[34-longterm 158/247] powerpc/pseries: Add hcall to read 4 ptes at a time in real mode

Paul Gortmaker
2011-06-23T18:01:59Z

From: Michael Neuling <mikey@neuling.org>

-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.
-------------------

commit f90ece28c1f5b3ec13fe481406857fe92f4bc7d1 upstream.

This adds plpar_pte_read_4_raw() which can be used read 4 PTEs from
PHYP at a time, while in real mode.

It also creates a new hcall9 which can be used in real mode. It's the
same as plpar_hcall9 but minus the tracing hcall statistics which may
require variables outside the RMO.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
arch/powerpc/include/asm/hvcall.h | 1 +
arch/powerpc/platforms/pseries/hvCall.S | 38 +++++++++++++++++++++++
arch/powerpc/platforms/pseries/plpar_wrappers.h | 18 +++++++++++
3 files changed, 57 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index f027581..f0d067c 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -281,6 +281,7 @@ long plpar_hcall_raw(unsigned long opcode, unsigned long *retbuf, ...);
*/
#define PLPAR_HCALL9_BUFSIZE 9
long plpar_hcall9(unsigned long opcode, unsigned long *retbuf, ...);
+long plpar_hcall9_raw(unsigned long opcode, unsigned long *retbuf, ...);

/* For hcall instrumentation. One structure per-hcall, per-CPU */
struct hcall_stats {
diff --git a/arch/powerpc/platforms/pseries/hvCall.S b/arch/powerpc/platforms/pseries/hvCall.S
index 383a5d0..48d2057 100644
--- a/arch/powerpc/platforms/pseries/hvCall.S
+++ b/arch/powerpc/platforms/pseries/hvCall.S
@@ -228,3 +228,41 @@ _GLOBAL(plpar_hcall9)
mtcrf 0xff,r0

blr /* return r3 = status */
+
+/* See plpar_hcall_raw to see why this is needed */
+_GLOBAL(plpar_hcall9_raw)
+ HMT_MEDIUM
+
+ mfcr r0
+ stw r0,8(r1)
+
+ std r4,STK_PARM(r4)(r1) /* Save ret buffer */
+
+ mr r4,r5
+ mr r5,r6
+ mr r6,r7
+ mr r7,r8
+ mr r8,r9
+ mr r9,r10
+ ld r10,STK_PARM(r11)(r1) /* put arg7 in R10 */
+ ld r11,STK_PARM(r12)(r1) /* put arg8 in R11 */
+ ld r12,STK_PARM(r13)(r1) /* put arg9 in R12 */
+
+ HVSC /* invoke the hypervisor */
+
+ mr r0,r12
+ ld r12,STK_PARM(r4)(r1)
+ std r4, 0(r12)
+ std r5, 8(r12)
+ std r6, 16(r12)
+ std r7, 24(r12)
+ std r8, 32(r12)
+ std r9, 40(r12)
+ std r10,48(r12)
+ std r11,56(r12)
+ std r0, 64(r12)
+
+ lwz r0,8(r1)
+ mtcrf 0xff,r0
+
+ blr /* return r3 = status */
diff --git a/arch/powerpc/platforms/pseries/plpar_wrappers.h b/arch/powerpc/platforms/pseries/plpar_wrappers.h
index 6c4fd2c..d980111 100644
--- a/arch/powerpc/platforms/pseries/plpar_wrappers.h
+++ b/arch/powerpc/platforms/pseries/plpar_wrappers.h
@@ -191,6 +191,24 @@ static inline long plpar_pte_read_raw(unsigned long flags, unsigned long ptex,
return rc;
}

+/*
+ * plpar_pte_read_4_raw can be called in real mode.
+ * ptes must be 8*sizeof(unsigned long)
+ */
+static inline long plpar_pte_read_4_raw(unsigned long flags, unsigned long ptex,
+ unsigned long *ptes)
+
+{
+ long rc;
+ unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
+
+ rc = plpar_hcall9_raw(H_READ, retbuf, flags | H_READ_4, ptex);
+
+ memcpy(ptes, retbuf, 8*sizeof(unsigned long));
+
+ return rc;
+}
+
static inline long plpar_pte_protect(unsigned long flags, unsigned long ptex,
unsigned long avpn)
{
--
1.7.4.4