[PATCH] i386: PARAVIRT: Use patch site IDs computed from offset in paravirt_ops structure

Use patch type identifiers derived from the offset of the operation in
the paravirt_ops structure.  This avoids having to maintain a separate
enum for patch site types.

Also, since the identifier is derived from the offset into
paravirt_ops, the offset can be derived from the identifier.  This is
used to remove replicated information in the various callsite macros,
which has been a source of bugs in the past.

This patch also drops the fused save_fl+cli operation, which doesn't
really add much and makes things more complex - specifically because
it breaks the 1:1 relationship between identifiers and offsets.  If
this operation turns out to be particularly beneficial, then the right
answer is to define a new entrypoint for it.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>

1 files changed, 6 insertions, 8 deletions

diff --git a/arch/i386/kernel/paravirt.c b/arch/i386/kernel/paravirt.c
index 54cc14d99740..f2982832d3b9 100644
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -58,7 +58,6 @@ DEF_NATIVE(cli, "cli");
 DEF_NATIVE(sti, "sti");
 DEF_NATIVE(popf, "push %eax; popf");
 DEF_NATIVE(pushf, "pushf; pop %eax");
-DEF_NATIVE(pushf_cli, "pushf; pop %eax; cli");
 DEF_NATIVE(iret, "iret");
 DEF_NATIVE(sti_sysexit, "sti; sysexit");
 
@@ -66,13 +65,12 @@ static const struct native_insns
 {
         const char *start, *end;
 } native_insns[] = {
-        [PARAVIRT_IRQ_DISABLE] = { start_cli, end_cli },
-        [PARAVIRT_IRQ_ENABLE] = { start_sti, end_sti },
-        [PARAVIRT_RESTORE_FLAGS] = { start_popf, end_popf },
-        [PARAVIRT_SAVE_FLAGS] = { start_pushf, end_pushf },
-        [PARAVIRT_SAVE_FLAGS_IRQ_DISABLE] = { start_pushf_cli, end_pushf_cli },
-        [PARAVIRT_INTERRUPT_RETURN] = { start_iret, end_iret },
-        [PARAVIRT_STI_SYSEXIT] = { start_sti_sysexit, end_sti_sysexit },
+        [PARAVIRT_PATCH(irq_disable)] = { start_cli, end_cli },
+        [PARAVIRT_PATCH(irq_enable)] = { start_sti, end_sti },
+        [PARAVIRT_PATCH(restore_fl)] = { start_popf, end_popf },
+        [PARAVIRT_PATCH(save_fl)] = { start_pushf, end_pushf },
+        [PARAVIRT_PATCH(iret)] = { start_iret, end_iret },
+        [PARAVIRT_PATCH(irq_enable_sysexit)] = { start_sti_sysexit, end_sti_sysexit },
 };
 
 static unsigned native_patch(u8 type, u16 clobbers, void *insns, unsigned len)