[PATCH 2 of 4] paravirt: add hooks for pte_rmw_start/commit

From: Jeremy Fitzhardinge
Date: Fri May 23 2008 - 10:26:32 EST


This patch adds paravirt-ops hooks in pv_mmu_ops for pte_rmw_start and
pte_rmw_commit. This allows the hypervisor-specific backends to
implement these in some more efficient way.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
arch/x86/kernel/paravirt.c | 3 +++
arch/x86/xen/enlighten.c | 3 +++
include/asm-x86/paravirt.h | 26 ++++++++++++++++++++++++++
3 files changed, 32 insertions(+)

diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -383,6 +383,9 @@
.pte_update = paravirt_nop,
.pte_update_defer = paravirt_nop,

+ .pte_rmw_start = __pte_rmw_start,
+ .pte_rmw_commit = __pte_rmw_commit,
+
#ifdef CONFIG_HIGHPTE
.kmap_atomic_pte = kmap_atomic,
#endif
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1103,6 +1103,9 @@
.set_pte_at = xen_set_pte_at,
.set_pmd = xen_set_pmd,

+ .pte_rmw_start = __pte_rmw_start,
+ .pte_rmw_commit = __pte_rmw_commit,
+
.pte_val = xen_pte_val,
.pte_flags = native_pte_val,
.pgd_val = xen_pgd_val,
diff --git a/include/asm-x86/paravirt.h b/include/asm-x86/paravirt.h
--- a/include/asm-x86/paravirt.h
+++ b/include/asm-x86/paravirt.h
@@ -238,6 +238,11 @@
pte_t *ptep);
void (*pte_update_defer)(struct mm_struct *mm,
unsigned long addr, pte_t *ptep);
+
+ pte_t (*pte_rmw_start)(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep);
+ void (*pte_rmw_commit)(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte);

pteval_t (*pte_val)(pte_t);
pteval_t (*pte_flags)(pte_t);
@@ -1040,6 +1045,27 @@
return ret;
}

+#define __HAVE_ARCH_PTE_RMW_TRANSACTION
+static inline pte_t pte_rmw_start(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep)
+{
+ pteval_t ret;
+
+ ret = PVOP_CALL3(pteval_t, pv_mmu_ops.pte_rmw_start, mm, addr, ptep);
+
+ return (pte_t) { .pte = ret };
+}
+
+static inline void pte_rmw_commit(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte)
+{
+ if (sizeof(pteval_t) > sizeof(long))
+ /* 5 arg words */
+ pv_mmu_ops.pte_rmw_commit(mm, addr, ptep, pte);
+ else
+ PVOP_VCALL4(pv_mmu_ops.pte_rmw_commit, mm, addr, ptep, pte.pte);
+}
+
static inline void set_pte(pte_t *ptep, pte_t pte)
{
if (sizeof(pteval_t) > sizeof(long))


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