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yaml
---
r: 112542
b: refs/heads/master
c: a2699e4
h: refs/heads/master
v: v3
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Suresh Siddha authored and Ingo Molnar committed Oct 10, 2008
1 parent 072f9ab commit 1a3beb3
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Showing 3 changed files with 145 additions and 21 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 3a85e770aa77e4f1a4096275c97b64c10cd7323e
refs/heads/master: a2699e477b8e6b17d4da64916f766dd5a2576c9c
65 changes: 60 additions & 5 deletions trunk/arch/x86/mm/init_32.c
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Original file line number Diff line number Diff line change
Expand Up @@ -194,11 +194,30 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base,
pgd_t *pgd;
pmd_t *pmd;
pte_t *pte;
unsigned pages_2m = 0, pages_4k = 0;
unsigned pages_2m, pages_4k;
int mapping_iter;

/*
* First iteration will setup identity mapping using large/small pages
* based on use_pse, with other attributes same as set by
* the early code in head_32.S
*
* Second iteration will setup the appropriate attributes (NX, GLOBAL..)
* as desired for the kernel identity mapping.
*
* This two pass mechanism conforms to the TLB app note which says:
*
* "Software should not write to a paging-structure entry in a way
* that would change, for any linear address, both the page size
* and either the page frame or attributes."
*/
mapping_iter = 1;

if (!cpu_has_pse)
use_pse = 0;

repeat:
pages_2m = pages_4k = 0;
pfn = start_pfn;
pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
pgd = pgd_base + pgd_idx;
Expand All @@ -224,6 +243,13 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base,
if (use_pse) {
unsigned int addr2;
pgprot_t prot = PAGE_KERNEL_LARGE;
/*
* first pass will use the same initial
* identity mapping attribute + _PAGE_PSE.
*/
pgprot_t init_prot =
__pgprot(PTE_IDENT_ATTR |
_PAGE_PSE);

addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
PAGE_OFFSET + PAGE_SIZE-1;
Expand All @@ -233,7 +259,10 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base,
prot = PAGE_KERNEL_LARGE_EXEC;

pages_2m++;
set_pmd(pmd, pfn_pmd(pfn, prot));
if (mapping_iter == 1)
set_pmd(pmd, pfn_pmd(pfn, init_prot));
else
set_pmd(pmd, pfn_pmd(pfn, prot));

pfn += PTRS_PER_PTE;
continue;
Expand All @@ -245,17 +274,43 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base,
for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn;
pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
pgprot_t prot = PAGE_KERNEL;
/*
* first pass will use the same initial
* identity mapping attribute.
*/
pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR);

if (is_kernel_text(addr))
prot = PAGE_KERNEL_EXEC;

pages_4k++;
set_pte(pte, pfn_pte(pfn, prot));
if (mapping_iter == 1)
set_pte(pte, pfn_pte(pfn, init_prot));
else
set_pte(pte, pfn_pte(pfn, prot));
}
}
}
update_page_count(PG_LEVEL_2M, pages_2m);
update_page_count(PG_LEVEL_4K, pages_4k);
if (mapping_iter == 1) {
/*
* update direct mapping page count only in the first
* iteration.
*/
update_page_count(PG_LEVEL_2M, pages_2m);
update_page_count(PG_LEVEL_4K, pages_4k);

/*
* local global flush tlb, which will flush the previous
* mappings present in both small and large page TLB's.
*/
__flush_tlb_all();

/*
* Second iteration will set the actual desired PTE attributes.
*/
mapping_iter = 2;
goto repeat;
}
}

/*
Expand Down
99 changes: 84 additions & 15 deletions trunk/arch/x86/mm/init_64.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -270,6 +270,8 @@ static __ref void unmap_low_page(void *adr)
early_iounmap(adr, PAGE_SIZE);
}

static int physical_mapping_iter;

static unsigned long __meminit
phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end)
{
Expand All @@ -290,16 +292,19 @@ phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end)
}

if (pte_val(*pte))
continue;
goto repeat_set_pte;

if (0)
printk(" pte=%p addr=%lx pte=%016lx\n",
pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
pages++;
repeat_set_pte:
set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL));
last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
pages++;
}
update_page_count(PG_LEVEL_4K, pages);

if (physical_mapping_iter == 1)
update_page_count(PG_LEVEL_4K, pages);

return last_map_addr;
}
Expand All @@ -318,7 +323,6 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
{
unsigned long pages = 0;
unsigned long last_map_addr = end;
unsigned long start = address;

int i = pmd_index(address);

Expand All @@ -341,15 +345,14 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
last_map_addr = phys_pte_update(pmd, address,
end);
spin_unlock(&init_mm.page_table_lock);
continue;
}
/* Count entries we're using from level2_ident_pgt */
if (start == 0)
pages++;
continue;
goto repeat_set_pte;
}

if (page_size_mask & (1<<PG_LEVEL_2M)) {
pages++;
repeat_set_pte:
spin_lock(&init_mm.page_table_lock);
set_pte((pte_t *)pmd,
pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
Expand All @@ -366,7 +369,8 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
spin_unlock(&init_mm.page_table_lock);
}
update_page_count(PG_LEVEL_2M, pages);
if (physical_mapping_iter == 1)
update_page_count(PG_LEVEL_2M, pages);
return last_map_addr;
}

Expand Down Expand Up @@ -405,14 +409,18 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
}

if (pud_val(*pud)) {
if (!pud_large(*pud))
if (!pud_large(*pud)) {
last_map_addr = phys_pmd_update(pud, addr, end,
page_size_mask);
continue;
continue;
}

goto repeat_set_pte;
}

if (page_size_mask & (1<<PG_LEVEL_1G)) {
pages++;
repeat_set_pte:
spin_lock(&init_mm.page_table_lock);
set_pte((pte_t *)pud,
pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
Expand All @@ -430,7 +438,9 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
spin_unlock(&init_mm.page_table_lock);
}
__flush_tlb_all();
update_page_count(PG_LEVEL_1G, pages);

if (physical_mapping_iter == 1)
update_page_count(PG_LEVEL_1G, pages);

return last_map_addr;
}
Expand Down Expand Up @@ -494,15 +504,54 @@ static void __init init_gbpages(void)
direct_gbpages = 0;
}

static int is_kernel(unsigned long pfn)
{
unsigned long pg_addresss = pfn << PAGE_SHIFT;

if (pg_addresss >= (unsigned long) __pa(_text) &&
pg_addresss <= (unsigned long) __pa(_end))
return 1;

return 0;
}

static unsigned long __init kernel_physical_mapping_init(unsigned long start,
unsigned long end,
unsigned long page_size_mask)
{

unsigned long next, last_map_addr = end;
unsigned long next, last_map_addr;
u64 cached_supported_pte_mask = __supported_pte_mask;
unsigned long cache_start = start;
unsigned long cache_end = end;

/*
* First iteration will setup identity mapping using large/small pages
* based on page_size_mask, with other attributes same as set by
* the early code in head_64.S
*
* Second iteration will setup the appropriate attributes
* as desired for the kernel identity mapping.
*
* This two pass mechanism conforms to the TLB app note which says:
*
* "Software should not write to a paging-structure entry in a way
* that would change, for any linear address, both the page size
* and either the page frame or attributes."
*
* For now, only difference between very early PTE attributes used in
* head_64.S and here is _PAGE_NX.
*/
BUILD_BUG_ON((__PAGE_KERNEL_LARGE & ~__PAGE_KERNEL_IDENT_LARGE_EXEC)
!= _PAGE_NX);
__supported_pte_mask &= ~(_PAGE_NX);
physical_mapping_iter = 1;

start = (unsigned long)__va(start);
end = (unsigned long)__va(end);
repeat:
last_map_addr = cache_end;

start = (unsigned long)__va(cache_start);
end = (unsigned long)__va(cache_end);

for (; start < end; start = next) {
pgd_t *pgd = pgd_offset_k(start);
Expand All @@ -514,11 +563,21 @@ static unsigned long __init kernel_physical_mapping_init(unsigned long start,
next = end;

if (pgd_val(*pgd)) {
/*
* Static identity mappings will be overwritten
* with run-time mappings. For example, this allows
* the static 0-1GB identity mapping to be mapped
* non-executable with this.
*/
if (is_kernel(pte_pfn(*((pte_t *) pgd))))
goto realloc;

last_map_addr = phys_pud_update(pgd, __pa(start),
__pa(end), page_size_mask);
continue;
}

realloc:
pud = alloc_low_page(&pud_phys);
last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
page_size_mask);
Expand All @@ -528,6 +587,16 @@ static unsigned long __init kernel_physical_mapping_init(unsigned long start,
pgd_populate(&init_mm, pgd, __va(pud_phys));
spin_unlock(&init_mm.page_table_lock);
}
__flush_tlb_all();

if (physical_mapping_iter == 1) {
physical_mapping_iter = 2;
/*
* Second iteration will set the actual desired PTE attributes.
*/
__supported_pte_mask = cached_supported_pte_mask;
goto repeat;
}

return last_map_addr;
}
Expand Down

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