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@xxxxxxxxxxxx>
[add Meson8/Meson8m2 support and allow taking CPU cores offline as well]
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
---
arch/arm/Makefile | 1 +
arch/arm/mach-meson/Kconfig | 1 +
arch/arm/mach-meson/Makefile | 1 +
arch/arm/mach-meson/platsmp.c | 502 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 505 insertions(+)
create mode 100644 arch/arm/mach-meson/platsmp.c
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 47d3a1ab08d2..82faa958ab88 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -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-$(CONFIG_ARCH_AXXIA) := 0x00308000
# Machine directory name. This list is sorted alphanumerically
diff --git a/arch/arm/mach-meson/Kconfig b/arch/arm/mach-meson/Kconfig
index ee30511849ca..a0c64762d961 100644
--- a/arch/arm/mach-meson/Kconfig
+++ b/arch/arm/mach-meson/Kconfig
@@ -9,6 +9,7 @@ menuconfig ARCH_MESON
select PINCTRL_MESON
select COMMON_CLK
select COMMON_CLK_AMLOGIC
+ select HAVE_ARM_SCU if SMP
if ARCH_MESON
diff --git a/arch/arm/mach-meson/Makefile b/arch/arm/mach-meson/Makefile
index 9d7380eeeedd..bc26c85a7e8f 100644
--- a/arch/arm/mach-meson/Makefile
+++ b/arch/arm/mach-meson/Makefile
@@ -1 +1,2 @@
obj-$(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
index 000000000000..3d640bc34345
--- /dev/null
+++ b/arch/arm/mach-meson/platsmp.c
@@ -0,0 +1,502 @@
+/*
+ * Copyright (C) 2015 Carlo Caione <carlo@xxxxxxxxxxxx>
+ * Copyright (C) 2017 Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
+ *
+ * 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 DEFINE_SPINLOCK(boot_lock);
+
+/*
+ * Write pen_release in a way that is guaranteed to be visible to all
+ * observers, irrespective of whether they're taking part in coherency
+ * or not. This is necessary for the hotplug code to work reliably.
+ */
+static void write_pen_release(int val)
+{
+ pen_release = val;
+ smp_wmb();
+ sync_cache_w(&pen_release);
+}
+
+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)
+{
+ /*
+ * The secondary processor is waiting to be released from
+ * the holding pen - release it, then wait for it to flag
+ * that it has been released by resetting pen_release.
+ */
+ write_pen_release(cpu_logical_map(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(virt_to_phys(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;
+
+ dsb();
+ dmb();
+
+ 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(virt_to_phys(secondary_startup),
+ sram_base + MESON_SMP_SRAM_CPU_CTRL_ADDR_REG(cpu));
+
+ meson_smp_set_cpu_ctrl(cpu, true);
+
+ smp_wmb();
+ mb();
+ dsb_sev();
+
+ timeout = jiffies + (10 * HZ);
+ while (time_before(jiffies, timeout)) {
+ smp_rmb();
+ if (pen_release != -1)
+ break;
+
+ udelay(10);
+ }
+
+ if (pen_release == -1) {
+ pr_err("Timeout while waiting for CPU%d pen release\n", cpu);
+ return -ETIMEDOUT;
+ }
+
+ 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);
+ }
+
+ spin_lock(&boot_lock);
+
+ 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:
+ spin_unlock(&boot_lock);
+
+ reset_control_put(rstc);
+
+ return pen_release != -1 ? ret : 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);
+ }
+
+ spin_lock(&boot_lock);
+
+ 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:
+ spin_unlock(&boot_lock);
+
+ reset_control_put(rstc);
+
+ return pen_release != -1 ? ret : 0;
+}
+
+static void meson8_smp_secondary_init(unsigned int cpu)
+{
+ write_pen_release(-1);
+
+ /* Synchronise with the boot thread. */
+ spin_lock(&boot_lock);
+ spin_unlock(&boot_lock);
+}
+
+#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 {
+ smp_rmb();
+ power_mode = scu_get_cpu_power_mode(scu_base, cpu);
+
+ if (power_mode == SCU_PM_POWEROFF)
+ break;
+
+ msleep(10);
+ } 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 {
+ smp_rmb();
+ 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,
+ .smp_secondary_init = meson8_smp_secondary_init,
+#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,
+ .smp_secondary_init = meson8_smp_secondary_init,
+#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);
--
2.13.2
--
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