diff mbox

[20/25] OMAP4: PM: Add L2X0 cache lowpower support

Message ID 1315144466-9395-21-git-send-email-santosh.shilimkar@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Santosh Shilimkar Sept. 4, 2011, 1:54 p.m. UTC 
When MPUSS hits off-mode e, L2 cache is lost. This patch adds L2X0
necessary maintenance operations and context restoration in the
low power code.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
---
 arch/arm/mach-omap2/include/mach/omap-secure.h |    5 +
 arch/arm/mach-omap2/omap-mpuss-lowpower.c      |   38 +++++++++-
 arch/arm/mach-omap2/omap4-sar-layout.h         |    4 +
 arch/arm/mach-omap2/sleep44xx.S                |   96 ++++++++++++++++++++++++
 4 files changed, 142 insertions(+), 1 deletions(-)

Comments

Lorenzo Pieralisi Sept. 5, 2011, 2:01 p.m. UTC | #1 
Hi Santosh,

just a question below.

On Sun, Sep 04, 2011 at 02:54:21PM +0100, Santosh Shilimkar wrote:
> When MPUSS hits off-mode e, L2 cache is lost. This patch adds L2X0
> necessary maintenance operations and context restoration in the
> low power code.
> 
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
> Cc: Kevin Hilman <khilman@ti.com>
> ---
>  arch/arm/mach-omap2/include/mach/omap-secure.h |    5 +
>  arch/arm/mach-omap2/omap-mpuss-lowpower.c      |   38 +++++++++-
>  arch/arm/mach-omap2/omap4-sar-layout.h         |    4 +
>  arch/arm/mach-omap2/sleep44xx.S                |   96 ++++++++++++++++++++++++
>  4 files changed, 142 insertions(+), 1 deletions(-)
> 

[...]

> diff --git a/arch/arm/mach-omap2/sleep44xx.S b/arch/arm/mach-omap2/sleep44xx.S
> index 230ab8c..a7cce0b 100644
> --- a/arch/arm/mach-omap2/sleep44xx.S
> +++ b/arch/arm/mach-omap2/sleep44xx.S
> @@ -32,6 +32,9 @@
>  ppa_zero_params:
>  	.word		0x0
>  
> +ppa_por_params:
> +	.word		1, 0
> +
>  /*
>   * =============================
>   * == CPU suspend finisher ==
> @@ -130,6 +133,55 @@ skip_scu_gp_set:
>  	mcrne	p15, 0, r0, c1, c0, 1
>  	isb
>  	dsb
> +#ifdef CONFIG_CACHE_L2X0
> +	/*
> +	 * Clean and invalidate the L2 cache.
> +	 * Common cache-l2x0.c functions can't be used here since it
> +	 * uses spinlocks. We are out of coherency here with data cache
> +	 * disabled. The spinlock implementation uses exclusive load/store
> +	 * instruction which can fail without data cache being enabled.
> +	 * OMAP4 hardware doesn't support exclusive monitor which can
> +	 * overcome exclusive access issue. Because of this, CPU can
> +	 * lead to deadlock.
> +	 */
> +l2x_clean_inv:
> +	bl	omap4_get_sar_ram_base
> +	mov	r8, r0
> +	mrc	p15, 0, r5, c0, c0, 5		@ Read MPIDR
> +	ands	r5, r5, #0x0f
> +	ldreq	r0, [r8, #L2X0_SAVE_OFFSET0]
> +	ldrne	r0, [r8, #L2X0_SAVE_OFFSET1]
> +	cmp	r0, #3
> +	bne	do_WFI
> +#ifdef CONFIG_PL310_ERRATA_727915
> +	mov	r0, #0x03
> +	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
> +	DO_SMC
> +#endif
> +	bl	omap4_get_l2cache_base
> +	mov	r2, r0
> +	ldr	r0, =0xffff
> +	str	r0, [r2, #L2X0_CLEAN_INV_WAY]
> +wait:
> +	ldr	r0, [r2, #L2X0_CLEAN_INV_WAY]
> +	ldr	r1, =0xffff
> +	ands	r0, r0, r1
> +	bne	wait
> +#ifdef CONFIG_PL310_ERRATA_727915
> +	mov	r0, #0x00
> +	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
> +	DO_SMC
> +#endif
> +l2x_sync:
> +	bl	omap4_get_l2cache_base
> +	mov	r2, r0
> +	mov	r0, #0x0
> +	str	r0, [r2, #L2X0_CACHE_SYNC]
> +sync:
> +	ldr	r0, [r2, #L2X0_CACHE_SYNC]
> +	ands	r0, r0, #0x1
> +	bne	sync
> +#endif
>

If I am not mistaken, here the PL310 is still on. Is it
safe to go to wfi (PL310 logic state is lost then ?) with the controller
enabled ? You still use the stack and I think prefetch is enabled,
do not know if you can end up having AXI bus transactions ongoing
whilst HW yanks the power. To disable it I think you need a secure call,
again it is just a question for my information.

Thanks,
Lorenzo

>  do_WFI:
>  	bl	omap_do_wfi
> @@ -222,6 +274,50 @@ enable_smp_bit:
>  	mcreq	p15, 0, r0, c1, c0, 1
>  	isb
>  skip_ns_smp_enable:
> +#ifdef CONFIG_CACHE_L2X0
> +	/*
> +	 * Restore the L2 AUXCTRL and enable the L2 cache.
> +	 * OMAP4_MON_L2X0_AUXCTRL_INDEX =  Program the L2X0 AUXCTRL
> +	 * OMAP4_MON_L2X0_CTRL_INDEX =  Enable the L2 using L2X0 CTRL
> +	 * register r0 contains value to be programmed.
> +	 * L2 cache is already invalidate by ROM code as part
> +	 * of MPUSS OFF wakeup path.
> +	 */
> +	ldr	r2, =OMAP44XX_L2CACHE_BASE
> +	ldr	r0, [r2, #L2X0_CTRL]
> +	and	r0, #0x0f
> +	cmp	r0, #1
> +	beq	skip_l2en			@ Skip if already enabled
> +	ldr	r3, =OMAP44XX_SAR_RAM_BASE
> +	ldr	r1, [r3, #OMAP_TYPE_OFFSET]
> +	cmp	r1, #0x1			@ Check for HS device
> +	bne     set_gp_por
> +	ldr     r0, =OMAP4_PPA_L2_POR_INDEX
> +	ldr     r1, =OMAP44XX_SAR_RAM_BASE
> +	ldr     r4, [r1, #L2X0_PREFETCH_CTRL_OFFSET]
> +	adr     r3, ppa_por_params
> +	str     r4, [r3, #0x04]
> +	mov	r1, #0x0			@ Process ID
> +	mov	r2, #0x4			@ Flag
> +	mov	r6, #0xff
> +	mov	r12, #0x00			@ Secure Service ID
> +	DO_SMC
> +	b	set_aux_ctrl
> +set_gp_por:
> +	ldr     r1, =OMAP44XX_SAR_RAM_BASE
> +	ldr     r0, [r1, #L2X0_PREFETCH_CTRL_OFFSET]
> +	ldr	r12, =OMAP4_MON_L2X0_PREFETCH_INDEX	@ Setup L2 PREFETCH
> +	DO_SMC
> +set_aux_ctrl:
> +	ldr     r1, =OMAP44XX_SAR_RAM_BASE
> +	ldr	r0, [r1, #L2X0_AUXCTRL_OFFSET]
> +	ldr	r12, =OMAP4_MON_L2X0_AUXCTRL_INDEX	@ Setup L2 AUXCTRL
> +	DO_SMC
> +	mov	r0, #0x1
> +	ldr	r12, =OMAP4_MON_L2X0_CTRL_INDEX		@ Enable L2 cache
> +	DO_SMC
> +skip_l2en:
> +#endif
>  
>  	b	cpu_resume			@ Jump to generic resume
>  ENDPROC(omap4_cpu_resume)
> -- 
> 1.7.4.1
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Santosh Shilimkar Sept. 5, 2011, 2:13 p.m. UTC | #2 
On Monday 05 September 2011 07:31 PM, Lorenzo Pieralisi wrote:
> Hi Santosh,
>
> just a question below.
>
> On Sun, Sep 04, 2011 at 02:54:21PM +0100, Santosh Shilimkar wrote:
>> When MPUSS hits off-mode e, L2 cache is lost. This patch adds L2X0
>> necessary maintenance operations and context restoration in the
>> low power code.
>>
>> Signed-off-by: Santosh Shilimkar<santosh.shilimkar@ti.com>
>> Cc: Kevin Hilman<khilman@ti.com>
>> ---
>>   arch/arm/mach-omap2/include/mach/omap-secure.h |    5 +
>>   arch/arm/mach-omap2/omap-mpuss-lowpower.c      |   38 +++++++++-
>>   arch/arm/mach-omap2/omap4-sar-layout.h         |    4 +
>>   arch/arm/mach-omap2/sleep44xx.S                |   96 ++++++++++++++++++++++++
>>   4 files changed, 142 insertions(+), 1 deletions(-)
>>
>
> [...]
>
>> diff --git a/arch/arm/mach-omap2/sleep44xx.S b/arch/arm/mach-omap2/sleep44xx.S
>> index 230ab8c..a7cce0b 100644
>> --- a/arch/arm/mach-omap2/sleep44xx.S
>> +++ b/arch/arm/mach-omap2/sleep44xx.S
>> @@ -32,6 +32,9 @@
>>   ppa_zero_params:
>>   	.word		0x0
>>
>> +ppa_por_params:
>> +	.word		1, 0
>> +
>>   /*
>>    * =============================
>>    * == CPU suspend finisher ==
>> @@ -130,6 +133,55 @@ skip_scu_gp_set:
>>   	mcrne	p15, 0, r0, c1, c0, 1
>>   	isb
>>   	dsb
>> +#ifdef CONFIG_CACHE_L2X0
>> +	/*
>> +	 * Clean and invalidate the L2 cache.
>> +	 * Common cache-l2x0.c functions can't be used here since it
>> +	 * uses spinlocks. We are out of coherency here with data cache
>> +	 * disabled. The spinlock implementation uses exclusive load/store
>> +	 * instruction which can fail without data cache being enabled.
>> +	 * OMAP4 hardware doesn't support exclusive monitor which can
>> +	 * overcome exclusive access issue. Because of this, CPU can
>> +	 * lead to deadlock.
>> +	 */
>> +l2x_clean_inv:
>> +	bl	omap4_get_sar_ram_base
>> +	mov	r8, r0
>> +	mrc	p15, 0, r5, c0, c0, 5		@ Read MPIDR
>> +	ands	r5, r5, #0x0f
>> +	ldreq	r0, [r8, #L2X0_SAVE_OFFSET0]
>> +	ldrne	r0, [r8, #L2X0_SAVE_OFFSET1]
>> +	cmp	r0, #3
>> +	bne	do_WFI
>> +#ifdef CONFIG_PL310_ERRATA_727915
>> +	mov	r0, #0x03
>> +	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
>> +	DO_SMC
>> +#endif
>> +	bl	omap4_get_l2cache_base
>> +	mov	r2, r0
>> +	ldr	r0, =0xffff
>> +	str	r0, [r2, #L2X0_CLEAN_INV_WAY]
>> +wait:
>> +	ldr	r0, [r2, #L2X0_CLEAN_INV_WAY]
>> +	ldr	r1, =0xffff
>> +	ands	r0, r0, r1
>> +	bne	wait
>> +#ifdef CONFIG_PL310_ERRATA_727915
>> +	mov	r0, #0x00
>> +	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
>> +	DO_SMC
>> +#endif
>> +l2x_sync:
>> +	bl	omap4_get_l2cache_base
>> +	mov	r2, r0
>> +	mov	r0, #0x0
>> +	str	r0, [r2, #L2X0_CACHE_SYNC]
>> +sync:
>> +	ldr	r0, [r2, #L2X0_CACHE_SYNC]
>> +	ands	r0, r0, #0x1
>> +	bne	sync
>> +#endif
>>
>
> If I am not mistaken, here the PL310 is still on. Is it
> safe to go to wfi (PL310 logic state is lost then ?) with the controller
> enabled ? You still use the stack and I think prefetch is enabled,
> do not know if you can end up having AXI bus transactions ongoing
> whilst HW yanks the power. To disable it I think you need a secure call,
> again it is just a question for my information.
>
PL310 is ON but C-bit is disabled. More over the Last sync will ensure
that all out-standing transactions are completed. So it should be
safe to go down. On OMAP, hardware waits for AXI transation complete
before CPU transitioning to low power, so that's not an issue.

For disabling, we need secure call. I didn't disable it because
we haven't seen any issue so far and AXI ack is already in
place.

Regards
Santosh
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/arch/arm/mach-omap2/include/mach/omap-secure.h b/arch/arm/mach-omap2/include/mach/omap-secure.h
index 0062d49..6e929c5 100644
--- a/arch/arm/mach-omap2/include/mach/omap-secure.h
+++ b/arch/arm/mach-omap2/include/mach/omap-secure.h
@@ -37,8 +37,13 @@ 
 
 /* Secure Monitor mode APIs */
 #define OMAP4_MON_SCU_PWR_INDEX		0x108
+#define OMAP4_MON_L2X0_DBG_CTRL_INDEX	0x100
+#define OMAP4_MON_L2X0_CTRL_INDEX	0x102
+#define OMAP4_MON_L2X0_AUXCTRL_INDEX	0x109
+#define OMAP4_MON_L2X0_PREFETCH_INDEX	0x113
 
 /* Secure PPA(Primary Protected Application) APIs */
+#define OMAP4_PPA_L2_POR_INDEX		0x23
 #define OMAP4_PPA_CPU_ACTRL_SMP_INDEX	0x25
 
 #ifndef __ASSEMBLER__
diff --git a/arch/arm/mach-omap2/omap-mpuss-lowpower.c b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
index 9f632fe..aea6deb 100644
--- a/arch/arm/mach-omap2/omap-mpuss-lowpower.c
+++ b/arch/arm/mach-omap2/omap-mpuss-lowpower.c
@@ -49,6 +49,7 @@ 
 #include <asm/system.h>
 #include <asm/pgalloc.h>
 #include <asm/suspend.h>
+#include <asm/hardware/cache-l2x0.h>
 
 #include <plat/omap44xx.h>
 #include <mach/omap4-common.h>
@@ -63,10 +64,12 @@  struct omap4_cpu_pm_info {
 	struct powerdomain *pwrdm;
 	void __iomem *scu_sar_addr;
 	void __iomem *wkup_sar_addr;
+	void __iomem *l2x0_sar_addr;
 };
 
 static DEFINE_PER_CPU(struct omap4_cpu_pm_info, omap4_pm_info);
 static struct powerdomain *mpuss_pd;
+static void __iomem *sar_base;
 
 /*
  * Program the wakeup routine address for the CPU0 and CPU1
@@ -135,6 +138,33 @@  static void scu_pwrst_prepare(unsigned int cpu_id, unsigned int cpu_state)
 	__raw_writel(scu_pwr_st, pm_info->scu_sar_addr);
 }
 
+/*
+ * Store the CPU cluster state for L2X0 low power operations.
+ */
+static void l2x0_pwrst_prepare(unsigned int cpu_id, unsigned int save_state)
+{
+	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
+
+	__raw_writel(save_state, pm_info->l2x0_sar_addr);
+}
+
+/*
+ * Save the L2X0 AUXCTRL and POR value to SAR memory. Its used to
+ * in every restore MPUSS OFF path.
+ */
+static void save_l2x0_context(void)
+{
+#ifdef CONFIG_CACHE_L2X0
+	u32 val;
+	void __iomem *l2x0_base = omap4_get_l2cache_base();
+
+	val = __raw_readl(l2x0_base + L2X0_AUX_CTRL);
+	__raw_writel(val, sar_base + L2X0_AUXCTRL_OFFSET);
+	val = __raw_readl(l2x0_base + L2X0_PREFETCH_CTRL);
+	__raw_writel(val, sar_base + L2X0_PREFETCH_CTRL_OFFSET);
+#endif
+}
+
 /**
  * omap4_enter_lowpower: OMAP4 MPUSS Low Power Entry Function
  * The purpose of this function is to manage low power programming
@@ -182,6 +212,7 @@  int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state)
 	set_cpu_next_pwrst(cpu, power_state);
 	set_cpu_wakeup_addr(cpu, virt_to_phys(omap4_cpu_resume));
 	scu_pwrst_prepare(cpu, power_state);
+	l2x0_pwrst_prepare(cpu, save_state);
 
 	/*
 	 * Call low level function  with targeted CPU id
@@ -241,17 +272,19 @@  int omap4_hotplug_cpu(unsigned int cpu, unsigned int power_state)
 int __init omap4_mpuss_init(void)
 {
 	struct omap4_cpu_pm_info *pm_info;
-	void __iomem *sar_base = omap4_get_sar_ram_base();
 
 	if (omap_rev() == OMAP4430_REV_ES1_0) {
 		WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
 		return -ENODEV;
 	}
 
+	sar_base = omap4_get_sar_ram_base();
+
 	/* Initilaise per CPU PM information */
 	pm_info = &per_cpu(omap4_pm_info, 0x0);
 	pm_info->scu_sar_addr = sar_base + SCU_OFFSET0;
 	pm_info->wkup_sar_addr = sar_base + CPU0_WAKEUP_NS_PA_ADDR_OFFSET;
+	pm_info->l2x0_sar_addr = sar_base + L2X0_SAVE_OFFSET0;
 	pm_info->pwrdm = pwrdm_lookup("cpu0_pwrdm");
 	if (!pm_info->pwrdm) {
 		pr_err("Lookup failed for CPU0 pwrdm\n");
@@ -267,6 +300,7 @@  int __init omap4_mpuss_init(void)
 	pm_info = &per_cpu(omap4_pm_info, 0x1);
 	pm_info->scu_sar_addr = sar_base + SCU_OFFSET1;
 	pm_info->wkup_sar_addr = sar_base + CPU1_WAKEUP_NS_PA_ADDR_OFFSET;
+	pm_info->l2x0_sar_addr = sar_base + L2X0_SAVE_OFFSET1;
 	pm_info->pwrdm = pwrdm_lookup("cpu1_pwrdm");
 	if (!pm_info->pwrdm) {
 		pr_err("Lookup failed for CPU1 pwrdm\n");
@@ -292,6 +326,8 @@  int __init omap4_mpuss_init(void)
 	else
 		__raw_writel(0, sar_base + OMAP_TYPE_OFFSET);
 
+	save_l2x0_context();
+
 	return 0;
 }
 
diff --git a/arch/arm/mach-omap2/omap4-sar-layout.h b/arch/arm/mach-omap2/omap4-sar-layout.h
index aa14a8d..fe5b545 100644
--- a/arch/arm/mach-omap2/omap4-sar-layout.h
+++ b/arch/arm/mach-omap2/omap4-sar-layout.h
@@ -23,6 +23,10 @@ 
 #define SCU_OFFSET0				0xd00
 #define SCU_OFFSET1				0xd04
 #define OMAP_TYPE_OFFSET			0xd10
+#define L2X0_SAVE_OFFSET0			0xd14
+#define L2X0_SAVE_OFFSET1			0xd18
+#define L2X0_AUXCTRL_OFFSET			0xd1c
+#define L2X0_PREFETCH_CTRL_OFFSET		0xd20
 
 /* CPUx Wakeup Non-Secure Physical Address offsets in SAR_BANK3 */
 #define CPU0_WAKEUP_NS_PA_ADDR_OFFSET		0xa04
diff --git a/arch/arm/mach-omap2/sleep44xx.S b/arch/arm/mach-omap2/sleep44xx.S
index 230ab8c..a7cce0b 100644
--- a/arch/arm/mach-omap2/sleep44xx.S
+++ b/arch/arm/mach-omap2/sleep44xx.S
@@ -32,6 +32,9 @@ 
 ppa_zero_params:
 	.word		0x0
 
+ppa_por_params:
+	.word		1, 0
+
 /*
  * =============================
  * == CPU suspend finisher ==
@@ -130,6 +133,55 @@  skip_scu_gp_set:
 	mcrne	p15, 0, r0, c1, c0, 1
 	isb
 	dsb
+#ifdef CONFIG_CACHE_L2X0
+	/*
+	 * Clean and invalidate the L2 cache.
+	 * Common cache-l2x0.c functions can't be used here since it
+	 * uses spinlocks. We are out of coherency here with data cache
+	 * disabled. The spinlock implementation uses exclusive load/store
+	 * instruction which can fail without data cache being enabled.
+	 * OMAP4 hardware doesn't support exclusive monitor which can
+	 * overcome exclusive access issue. Because of this, CPU can
+	 * lead to deadlock.
+	 */
+l2x_clean_inv:
+	bl	omap4_get_sar_ram_base
+	mov	r8, r0
+	mrc	p15, 0, r5, c0, c0, 5		@ Read MPIDR
+	ands	r5, r5, #0x0f
+	ldreq	r0, [r8, #L2X0_SAVE_OFFSET0]
+	ldrne	r0, [r8, #L2X0_SAVE_OFFSET1]
+	cmp	r0, #3
+	bne	do_WFI
+#ifdef CONFIG_PL310_ERRATA_727915
+	mov	r0, #0x03
+	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
+	DO_SMC
+#endif
+	bl	omap4_get_l2cache_base
+	mov	r2, r0
+	ldr	r0, =0xffff
+	str	r0, [r2, #L2X0_CLEAN_INV_WAY]
+wait:
+	ldr	r0, [r2, #L2X0_CLEAN_INV_WAY]
+	ldr	r1, =0xffff
+	ands	r0, r0, r1
+	bne	wait
+#ifdef CONFIG_PL310_ERRATA_727915
+	mov	r0, #0x00
+	mov	r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
+	DO_SMC
+#endif
+l2x_sync:
+	bl	omap4_get_l2cache_base
+	mov	r2, r0
+	mov	r0, #0x0
+	str	r0, [r2, #L2X0_CACHE_SYNC]
+sync:
+	ldr	r0, [r2, #L2X0_CACHE_SYNC]
+	ands	r0, r0, #0x1
+	bne	sync
+#endif
 
 do_WFI:
 	bl	omap_do_wfi
@@ -222,6 +274,50 @@  enable_smp_bit:
 	mcreq	p15, 0, r0, c1, c0, 1
 	isb
 skip_ns_smp_enable:
+#ifdef CONFIG_CACHE_L2X0
+	/*
+	 * Restore the L2 AUXCTRL and enable the L2 cache.
+	 * OMAP4_MON_L2X0_AUXCTRL_INDEX =  Program the L2X0 AUXCTRL
+	 * OMAP4_MON_L2X0_CTRL_INDEX =  Enable the L2 using L2X0 CTRL
+	 * register r0 contains value to be programmed.
+	 * L2 cache is already invalidate by ROM code as part
+	 * of MPUSS OFF wakeup path.
+	 */
+	ldr	r2, =OMAP44XX_L2CACHE_BASE
+	ldr	r0, [r2, #L2X0_CTRL]
+	and	r0, #0x0f
+	cmp	r0, #1
+	beq	skip_l2en			@ Skip if already enabled
+	ldr	r3, =OMAP44XX_SAR_RAM_BASE
+	ldr	r1, [r3, #OMAP_TYPE_OFFSET]
+	cmp	r1, #0x1			@ Check for HS device
+	bne     set_gp_por
+	ldr     r0, =OMAP4_PPA_L2_POR_INDEX
+	ldr     r1, =OMAP44XX_SAR_RAM_BASE
+	ldr     r4, [r1, #L2X0_PREFETCH_CTRL_OFFSET]
+	adr     r3, ppa_por_params
+	str     r4, [r3, #0x04]
+	mov	r1, #0x0			@ Process ID
+	mov	r2, #0x4			@ Flag
+	mov	r6, #0xff
+	mov	r12, #0x00			@ Secure Service ID
+	DO_SMC
+	b	set_aux_ctrl
+set_gp_por:
+	ldr     r1, =OMAP44XX_SAR_RAM_BASE
+	ldr     r0, [r1, #L2X0_PREFETCH_CTRL_OFFSET]
+	ldr	r12, =OMAP4_MON_L2X0_PREFETCH_INDEX	@ Setup L2 PREFETCH
+	DO_SMC
+set_aux_ctrl:
+	ldr     r1, =OMAP44XX_SAR_RAM_BASE
+	ldr	r0, [r1, #L2X0_AUXCTRL_OFFSET]
+	ldr	r12, =OMAP4_MON_L2X0_AUXCTRL_INDEX	@ Setup L2 AUXCTRL
+	DO_SMC
+	mov	r0, #0x1
+	ldr	r12, =OMAP4_MON_L2X0_CTRL_INDEX		@ Enable L2 cache
+	DO_SMC
+skip_l2en:
+#endif
 
 	b	cpu_resume			@ Jump to generic resume
 ENDPROC(omap4_cpu_resume)