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arm: vfp: Add additional vfp interfaces

RFC PATCH New Daniel Walker 3 participants 3 messages Jan 28, 2010 – Jan 29, 2010

Subsystems (2)
Arm (32-bit) Arm/vfp support
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Daniel Walker

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#0 lore raw

RFC PATCH 11/12 arm: vfp: Add additional vfp interfaces

From: Dave Estes <[email protected]>

Refactor common code to vfp_flush_context() and vfp_reinit(). Allow use by other client beside suspend/resume. Currently intended for idle power collapse.

Signed-off-by Dave Estes <[email protected]>
Signed-off-by Daniel Walker <[email protected]>
---
 arch/arm/include/asm/vfp.h |    6 ++++++
 arch/arm/vfp/vfpmodule.c   |   37 ++++++++++++++++++++++++++++---------
 2 files changed, 34 insertions(+), 9 deletions(-)
arch/arm/include/asm/vfp.h +6 -0
index f4ab34f..ea2e3ac 100644
@@ -82,3 +82,9 @@
 #define VFPOPDESC_UNUSED_BIT	(24)
 #define VFPOPDESC_UNUSED_MASK	(0xFF << VFPOPDESC_UNUSED_BIT)
 #define VFPOPDESC_OPDESC_MASK	(~(VFPOPDESC_LENGTH_MASK | VFPOPDESC_UNUSED_MASK))
+
+#ifndef __ASSEMBLY__
+int vfp_flush_context(void);
+void vfp_reinit(void);
+#endif
+
arch/arm/vfp/vfpmodule.c +28 -9
index f60a540..c3a088c 100644
@@ -370,13 +370,12 @@ static void vfp_enable(void *unused)
 	set_copro_access(access | CPACC_FULL(10) | CPACC_FULL(11));
 }
 
-#ifdef CONFIG_PM
-#include <linux/sysdev.h>
-
-static int vfp_pm_suspend(struct sys_device *dev, pm_message_t state)
+int vfp_flush_context(void)
 {
 	struct thread_info *ti = current_thread_info();
 	u32 fpexc = fmrx(FPEXC);
+	u32 cpu = ti->cpu;
+	int saved = 0;
 
 	/* if vfp is on, then save state for resumption */
 	if (fpexc & FPEXC_EN) {

@@ -385,7 +384,31 @@ static int vfp_pm_suspend(struct sys_device *dev, pm_message_t state)
 
 		/* disable, just in case */
 		fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
+
+		last_VFP_context[cpu] = NULL;
+		saved = 1;
 	}
+	return saved;
+}
+
+void vfp_reinit(void)
+{
+	/* ensure we have access to the vfp */
+	vfp_enable(NULL);
+
+	/* and disable it to ensure the next usage restores the state */
+	fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
+}
+
+#ifdef CONFIG_PM
+#include <linux/sysdev.h>
+
+static int vfp_pm_suspend(struct sys_device *dev, pm_message_t state)
+{
+	int saved = vfp_flush_context();
+
+	if (saved)
+		printk(KERN_DEBUG "%s: saved vfp state\n", __func__);
 
 	/* clear any information we had about last context state */
 	memset(last_VFP_context, 0, sizeof(last_VFP_context));

@@ -395,11 +418,7 @@ static int vfp_pm_suspend(struct sys_device *dev, pm_message_t state)
 
 static int vfp_pm_resume(struct sys_device *dev)
 {
-	/* ensure we have access to the vfp */
-	vfp_enable(NULL);
-
-	/* and disable it to ensure the next usage restores the state */
-	fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
+	vfp_reinit();
 
 	return 0;
 }
Signature · 1 line
1.6.3.3
#1 lore raw

RFC PATCH 11/12 arm: vfp: Add additional vfp interfaces

Quoted 8 lines · Daniel Walker

From: Dave Estes <[email protected]>

Refactor common code to vfp_flush_context() and vfp_reinit(). Allow use by other client beside suspend/resume. Currently intended for idle power collapse.

Signed-off-by Dave Estes <[email protected]>
Signed-off-by Daniel Walker <[email protected]>

ack.

Signature · 2 lines
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
#2 lore raw

RFC PATCH 11/12 arm: vfp: Add additional vfp interfaces

In reply to Daniel Walker
Quoted 5 lines · Daniel Walker

From: Dave Estes <[email protected]>

Refactor common code to vfp_flush_context() and vfp_reinit(). Allow use by other client beside suspend/resume. Currently intended for idle power collapse.

I'm sure the OMAP people would be interested in this kind of thing as well - maybe rather than creating a raft of global functions where the callers have to be #ifdef'd, we could use the technology which we have in the kernel such as a notifier list?

That'd mean that VFP and L2 cache could hook themselves onto that list and get notified about these power down/up events.