Thread (35 messages) read the whole thread 35 messages, 12 authors, 2013-02-19

[PATCH 8/9] [HACK] ARM: imx: work around v7_cpu_resume link error

From: Shawn Guo <hidden>
Date: 2013-02-19 01:42:40
Also in: lkml

On Mon, Feb 18, 2013 at 12:06:32PM -0500, Nicolas Pitre wrote:
Try the following instead.  It makes the code simpler and easier to 
debug.
It works now.  Thanks, Nico.  Care to send a patch for it?  I'd like
to apply it.

Shawn
quoted hunk ↗ jump to hunk
diff --git a/arch/arm/mach-imx/headsmp.S b/arch/arm/mach-imx/headsmp.S
index 7e49deb128..27bc06e910 100644
--- a/arch/arm/mach-imx/headsmp.S
+++ b/arch/arm/mach-imx/headsmp.S
@@ -73,16 +73,16 @@ ENDPROC(v7_secondary_startup)
 
 #ifdef CONFIG_PM
 /*
- * The following code is located into the .data section.  This is to
- * allow phys_l2x0_saved_regs to be accessed with a relative load
- * as we are running on physical address here.
+ * The following code must assume it is running from physical address
+ * where absolute virtual addresses to the data section have to be
+ * turned into relative ones.
  */
-	.data
-	.align
 
 #ifdef CONFIG_CACHE_L2X0
 	.macro	pl310_resume
-	ldr	r2, phys_l2x0_saved_regs
+	adr	r0, l2x0_saved_regs_offset
+	ldr	r2, [r0]
+	add	r2, r2, r0
 	ldr	r0, [r2, #L2X0_R_PHY_BASE]	@ get physical base of l2x0
 	ldr	r1, [r2, #L2X0_R_AUX_CTRL]	@ get aux_ctrl value
 	str	r1, [r0, #L2X0_AUX_CTRL]	@ restore aux_ctrl
@@ -90,9 +90,9 @@ ENDPROC(v7_secondary_startup)
 	str	r1, [r0, #L2X0_CTRL]		@ re-enable L2
 	.endm
 
-	.globl	phys_l2x0_saved_regs
-phys_l2x0_saved_regs:
-        .long   0
+l2x0_saved_regs_offset:
+	.word	l2x0_saved_regs - .
+
 #else
 	.macro	pl310_resume
 	.endm
diff --git a/arch/arm/mach-imx/pm-imx6q.c b/arch/arm/mach-imx/pm-imx6q.c
index f7b0c2b1b9..f3791f980d 100644
--- a/arch/arm/mach-imx/pm-imx6q.c
+++ b/arch/arm/mach-imx/pm-imx6q.c
@@ -21,8 +21,6 @@
 #include <mach/common.h>
 #include <mach/hardware.h>
 
-extern unsigned long phys_l2x0_saved_regs;
-
 static int imx6q_suspend_finish(unsigned long val)
 {
 	cpu_do_idle();
@@ -55,18 +53,5 @@ static const struct platform_suspend_ops imx6q_pm_ops = {
 
 void __init imx6q_pm_init(void)
 {
-	/*
-	 * The l2x0 core code provides an infrastucture to save and restore
-	 * l2x0 registers across suspend/resume cycle.  But because imx6q
-	 * retains L2 content during suspend and needs to resume L2 before
-	 * MMU is enabled, it can only utilize register saving support and
-	 * have to take care of restoring on its own.  So we save physical
-	 * address of the data structure used by l2x0 core to save registers,
-	 * and later restore the necessary ones in imx6q resume entry.
-	 */
-#ifdef CONFIG_CACHE_L2X0
-	phys_l2x0_saved_regs = __pa(&l2x0_saved_regs);
-#endif
-
 	suspend_set_ops(&imx6q_pm_ops);
 }
Nicolas
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