[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>

5 files changed, 10 insertions, 28 deletions

diff --git a/arch/ppc64/kernel/entry.S b/arch/ppc64/kernel/entry.S
index d3604056e1a..b61572eb2a7 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 92a744c31ab..346dbf606b5 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 6abc621d3ba..f24ce2b8720 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 8b068612273..cdfecbeb331 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 0925694c3ce..c8fa6569b2f 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 */
 }