# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID 0d415d73f8f208a2053ceb104fd332ee3a81639b
# Parent de2e58cdec3779c9160dfdc937938496da63b497
This adds a patch for the vanilla kernel, to be pushed upstream some
day. It adds a #define which is 1 or 0 depending on whether the pmd
for the kernel address space is shared or not. Xen can't use a
shared pmd due to linear mappings in the Xen private area.
Also includes patches for modified files in the sparse tree.
Signed-off-by: Gerd Knorr <kraxel@xxxxxxx>
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
diff -r de2e58cdec37 -r 0d415d73f8f2
linux-2.6-xen-sparse/include/asm-xen/asm-i386/pgtable-2level-defs.h
--- a/linux-2.6-xen-sparse/include/asm-xen/asm-i386/pgtable-2level-defs.h
Mon Jul 11 15:43:12 2005
+++ b/linux-2.6-xen-sparse/include/asm-xen/asm-i386/pgtable-2level-defs.h
Mon Jul 11 15:46:46 2005
@@ -1,5 +1,7 @@
#ifndef _I386_PGTABLE_2LEVEL_DEFS_H
#define _I386_PGTABLE_2LEVEL_DEFS_H
+
+#define HAVE_SHARED_KERNEL_PMD 0
/*
* traditional i386 two-level paging structure:
diff -r de2e58cdec37 -r 0d415d73f8f2
linux-2.6-xen-sparse/arch/xen/i386/mm/pgtable.c
--- a/linux-2.6-xen-sparse/arch/xen/i386/mm/pgtable.c Mon Jul 11 15:43:12 2005
+++ b/linux-2.6-xen-sparse/arch/xen/i386/mm/pgtable.c Mon Jul 11 15:46:46 2005
@@ -274,14 +274,14 @@
{
unsigned long flags;
- if (PTRS_PER_PMD == 1)
+ if (!HAVE_SHARED_KERNEL_PMD)
spin_lock_irqsave(&pgd_lock, flags);
memcpy((pgd_t *)pgd + USER_PTRS_PER_PGD,
swapper_pg_dir + USER_PTRS_PER_PGD,
(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
- if (PTRS_PER_PMD > 1)
+ if (HAVE_SHARED_KERNEL_PMD)
return;
pgd_list_add(pgd);
@@ -289,12 +289,11 @@
memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
}
-/* never called when PTRS_PER_PMD > 1 */
void pgd_dtor(void *pgd, kmem_cache_t *cache, unsigned long unused)
{
unsigned long flags; /* can be called from interrupt context */
- if (PTRS_PER_PMD > 1)
+ if (HAVE_SHARED_KERNEL_PMD)
return;
spin_lock_irqsave(&pgd_lock, flags);
@@ -304,12 +303,30 @@
pgd_t *pgd_alloc(struct mm_struct *mm)
{
- int i;
+ int i = 0;
pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL);
if (PTRS_PER_PMD == 1 || !pgd)
return pgd;
+ if (!HAVE_SHARED_KERNEL_PMD) {
+ /* alloc and copy kernel pmd */
+ unsigned long flags;
+ pgd_t *copy_pgd = pgd_offset_k(PAGE_OFFSET);
+ pud_t *copy_pud = pud_offset(copy_pgd, PAGE_OFFSET);
+ pmd_t *copy_pmd = pmd_offset(copy_pud, PAGE_OFFSET);
+ pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
+ if (0 == pmd)
+ goto out_oom;
+
+ spin_lock_irqsave(&pgd_lock, flags);
+ memcpy(pmd, copy_pmd, PAGE_SIZE);
+ spin_unlock_irqrestore(&pgd_lock, flags);
+ make_page_readonly(pmd);
+ set_pgd(&pgd[USER_PTRS_PER_PGD], __pgd(1 + __pa(pmd)));
+ }
+
+ /* alloc user pmds */
for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
if (!pmd)
@@ -339,9 +356,17 @@
}
/* in the PAE case user pgd entries are overwritten before usage */
- if (PTRS_PER_PMD > 1)
- for (i = 0; i < USER_PTRS_PER_PGD; ++i)
- kmem_cache_free(pmd_cache, (void
*)__va(pgd_val(pgd[i])-1));
+ if (PTRS_PER_PMD > 1) {
+ for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
+ pmd_t *pmd = (void *)__va(pgd_val(pgd[i])-1);
+ kmem_cache_free(pmd_cache, pmd);
+ }
+ if (!HAVE_SHARED_KERNEL_PMD) {
+ pmd_t *pmd = (void
*)__va(pgd_val(pgd[USER_PTRS_PER_PGD])-1);
+ make_page_writable(pmd);
+ kmem_cache_free(pmd_cache, pmd);
+ }
+ }
/* in the non-PAE case, free_pgtables() clears user pgd entries */
kmem_cache_free(pgd_cache, pgd);
}
diff -r de2e58cdec37 -r 0d415d73f8f2 patches/linux-2.6.12/pmd-shared.patch
--- /dev/null Mon Jul 11 15:43:12 2005
+++ b/patches/linux-2.6.12/pmd-shared.patch Mon Jul 11 15:46:46 2005
@@ -0,0 +1,134 @@
+diff -urNpP linux-2.6.12/arch/i386/mm/init.c
linux-2.6.12.new/arch/i386/mm/init.c
+--- linux-2.6.12/arch/i386/mm/init.c 2005-06-17 20:48:29.000000000 +0100
++++ linux-2.6.12.new/arch/i386/mm/init.c 2005-07-11 16:28:09.778165582
+0100
+@@ -634,7 +634,7 @@ void __init pgtable_cache_init(void)
+ PTRS_PER_PGD*sizeof(pgd_t),
+ 0,
+ pgd_ctor,
+- PTRS_PER_PMD == 1 ? pgd_dtor : NULL);
++ pgd_dtor);
+ if (!pgd_cache)
+ panic("pgtable_cache_init(): Cannot create pgd cache");
+ }
+diff -urNpP linux-2.6.12/arch/i386/mm/pageattr.c
linux-2.6.12.new/arch/i386/mm/pageattr.c
+--- linux-2.6.12/arch/i386/mm/pageattr.c 2005-06-17 20:48:29.000000000
+0100
++++ linux-2.6.12.new/arch/i386/mm/pageattr.c 2005-07-11 16:28:09.775165494
+0100
+@@ -75,7 +75,7 @@ static void set_pmd_pte(pte_t *kpte, uns
+ unsigned long flags;
+
+ set_pte_atomic(kpte, pte); /* change init_mm */
+- if (PTRS_PER_PMD > 1)
++ if (HAVE_SHARED_KERNEL_PMD)
+ return;
+
+ spin_lock_irqsave(&pgd_lock, flags);
+diff -urNpP linux-2.6.12/arch/i386/mm/pgtable.c
linux-2.6.12.new/arch/i386/mm/pgtable.c
+--- linux-2.6.12/arch/i386/mm/pgtable.c 2005-06-17 20:48:29.000000000
+0100
++++ linux-2.6.12.new/arch/i386/mm/pgtable.c 2005-07-11 16:32:01.478023726
+0100
+@@ -199,14 +199,14 @@ void pgd_ctor(void *pgd, kmem_cache_t *c
+ {
+ unsigned long flags;
+
+- if (PTRS_PER_PMD == 1)
++ if (!HAVE_SHARED_KERNEL_PMD)
+ spin_lock_irqsave(&pgd_lock, flags);
+
+ memcpy((pgd_t *)pgd + USER_PTRS_PER_PGD,
+ swapper_pg_dir + USER_PTRS_PER_PGD,
+ (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+
+- if (PTRS_PER_PMD > 1)
++ if (HAVE_SHARED_KERNEL_PMD)
+ return;
+
+ pgd_list_add(pgd);
+@@ -214,11 +214,13 @@ void pgd_ctor(void *pgd, kmem_cache_t *c
+ memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
+ }
+
+-/* never called when PTRS_PER_PMD > 1 */
+ void pgd_dtor(void *pgd, kmem_cache_t *cache, unsigned long unused)
+ {
+ unsigned long flags; /* can be called from interrupt context */
+
++ if (HAVE_SHARED_KERNEL_PMD)
++ return;
++
+ spin_lock_irqsave(&pgd_lock, flags);
+ pgd_list_del(pgd);
+ spin_unlock_irqrestore(&pgd_lock, flags);
+@@ -226,12 +228,29 @@ void pgd_dtor(void *pgd, kmem_cache_t *c
+
+ pgd_t *pgd_alloc(struct mm_struct *mm)
+ {
+- int i;
++ int i = 0;
+ pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL);
+
+ if (PTRS_PER_PMD == 1 || !pgd)
+ return pgd;
+
++ if (!HAVE_SHARED_KERNEL_PMD) {
++ /* alloc and copy kernel pmd */
++ unsigned long flags;
++ pgd_t *copy_pgd = pgd_offset_k(PAGE_OFFSET);
++ pud_t *copy_pud = pud_offset(copy_pgd, PAGE_OFFSET);
++ pmd_t *copy_pmd = pmd_offset(copy_pud, PAGE_OFFSET);
++ pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
++ if (0 == pmd)
++ goto out_oom;
++
++ spin_lock_irqsave(&pgd_lock, flags);
++ memcpy(pmd, copy_pmd, PAGE_SIZE);
++ spin_unlock_irqrestore(&pgd_lock, flags);
++ set_pgd(&pgd[USER_PTRS_PER_PGD], __pgd(1 + __pa(pmd)));
++ }
++
++ /* alloc user pmds */
+ for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
+ pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
+ if (!pmd)
+@@ -252,9 +271,16 @@ void pgd_free(pgd_t *pgd)
+ int i;
+
+ /* in the PAE case user pgd entries are overwritten before usage */
+- if (PTRS_PER_PMD > 1)
+- for (i = 0; i < USER_PTRS_PER_PGD; ++i)
+- kmem_cache_free(pmd_cache, (void
*)__va(pgd_val(pgd[i])-1));
++ if (PTRS_PER_PMD > 1) {
++ for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
++ pmd_t *pmd = (void *)__va(pgd_val(pgd[i])-1);
++ kmem_cache_free(pmd_cache, pmd);
++ }
++ if (!HAVE_SHARED_KERNEL_PMD) {
++ pmd_t *pmd = (void
*)__va(pgd_val(pgd[USER_PTRS_PER_PGD])-1);
++ kmem_cache_free(pmd_cache, pmd);
++ }
++ }
+ /* in the non-PAE case, free_pgtables() clears user pgd entries */
+ kmem_cache_free(pgd_cache, pgd);
+ }
+diff -urNpP linux-2.6.12/include/asm-i386/pgtable-2level-defs.h
linux-2.6.12.new/include/asm-i386/pgtable-2level-defs.h
+--- linux-2.6.12/include/asm-i386/pgtable-2level-defs.h 2005-06-17
20:48:29.000000000 +0100
++++ linux-2.6.12.new/include/asm-i386/pgtable-2level-defs.h 2005-07-11
16:28:09.733164251 +0100
+@@ -1,6 +1,8 @@
+ #ifndef _I386_PGTABLE_2LEVEL_DEFS_H
+ #define _I386_PGTABLE_2LEVEL_DEFS_H
+
++#define HAVE_SHARED_KERNEL_PMD 0
++
+ /*
+ * traditional i386 two-level paging structure:
+ */
+diff -urNpP linux-2.6.12/include/asm-i386/pgtable-3level-defs.h
linux-2.6.12.new/include/asm-i386/pgtable-3level-defs.h
+--- linux-2.6.12/include/asm-i386/pgtable-3level-defs.h 2005-06-17
20:48:29.000000000 +0100
++++ linux-2.6.12.new/include/asm-i386/pgtable-3level-defs.h 2005-07-11
16:28:09.755164902 +0100
+@@ -1,6 +1,8 @@
+ #ifndef _I386_PGTABLE_3LEVEL_DEFS_H
+ #define _I386_PGTABLE_3LEVEL_DEFS_H
+
++#define HAVE_SHARED_KERNEL_PMD 1
++
+ /*
+ * PGDIR_SHIFT determines what a top-level page table entry can map
+ */
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