This patch restores the table entry that was modified for
enabling the MMU in the sram code.
Signed-off-by: Rajendra Nayak <rnayak@xxxxxx>
---
arch/arm/mach-omap2/pm.h | 3 +++
arch/arm/mach-omap2/pm34xx.c | 36 ++++++++++++++++++++++++++++++++++++
2 files changed, 39 insertions(+)
Index: linux-omap-2.6/arch/arm/mach-omap2/pm.h
===================================================================
--- linux-omap-2.6.orig/arch/arm/mach-omap2/pm.h 2008-08-26 17:22:23.000000000
+0530
+++ linux-omap-2.6/arch/arm/mach-omap2/pm.h 2008-08-26 17:33:54.000000000 +0530
@@ -23,6 +23,9 @@ extern atomic_t sleep_block;
extern void omap2_block_sleep(void);
extern void omap2_allow_sleep(void);
+#define OMAP343X_TABLE_ADDRESS_OFFSET 0x31
+#define OMAP343X_TABLE_VALUE_OFFSET 0x30
+#define OMAP343X_CONTROL_REG_VALUE_OFFSET 0x32
#ifdef CONFIG_PM_DEBUG
extern void omap2_pm_dump(int mode, int resume, unsigned int us);
Index: linux-omap-2.6/arch/arm/mach-omap2/pm34xx.c
===================================================================
--- linux-omap-2.6.orig/arch/arm/mach-omap2/pm34xx.c 2008-08-26
17:30:53.000000000 +0530
+++ linux-omap-2.6/arch/arm/mach-omap2/pm34xx.c 2008-08-26 17:33:54.000000000
+0530
@@ -30,6 +30,8 @@
#include <mach/clockdomain.h>
#include <mach/powerdomain.h>
#include <mach/common.h>
+#include <mach/control.h>
+#include <asm/tlbflush.h>
#include "cm.h"
#include "cm-regbits-34xx.h"
@@ -181,6 +183,36 @@ static irqreturn_t prcm_interrupt_handle
return IRQ_HANDLED;
}
+static void restore_control_register(u32 val)
+{
+ __asm__ __volatile__ ("mcr p15, 0, %0, c1, c0, 0" : : "r" (val));
+}
+
+/* Function to restore the table entry that was modified for enabling MMU*/
+static void restore_table_entry(void)
+{
+ u32 *scratchpad_address;
+ u32 previous_value, control_reg_value;
+ u32 *address;
+ /* Get virtual address of SCRATCHPAD */
+ scratchpad_address = (u32 *) io_p2v(OMAP343X_SCRATCHPAD);
+ /* Get address of entry that was modified */
+ address = (u32 *) *(scratchpad_address + OMAP343X_TABLE_ADDRESS_OFFSET);
+ /* Get the previous value which needs to be restored */
+ previous_value = *(scratchpad_address + OMAP343X_TABLE_VALUE_OFFSET);
+ /* Convert address to virtual address */
+ address = __va(address);
+ /* Restore table entry */
+ *address = previous_value;
+ /* Flush TLB */
+ flush_tlb_all();
+ control_reg_value = *(scratchpad_address
+ + OMAP343X_CONTROL_REG_VALUE_OFFSET);
+ /* Restore control register*/
+ /* This will enable caches and prediction */
+ restore_control_register(control_reg_value);
+}
+
void omap_sram_idle(void)
{
/* Variable to tell what needs to be saved and restored
@@ -240,6 +272,10 @@ void omap_sram_idle(void)
}
_omap_sram_idle(NULL, save_state);
+ /* Restore table entry modified during MMU restoration */
+ if (pwrdm_read_prev_pwrst(mpu_pwrdm) == PWRDM_POWER_OFF)
+ restore_table_entry();
+
if (core_next_state < PWRDM_POWER_ON) {
/* Disable IO-PAD wakeup */
--
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