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authorTimur Tabi <timur@freescale.com>2012-03-15 17:41:02 -0500
committerKumar Gala <galak@kernel.crashing.org>2012-03-29 08:14:14 -0500
commit3b588c7efc84f15548afdda6a0d2f892fe83babc (patch)
tree0978d6ec180f899259b5a4a8f8569e29cc6bef7d
parent2a78aeb1078994f6dab0173c2ecf5d9803ef0e8e (diff)
powerpc/epapr: add "memory" as a clobber to all hypercalls
The "memory" clobber tells the compiler to ensure that all writes to memory are committed before the hypercall is made. "memory" is only necessary for hcalls where the Hypervisor will read or write guest memory. However, we add it to all hcalls because the impact is minimal, and we want to ensure that it's present for the hcalls that need it. Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
-rw-r--r--arch/powerpc/include/asm/epapr_hcalls.h7
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/epapr_hcalls.h b/arch/powerpc/include/asm/epapr_hcalls.h
index f3b0c2cc9fe..976835d8f22 100644
--- a/arch/powerpc/include/asm/epapr_hcalls.h
+++ b/arch/powerpc/include/asm/epapr_hcalls.h
@@ -134,10 +134,15 @@
* whether they will be clobbered.
*
* Note that r11 can be used as an output parameter.
+ *
+ * The "memory" clobber is only necessary for hcalls where the Hypervisor
+ * will read or write guest memory. However, we add it to all hcalls because
+ * the impact is minimal, and we want to ensure that it's present for the
+ * hcalls that need it.
*/
/* List of common clobbered registers. Do not use this macro. */
-#define EV_HCALL_CLOBBERS "r0", "r12", "xer", "ctr", "lr", "cc"
+#define EV_HCALL_CLOBBERS "r0", "r12", "xer", "ctr", "lr", "cc", "memory"
#define EV_HCALL_CLOBBERS8 EV_HCALL_CLOBBERS
#define EV_HCALL_CLOBBERS7 EV_HCALL_CLOBBERS8, "r10"