[PATCH] ppc64: cleanup iseries runlight support

The iseries has a bar graph on the front panel that shows how busy it is.
The operating system sets and clears a bit in the CTRL register to control
it.

Instead of going to the complexity of using a thread info bit, just set and
clear it in the idle loop.

Also create two helper functions, ppc64_runlatch_on and ppc64_runlatch_off.

Finally don't use the short form of the SPR defines.

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

7 files changed, 33 insertions, 36 deletions

diff --git a/arch/ppc64/kernel/entry.S b/arch/ppc64/kernel/entry.S
index d3604056e1a9..b61572eb2a71 100644
--- a/arch/ppc64/kernel/entry.S
+++ b/arch/ppc64/kernel/entry.S
@@ -436,15 +436,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
         REST_8GPRS(14, r1)
         REST_10GPRS(22, r1)
 
-#ifdef CONFIG_PPC_ISERIES
-        clrrdi  r7,r1,THREAD_SHIFT      /* get current_thread_info() */
-        ld      r7,TI_FLAGS(r7)         /* Get run light flag */
-        mfspr   r9,CTRLF
-        srdi    r7,r7,TIF_RUN_LIGHT
-        insrdi  r9,r7,1,63              /* Insert run light into CTRL */
-        mtspr   CTRLT,r9
-#endif
-
         /* convert old thread to its task_struct for return value */
         addi    r3,r3,-THREAD
         ld      r7,_NIP(r1)     /* Return to _switch caller in new task */
diff --git a/arch/ppc64/kernel/head.S b/arch/ppc64/kernel/head.S
index 92a744c31ab1..346dbf606b5d 100644
--- a/arch/ppc64/kernel/head.S
+++ b/arch/ppc64/kernel/head.S
@@ -626,10 +626,10 @@ system_reset_iSeries:
         lhz     r24,PACAPACAINDEX(r13)  /* Get processor # */
         cmpwi   0,r24,0                 /* Are we processor 0? */
         beq     .__start_initialization_iSeries /* Start up the first processor */
-        mfspr   r4,CTRLF
-        li      r5,RUNLATCH             /* Turn off the run light */
+        mfspr   r4,SPRN_CTRLF
+        li      r5,CTRL_RUNLATCH        /* Turn off the run light */
         andc    r4,r4,r5
-        mtspr   CTRLT,r4
+        mtspr   SPRN_CTRLT,r4
 
 1:
         HMT_LOW
@@ -2082,9 +2082,9 @@ _GLOBAL(hmt_start_secondary)
         mfspr   r4, HID0
         ori     r4, r4, 0x1
         mtspr   HID0, r4
-        mfspr   r4, CTRLF
+        mfspr   r4, SPRN_CTRLF
         oris    r4, r4, 0x40
-        mtspr   CTRLT, r4
+        mtspr   SPRN_CTRLT, r4
         blr
 #endif
 
diff --git a/arch/ppc64/kernel/idle.c b/arch/ppc64/kernel/idle.c
index 6abc621d3ba0..f24ce2b87200 100644
--- a/arch/ppc64/kernel/idle.c
+++ b/arch/ppc64/kernel/idle.c
@@ -75,13 +75,9 @@ static int iSeries_idle(void)
 {
         struct paca_struct *lpaca;
         long oldval;
-        unsigned long CTRL;
 
         /* ensure iSeries run light will be out when idle */
-        clear_thread_flag(TIF_RUN_LIGHT);
-        CTRL = mfspr(CTRLF);
-        CTRL &= ~RUNLATCH;
-        mtspr(CTRLT, CTRL);
+        ppc64_runlatch_off();
 
         lpaca = get_paca();
 
@@ -111,7 +107,9 @@ static int iSeries_idle(void)
                         }
                 }
 
+                ppc64_runlatch_on();
                 schedule();
+                ppc64_runlatch_off();
         }
 
         return 0;
diff --git a/arch/ppc64/kernel/process.c b/arch/ppc64/kernel/process.c
index 8b0686122738..cdfecbeb331f 100644
--- a/arch/ppc64/kernel/process.c
+++ b/arch/ppc64/kernel/process.c
@@ -378,9 +378,6 @@ copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
                 childregs->gpr[1] = sp + sizeof(struct pt_regs);
                 p->thread.regs = NULL;  /* no user register state */
                 clear_ti_thread_flag(p->thread_info, TIF_32BIT);
-#ifdef CONFIG_PPC_ISERIES
-                set_ti_thread_flag(p->thread_info, TIF_RUN_LIGHT);
-#endif
         } else {
                 childregs->gpr[1] = usp;
                 p->thread.regs = childregs;
diff --git a/arch/ppc64/kernel/sysfs.c b/arch/ppc64/kernel/sysfs.c
index 0925694c3ce5..c8fa6569b2fd 100644
--- a/arch/ppc64/kernel/sysfs.c
+++ b/arch/ppc64/kernel/sysfs.c
@@ -113,7 +113,6 @@ void ppc64_enable_pmcs(void)
 #ifdef CONFIG_PPC_PSERIES
         unsigned long set, reset;
         int ret;
-        unsigned int ctrl;
 #endif /* CONFIG_PPC_PSERIES */
 
         /* Only need to enable them once */
@@ -167,11 +166,8 @@ void ppc64_enable_pmcs(void)
          * On SMT machines we have to set the run latch in the ctrl register
          * in order to make PMC6 spin.
          */
-        if (cpu_has_feature(CPU_FTR_SMT)) {
-                ctrl = mfspr(CTRLF);
-                ctrl |= RUNLATCH;
-                mtspr(CTRLT, ctrl);
-        }
+        if (cpu_has_feature(CPU_FTR_SMT))
+                ppc64_runlatch_on();
 #endif /* CONFIG_PPC_PSERIES */
 }
 
diff --git a/include/asm-ppc64/processor.h b/include/asm-ppc64/processor.h
index 5ba6aa45e1e2..809c634ba1df 100644
--- a/include/asm-ppc64/processor.h
+++ b/include/asm-ppc64/processor.h
@@ -164,6 +164,9 @@
 #define SPRN_USIA       0x3AB   /* User Sampled Instruction Address Register */
 #define SPRN_XER        0x001   /* Fixed Point Exception Register */
 #define SPRN_VRSAVE     0x100   /* Vector save */
+#define SPRN_CTRLF      0x088
+#define SPRN_CTRLT      0x098
+#define   CTRL_RUNLATCH 0x1
 
 /* Performance monitor SPRs */
 #define SPRN_SIAR       780
@@ -279,12 +282,6 @@
 #define XGLUE(a,b) a##b
 #define GLUE(a,b) XGLUE(a,b)
 
-/* iSeries CTRL register (for runlatch) */
-
-#define CTRLT           0x098
-#define CTRLF           0x088
-#define RUNLATCH        0x0001
-
 #ifdef __ASSEMBLY__
 
 #define _GLOBAL(name) \
@@ -499,6 +496,24 @@ static inline void prefetchw(const void *x)
 
 #define HAVE_ARCH_PICK_MMAP_LAYOUT
 
+static inline void ppc64_runlatch_on(void)
+{
+        unsigned long ctrl;
+
+        ctrl = mfspr(SPRN_CTRLF);
+        ctrl |= CTRL_RUNLATCH;
+        mtspr(SPRN_CTRLT, ctrl);
+}
+
+static inline void ppc64_runlatch_off(void)
+{
+        unsigned long ctrl;
+
+        ctrl = mfspr(SPRN_CTRLF);
+        ctrl &= ~CTRL_RUNLATCH;
+        mtspr(SPRN_CTRLT, ctrl);
+}
+
 #endif /* __KERNEL__ */
 
 #endif /* __ASSEMBLY__ */
diff --git a/include/asm-ppc64/thread_info.h b/include/asm-ppc64/thread_info.h
index 037b5e06083c..48b7900e90ec 100644
--- a/include/asm-ppc64/thread_info.h
+++ b/include/asm-ppc64/thread_info.h
@@ -96,7 +96,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_POLLING_NRFLAG      4       /* true if poll_idle() is polling
                                            TIF_NEED_RESCHED */
 #define TIF_32BIT               5       /* 32 bit binary */
-#define TIF_RUN_LIGHT           6       /* iSeries run light */
+/* #define SPARE                6 */
 #define TIF_ABI_PENDING         7       /* 32/64 bit switch needed */
 #define TIF_SYSCALL_AUDIT       8       /* syscall auditing active */
 #define TIF_SINGLESTEP          9       /* singlestepping active */
@@ -110,7 +110,7 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
 #define _TIF_POLLING_NRFLAG     (1<<TIF_POLLING_NRFLAG)
 #define _TIF_32BIT              (1<<TIF_32BIT)
-#define _TIF_RUN_LIGHT          (1<<TIF_RUN_LIGHT)
+/* #define _SPARE               (1<<SPARE) */
 #define _TIF_ABI_PENDING        (1<<TIF_ABI_PENDING)
 #define _TIF_SYSCALL_AUDIT      (1<<TIF_SYSCALL_AUDIT)
 #define _TIF_SINGLESTEP         (1<<TIF_SINGLESTEP)