The patch titled
paravirt_ops: add kmap_atomic_pte for mapping highpte pages
has been added to the -mm tree. Its filename is
paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: paravirt_ops: add kmap_atomic_pte for mapping highpte pages
From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Xen and VMI both have special requirements when mapping a highmem pte page
into the kernel address space. These can be dealt with by adding a new
kmap_atomic_pte() function for mapping highptes, and hooking it into the
paravirt_ops infrastructure.
Xen specifically wants to map the pte page RO, so this patch exposes a helper
function, kmap_atomic_prot, which maps the page with the specified page
protections.
This also adds a kmap_flush_unused() function to clear out the cached kmap
mappings. Xen needs this to clear out any potential stray RW mappings of
pages which will become part of a pagetable.
[ Zach - vmi.c will need some attention after this patch. It wasn't
immediately obvious to me what needs to be done. ]
Signed-off-by: Jeremy Fitzhardinge <jeremy@xxxxxxxxxxxxx>
Cc: Zachary Amsden <zach@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/i386/kernel/paravirt.c | 7 +++++++
arch/i386/mm/highmem.c | 9 +++++++--
include/asm-i386/highmem.h | 11 +++++++++++
include/asm-i386/paravirt.h | 11 +++++++++++
include/asm-i386/pgtable.h | 4 ++--
include/linux/highmem.h | 6 ++++++
mm/highmem.c | 9 +++++++++
7 files changed, 53 insertions(+), 4 deletions(-)
diff -puN arch/i386/kernel/paravirt.c~paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages arch/i386/kernel/paravirt.c
--- a/arch/i386/kernel/paravirt.c~paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages
+++ a/arch/i386/kernel/paravirt.c
@@ -20,6 +20,7 @@
#include <linux/efi.h>
#include <linux/bcd.h>
#include <linux/start_kernel.h>
+#include <linux/highmem.h>
#include <asm/bug.h>
#include <asm/paravirt.h>
@@ -316,6 +317,12 @@ struct paravirt_ops paravirt_ops = {
.ptep_get_and_clear = native_ptep_get_and_clear,
+#ifdef CONFIG_HIGHPTE
+ .kmap_atomic_pte = native_kmap_atomic_pte,
+#else
+ .kmap_atomic_pte = paravirt_nop,
+#endif
+
#ifdef CONFIG_X86_PAE
.set_pte_atomic = native_set_pte_atomic,
.set_pte_present = native_set_pte_present,
diff -puN arch/i386/mm/highmem.c~paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages arch/i386/mm/highmem.c
--- a/arch/i386/mm/highmem.c~paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages
+++ a/arch/i386/mm/highmem.c
@@ -26,7 +26,7 @@ void kunmap(struct page *page)
* However when holding an atomic kmap is is not legal to sleep, so atomic
* kmaps are appropriate for short, tight code paths only.
*/
-void *kmap_atomic(struct page *page, enum km_type type)
+void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot)
{
enum fixed_addresses idx;
unsigned long vaddr;
@@ -41,11 +41,16 @@ void *kmap_atomic(struct page *page, enu
return page_address(page);
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
- set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
+ set_pte(kmap_pte-idx, mk_pte(page, prot));
return (void*) vaddr;
}
+void *kmap_atomic(struct page *page, enum km_type type)
+{
+ return kmap_atomic_prot(page, type, kmap_prot);
+}
+
void kunmap_atomic(void *kvaddr, enum km_type type)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
diff -puN include/asm-i386/highmem.h~paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages include/asm-i386/highmem.h
--- a/include/asm-i386/highmem.h~paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages
+++ a/include/asm-i386/highmem.h
@@ -24,6 +24,7 @@
#include <linux/threads.h>
#include <asm/kmap_types.h>
#include <asm/tlbflush.h>
+#include <asm/paravirt.h>
/* declarations for highmem.c */
extern unsigned long highstart_pfn, highend_pfn;
@@ -67,11 +68,21 @@ extern void FASTCALL(kunmap_high(struct
void *kmap(struct page *page);
void kunmap(struct page *page);
+void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot);
void *kmap_atomic(struct page *page, enum km_type type);
void kunmap_atomic(void *kvaddr, enum km_type type);
void *kmap_atomic_pfn(unsigned long pfn, enum km_type type);
struct page *kmap_atomic_to_page(void *ptr);
+static inline void *native_kmap_atomic_pte(struct page *page, enum km_type type)
+{
+ return kmap_atomic(page, type);
+}
+
+#ifndef CONFIG_PARAVIRT
+#define kmap_atomic_pte(page, type) kmap_atomic(page, type)
+#endif
+
#define flush_cache_kmaps() do { } while (0)
#endif /* __KERNEL__ */
diff -puN include/asm-i386/paravirt.h~paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages include/asm-i386/paravirt.h
--- a/include/asm-i386/paravirt.h~paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages
+++ a/include/asm-i386/paravirt.h
@@ -16,7 +16,9 @@
#ifndef __ASSEMBLY__
#include <linux/types.h>
#include <linux/cpumask.h>
+#include <asm/kmap_types.h>
+struct page;
struct thread_struct;
struct Xgt_desc_struct;
struct tss_struct;
@@ -187,6 +189,8 @@ struct paravirt_ops
pte_t (*ptep_get_and_clear)(pte_t *ptep);
+ void *(*kmap_atomic_pte)(struct page *page, enum km_type type);
+
#ifdef CONFIG_X86_PAE
void (*set_pte_atomic)(pte_t *ptep, pte_t pteval);
void (*set_pte_present)(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte);
@@ -884,6 +888,13 @@ static inline void paravirt_release_pd(u
PVOP_VCALL1(release_pd, pfn);
}
+static inline void *kmap_atomic_pte(struct page *page, enum km_type type)
+{
+ unsigned long ret;
+ ret = PVOP_CALL2(unsigned long, kmap_atomic_pte, page, type);
+ return (void *)ret;
+}
+
static inline void pte_update(struct mm_struct *mm, unsigned long addr,
pte_t *ptep)
{
diff -puN include/asm-i386/pgtable.h~paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages include/asm-i386/pgtable.h
--- a/include/asm-i386/pgtable.h~paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages
+++ a/include/asm-i386/pgtable.h
@@ -481,9 +481,9 @@ extern pte_t *lookup_address(unsigned lo
#if defined(CONFIG_HIGHPTE)
#define pte_offset_map(dir, address) \
- ((pte_t *)kmap_atomic(pmd_page(*(dir)),KM_PTE0) + pte_index(address))
+ ((pte_t *)kmap_atomic_pte(pmd_page(*(dir)),KM_PTE0) + pte_index(address))
#define pte_offset_map_nested(dir, address) \
- ((pte_t *)kmap_atomic(pmd_page(*(dir)),KM_PTE1) + pte_index(address))
+ ((pte_t *)kmap_atomic_pte(pmd_page(*(dir)),KM_PTE1) + pte_index(address))
#define pte_unmap(pte) kunmap_atomic(pte, KM_PTE0)
#define pte_unmap_nested(pte) kunmap_atomic(pte, KM_PTE1)
#else
diff -puN include/linux/highmem.h~paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages include/linux/highmem.h
--- a/include/linux/highmem.h~paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages
+++ a/include/linux/highmem.h
@@ -27,6 +27,8 @@ static inline void flush_kernel_dcache_p
unsigned int nr_free_highpages(void);
extern unsigned long totalhigh_pages;
+void kmap_flush_unused(void);
+
#else /* CONFIG_HIGHMEM */
static inline unsigned int nr_free_highpages(void) { return 0; }
@@ -44,9 +46,13 @@ static inline void *kmap(struct page *pa
#define kmap_atomic(page, idx) \
({ pagefault_disable(); page_address(page); })
+#define kmap_atomic_prot(page, idx, prot) kmap_atomic(page, idx)
+
#define kunmap_atomic(addr, idx) do { pagefault_enable(); } while (0)
#define kmap_atomic_pfn(pfn, idx) kmap_atomic(pfn_to_page(pfn), (idx))
#define kmap_atomic_to_page(ptr) virt_to_page(ptr)
+
+#define kmap_flush_unused() do {} while(0)
#endif
#endif /* CONFIG_HIGHMEM */
diff -puN mm/highmem.c~paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages mm/highmem.c
--- a/mm/highmem.c~paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages
+++ a/mm/highmem.c
@@ -99,6 +99,15 @@ static void flush_all_zero_pkmaps(void)
flush_tlb_kernel_range(PKMAP_ADDR(0), PKMAP_ADDR(LAST_PKMAP));
}
+/* Flush all unused kmap mappings in order to remove stray
+ mappings. */
+void kmap_flush_unused(void)
+{
+ spin_lock(&kmap_lock);
+ flush_all_zero_pkmaps();
+ spin_unlock(&kmap_lock);
+}
+
static inline unsigned long map_new_virtual(struct page *page)
{
unsigned long vaddr;
_
Patches currently in -mm which might be from jeremy@xxxxxxxx are
paravirt_ops-update-maintainers.patch
paravirt_ops-remove-config_debug_paravirt.patch
paravirt_ops-use-paravirt_nop-to-consistently-mark-no-op-operations.patch
paravirt_ops-add-pagetable-accessors-to-pack-and-unpack-pagetable-entries.patch
paravirt_ops-hooks-to-set-up-initial-pagetable.patch
paravirt_ops-allocate-a-fixmap-slot.patch
paravirt_ops-allow-paravirt-backend-to-choose-kernel-pmd-sharing.patch
paravirt_ops-add-hooks-to-intercept-mm-creation-and-destruction.patch
paravirt_ops-rename-struct-paravirt_patch-to-paravirt_patch_site-for-clarity.patch
paravirt_ops-use-patch-site-ids-computed-from-offset-in-paravirt_ops-structure.patch
paravirt_ops-fix-patch-site-clobbers-to-include-return-register.patch
paravirt_ops-consistently-wrap-paravirt-ops-callsites-to-make-them-patchable.patch
paravirt_ops-document-asm-i386-paravirth.patch
paravirt_ops-add-common-patching-machinery.patch
paravirt_ops-add-flush_tlb_others-paravirt_op.patch
paravirt_ops-revert-map_pt_hook.patch
paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages.patch
add-apply_to_page_range-which-applies-a-function-to-a-pte-range.patch
re-enable-vdso-by-default-with-paravirt.patch
remove-noreplacement-option.patch
remove-smp_alt_instructions.patch
rename-the-parainstructions-symbols-to-be-consistent-with-the-others.patch
allow-boot-time-disable-of-smp-altinstructions.patch
allow-boot-time-disable-of-paravirt_ops-patching.patch
paravirt_ops-update-maintainers.patch
paravirt_ops-remove-config_debug_paravirt.patch
paravirt_ops-use-paravirt_nop-to-consistently-mark-no-op-operations.patch
paravirt_ops-add-pagetable-accessors-to-pack-and-unpack-pagetable-entries.patch
paravirt_ops-hooks-to-set-up-initial-pagetable.patch
paravirt_ops-allocate-a-fixmap-slot.patch
paravirt_ops-allow-paravirt-backend-to-choose-kernel-pmd-sharing.patch
paravirt_ops-add-hooks-to-intercept-mm-creation-and-destruction.patch
paravirt_ops-rename-struct-paravirt_patch-to-paravirt_patch_site-for-clarity.patch
paravirt_ops-use-patch-site-ids-computed-from-offset-in-paravirt_ops-structure.patch
paravirt_ops-fix-patch-site-clobbers-to-include-return-register.patch
paravirt_ops-consistently-wrap-paravirt-ops-callsites-to-make-them-patchable.patch
paravirt_ops-document-asm-i386-paravirth.patch
paravirt_ops-add-common-patching-machinery.patch
paravirt_ops-add-flush_tlb_others-paravirt_op.patch
paravirt_ops-revert-map_pt_hook.patch
paravirt_ops-add-kmap_atomic_pte-for-mapping-highpte-pages.patch
add-apply_to_page_range-which-applies-a-function-to-a-pte-range.patch
fixes-and-cleanups-for-earlyprintk-aka-boot-console.patch
ignore-stolen-time-in-the-softlockup-watchdog.patch
add-touch_all_softlockup_watchdogs.patch
clean-up-elf-note-generation.patch
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