xen: lazy-mmu operations

This patch uses the lazy-mmu hooks to batch mmu operations where
possible.  This is primarily useful for batching operations applied to
active pagetables, which happens during mprotect, munmap, mremap and
the like (mmap does not do bulk pagetable operations, so it isn't
helped).

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>

1 files changed, 31 insertions, 17 deletions

diff --git a/arch/i386/xen/enlighten.c b/arch/i386/xen/enlighten.c
index a1124b7f1d14..031dc1dcf819 100644
--- a/arch/i386/xen/enlighten.c
+++ b/arch/i386/xen/enlighten.c
@@ -472,28 +472,38 @@ static void xen_apic_write(unsigned long reg, unsigned long val)
 
 static void xen_flush_tlb(void)
 {
-        struct mmuext_op op;
+        struct mmuext_op *op;
+        struct multicall_space mcs = xen_mc_entry(sizeof(*op));
 
-        op.cmd = MMUEXT_TLB_FLUSH_LOCAL;
-        if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
-                BUG();
+        op = mcs.args;
+        op->cmd = MMUEXT_TLB_FLUSH_LOCAL;
+        MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
+
+        xen_mc_issue(PARAVIRT_LAZY_MMU);
 }
 
 static void xen_flush_tlb_single(unsigned long addr)
 {
-        struct mmuext_op op;
+        struct mmuext_op *op;
+        struct multicall_space mcs = xen_mc_entry(sizeof(*op));
 
-        op.cmd = MMUEXT_INVLPG_LOCAL;
-        op.arg1.linear_addr = addr & PAGE_MASK;
-        if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
-                BUG();
+        op = mcs.args;
+        op->cmd = MMUEXT_INVLPG_LOCAL;
+        op->arg1.linear_addr = addr & PAGE_MASK;
+        MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
+
+        xen_mc_issue(PARAVIRT_LAZY_MMU);
 }
 
 static void xen_flush_tlb_others(const cpumask_t *cpus, struct mm_struct *mm,
                                  unsigned long va)
 {
-        struct mmuext_op op;
+        struct {
+                struct mmuext_op op;
+                cpumask_t mask;
+        } *args;
         cpumask_t cpumask = *cpus;
+        struct multicall_space mcs;
 
         /*
          * A couple of (to be removed) sanity checks:
@@ -510,17 +520,21 @@ static void xen_flush_tlb_others(const cpumask_t *cpus, struct mm_struct *mm,
         if (cpus_empty(cpumask))
                 return;
 
+        mcs = xen_mc_entry(sizeof(*args));
+        args = mcs.args;
+        args->mask = cpumask;
+        args->op.arg2.vcpumask = &args->mask;
+
         if (va == TLB_FLUSH_ALL) {
-                op.cmd = MMUEXT_TLB_FLUSH_MULTI;
-                op.arg2.vcpumask = (void *)cpus;
+                args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
         } else {
-                op.cmd = MMUEXT_INVLPG_MULTI;
-                op.arg1.linear_addr = va;
-                op.arg2.vcpumask = (void *)cpus;
+                args->op.cmd = MMUEXT_INVLPG_MULTI;
+                args->op.arg1.linear_addr = va;
         }
 
-        if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
-                BUG();
+        MULTI_mmuext_op(mcs.mc, &args->op, 1, NULL, DOMID_SELF);
+
+        xen_mc_issue(PARAVIRT_LAZY_MMU);
 }
 
 static unsigned long xen_read_cr2(void)