:36 +02:00
* PHB_IO_BASE = ISA_IO_BASE + 64K to ISA_IO_BASE + 2G, PHB IO spaces
* IOREMAP_BASE = ISA_IO_BASE + 2G to VMALLOC_START + PGTABLE_RANGE
*/
#define KERN_IO_START (KERN_VIRT_START + (KERN_VIRT_SIZE >> 1))
[POWERPC] Rewrite IO allocation & mapping on powerpc64 This rewrites pretty much from scratch the handling of MMIO and PIO space allocations on powerpc64. The main goals are: - Get rid of imalloc and use more common code where possible - Simplify the current mess so that PIO space is allocated and mapped in a single place for PCI bridges - Handle allocation constraints of PIO for all bridges including hot plugged ones within the 2GB space reserved for IO ports, so that devices on hotplugged busses will now work with drivers that assume IO ports fit in an int. - Cleanup and separate tracking of the ISA space in the reserved low 64K of IO space. No ISA -> Nothing mapped there. I booted a cell blade with IDE on PIO and MMIO and a dual G5 so far, that's it :-) With this patch, all allocations are done using the code in mm/vmalloc.c, though we use the low level __get_vm_area with explicit start/stop constraints in order to manage separate areas for vmalloc/vmap, ioremap, and PCI IOs. This greatly simplifies a lot of things, as you can see in the diffstat of that patch :-) A new pair of functions pcibios_map/unmap_io_space() now replace all of the previous code that used to manipulate PCI IOs space. The allocation is done at mapping time, which is now called from scan_phb's, just before the devices are probed (instead of after, which is by itself a bug fix). The only other caller is the PCI hotplug code for hot adding PCI-PCI bridges (slots). imalloc is gone, as is the "sub-allocation" thing, but I do beleive that hotplug should still work in the sense that the space allocation is always done by the PHB, but if you unmap a child bus of this PHB (which seems to be possible), then the code should properly tear down all the HPTE mappings for that area of the PHB allocated IO space. I now always reserve the first 64K of IO space for the bridge with the ISA bus on it. I have moved the code for tracking ISA in a separate file which should also make it smarter if we ever are capable of hot unplugging or re-plugging an ISA bridge. This should have a side effect on platforms like powermac where VGA IOs will no longer work. This is done on purpose though as they would have worked semi-randomly before. The idea at this point is to isolate drivers that might need to access those and fix them by providing a proper function to obtain an offset to the legacy IOs of a given bus. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-04 07:15:36 +02:00
#define FULL_IO_SIZE 0x80000000ul
#define ISA_IO_BASE (KERN_IO_START)
#define ISA_IO_END (KERN_IO_START + 0x10000ul)
[POWERPC] Rewrite IO allocation & mapping on powerpc64 This rewrites pretty much from scratch the handling of MMIO and PIO space allocations on powerpc64. The main goals are: - Get rid of imalloc and use more common code where possible - Simplify the current mess so that PIO space is allocated and mapped in a single place for PCI bridges - Handle allocation constraints of PIO for all bridges including hot plugged ones within the 2GB space reserved for IO ports, so that devices on hotplugged busses will now work with drivers that assume IO ports fit in an int. - Cleanup and separate tracking of the ISA space in the reserved low 64K of IO space. No ISA -> Nothing mapped there. I booted a cell blade with IDE on PIO and MMIO and a dual G5 so far, that's it :-) With this patch, all allocations are done using the code in mm/vmalloc.c, though we use the low level __get_vm_area with explicit start/stop constraints in order to manage separate areas for vmalloc/vmap, ioremap, and PCI IOs. This greatly simplifies a lot of things, as you can see in the diffstat of that patch :-) A new pair of functions pcibios_map/unmap_io_space() now replace all of the previous code that used to manipulate PCI IOs space. The allocation is done at mapping time, which is now called from scan_phb's, just before the devices are probed (instead of after, which is by itself a bug fix). The only other caller is the PCI hotplug code for hot adding PCI-PCI bridges (slots). imalloc is gone, as is the "sub-allocation" thing, but I do beleive that hotplug should still work in the sense that the space allocation is always done by the PHB, but if you unmap a child bus of this PHB (which seems to be possible), then the code should properly tear down all the HPTE mappings for that area of the PHB allocated IO space. I now always reserve the first 64K of IO space for the bridge with the ISA bus on it. I have moved the code for tracking ISA in a separate file which should also make it smarter if we ever are capable of hot unplugging or re-plugging an ISA bridge. This should have a side effect on platforms like powermac where VGA IOs will no longer work. This is done on purpose though as they would have worked semi-randomly before. The idea at this point is to isolate drivers that might need to access those and fix them by providing a proper function to obtain an offset to the legacy IOs of a given bus. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-04 07:15:36 +02:00
#define PHB_IO_BASE (ISA_IO_END)
#define PHB_IO_END (KERN_IO_START + FULL_IO_SIZE)
[POWERPC] Rewrite IO allocation & mapping on powerpc64 This rewrites pretty much from scratch the handling of MMIO and PIO space allocations on powerpc64. The main goals are: - Get rid of imalloc and use more common code where possible - Simplify the current mess so that PIO space is allocated and mapped in a single place for PCI bridges - Handle allocation constraints of PIO for all bridges including hot plugged ones within the 2GB space reserved for IO ports, so that devices on hotplugged busses will now work with drivers that assume IO ports fit in an int. - Cleanup and separate tracking of the ISA space in the reserved low 64K of IO space. No ISA -> Nothing mapped there. I booted a cell blade with IDE on PIO and MMIO and a dual G5 so far, that's it :-) With this patch, all allocations are done using the code in mm/vmalloc.c, though we use the low level __get_vm_area with explicit start/stop constraints in order to manage separate areas for vmalloc/vmap, ioremap, and PCI IOs. This greatly simplifies a lot of things, as you can see in the diffstat of that patch :-) A new pair of functions pcibios_map/unmap_io_space() now replace all of the previous code that used to manipulate PCI IOs space. The allocation is done at mapping time, which is now called from scan_phb's, just before the devices are probed (instead of after, which is by itself a bug fix). The only other caller is the PCI hotplug code for hot adding PCI-PCI bridges (slots). imalloc is gone, as is the "sub-allocation" thing, but I do beleive that hotplug should still work in the sense that the space allocation is always done by the PHB, but if you unmap a child bus of this PHB (which seems to be possible), then the code should properly tear down all the HPTE mappings for that area of the PHB allocated IO space. I now always reserve the first 64K of IO space for the bridge with the ISA bus on it. I have moved the code for tracking ISA in a separate file which should also make it smarter if we ever are capable of hot unplugging or re-plugging an ISA bridge. This should have a side effect on platforms like powermac where VGA IOs will no longer work. This is done on purpose though as they would have worked semi-randomly before. The idea at this point is to isolate drivers that might need to access those and fix them by providing a proper function to obtain an offset to the legacy IOs of a given bus. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-04 07:15:36 +02:00
#define IOREMAP_BASE (PHB_IO_END)
#define IOREMAP_END (KERN_VIRT_START + KERN_VIRT_SIZE)
/*
* Region IDs
*/
#define REGION_SHIFT 60UL
#define REGION_MASK (0xfUL << REGION_SHIFT)
#define REGION_ID(ea) (((unsigned long)(ea)) >> REGION_SHIFT)
#define VMALLOC_REGION_ID (REGION_ID(VMALLOC_START))
#define KERNEL_REGION_ID (REGION_ID(PAGE_OFFSET))
#define VMEMMAP_REGION_ID (0xfUL)
#define USER_REGION_ID (0UL)
/*
* Defines the address of the vmemap area, in its own region on
* hash table CPUs and after the vmalloc space on Book3E
*/
#ifdef CONFIG_PPC_BOOK3E
#define VMEMMAP_BASE VMALLOC_END
#define VMEMMAP_END KERN_IO_START
#else
#define VMEMMAP_BASE (VMEMMAP_REGION_ID << REGION_SHIFT)
#endif
#define vmemmap ((struct page *)VMEMMAP_BASE)
/*
* Include the PTE bits definitions
*/
#ifdef CONFIG_PPC_BOOK3S
#include <asm/pte-hash64.h>
#else
#include <asm/pte-book3e.h>
#endif
#include <asm/pte-common.h>
#ifdef CONFIG_PPC_MM_SLICES
#define HAVE_ARCH_UNMAPPED_AREA
#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
#endif /* CONFIG_PPC_MM_SLICES */
#ifndef __ASSEMBLY__
#include <linux/stddef.h>
#include <asm/tlbflush.h>
/*
* This is the default implementation of various PTE accessors, it's
* used in all cases except Book3S with 64K pages where we have a
* concept of sub-pages
*/
#ifndef __real_pte
#ifdef STRICT_MM_TYPECHECKS
#define __real_pte(e,p) ((real_pte_t){(e)})
#define __rpte_to_pte(r) ((r).pte)
#else
#define __real_pte(e,p) (e)
#define __rpte_to_pte(r) (__pte(r))
#endif
#define __rpte_to_hidx(r,index) (pte_val(__rpte_to_pte(r)) >> 12)
#define pte_iterate_hashed_subpages(rpte, psize, va, index, shift) \
do { \
index = 0; \
shift = mmu_psize_defs[psize].shift; \
#define pte_iterate_hashed_end() } while(0)
#ifdef CONFIG_PPC_HAS_HASH_64K
#define pte_pagesize_index(mm, addr, pte) get_slice_psize(mm, addr)
#else
#define pte_pagesize_index(mm, addr, pte) MMU_PAGE_4K
#endif
#endif /* __real_pte */
/* pte_clear moved to later in this file */
#define PMD_BAD_BITS (PTE_TABLE_SIZE-1)
#define PUD_BAD_BITS (PMD_TABLE_SIZE-1)
#define pmd_set(pmdp, pmdval) (pmd_val(*(pmdp)) = (pmdval))
#define pmd_none(pmd) (!pmd_val(pmd))
#define pmd_bad(pmd) (!is_kernel_addr(pmd_val(pmd)) \
|| (pmd_val(pmd) & PMD_BAD_BITS))
#define pmd_present(pmd) (pmd_val(pmd) != 0)
#define pmd_clear(pmdp) (pmd_val(*(pmdp)) = 0)
#define pmd_page_vaddr(pmd) (pmd_val(pmd) & ~PMD_MASKED_BITS)
#define pmd_page(pmd) virt_to_page(pmd_page_vaddr(pmd))
#define pud_set(pudp, pudval) (pud_val(*(pudp)) = (pudval))
#define pud_none(pud) (!pud_val(pud))
#define pud_bad(pud) (!is_kernel_addr(pud_val(pud)) \
|| (pud_val(pud) & PUD_BAD_BITS))
#define pud_present(pud) (pud_val(pud) != 0)
#define pud_clear(pudp) (pud_val(*(pudp)) = 0)
#define pud_page_vaddr(pud) (pud_val(pud) & ~PUD_MASKED_BITS)
#define pud_page(pud) virt_to_page(pud_page_vaddr(pud))
#define pgd_set(pgdp, pudp) ({pgd_val(*(pgdp)) = (unsigned long)(pudp);})
/*
* Find an entry in a page-table-directory. We combine the address region
* (the high order N bits) and the pgd portion of the address.
*/
/* to avoid overflow in free_pgtables we don't use PTRS_PER_PGD here */
#define pgd_index(address) (((address) >> (PGDIR_SHIFT)) & 0x1ff)
#define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
#define pmd_offset(pudp,addr) \
(((pmd_t *) pud_page_vaddr(*(pudp))) + (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)))
#define pte_offset_kernel(dir,addr) \
(((pte_t *) pmd_page_vaddr(*(dir))) + (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
#define pte_offset_map(dir,addr) pte_offset_kernel((dir), (addr))
#define pte_offset_map_nested(dir,addr) pte_offset_kernel((dir), (addr))
#define pte_unmap(pte) do { } while(0)
#define pte_unmap_nested(pte) do { } while(0)
/* to find an entry in a kernel page-table-directory */
/* This now only contains the vmalloc pages */
#define pgd_offset_k(address) pgd_offset(&init_mm, address)
/* Atomic PTE updates */
static inline unsigned long pte_update(struct mm_struct *mm,
unsigned long addr,
pte_t *ptep, unsigned long clr,
int huge)
{
#ifdef PTE_ATOMIC_UPDATES
unsigned long old, tmp;
__asm__ __volatile__(
"1: ldarx %0,0,%3 # pte_update\n\
andi. %1,%0,%6\n\
bne- 1b \n\
andc %1,%0,%4 \n\
stdcx. %1,0,%3 \n\
bne- 1b"
: "=&r" (old), "=&r" (tmp), "=m" (*ptep)
: "r" (ptep), "r" (clr), "m" (*ptep), "i" (_PAGE_BUSY)
: "cc" );
#else
unsigned long old = pte_val(*ptep);
*ptep = __pte(old & ~clr);
#endif
powerpc/mm: Rework I$/D$ coherency (v3) This patch reworks the way we do I and D cache coherency on PowerPC. The "old" way was split in 3 different parts depending on the processor type: - Hash with per-page exec support (64-bit and >= POWER4 only) does it at hashing time, by preventing exec on unclean pages and cleaning pages on exec faults. - Everything without per-page exec support (32-bit hash, 8xx, and 64-bit < POWER4) does it for all page going to user space in update_mmu_cache(). - Embedded with per-page exec support does it from do_page_fault() on exec faults, in a way similar to what the hash code does. That leads to confusion, and bugs. For example, the method using update_mmu_cache() is racy on SMP where another processor can see the new PTE and hash it in before we have cleaned the cache, and then blow trying to execute. This is hard to hit but I think it has bitten us in the past. Also, it's inefficient for embedded where we always end up having to do at least one more page fault. This reworks the whole thing by moving the cache sync into two main call sites, though we keep different behaviours depending on the HW capability. The call sites are set_pte_at() which is now made out of line, and ptep_set_access_flags() which joins the former in pgtable.c The base idea for Embedded with per-page exec support, is that we now do the flush at set_pte_at() time when coming from an exec fault, which allows us to avoid the double fault problem completely (we can even improve the situation more by implementing TLB preload in update_mmu_cache() but that's for later). If for some reason we didn't do it there and we try to execute, we'll hit the page fault, which will do a minor fault, which will hit ptep_set_access_flags() to do things like update _PAGE_ACCESSED or _PAGE_DIRTY if needed, we just make this guys also perform the I/D cache sync for exec faults now. This second path is the catch all for things that weren't cleaned at set_pte_at() time. For cpus without per-pag exec support, we always do the sync at set_pte_at(), thus guaranteeing that when the PTE is visible to other processors, the cache is clean. For the 64-bit hash with per-page exec support case, we keep the old mechanism for now. I'll look into changing it later, once I've reworked a bit how we use _PAGE_EXEC. This is also a first step for adding _PAGE_EXEC support for embedded platforms Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-10 17:02:37 +01:00
/* huge pages use the old page table lock */
if (!huge)
assert_pte_locked(mm, addr);
#ifdef CONFIG_PPC_STD_MMU_64
if (old & _PAGE_HASHPTE)
hpte_need_flush(mm, addr, ptep, old, huge);
#endif
return old;
}
static inline int __ptep_test_and_clear_young(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
unsigned long old;
if ((pte_val(*ptep) & (_PAGE_ACCESSED | _PAGE_HASHPTE)) == 0)
return 0;
old = pte_update(mm, addr, ptep, _PAGE_ACCESSED, 0);
return (old & _PAGE_ACCESSED) != 0;
}
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
#define ptep_test_and_clear_young(__vma, __addr, __ptep) \
({ \
int __r; \
__r = __ptep_test_and_clear_young((__vma)->vm_mm, __addr, __ptep); \
__r; \
})
#define __HAVE_ARCH_PTEP_SET_WRPROTECT
static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
pte_t *ptep)
{
unsigned long old;
if ((pte_val(*ptep) & _PAGE_RW) == 0)
return;
old = pte_update(mm, addr, ptep, _PAGE_RW, 0);
}
static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
unsigned long old;
Correct hash flushing from huge_ptep_set_wrprotect() As Andy Whitcroft recently pointed out, the current powerpc version of huge_ptep_set_wrprotect() has a bug. It just calls ptep_set_wrprotect() which in turn calls pte_update() then hpte_need_flush() with the 'huge' argument set to 0. This will cause hpte_need_flush() to flush the wrong hash entries (of any). Andy's fix for this is already in the powerpc tree as commit 016b33c4958681c24056abed8ec95844a0da80a3. I have confirmed this is a real bug, not masked by some other synchronization, with a new testcase for libhugetlbfs. A process write a (MAP_PRIVATE) hugepage mapping, fork(), then alter the mapping and have the child incorrectly see the second write. Therefore, this should be fixed for 2.6.26, and for the stable tree. Here is a suitable patch for 2.6.26, which I think will also be suitable for the stable tree (neither of the headers in question has been changed much recently). It is cut down slighlty from Andy's original version, in that it does not include a 32-bit version of huge_ptep_set_wrprotect(). Currently, hugepages are not supported on any 32-bit powerpc platform. When they are, a suitable 32-bit version can be added - the only 32-bit hardware which supports hugepages does not use the conventional hashtable MMU and so will have different needs anyway. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-08 07:58:16 +02:00
if ((pte_val(*ptep) & _PAGE_RW) == 0)
return;
old = pte_update(mm, addr, ptep, _PAGE_RW, 1);
}
/*
* We currently remove entries from the hashtable regardless of whether
* the entry was young or dirty. The generic routines only flush if the
* entry was young or dirty which is not good enough.
*
* We should be more intelligent about this but for the moment we override
* these functions and force a tlb flush unconditionally
*/
#define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
#define ptep_clear_flush_young(__vma, __address, __ptep) \
({ \
int __young = __ptep_test_and_clear_young((__vma)->vm_mm, __address, \
__ptep); \
__young; \
})
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
unsigned long old = pte_update(mm, addr, ptep, ~0UL, 0);
return __pte(old);
}
static inline void pte_clear(struct mm_struct *mm, unsigned long addr,
pte_t * ptep)
{
pte_update(mm, addr, ptep, ~0UL, 0);
}
/* Set the dirty and/or accessed bits atomically in a linux PTE, this
* function doesn't need to flush the hash entry
*/
powerpc/mm: Rework I$/D$ coherency (v3) This patch reworks the way we do I and D cache coherency on PowerPC. The "old" way was split in 3 different parts depending on the processor type: - Hash with per-page exec support (64-bit and >= POWER4 only) does it at hashing time, by preventing exec on unclean pages and cleaning pages on exec faults. - Everything without per-page exec support (32-bit hash, 8xx, and 64-bit < POWER4) does it for all page going to user space in update_mmu_cache(). - Embedded with per-page exec support does it from do_page_fault() on exec faults, in a way similar to what the hash code does. That leads to confusion, and bugs. For example, the method using update_mmu_cache() is racy on SMP where another processor can see the new PTE and hash it in before we have cleaned the cache, and then blow trying to execute. This is hard to hit but I think it has bitten us in the past. Also, it's inefficient for embedded where we always end up having to do at least one more page fault. This reworks the whole thing by moving the cache sync into two main call sites, though we keep different behaviours depending on the HW capability. The call sites are set_pte_at() which is now made out of line, and ptep_set_access_flags() which joins the former in pgtable.c The base idea for Embedded with per-page exec support, is that we now do the flush at set_pte_at() time when coming from an exec fault, which allows us to avoid the double fault problem completely (we can even improve the situation more by implementing TLB preload in update_mmu_cache() but that's for later). If for some reason we didn't do it there and we try to execute, we'll hit the page fault, which will do a minor fault, which will hit ptep_set_access_flags() to do things like update _PAGE_ACCESSED or _PAGE_DIRTY if needed, we just make this guys also perform the I/D cache sync for exec faults now. This second path is the catch all for things that weren't cleaned at set_pte_at() time. For cpus without per-pag exec support, we always do the sync at set_pte_at(), thus guaranteeing that when the PTE is visible to other processors, the cache is clean. For the 64-bit hash with per-page exec support case, we keep the old mechanism for now. I'll look into changing it later, once I've reworked a bit how we use _PAGE_EXEC. This is also a first step for adding _PAGE_EXEC support for embedded platforms Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-10 17:02:37 +01:00
static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry)
{
unsigned long bits = pte_val(entry) &
(_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW |
_PAGE_EXEC | _PAGE_HWEXEC);
#ifdef PTE_ATOMIC_UPDATES
unsigned long old, tmp;
__asm__ __volatile__(
"1: ldarx %0,0,%4\n\
andi. %1,%0,%6\n\
bne- 1b \n\
or %0,%3,%0\n\
stdcx. %0,0,%4\n\
bne- 1b"
:"=&r" (old), "=&r" (tmp), "=m" (*ptep)
:"r" (bits), "r" (ptep), "m" (*ptep), "i" (_PAGE_BUSY)
:"cc");
#else
unsigned long old = pte_val(*ptep);
*ptep = __pte(old | bits);
#endif
}
#define __HAVE_ARCH_PTE_SAME
#define pte_same(A,B) (((pte_val(A) ^ pte_val(B)) & ~_PAGE_HPTEFLAGS) == 0)
#define pte_ERROR(e) \
printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
#define pmd_ERROR(e) \
printk("%s:%d: bad pmd %08lx.\n", __FILE__, __LINE__, pmd_val(e))
#define pgd_ERROR(e) \
printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
/* Encode and de-code a swap entry */
#define __swp_type(entry) (((entry).val >> 1) & 0x3f)
#define __swp_offset(entry) ((entry).val >> 8)
#define __swp_entry(type, offset) ((swp_entry_t){((type)<< 1)|((offset)<<8)})
#define __pte_to_swp_entry(pte) ((swp_entry_t){pte_val(pte) >> PTE_RPN_SHIFT})
#define __swp_entry_to_pte(x) ((pte_t) { (x).val << PTE_RPN_SHIFT })
#define pte_to_pgoff(pte) (pte_val(pte) >> PTE_RPN_SHIFT)
#define pgoff_to_pte(off) ((pte_t) {((off) << PTE_RPN_SHIFT)|_PAGE_FILE})
#define PTE_FILE_MAX_BITS (BITS_PER_LONG - PTE_RPN_SHIFT)
void pgtable_cache_init(void);
/*
* find_linux_pte returns the address of a linux pte for a given
* effective address and directory. If not found, it returns zero.
*/static inline pte_t *find_linux_pte(pgd_t *pgdir, unsigned long ea)
{
pgd_t *pg;
pud_t *pu;
pmd_t *pm;
pte_t *pt = NULL;
pg = pgdir + pgd_index(ea);
if (!pgd_none(*pg)) {
pu = pud_offset(pg, ea);
if (!pud_none(*pu)) {
pm = pmd_offset(pu, ea);
if (pmd_present(*pm))
pt = pte_offset_kernel(pm, ea);
}
}
return pt;
}
pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long address);
#endif /* __ASSEMBLY__ */
#endif /* _ASM_POWERPC_PGTABLE_PPC64_H_ */