powerpc/pseries: Add hcall to read 4 ptes at a time in real mode

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>

3 files changed, 57 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index ebe7493e93e3..5119b7db3142 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -282,6 +282,7 @@ 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 383a5d0e9818..48d20573e4de 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 6c4fd2c3f385..d9801117124b 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)
 {