[RFC PATCH v3] ARM: EXYNOS: Use MCPM call-backs to support S2R on Exynos5420
Abhilash Kesavan
a.kesavan at samsung.com
Wed Jul 2 07:59:02 PDT 2014
Use the MCPM layer to handle core suspend/resume on Exynos5420.
Also, restore the entry address setup code post-resume.
Signed-off-by: Abhilash Kesavan <a.kesavan at samsung.com>
---
Hi Lorenzo and Nicolas,
I have re-worked the patch to use the residency value as an indicator of the
current state. This is untested and I haven't taken care of any changes that
tc2 might require. Posting this as an RFC to check if this is the expected
approach.
Depencies remain the same as v2.
arch/arm/include/asm/mcpm.h | 6 +++++
arch/arm/mach-exynos/mcpm-exynos.c | 50 ++++++++++++++++++++++++++----------
arch/arm/mach-exynos/pm.c | 38 ++++++++++++++++++++++++---
arch/arm/mach-exynos/regs-pmu.h | 1 +
drivers/cpuidle/cpuidle-big_little.c | 2 +-
5 files changed, 79 insertions(+), 18 deletions(-)
diff --git a/arch/arm/include/asm/mcpm.h b/arch/arm/include/asm/mcpm.h
index ff73aff..0848829 100644
--- a/arch/arm/include/asm/mcpm.h
+++ b/arch/arm/include/asm/mcpm.h
@@ -272,4 +272,10 @@ void __init mcpm_smp_set_ops(void);
#define MCPM_SYNC_CLUSTER_SIZE \
(MCPM_SYNC_CLUSTER_INBOUND + __CACHE_WRITEBACK_GRANULE)
+/* Definitions for various MCPM scenarios that might need special handling */
+#define MCPM_CPU_IDLE 0x0
+#define MCPM_CPU_SUSPEND 0x1
+#define MCPM_CPU_SWITCH 0x2
+#define MCPM_CPU_HOTPLUG 0x3
+
#endif
diff --git a/arch/arm/mach-exynos/mcpm-exynos.c b/arch/arm/mach-exynos/mcpm-exynos.c
index 1baca55..c3673bd 100644
--- a/arch/arm/mach-exynos/mcpm-exynos.c
+++ b/arch/arm/mach-exynos/mcpm-exynos.c
@@ -15,6 +15,7 @@
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/of_address.h>
+#include <linux/syscore_ops.h>
#include <asm/cputype.h>
#include <asm/cp15.h>
@@ -30,6 +31,8 @@
#define EXYNOS5420_USE_ARM_CORE_DOWN_STATE BIT(29)
#define EXYNOS5420_USE_L2_COMMON_UP_STATE BIT(30)
+static void __iomem *ns_sram_base_addr;
+
/*
* The common v7_exit_coherency_flush API could not be used because of the
* Erratum 799270 workaround. This macro is the same as the common one (in
@@ -129,7 +132,7 @@ static int exynos_power_up(unsigned int cpu, unsigned int cluster)
* and can only be executed on processors like A15 and A7 that hit the cache
* with the C bit clear in the SCTLR register.
*/
-static void exynos_power_down(void)
+static void exynos_mcpm_power_down(u64 residency)
{
unsigned int mpidr, cpu, cluster;
bool last_man = false, skip_wfi = false;
@@ -150,7 +153,12 @@ static void exynos_power_down(void)
BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP);
cpu_use_count[cpu][cluster]--;
if (cpu_use_count[cpu][cluster] == 0) {
- exynos_cpu_power_down(cpunr);
+ /*
+ * Bypass power down for CPU0 during suspend. This is being
+ * taken care by the SYS_PWR_CFG bit in CORE0_SYS_PWR_REG.
+ */
+ if ((cpunr != 0) || (residency != MCPM_CPU_SUSPEND))
+ exynos_cpu_power_down(cpunr);
if (exynos_cluster_unused(cluster)) {
exynos_cluster_power_down(cluster);
@@ -209,6 +217,11 @@ static void exynos_power_down(void)
/* Not dead at this point? Let our caller cope. */
}
+static void exynos_power_down(void)
+{
+ exynos_mcpm_power_down(MCPM_CPU_SWITCH | MCPM_CPU_HOTPLUG);
+}
+
static int exynos_wait_for_powerdown(unsigned int cpu, unsigned int cluster)
{
unsigned int tries = 100;
@@ -250,11 +263,11 @@ static void exynos_suspend(u64 residency)
{
unsigned int mpidr, cpunr;
- exynos_power_down();
+ exynos_mcpm_power_down(residency);
/*
* Execution reaches here only if cpu did not power down.
- * Hence roll back the changes done in exynos_power_down function.
+ * Hence roll back the changes done in exynos_mcpm_power_down function.
*
* CAUTION: "This function requires the stack data to be visible through
* power down and can only be executed on processors like A15 and A7
@@ -319,10 +332,26 @@ static const struct of_device_id exynos_dt_mcpm_match[] = {
{},
};
+static void exynos_mcpm_setup_entry_point(void)
+{
+ /*
+ * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
+ * as part of secondary_cpu_start(). Let's redirect it to the
+ * mcpm_entry_point(). This is done during both secondary boot-up as
+ * well as system resume.
+ */
+ __raw_writel(0xe59f0000, ns_sram_base_addr); /* ldr r0, [pc, #0] */
+ __raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx r0 */
+ __raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
+}
+
+static struct syscore_ops exynos_mcpm_syscore_ops = {
+ .resume = exynos_mcpm_setup_entry_point,
+};
+
static int __init exynos_mcpm_init(void)
{
struct device_node *node;
- void __iomem *ns_sram_base_addr;
unsigned int value, i;
int ret;
@@ -389,16 +418,9 @@ static int __init exynos_mcpm_init(void)
__raw_writel(value, EXYNOS_COMMON_OPTION(i));
}
- /*
- * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
- * as part of secondary_cpu_start(). Let's redirect it to the
- * mcpm_entry_point().
- */
- __raw_writel(0xe59f0000, ns_sram_base_addr); /* ldr r0, [pc, #0] */
- __raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx r0 */
- __raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
+ exynos_mcpm_setup_entry_point();
- iounmap(ns_sram_base_addr);
+ register_syscore_ops(&exynos_mcpm_syscore_ops);
return ret;
}
diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
index bf8564a..1dce5d2 100644
--- a/arch/arm/mach-exynos/pm.c
+++ b/arch/arm/mach-exynos/pm.c
@@ -24,6 +24,7 @@
#include <asm/cacheflush.h>
#include <asm/hardware/cache-l2x0.h>
+#include <asm/mcpm.h>
#include <asm/smp_scu.h>
#include <asm/suspend.h>
@@ -191,7 +192,6 @@ int exynos_cluster_power_state(int cluster)
pmu_base_addr + S5P_INFORM1))
#define S5P_CHECK_AFTR 0xFCBA0D10
-#define S5P_CHECK_SLEEP 0x00000BAD
/* Ext-GIC nIRQ/nFIQ is the only wakeup source in AFTR */
static void exynos_set_wakeupmask(long mask)
@@ -318,7 +318,10 @@ static void exynos_pm_prepare(void)
/* ensure at least INFORM0 has the resume address */
- pmu_raw_writel(virt_to_phys(exynos_cpu_resume), S5P_INFORM0);
+ if (soc_is_exynos5420())
+ pmu_raw_writel(virt_to_phys(mcpm_entry_point), S5P_INFORM0);
+ else
+ pmu_raw_writel(virt_to_phys(exynos_cpu_resume), S5P_INFORM0);
if (soc_is_exynos5420()) {
tmp = __raw_readl(pmu_base_addr + EXYNOS5_ARM_L2_OPTION);
@@ -490,6 +493,28 @@ static struct syscore_ops exynos_pm_syscore_ops = {
.resume = exynos_pm_resume,
};
+static int notrace exynos_mcpm_cpu_suspend(unsigned long arg)
+{
+ /* MCPM works with HW CPU identifiers */
+ unsigned int mpidr = read_cpuid_mpidr();
+ unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+ unsigned int cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+
+ __raw_writel(0x0, sysram_base_addr + EXYNOS5420_CPU_STATE);
+
+ mcpm_set_entry_vector(cpu, cluster, exynos_cpu_resume);
+
+ /*
+ * Residency value passed to mcpm_cpu_suspend back-end
+ * has to be given clear semantics. Set to 0 as a
+ * temporary value.
+ */
+ mcpm_cpu_suspend(MCPM_CPU_SUSPEND);
+
+ /* return value != 0 means failure */
+ return 1;
+}
+
/*
* Suspend Ops
*/
@@ -517,10 +542,17 @@ static int exynos_suspend_enter(suspend_state_t state)
flush_cache_all();
s3c_pm_check_store();
- ret = cpu_suspend(0, exynos_cpu_suspend);
+ /* Use the MCPM layer to suspend 5420 which is a multi-cluster SoC */
+ if (soc_is_exynos5420())
+ ret = cpu_suspend(0, exynos_mcpm_cpu_suspend);
+ else
+ ret = cpu_suspend(0, exynos_cpu_suspend);
if (ret)
return ret;
+ if (soc_is_exynos5420())
+ mcpm_cpu_powered_up();
+
s3c_pm_restore_uarts();
S3C_PMDBG("%s: wakeup stat: %08x\n", __func__,
diff --git a/arch/arm/mach-exynos/regs-pmu.h b/arch/arm/mach-exynos/regs-pmu.h
index 3cf0454..e8c75db 100644
--- a/arch/arm/mach-exynos/regs-pmu.h
+++ b/arch/arm/mach-exynos/regs-pmu.h
@@ -152,6 +152,7 @@
#define S5P_PAD_RET_EBIB_OPTION 0x31A8
#define S5P_CORE_LOCAL_PWR_EN 0x3
+#define S5P_CHECK_SLEEP 0x00000BAD
/* Only for EXYNOS4210 */
#define S5P_CMU_CLKSTOP_LCD1_LOWPWR 0x1154
diff --git a/drivers/cpuidle/cpuidle-big_little.c b/drivers/cpuidle/cpuidle-big_little.c
index 344d79fa..fab2270 100644
--- a/drivers/cpuidle/cpuidle-big_little.c
+++ b/drivers/cpuidle/cpuidle-big_little.c
@@ -108,7 +108,7 @@ static int notrace bl_powerdown_finisher(unsigned long arg)
* has to be given clear semantics. Set to 0 as a
* temporary value.
*/
- mcpm_cpu_suspend(0);
+ mcpm_cpu_suspend(MCPM_CPU_IDLE);
/* return value != 0 means failure */
return 1;
--
2.0.0
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