Some additional register writes are required when hotplugging CPUs
on gs101, without these the system hangs when hotplugging.
Specifically a CPU_INFORM register needs to be programmed with
a hint value which is used by the EL3 firmware (el3mon) and the
pmu-intr-gen registers need to be programmed.
With this patch applied, and corresponding DT update CPU hotplug
now works as expected. e.g.
echo 0 > /sys/devices/system/cpu/cpu6/online
echo 1 > /sys/devices/system/cpu/cpu6/online
Note: to maintain compatibility with older DTs that didn't specify
pmu-intr-gen register region only a warning is issued if the
registers can't be mapped, and the old behaviour is maintained.
Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
---
drivers/soc/samsung/exynos-pmu.c | 73 ++++++++++++++++++++++++++++-
drivers/soc/samsung/exynos-pmu.h | 1 +
include/linux/soc/samsung/exynos-regs-pmu.h | 11 +++++
3 files changed, 84 insertions(+), 1 deletion(-)
diff --git a/drivers/soc/samsung/exynos-pmu.c b/drivers/soc/samsung/exynos-pmu.c
index d8c53cec7f37..68eb4eb3813b 100644
--- a/drivers/soc/samsung/exynos-pmu.c
+++ b/drivers/soc/samsung/exynos-pmu.c
@@ -6,6 +6,7 @@
// Exynos - CPU PMU(Power Management Unit) support
#include <linux/arm-smccc.h>
+#include <linux/cpuhotplug.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/mfd/core.h>
@@ -32,6 +33,7 @@ struct exynos_pmu_context {
struct device *dev;
const struct exynos_pmu_data *pmu_data;
struct regmap *pmureg;
+ void __iomem *pmuintrgen_base;
};
void __iomem *pmu_base_addr;
@@ -221,7 +223,8 @@ static const struct regmap_config regmap_smccfg = {
};
static const struct exynos_pmu_data gs101_pmu_data = {
- .pmu_secure = true
+ .pmu_secure = true,
+ .pmu_cpuhp = true,
};
/*
@@ -325,6 +328,52 @@ struct regmap *exynos_get_pmu_regmap_by_phandle(struct device_node *np,
}
EXPORT_SYMBOL_GPL(exynos_get_pmu_regmap_by_phandle);
+/*
+ * CPU_INFORM register hint values which are used by
+ * EL3 firmware (el3mon).
+ */
+#define CPU_INFORM_CLEAR 0
+#define CPU_INFORM_C2 1
+
+static int cpuhp_pmu_online(unsigned int cpu)
+{
+ void __iomem *base = pmu_context->pmuintrgen_base;
+ u32 reg;
+ u32 mask;
+
+ /* clear cpu inform hint */
+ regmap_write(pmu_context->pmureg, GS101_CPU_INFORM(cpu),
+ CPU_INFORM_CLEAR);
+
+ mask = (1 << cpu);
+
+ writel(((0 << cpu) & mask), base + GS101_GRP2_INTR_BID_ENABLE);
+
+ reg = readl(base + GS101_GRP2_INTR_BID_UPEND) & mask;
+ writel(reg & mask, base + GS101_GRP2_INTR_BID_CLEAR);
+
+ return 0;
+}
+
+static int cpuhp_pmu_offline(unsigned int cpu)
+{
+ void __iomem *base = pmu_context->pmuintrgen_base;
+ u32 reg, mask;
+
+ /* set cpu inform hint */
+ regmap_write(pmu_context->pmureg, GS101_CPU_INFORM(cpu),
+ CPU_INFORM_C2);
+
+ writel((1 << cpu), base + GS101_GRP2_INTR_BID_ENABLE);
+
+ mask = ((1 << cpu) | (1 << (cpu+8)));
+
+ reg = readl(base + GS101_GRP1_INTR_BID_UPEND) & mask;
+ writel(reg & mask, base + GS101_GRP1_INTR_BID_CLEAR);
+
+ return 0;
+}
+
static int exynos_pmu_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -377,6 +426,28 @@ static int exynos_pmu_probe(struct platform_device *pdev)
pmu_context->pmureg = regmap;
pmu_context->dev = dev;
+ if (pmu_context->pmu_data && pmu_context->pmu_data->pmu_cpuhp) {
+
+ pmu_context->pmuintrgen_base =
+ devm_platform_ioremap_resource_byname(pdev, "pmu-intr-gen");
+ /*
+ * To maintain support for older DTs that didn't specify pmu-intr-gen
+ * register region, just issue a warning rather than fail to probe.
+ */
+ if (IS_ERR(pmu_context->pmuintrgen_base)) {
+ dev_warn(&pdev->dev,
+ "failed to map pmu-intr-gen registers\n");
+ } else {
+ cpuhp_setup_state(CPUHP_BP_PREPARE_DYN,
+ "soc/exynos-pmu:prepare",
+ cpuhp_pmu_online, NULL);
+
+ cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+ "soc/exynos-pmu:online",
+ NULL, cpuhp_pmu_offline);
+ }
+ }
+
if (pmu_context->pmu_data && pmu_context->pmu_data->pmu_init)
pmu_context->pmu_data->pmu_init();
diff --git a/drivers/soc/samsung/exynos-pmu.h b/drivers/soc/samsung/exynos-pmu.h
index 0a49a2c9a08e..0938bb4fe15f 100644
--- a/drivers/soc/samsung/exynos-pmu.h
+++ b/drivers/soc/samsung/exynos-pmu.h
@@ -22,6 +22,7 @@ struct exynos_pmu_data {
const struct exynos_pmu_conf *pmu_config;
const struct exynos_pmu_conf *pmu_config_extra;
bool pmu_secure;
+ bool pmu_cpuhp;
void (*pmu_init)(void);
void (*powerdown_conf)(enum sys_powerdown);
diff --git a/include/linux/soc/samsung/exynos-regs-pmu.h b/include/linux/soc/samsung/exynos-regs-pmu.h
index ce1a3790d6fb..0d5a17ea8fb8 100644
--- a/include/linux/soc/samsung/exynos-regs-pmu.h
+++ b/include/linux/soc/samsung/exynos-regs-pmu.h
@@ -658,9 +658,20 @@
#define EXYNOS5433_PAD_RETENTION_FSYSGENIO_OPTION (0x32A8)
/* For Tensor GS101 */
+/* PMU ALIVE */
#define GS101_SYSIP_DAT0 (0x810)
+#define GS101_CPU0_INFORM (0x860)
+#define GS101_CPU_INFORM(cpu) \
+ (GS101_CPU0_INFORM + (cpu*4))
#define GS101_SYSTEM_CONFIGURATION (0x3A00)
#define GS101_PHY_CTRL_USB20 (0x3EB0)
#define GS101_PHY_CTRL_USBDP (0x3EB4)
+/* PMU INTR GEN */
+#define GS101_GRP1_INTR_BID_UPEND (0x0108)
+#define GS101_GRP1_INTR_BID_CLEAR (0x010c)
+#define GS101_GRP2_INTR_BID_ENABLE (0x0200)
+#define GS101_GRP2_INTR_BID_UPEND (0x0208)
+#define GS101_GRP2_INTR_BID_CLEAR (0x020c)
+
#endif /* __LINUX_SOC_EXYNOS_REGS_PMU_H */
--
2.47.1.613.gc27f4b7a9f-goog
