Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6

[pandora-kernel.git] / arch / powerpc / kernel / entry_64.S

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 42e9d90..d82878c 100644 (file)
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -97,6 +97,24 @@ system_call_common:
        addi    r9,r1,STACK_FRAME_OVERHEAD
        ld      r11,exception_marker@toc(r2)
        std     r11,-16(r9)             /* "regshere" marker */
+#if defined(CONFIG_VIRT_CPU_ACCOUNTING) && defined(CONFIG_PPC_SPLPAR)
+BEGIN_FW_FTR_SECTION
+       beq     33f
+       /* if from user, see if there are any DTL entries to process */
+       ld      r10,PACALPPACAPTR(r13)  /* get ptr to VPA */
+       ld      r11,PACA_DTL_RIDX(r13)  /* get log read index */
+       ld      r10,LPPACA_DTLIDX(r10)  /* get log write index */
+       cmpd    cr1,r11,r10
+       beq+    cr1,33f
+       bl      .accumulate_stolen_time
+       REST_GPR(0,r1)
+       REST_4GPRS(3,r1)
+       REST_2GPRS(7,r1)
+       addi    r9,r1,STACK_FRAME_OVERHEAD
+33:
+END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
+#endif /* CONFIG_VIRT_CPU_ACCOUNTING && CONFIG_PPC_SPLPAR */
+
 #ifdef CONFIG_TRACE_IRQFLAGS
        bl      .trace_hardirqs_on
        REST_GPR(0,r1)
@@ -202,7 +220,9 @@ syscall_exit:
        bge-    syscall_error
 syscall_error_cont:
        ld      r7,_NIP(r1)
+BEGIN_FTR_SECTION
        stdcx.  r0,0,r1                 /* to clear the reservation */
+END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
        andi.   r6,r8,MSR_PR
        ld      r4,_LINK(r1)
        /*
@@ -419,6 +439,17 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
        sync
 #endif /* CONFIG_SMP */
 
+       /*
+        * If we optimise away the clear of the reservation in system
+        * calls because we know the CPU tracks the address of the
+        * reservation, then we need to clear it here to cover the
+        * case that the kernel context switch path has no larx
+        * instructions.
+        */
+BEGIN_FTR_SECTION
+       ldarx   r6,0,r1
+END_FTR_SECTION_IFSET(CPU_FTR_STCX_CHECKS_ADDRESS)
+
        addi    r6,r4,-THREAD   /* Convert THREAD to 'current' */
        std     r6,PACACURRENT(r13)     /* Set new 'current' */
 
@@ -576,7 +607,16 @@ ALT_FW_FTR_SECTION_END_IFCLR(FW_FEATURE_ISERIES)
        andi.   r0,r3,MSR_RI
        beq-    unrecov_restore
 
+       /*
+        * Clear the reservation. If we know the CPU tracks the address of
+        * the reservation then we can potentially save some cycles and use
+        * a larx. On POWER6 and POWER7 this is significantly faster.
+        */
+BEGIN_FTR_SECTION
        stdcx.  r0,0,r1         /* to clear the reservation */
+FTR_SECTION_ELSE
+       ldarx   r4,0,r1
+ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
 
        /*
         * Clear RI before restoring r13.  If we are returning to