ARM: 6649/1: omap: use fncpy to copy the PM code functions to SRAM

The new fncpy API is better suited* for copying some
code to SRAM at runtime. This patch changes the ad-hoc
code to the more generic fncpy API.

*: 1. fncpy ensures that the thumb mode bit is propagated,
   2. fncpy provides the security of type safety between the
     original function and the sram function pointer.

Tested OK on OMAP3 in low power modes (RET/OFF)
using omap2plus_defconfig with !CONFIG_THUMB2_KERNEL.
Compile tested on OMAP1/2 using omap1_defconfig.

Boot tested on OMAP1 & OMAP2
Tested OK with suspend/resume on OMAP2420/n810

Boots fine on osk5912 and n800

Signed-off-by: Jean Pihet <j-pihet@ti.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Dave Martin <dave.martin@linaro.org>
Tested-by: Kevin Hilman <khilman@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-omap1/pm.h

@@ -123,9 +123,9 @@ extern void allow_idle_sleep(void);
 extern void omap1_pm_idle(void);
 extern void omap1_pm_suspend(void);
 
-extern void omap7xx_cpu_suspend(unsigned short, unsigned short);
-extern void omap1510_cpu_suspend(unsigned short, unsigned short);
-extern void omap1610_cpu_suspend(unsigned short, unsigned short);
+extern void omap7xx_cpu_suspend(unsigned long, unsigned long);
+extern void omap1510_cpu_suspend(unsigned long, unsigned long);
+extern void omap1610_cpu_suspend(unsigned long, unsigned long);
 extern void omap7xx_idle_loop_suspend(void);
 extern void omap1510_idle_loop_suspend(void);
 extern void omap1610_idle_loop_suspend(void);

arch/arm/mach-omap1/sleep.S

@@ -58,6 +58,7 @@
  */
 
 #if defined(CONFIG_ARCH_OMAP730) || defined(CONFIG_ARCH_OMAP850)
+	.align	3
 ENTRY(omap7xx_cpu_suspend)
 
 	@ save registers on stack
@@ -137,6 +138,7 @@ ENTRY(omap7xx_cpu_suspend_sz)
 #endif /* CONFIG_ARCH_OMAP730 || CONFIG_ARCH_OMAP850 */
 
 #ifdef CONFIG_ARCH_OMAP15XX
+	.align	3
 ENTRY(omap1510_cpu_suspend)
 
 	@ save registers on stack
@@ -211,6 +213,7 @@ ENTRY(omap1510_cpu_suspend_sz)
 #endif /* CONFIG_ARCH_OMAP15XX */
 
 #if defined(CONFIG_ARCH_OMAP16XX)
+	.align	3
 ENTRY(omap1610_cpu_suspend)
 
 	@ save registers on stack

arch/arm/mach-omap1/sram.S

@@ -18,6 +18,7 @@
 /*
  * Reprograms ULPD and CKCTL.
  */
+	.align	3
 ENTRY(omap1_sram_reprogram_clock)
 	stmfd	sp!, {r0 - r12, lr}		@ save registers on stack
 

arch/arm/mach-omap2/pm.h

@@ -92,7 +92,7 @@ extern void omap24xx_idle_loop_suspend(void);
 extern void omap24xx_cpu_suspend(u32 dll_ctrl, void __iomem *sdrc_dlla_ctrl,
 					void __iomem *sdrc_power);
 extern void omap34xx_cpu_suspend(u32 *addr, int save_state);
-extern void save_secure_ram_context(u32 *addr);
+extern int save_secure_ram_context(u32 *addr);
 extern void omap3_save_scratchpad_contents(void);
 
 extern unsigned int omap24xx_idle_loop_suspend_sz;

arch/arm/mach-omap2/sleep24xx.S

@@ -47,6 +47,7 @@
  * Note: This code get's copied to internal SRAM at boot. When the OMAP
  *	 wakes up it continues execution at the point it went to sleep.
  */
+	.align	3
 ENTRY(omap24xx_idle_loop_suspend)
 	stmfd	sp!, {r0, lr}		@ save registers on stack
 	mov	r0, #0			@ clear for mcr setup
@@ -82,6 +83,7 @@ ENTRY(omap24xx_idle_loop_suspend_sz)
  * The DLL load value is not kept in RETENTION or OFF.	It needs to be restored
  * at wake
  */
+	.align	3
 ENTRY(omap24xx_cpu_suspend)
 	stmfd	sp!, {r0 - r12, lr}	@ save registers on stack
 	mov	r3, #0x0		@ clear for mcr call

arch/arm/mach-omap2/sleep34xx.S

@@ -118,6 +118,7 @@ ENTRY(enable_omap3630_toggle_l2_on_restore)
 
 	.text
 /* Function to call rom code to save secure ram context */
+	.align	3
 ENTRY(save_secure_ram_context)
 	stmfd	sp!, {r1-r12, lr}	@ save registers on stack
 	adr	r3, api_params		@ r3 points to parameters
@@ -169,6 +170,7 @@ ENTRY(save_secure_ram_context_sz)
  *   depending on the low power mode (non-OFF vs OFF modes),
  *   cf. 'Resume path for xxx mode' comments.
  */
+	.align	3
 ENTRY(omap34xx_cpu_suspend)
 	stmfd	sp!, {r0-r12, lr}	@ save registers on stack
 

arch/arm/mach-omap2/sram242x.S

@@ -39,6 +39,7 @@
 
 	.text
 
+	.align	3
 ENTRY(omap242x_sram_ddr_init)
 	stmfd	sp!, {r0 - r12, lr}	@ save registers on stack
 
@@ -143,6 +144,7 @@ ENTRY(omap242x_sram_ddr_init_sz)
  * r0 = [PRCM_FULL | PRCM_HALF] r1 = SDRC_DLLA_CTRL value r2 = [DDR | SDR]
  * PRCM_FULL = 2, PRCM_HALF = 1, DDR = 1, SDR = 0
  */
+	.align	3
 ENTRY(omap242x_sram_reprogram_sdrc)
 	stmfd	sp!, {r0 - r10, lr}	@ save registers on stack
 	mov	r3, #0x0		@ clear for mrc call
@@ -238,6 +240,7 @@ ENTRY(omap242x_sram_reprogram_sdrc_sz)
 /*
  * Set dividers and pll. Also recalculate DLL value for DDR and unlock mode.
  */
+	.align	3
 ENTRY(omap242x_sram_set_prcm)
 	stmfd	sp!, {r0-r12, lr}	@ regs to stack
 	adr	r4, pbegin		@ addr of preload start

arch/arm/mach-omap2/sram243x.S

@@ -39,6 +39,7 @@
 
 	.text
 
+	.align	3
 ENTRY(omap243x_sram_ddr_init)
 	stmfd	sp!, {r0 - r12, lr}	@ save registers on stack
 
@@ -143,6 +144,7 @@ ENTRY(omap243x_sram_ddr_init_sz)
  * r0 = [PRCM_FULL | PRCM_HALF] r1 = SDRC_DLLA_CTRL value r2 = [DDR | SDR]
  * PRCM_FULL = 2, PRCM_HALF = 1, DDR = 1, SDR = 0
  */
+	.align	3
 ENTRY(omap243x_sram_reprogram_sdrc)
 	stmfd	sp!, {r0 - r10, lr}	@ save registers on stack
 	mov	r3, #0x0		@ clear for mrc call
@@ -238,6 +240,7 @@ ENTRY(omap243x_sram_reprogram_sdrc_sz)
 /*
  * Set dividers and pll. Also recalculate DLL value for DDR and unlock mode.
  */
+	.align	3
 ENTRY(omap243x_sram_set_prcm)
 	stmfd	sp!, {r0-r12, lr}	@ regs to stack
 	adr	r4, pbegin		@ addr of preload start

arch/arm/mach-omap2/sram34xx.S

@@ -111,6 +111,7 @@
  * since it will cause the ARM MMU to attempt to walk the page tables.
  * These crashes may be intermittent.
  */
+	.align	3
 ENTRY(omap3_sram_configure_core_dpll)
 	stmfd	sp!, {r1-r12, lr}	@ store regs to stack
 

arch/arm/plat-omap/include/plat/sram.h

@@ -12,7 +12,19 @@
 #define __ARCH_ARM_OMAP_SRAM_H
 
 #ifndef __ASSEMBLY__
-extern void * omap_sram_push(void * start, unsigned long size);
+#include <asm/fncpy.h>
+
+extern void *omap_sram_push_address(unsigned long size);
+
+/* Macro to push a function to the internal SRAM, using the fncpy API */
+#define omap_sram_push(funcp, size) ({				\
+	typeof(&(funcp)) _res = NULL;				\
+	void *_sram_address = omap_sram_push_address(size);	\
+	if (_sram_address)					\
+		_res = fncpy(_sram_address, &(funcp), size);	\
+	_res;							\
+})
+
 extern void omap_sram_reprogram_clock(u32 dpllctl, u32 ckctl);
 
 extern void omap2_sram_ddr_init(u32 *slow_dll_ctrl, u32 fast_dll_ctrl,

arch/arm/plat-omap/sram.c

@@ -242,7 +242,14 @@ static void __init omap_map_sram(void)
 	       omap_sram_size - SRAM_BOOTLOADER_SZ);
 }
 
-void * omap_sram_push(void * start, unsigned long size)
+/*
+ * Memory allocator for SRAM: calculates the new ceiling address
+ * for pushing a function using the fncpy API.
+ *
+ * Note that fncpy requires the returned address to be aligned
+ * to an 8-byte boundary.
+ */
+void *omap_sram_push_address(unsigned long size)
 {
 	if (size > (omap_sram_ceil - (omap_sram_base + SRAM_BOOTLOADER_SZ))) {
 		printk(KERN_ERR "Not enough space in SRAM\n");
@@ -250,10 +257,7 @@ void * omap_sram_push(void * start, unsigned long size)
 	}
 
 	omap_sram_ceil -= size;
-	omap_sram_ceil = ROUND_DOWN(omap_sram_ceil, sizeof(void *));
-	memcpy((void *)omap_sram_ceil, start, size);
-	flush_icache_range((unsigned long)omap_sram_ceil,
-		(unsigned long)(omap_sram_ceil + size));
+	omap_sram_ceil = ROUND_DOWN(omap_sram_ceil, FNCPY_ALIGN);
 
 	return (void *)omap_sram_ceil;
 }