ARM: meson: Add SMP bringup code for Meson8 and Meson8b
authorMartin Blumenstingl <martin.blumenstingl@googlemail.com>
Sun, 17 Sep 2017 16:45:21 +0000 (18:45 +0200)
committerKevin Hilman <khilman@baylibre.com>
Sun, 29 Oct 2017 15:29:41 +0000 (08:29 -0700)
This adds the necessary SMP-operations and startup code to use the
additional cores on the Amlogic Meson8/Meson8m2 (both are using the same
sequence) and Meson8b (using a slightly difference sequence) SoCs.

Signed-off-by: Carlo Caione <carlo@endlessm.com>
[add Meson8/Meson8m2 support and allow taking CPU cores offline as well]
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
arch/arm/Makefile
arch/arm/mach-meson/Kconfig
arch/arm/mach-meson/Makefile
arch/arm/mach-meson/platsmp.c [new file with mode: 0644]

index 47d3a1a..82faa95 100644 (file)
@@ -147,6 +147,7 @@ textofs-$(CONFIG_SA1111) := 0x00208000
 endif
 textofs-$(CONFIG_ARCH_MSM8X60) := 0x00208000
 textofs-$(CONFIG_ARCH_MSM8960) := 0x00208000
+textofs-$(CONFIG_ARCH_MESON) := 0x00208000
 textofs-$(CONFIG_ARCH_AXXIA) := 0x00308000
 
 # Machine directory name.  This list is sorted alphanumerically
index ee30511..a0c6476 100644 (file)
@@ -9,6 +9,7 @@ menuconfig ARCH_MESON
        select PINCTRL_MESON
        select COMMON_CLK
        select COMMON_CLK_AMLOGIC
+       select HAVE_ARM_SCU if SMP
 
 if ARCH_MESON
 
index 9d7380e..bc26c85 100644 (file)
@@ -1 +1,2 @@
 obj-$(CONFIG_ARCH_MESON) += meson.o
+obj-$(CONFIG_SMP) += platsmp.o
diff --git a/arch/arm/mach-meson/platsmp.c b/arch/arm/mach-meson/platsmp.c
new file mode 100644 (file)
index 0000000..2555f90
--- /dev/null
@@ -0,0 +1,440 @@
+/*
+ * Copyright (C) 2015 Carlo Caione <carlo@endlessm.com>
+ * Copyright (C) 2017 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/smp.h>
+#include <linux/mfd/syscon.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
+#include <asm/smp_scu.h>
+#include <asm/smp_plat.h>
+
+#define MESON_SMP_SRAM_CPU_CTRL_REG            (0x00)
+#define MESON_SMP_SRAM_CPU_CTRL_ADDR_REG(c)    (0x04 + ((c - 1) << 2))
+
+#define MESON_CPU_AO_RTI_PWR_A9_CNTL0          (0x00)
+#define MESON_CPU_AO_RTI_PWR_A9_CNTL1          (0x04)
+#define MESON_CPU_AO_RTI_PWR_A9_MEM_PD0                (0x14)
+
+#define MESON_CPU_PWR_A9_CNTL0_M(c)            (0x03 << ((c * 2) + 16))
+#define MESON_CPU_PWR_A9_CNTL1_M(c)            (0x03 << ((c + 1) << 1))
+#define MESON_CPU_PWR_A9_MEM_PD0_M(c)          (0x0f << (32 - (c * 4)))
+#define MESON_CPU_PWR_A9_CNTL1_ST(c)           (0x01 << (c + 16))
+
+static void __iomem *sram_base;
+static void __iomem *scu_base;
+static struct regmap *pmu;
+
+static struct reset_control *meson_smp_get_core_reset(int cpu)
+{
+       struct device_node *np = of_get_cpu_node(cpu, 0);
+
+       return of_reset_control_get_exclusive(np, NULL);
+}
+
+static void meson_smp_set_cpu_ctrl(int cpu, bool on_off)
+{
+       u32 val = readl(sram_base + MESON_SMP_SRAM_CPU_CTRL_REG);
+
+       if (on_off)
+               val |= BIT(cpu);
+       else
+               val &= ~BIT(cpu);
+
+       /* keep bit 0 always enabled */
+       val |= BIT(0);
+
+       writel(val, sram_base + MESON_SMP_SRAM_CPU_CTRL_REG);
+}
+
+static void __init meson_smp_prepare_cpus(const char *scu_compatible,
+                                         const char *pmu_compatible,
+                                         const char *sram_compatible)
+{
+       static struct device_node *node;
+
+       /* SMP SRAM */
+       node = of_find_compatible_node(NULL, NULL, sram_compatible);
+       if (!node) {
+               pr_err("Missing SRAM node\n");
+               return;
+       }
+
+       sram_base = of_iomap(node, 0);
+       if (!sram_base) {
+               pr_err("Couldn't map SRAM registers\n");
+               return;
+       }
+
+       /* PMU */
+       pmu = syscon_regmap_lookup_by_compatible(pmu_compatible);
+       if (IS_ERR(pmu)) {
+               pr_err("Couldn't map PMU registers\n");
+               return;
+       }
+
+       /* SCU */
+       node = of_find_compatible_node(NULL, NULL, scu_compatible);
+       if (!node) {
+               pr_err("Missing SCU node\n");
+               return;
+       }
+
+       scu_base = of_iomap(node, 0);
+       if (!scu_base) {
+               pr_err("Couln't map SCU registers\n");
+               return;
+       }
+
+       scu_enable(scu_base);
+}
+
+static void __init meson8b_smp_prepare_cpus(unsigned int max_cpus)
+{
+       meson_smp_prepare_cpus("arm,cortex-a5-scu", "amlogic,meson8b-pmu",
+                              "amlogic,meson8b-smp-sram");
+}
+
+static void __init meson8_smp_prepare_cpus(unsigned int max_cpus)
+{
+       meson_smp_prepare_cpus("arm,cortex-a9-scu", "amlogic,meson8-pmu",
+                              "amlogic,meson8-smp-sram");
+}
+
+static void meson_smp_begin_secondary_boot(unsigned int cpu)
+{
+       /*
+        * Set the entry point before powering on the CPU through the SCU. This
+        * is needed if the CPU is in "warm" state (= after rebooting the
+        * system without power-cycling, or when taking the CPU offline and
+        * then taking it online again.
+        */
+       writel(__pa_symbol(secondary_startup),
+              sram_base + MESON_SMP_SRAM_CPU_CTRL_ADDR_REG(cpu));
+
+       /*
+        * SCU Power on CPU (needs to be done before starting the CPU,
+        * otherwise the secondary CPU will not start).
+        */
+       scu_cpu_power_enable(scu_base, cpu);
+}
+
+static int meson_smp_finalize_secondary_boot(unsigned int cpu)
+{
+       unsigned long timeout;
+
+       timeout = jiffies + (10 * HZ);
+       while (readl(sram_base + MESON_SMP_SRAM_CPU_CTRL_ADDR_REG(cpu))) {
+               if (!time_before(jiffies, timeout)) {
+                       pr_err("Timeout while waiting for CPU%d status\n",
+                              cpu);
+                       return -ETIMEDOUT;
+               }
+       }
+
+       writel(__pa_symbol(secondary_startup),
+              sram_base + MESON_SMP_SRAM_CPU_CTRL_ADDR_REG(cpu));
+
+       meson_smp_set_cpu_ctrl(cpu, true);
+
+       return 0;
+}
+
+static int meson8_smp_boot_secondary(unsigned int cpu,
+                                    struct task_struct *idle)
+{
+       struct reset_control *rstc;
+       int ret;
+
+       rstc = meson_smp_get_core_reset(cpu);
+       if (IS_ERR(rstc)) {
+               pr_err("Couldn't get the reset controller for CPU%d\n", cpu);
+               return PTR_ERR(rstc);
+       }
+
+       meson_smp_begin_secondary_boot(cpu);
+
+       /* Reset enable */
+       ret = reset_control_assert(rstc);
+       if (ret) {
+               pr_err("Failed to assert CPU%d reset\n", cpu);
+               goto out;
+       }
+
+       /* CPU power ON */
+       ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL1,
+                                MESON_CPU_PWR_A9_CNTL1_M(cpu), 0);
+       if (ret < 0) {
+               pr_err("Couldn't wake up CPU%d\n", cpu);
+               goto out;
+       }
+
+       udelay(10);
+
+       /* Isolation disable */
+       ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0, BIT(cpu),
+                                0);
+       if (ret < 0) {
+               pr_err("Error when disabling isolation of CPU%d\n", cpu);
+               goto out;
+       }
+
+       /* Reset disable */
+       ret = reset_control_deassert(rstc);
+       if (ret) {
+               pr_err("Failed to de-assert CPU%d reset\n", cpu);
+               goto out;
+       }
+
+       ret = meson_smp_finalize_secondary_boot(cpu);
+       if (ret)
+               goto out;
+
+out:
+       reset_control_put(rstc);
+
+       return 0;
+}
+
+static int meson8b_smp_boot_secondary(unsigned int cpu,
+                                    struct task_struct *idle)
+{
+       struct reset_control *rstc;
+       int ret;
+       u32 val;
+
+       rstc = meson_smp_get_core_reset(cpu);
+       if (IS_ERR(rstc)) {
+               pr_err("Couldn't get the reset controller for CPU%d\n", cpu);
+               return PTR_ERR(rstc);
+       }
+
+       meson_smp_begin_secondary_boot(cpu);
+
+       /* CPU power UP */
+       ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0,
+                                MESON_CPU_PWR_A9_CNTL0_M(cpu), 0);
+       if (ret < 0) {
+               pr_err("Couldn't power up CPU%d\n", cpu);
+               goto out;
+       }
+
+       udelay(5);
+
+       /* Reset enable */
+       ret = reset_control_assert(rstc);
+       if (ret) {
+               pr_err("Failed to assert CPU%d reset\n", cpu);
+               goto out;
+       }
+
+       /* Memory power UP */
+       ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_MEM_PD0,
+                                MESON_CPU_PWR_A9_MEM_PD0_M(cpu), 0);
+       if (ret < 0) {
+               pr_err("Couldn't power up the memory for CPU%d\n", cpu);
+               goto out;
+       }
+
+       /* Wake up CPU */
+       ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL1,
+                                MESON_CPU_PWR_A9_CNTL1_M(cpu), 0);
+       if (ret < 0) {
+               pr_err("Couldn't wake up CPU%d\n", cpu);
+               goto out;
+       }
+
+       udelay(10);
+
+       ret = regmap_read_poll_timeout(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL1, val,
+                                      val & MESON_CPU_PWR_A9_CNTL1_ST(cpu),
+                                      10, 10000);
+       if (ret) {
+               pr_err("Timeout while polling PMU for CPU%d status\n", cpu);
+               goto out;
+       }
+
+       /* Isolation disable */
+       ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0, BIT(cpu),
+                                0);
+       if (ret < 0) {
+               pr_err("Error when disabling isolation of CPU%d\n", cpu);
+               goto out;
+       }
+
+       /* Reset disable */
+       ret = reset_control_deassert(rstc);
+       if (ret) {
+               pr_err("Failed to de-assert CPU%d reset\n", cpu);
+               goto out;
+       }
+
+       ret = meson_smp_finalize_secondary_boot(cpu);
+       if (ret)
+               goto out;
+
+out:
+       reset_control_put(rstc);
+
+       return 0;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void meson8_smp_cpu_die(unsigned int cpu)
+{
+       meson_smp_set_cpu_ctrl(cpu, false);
+
+       v7_exit_coherency_flush(louis);
+
+       scu_power_mode(scu_base, SCU_PM_POWEROFF);
+
+       dsb();
+       wfi();
+
+       /* we should never get here */
+       WARN_ON(1);
+}
+
+static int meson8_smp_cpu_kill(unsigned int cpu)
+{
+       int ret, power_mode;
+       unsigned long timeout;
+
+       timeout = jiffies + (50 * HZ);
+       do {
+               power_mode = scu_get_cpu_power_mode(scu_base, cpu);
+
+               if (power_mode == SCU_PM_POWEROFF)
+                       break;
+
+               usleep_range(10000, 15000);
+       } while (time_before(jiffies, timeout));
+
+       if (power_mode != SCU_PM_POWEROFF) {
+               pr_err("Error while waiting for SCU power-off on CPU%d\n",
+                      cpu);
+               return -ETIMEDOUT;
+       }
+
+       msleep(30);
+
+       /* Isolation enable */
+       ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0, BIT(cpu),
+                                0x3);
+       if (ret < 0) {
+               pr_err("Error when enabling isolation for CPU%d\n", cpu);
+               return ret;
+       }
+
+       udelay(10);
+
+       /* CPU power OFF */
+       ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL1,
+                                MESON_CPU_PWR_A9_CNTL1_M(cpu), 0x3);
+       if (ret < 0) {
+               pr_err("Couldn't change sleep status of CPU%d\n", cpu);
+               return ret;
+       }
+
+       return 1;
+}
+
+static int meson8b_smp_cpu_kill(unsigned int cpu)
+{
+       int ret, power_mode, count = 5000;
+
+       do {
+               power_mode = scu_get_cpu_power_mode(scu_base, cpu);
+
+               if (power_mode == SCU_PM_POWEROFF)
+                       break;
+
+               udelay(10);
+       } while (++count);
+
+       if (power_mode != SCU_PM_POWEROFF) {
+               pr_err("Error while waiting for SCU power-off on CPU%d\n",
+                      cpu);
+               return -ETIMEDOUT;
+       }
+
+       udelay(10);
+
+       /* CPU power DOWN */
+       ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0,
+                                MESON_CPU_PWR_A9_CNTL0_M(cpu), 0x3);
+       if (ret < 0) {
+               pr_err("Couldn't power down CPU%d\n", cpu);
+               return ret;
+       }
+
+       /* Isolation enable */
+       ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0, BIT(cpu),
+                                0x3);
+       if (ret < 0) {
+               pr_err("Error when enabling isolation for CPU%d\n", cpu);
+               return ret;
+       }
+
+       udelay(10);
+
+       /* Sleep status */
+       ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL1,
+                                MESON_CPU_PWR_A9_CNTL1_M(cpu), 0x3);
+       if (ret < 0) {
+               pr_err("Couldn't change sleep status of CPU%d\n", cpu);
+               return ret;
+       }
+
+       /* Memory power DOWN */
+       ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_MEM_PD0,
+                                MESON_CPU_PWR_A9_MEM_PD0_M(cpu), 0xf);
+       if (ret < 0) {
+               pr_err("Couldn't power down the memory of CPU%d\n", cpu);
+               return ret;
+       }
+
+       return 1;
+}
+#endif
+
+static struct smp_operations meson8_smp_ops __initdata = {
+       .smp_prepare_cpus       = meson8_smp_prepare_cpus,
+       .smp_boot_secondary     = meson8_smp_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+       .cpu_die                = meson8_smp_cpu_die,
+       .cpu_kill               = meson8_smp_cpu_kill,
+#endif
+};
+
+static struct smp_operations meson8b_smp_ops __initdata = {
+       .smp_prepare_cpus       = meson8b_smp_prepare_cpus,
+       .smp_boot_secondary     = meson8b_smp_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+       .cpu_die                = meson8_smp_cpu_die,
+       .cpu_kill               = meson8b_smp_cpu_kill,
+#endif
+};
+
+CPU_METHOD_OF_DECLARE(meson8_smp, "amlogic,meson8-smp", &meson8_smp_ops);
+CPU_METHOD_OF_DECLARE(meson8b_smp, "amlogic,meson8b-smp", &meson8b_smp_ops);