1 files changed, 363 insertions, 0 deletions
diff --git a/arch/arm/mach-bcm/platsmp-brcmstb.c b/arch/arm/mach-bcm/platsmp-brcmstb.c
new file mode 100644
index 000000000..8989299eb
--- /dev/null
+++ b/arch/arm/mach-bcm/platsmp-brcmstb.c
@@ -0,0 +1,363 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Broadcom STB CPU SMP and hotplug support for ARM
+ *
+ * Copyright (C) 2013-2014 Broadcom Corporation
+ */
+
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/jiffies.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/printk.h>
+#include <linux/regmap.h>
+#include <linux/smp.h>
+#include <linux/mfd/syscon.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
+#include <asm/mach-types.h>
+#include <asm/smp_plat.h>
+
+enum {
+	ZONE_MAN_CLKEN_MASK		= BIT(0),
+	ZONE_MAN_RESET_CNTL_MASK	= BIT(1),
+	ZONE_MAN_MEM_PWR_MASK		= BIT(4),
+	ZONE_RESERVED_1_MASK		= BIT(5),
+	ZONE_MAN_ISO_CNTL_MASK		= BIT(6),
+	ZONE_MANUAL_CONTROL_MASK	= BIT(7),
+	ZONE_PWR_DN_REQ_MASK		= BIT(9),
+	ZONE_PWR_UP_REQ_MASK		= BIT(10),
+	ZONE_BLK_RST_ASSERT_MASK	= BIT(12),
+	ZONE_PWR_OFF_STATE_MASK		= BIT(25),
+	ZONE_PWR_ON_STATE_MASK		= BIT(26),
+	ZONE_DPG_PWR_STATE_MASK		= BIT(28),
+	ZONE_MEM_PWR_STATE_MASK		= BIT(29),
+	ZONE_RESET_STATE_MASK		= BIT(31),
+	CPU0_PWR_ZONE_CTRL_REG		= 1,
+	CPU_RESET_CONFIG_REG		= 2,
+};
+
+static void __iomem *cpubiuctrl_block;
+static void __iomem *hif_cont_block;
+static u32 cpu0_pwr_zone_ctrl_reg;
+static u32 cpu_rst_cfg_reg;
+static u32 hif_cont_reg;
+
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * We must quiesce a dying CPU before it can be killed by the boot CPU. Because
+ * one or more cache may be disabled, we must flush to ensure coherency. We
+ * cannot use traditional completion structures or spinlocks as they rely on
+ * coherency.
+ */
+static DEFINE_PER_CPU_ALIGNED(int, per_cpu_sw_state);
+
+static int per_cpu_sw_state_rd(u32 cpu)
+{
+	sync_cache_r(SHIFT_PERCPU_PTR(&per_cpu_sw_state, per_cpu_offset(cpu)));
+	return per_cpu(per_cpu_sw_state, cpu);
+}
+
+static void per_cpu_sw_state_wr(u32 cpu, int val)
+{
+	dmb();
+	per_cpu(per_cpu_sw_state, cpu) = val;
+	sync_cache_w(SHIFT_PERCPU_PTR(&per_cpu_sw_state, per_cpu_offset(cpu)));
+}
+#else
+static inline void per_cpu_sw_state_wr(u32 cpu, int val) { }
+#endif
+
+static void __iomem *pwr_ctrl_get_base(u32 cpu)
+{
+	void __iomem *base = cpubiuctrl_block + cpu0_pwr_zone_ctrl_reg;
+	base += (cpu_logical_map(cpu) * 4);
+	return base;
+}
+
+static u32 pwr_ctrl_rd(u32 cpu)
+{
+	void __iomem *base = pwr_ctrl_get_base(cpu);
+	return readl_relaxed(base);
+}
+
+static void pwr_ctrl_set(unsigned int cpu, u32 val, u32 mask)
+{
+	void __iomem *base = pwr_ctrl_get_base(cpu);
+	writel((readl(base) & mask) | val, base);
+}
+
+static void pwr_ctrl_clr(unsigned int cpu, u32 val, u32 mask)
+{
+	void __iomem *base = pwr_ctrl_get_base(cpu);
+	writel((readl(base) & mask) & ~val, base);
+}
+
+#define POLL_TMOUT_MS 500
+static int pwr_ctrl_wait_tmout(unsigned int cpu, u32 set, u32 mask)
+{
+	const unsigned long timeo = jiffies + msecs_to_jiffies(POLL_TMOUT_MS);
+	u32 tmp;
+
+	do {
+		tmp = pwr_ctrl_rd(cpu) & mask;
+		if (!set == !tmp)
+			return 0;
+	} while (time_before(jiffies, timeo));
+
+	tmp = pwr_ctrl_rd(cpu) & mask;
+	if (!set == !tmp)
+		return 0;
+
+	return -ETIMEDOUT;
+}
+
+static void cpu_rst_cfg_set(u32 cpu, int set)
+{
+	u32 val;
+	val = readl_relaxed(cpubiuctrl_block + cpu_rst_cfg_reg);
+	if (set)
+		val |= BIT(cpu_logical_map(cpu));
+	else
+		val &= ~BIT(cpu_logical_map(cpu));
+	writel_relaxed(val, cpubiuctrl_block + cpu_rst_cfg_reg);
+}
+
+static void cpu_set_boot_addr(u32 cpu, unsigned long boot_addr)
+{
+	const int reg_ofs = cpu_logical_map(cpu) * 8;
+	writel_relaxed(0, hif_cont_block + hif_cont_reg + reg_ofs);
+	writel_relaxed(boot_addr, hif_cont_block + hif_cont_reg + 4 + reg_ofs);
+}
+
+static void brcmstb_cpu_boot(u32 cpu)
+{
+	/* Mark this CPU as "up" */
+	per_cpu_sw_state_wr(cpu, 1);
+
+	/*
+	 * Set the reset vector to point to the secondary_startup
+	 * routine
+	 */
+	cpu_set_boot_addr(cpu, __pa_symbol(secondary_startup));
+
+	/* Unhalt the cpu */
+	cpu_rst_cfg_set(cpu, 0);
+}
+
+static void brcmstb_cpu_power_on(u32 cpu)
+{
+	/*
+	 * The secondary cores power was cut, so we must go through
+	 * power-on initialization.
+	 */
+	pwr_ctrl_set(cpu, ZONE_MAN_ISO_CNTL_MASK, 0xffffff00);
+	pwr_ctrl_set(cpu, ZONE_MANUAL_CONTROL_MASK, -1);
+	pwr_ctrl_set(cpu, ZONE_RESERVED_1_MASK, -1);
+
+	pwr_ctrl_set(cpu, ZONE_MAN_MEM_PWR_MASK, -1);
+
+	if (pwr_ctrl_wait_tmout(cpu, 1, ZONE_MEM_PWR_STATE_MASK))
+		panic("ZONE_MEM_PWR_STATE_MASK set timeout");
+
+	pwr_ctrl_set(cpu, ZONE_MAN_CLKEN_MASK, -1);
+
+	if (pwr_ctrl_wait_tmout(cpu, 1, ZONE_DPG_PWR_STATE_MASK))
+		panic("ZONE_DPG_PWR_STATE_MASK set timeout");
+
+	pwr_ctrl_clr(cpu, ZONE_MAN_ISO_CNTL_MASK, -1);
+	pwr_ctrl_set(cpu, ZONE_MAN_RESET_CNTL_MASK, -1);
+}
+
+static int brcmstb_cpu_get_power_state(u32 cpu)
+{
+	int tmp = pwr_ctrl_rd(cpu);
+	return (tmp & ZONE_RESET_STATE_MASK) ? 0 : 1;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+static void brcmstb_cpu_die(u32 cpu)
+{
+	v7_exit_coherency_flush(all);
+
+	per_cpu_sw_state_wr(cpu, 0);
+
+	/* Sit and wait to die */
+	wfi();
+
+	/* We should never get here... */
+	while (1)
+		;
+}
+
+static int brcmstb_cpu_kill(u32 cpu)
+{
+	/*
+	 * Ordinarily, the hardware forbids power-down of CPU0 (which is good
+	 * because it is the boot CPU), but this is not true when using BPCM
+	 * manual mode.  Consequently, we must avoid turning off CPU0 here to
+	 * ensure that TI2C master reset will work.
+	 */
+	if (cpu == 0) {
+		pr_warn("SMP: refusing to power off CPU0\n");
+		return 1;
+	}
+
+	while (per_cpu_sw_state_rd(cpu))
+		;
+
+	pwr_ctrl_set(cpu, ZONE_MANUAL_CONTROL_MASK, -1);
+	pwr_ctrl_clr(cpu, ZONE_MAN_RESET_CNTL_MASK, -1);
+	pwr_ctrl_clr(cpu, ZONE_MAN_CLKEN_MASK, -1);
+	pwr_ctrl_set(cpu, ZONE_MAN_ISO_CNTL_MASK, -1);
+	pwr_ctrl_clr(cpu, ZONE_MAN_MEM_PWR_MASK, -1);
+
+	if (pwr_ctrl_wait_tmout(cpu, 0, ZONE_MEM_PWR_STATE_MASK))
+		panic("ZONE_MEM_PWR_STATE_MASK clear timeout");
+
+	pwr_ctrl_clr(cpu, ZONE_RESERVED_1_MASK, -1);
+
+	if (pwr_ctrl_wait_tmout(cpu, 0, ZONE_DPG_PWR_STATE_MASK))
+		panic("ZONE_DPG_PWR_STATE_MASK clear timeout");
+
+	/* Flush pipeline before resetting CPU */
+	mb();
+
+	/* Assert reset on the CPU */
+	cpu_rst_cfg_set(cpu, 1);
+
+	return 1;
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
+static int __init setup_hifcpubiuctrl_regs(struct device_node *np)
+{
+	int rc = 0;
+	char *name;
+	struct device_node *syscon_np = NULL;
+
+	name = "syscon-cpu";
+
+	syscon_np = of_parse_phandle(np, name, 0);
+	if (!syscon_np) {
+		pr_err("can't find phandle %s\n", name);
+		rc = -EINVAL;
+		goto cleanup;
+	}
+
+	cpubiuctrl_block = of_iomap(syscon_np, 0);
+	if (!cpubiuctrl_block) {
+		pr_err("iomap failed for cpubiuctrl_block\n");
+		rc = -EINVAL;
+		goto cleanup;
+	}
+
+	rc = of_property_read_u32_index(np, name, CPU0_PWR_ZONE_CTRL_REG,
+					&cpu0_pwr_zone_ctrl_reg);
+	if (rc) {
+		pr_err("failed to read 1st entry from %s property (%d)\n", name,
+			rc);
+		rc = -EINVAL;
+		goto cleanup;
+	}
+
+	rc = of_property_read_u32_index(np, name, CPU_RESET_CONFIG_REG,
+					&cpu_rst_cfg_reg);
+	if (rc) {
+		pr_err("failed to read 2nd entry from %s property (%d)\n", name,
+			rc);
+		rc = -EINVAL;
+		goto cleanup;
+	}
+
+cleanup:
+	of_node_put(syscon_np);
+	return rc;
+}
+
+static int __init setup_hifcont_regs(struct device_node *np)
+{
+	int rc = 0;
+	char *name;
+	struct device_node *syscon_np = NULL;
+
+	name = "syscon-cont";
+
+	syscon_np = of_parse_phandle(np, name, 0);
+	if (!syscon_np) {
+		pr_err("can't find phandle %s\n", name);
+		rc = -EINVAL;
+		goto cleanup;
+	}
+
+	hif_cont_block = of_iomap(syscon_np, 0);
+	if (!hif_cont_block) {
+		pr_err("iomap failed for hif_cont_block\n");
+		rc = -EINVAL;
+		goto cleanup;
+	}
+
+	/* Offset is at top of hif_cont_block */
+	hif_cont_reg = 0;
+
+cleanup:
+	of_node_put(syscon_np);
+	return rc;
+}
+
+static void __init brcmstb_cpu_ctrl_setup(unsigned int max_cpus)
+{
+	int rc;
+	struct device_node *np;
+	char *name;
+
+	name = "brcm,brcmstb-smpboot";
+	np = of_find_compatible_node(NULL, NULL, name);
+	if (!np) {
+		pr_err("can't find compatible node %s\n", name);
+		return;
+	}
+
+	rc = setup_hifcpubiuctrl_regs(np);
+	if (rc)
+		goto out_put_node;
+
+	rc = setup_hifcont_regs(np);
+	if (rc)
+		goto out_put_node;
+
+out_put_node:
+	of_node_put(np);
+}
+
+static int brcmstb_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	/* Missing the brcm,brcmstb-smpboot DT node? */
+	if (!cpubiuctrl_block || !hif_cont_block)
+		return -ENODEV;
+
+	/* Bring up power to the core if necessary */
+	if (brcmstb_cpu_get_power_state(cpu) == 0)
+		brcmstb_cpu_power_on(cpu);
+
+	brcmstb_cpu_boot(cpu);
+
+	return 0;
+}
+
+static const struct smp_operations brcmstb_smp_ops __initconst = {
+	.smp_prepare_cpus	= brcmstb_cpu_ctrl_setup,
+	.smp_boot_secondary	= brcmstb_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_kill		= brcmstb_cpu_kill,
+	.cpu_die		= brcmstb_cpu_die,
+#endif
+};
+
+CPU_METHOD_OF_DECLARE(brcmstb_smp, "brcm,brahma-b15", &brcmstb_smp_ops);