diff options
Diffstat (limited to 'arch/arm/mach-sunxi')
| -rw-r--r-- | arch/arm/mach-sunxi/Kconfig | 7 | ||||
| -rw-r--r-- | arch/arm/mach-sunxi/Makefile | 3 | ||||
| -rw-r--r-- | arch/arm/mach-sunxi/mc_smp.c | 856 |
3 files changed, 866 insertions, 0 deletions
diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig index 58153cdf025b..ce53ceaf4cc5 100644 --- a/arch/arm/mach-sunxi/Kconfig +++ b/arch/arm/mach-sunxi/Kconfig @@ -48,4 +48,11 @@ config MACH_SUN9I default ARCH_SUNXI select ARM_GIC +config ARCH_SUNXI_MC_SMP + bool + depends on SMP + default MACH_SUN9I + select ARM_CCI400_PORT_CTRL + select ARM_CPU_SUSPEND + endif diff --git a/arch/arm/mach-sunxi/Makefile b/arch/arm/mach-sunxi/Makefile index 27b168f121a1..7de9cc286d53 100644 --- a/arch/arm/mach-sunxi/Makefile +++ b/arch/arm/mach-sunxi/Makefile @@ -1,2 +1,5 @@ +CFLAGS_mc_smp.o += -march=armv7-a + obj-$(CONFIG_ARCH_SUNXI) += sunxi.o +obj-$(CONFIG_ARCH_SUNXI_MC_SMP) += mc_smp.o obj-$(CONFIG_SMP) += platsmp.o diff --git a/arch/arm/mach-sunxi/mc_smp.c b/arch/arm/mach-sunxi/mc_smp.c new file mode 100644 index 000000000000..c0246ec54a0a --- /dev/null +++ b/arch/arm/mach-sunxi/mc_smp.c @@ -0,0 +1,856 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2018 Chen-Yu Tsai + * + * Chen-Yu Tsai <wens@csie.org> + * + * arch/arm/mach-sunxi/mc_smp.c + * + * Based on Allwinner code, arch/arm/mach-exynos/mcpm-exynos.c, and + * arch/arm/mach-hisi/platmcpm.c + * Cluster cache enable trampoline code adapted from MCPM framework + */ + +#include <linux/arm-cci.h> +#include <linux/cpu_pm.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/irqchip/arm-gic.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/smp.h> + +#include <asm/cacheflush.h> +#include <asm/cp15.h> +#include <asm/cputype.h> +#include <asm/idmap.h> +#include <asm/smp_plat.h> +#include <asm/suspend.h> + +#define SUNXI_CPUS_PER_CLUSTER 4 +#define SUNXI_NR_CLUSTERS 2 + +#define POLL_USEC 100 +#define TIMEOUT_USEC 100000 + +#define CPUCFG_CX_CTRL_REG0(c) (0x10 * (c)) +#define CPUCFG_CX_CTRL_REG0_L1_RST_DISABLE(n) BIT(n) +#define CPUCFG_CX_CTRL_REG0_L1_RST_DISABLE_ALL 0xf +#define CPUCFG_CX_CTRL_REG0_L2_RST_DISABLE_A7 BIT(4) +#define CPUCFG_CX_CTRL_REG0_L2_RST_DISABLE_A15 BIT(0) +#define CPUCFG_CX_CTRL_REG1(c) (0x10 * (c) + 0x4) +#define CPUCFG_CX_CTRL_REG1_ACINACTM BIT(0) +#define CPUCFG_CX_STATUS(c) (0x30 + 0x4 * (c)) +#define CPUCFG_CX_STATUS_STANDBYWFI(n) BIT(16 + (n)) +#define CPUCFG_CX_STATUS_STANDBYWFIL2 BIT(0) +#define CPUCFG_CX_RST_CTRL(c) (0x80 + 0x4 * (c)) +#define CPUCFG_CX_RST_CTRL_DBG_SOC_RST BIT(24) +#define CPUCFG_CX_RST_CTRL_ETM_RST(n) BIT(20 + (n)) +#define CPUCFG_CX_RST_CTRL_ETM_RST_ALL (0xf << 20) +#define CPUCFG_CX_RST_CTRL_DBG_RST(n) BIT(16 + (n)) +#define CPUCFG_CX_RST_CTRL_DBG_RST_ALL (0xf << 16) +#define CPUCFG_CX_RST_CTRL_H_RST BIT(12) +#define CPUCFG_CX_RST_CTRL_L2_RST BIT(8) +#define CPUCFG_CX_RST_CTRL_CX_RST(n) BIT(4 + (n)) +#define CPUCFG_CX_RST_CTRL_CORE_RST(n) BIT(n) + +#define PRCM_CPU_PO_RST_CTRL(c) (0x4 + 0x4 * (c)) +#define PRCM_CPU_PO_RST_CTRL_CORE(n) BIT(n) +#define PRCM_CPU_PO_RST_CTRL_CORE_ALL 0xf +#define PRCM_PWROFF_GATING_REG(c) (0x100 + 0x4 * (c)) +#define PRCM_PWROFF_GATING_REG_CLUSTER BIT(4) +#define PRCM_PWROFF_GATING_REG_CORE(n) BIT(n) +#define PRCM_PWR_SWITCH_REG(c, cpu) (0x140 + 0x10 * (c) + 0x4 * (cpu)) +#define PRCM_CPU_SOFT_ENTRY_REG 0x164 + +#define CPU0_SUPPORT_HOTPLUG_MAGIC0 0xFA50392F +#define CPU0_SUPPORT_HOTPLUG_MAGIC1 0x790DCA3A + +static void __iomem *cpucfg_base; +static void __iomem *prcm_base; +static void __iomem *sram_b_smp_base; + +static bool sunxi_core_is_cortex_a15(unsigned int core, unsigned int cluster) +{ + struct device_node *node; + int cpu = cluster * SUNXI_CPUS_PER_CLUSTER + core; + + node = of_cpu_device_node_get(cpu); + + /* In case of_cpu_device_node_get fails */ + if (!node) + node = of_get_cpu_node(cpu, NULL); + + if (!node) { + /* + * There's no point in returning an error, since we + * would be mid way in a core or cluster power sequence. + */ + pr_err("%s: Couldn't get CPU cluster %u core %u device node\n", + __func__, cluster, core); + + return false; + } + + return of_device_is_compatible(node, "arm,cortex-a15"); +} + +static int sunxi_cpu_power_switch_set(unsigned int cpu, unsigned int cluster, + bool enable) +{ + u32 reg; + + /* control sequence from Allwinner A80 user manual v1.2 PRCM section */ + reg = readl(prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu)); + if (enable) { + if (reg == 0x00) { + pr_debug("power clamp for cluster %u cpu %u already open\n", + cluster, cpu); + return 0; + } + + writel(0xff, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu)); + udelay(10); + writel(0xfe, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu)); + udelay(10); + writel(0xf8, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu)); + udelay(10); + writel(0xf0, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu)); + udelay(10); + writel(0x00, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu)); + udelay(10); + } else { + writel(0xff, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu)); + udelay(10); + } + + return 0; +} + +static void sunxi_cpu0_hotplug_support_set(bool enable) +{ + if (enable) { + writel(CPU0_SUPPORT_HOTPLUG_MAGIC0, sram_b_smp_base); + writel(CPU0_SUPPORT_HOTPLUG_MAGIC1, sram_b_smp_base + 0x4); + } else { + writel(0x0, sram_b_smp_base); + writel(0x0, sram_b_smp_base + 0x4); + } +} + +static int sunxi_cpu_powerup(unsigned int cpu, unsigned int cluster) +{ + u32 reg; + + pr_debug("%s: cluster %u cpu %u\n", __func__, cluster, cpu); + if (cpu >= SUNXI_CPUS_PER_CLUSTER || cluster >= SUNXI_NR_CLUSTERS) + return -EINVAL; + + /* Set hotplug support magic flags for cpu0 */ + if (cluster == 0 && cpu == 0) + sunxi_cpu0_hotplug_support_set(true); + + /* assert processor power-on reset */ + reg = readl(prcm_base + PRCM_CPU_PO_RST_CTRL(cluster)); + reg &= ~PRCM_CPU_PO_RST_CTRL_CORE(cpu); + writel(reg, prcm_base + PRCM_CPU_PO_RST_CTRL(cluster)); + + /* Cortex-A7: hold L1 reset disable signal low */ + if (!sunxi_core_is_cortex_a15(cpu, cluster)) { + reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG0(cluster)); + reg &= ~CPUCFG_CX_CTRL_REG0_L1_RST_DISABLE(cpu); + writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG0(cluster)); + } + + /* assert processor related resets */ + reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster)); + reg &= ~CPUCFG_CX_RST_CTRL_DBG_RST(cpu); + + /* + * Allwinner code also asserts resets for NEON on A15. According + * to ARM manuals, asserting power-on reset is sufficient. + */ + if (!sunxi_core_is_cortex_a15(cpu, cluster)) + reg &= ~CPUCFG_CX_RST_CTRL_ETM_RST(cpu); + + writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster)); + + /* open power switch */ + sunxi_cpu_power_switch_set(cpu, cluster, true); + + /* clear processor power gate */ + reg = readl(prcm_base + PRCM_PWROFF_GATING_REG(cluster)); + reg &= ~PRCM_PWROFF_GATING_REG_CORE(cpu); + writel(reg, prcm_base + PRCM_PWROFF_GATING_REG(cluster)); + udelay(20); + + /* de-assert processor power-on reset */ + reg = readl(prcm_base + PRCM_CPU_PO_RST_CTRL(cluster)); + reg |= PRCM_CPU_PO_RST_CTRL_CORE(cpu); + writel(reg, prcm_base + PRCM_CPU_PO_RST_CTRL(cluster)); + + /* de-assert all processor resets */ + reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster)); + reg |= CPUCFG_CX_RST_CTRL_DBG_RST(cpu); + reg |= CPUCFG_CX_RST_CTRL_CORE_RST(cpu); + if (!sunxi_core_is_cortex_a15(cpu, cluster)) + reg |= CPUCFG_CX_RST_CTRL_ETM_RST(cpu); + else + reg |= CPUCFG_CX_RST_CTRL_CX_RST(cpu); /* NEON */ + writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster)); + + return 0; +} + +static int sunxi_cluster_powerup(unsigned int cluster) +{ + u32 reg; + + pr_debug("%s: cluster %u\n", __func__, cluster); + if (cluster >= SUNXI_NR_CLUSTERS) + return -EINVAL; + + /* assert ACINACTM */ + reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster)); + reg |= CPUCFG_CX_CTRL_REG1_ACINACTM; + writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster)); + + /* assert cluster processor power-on resets */ + reg = readl(prcm_base + PRCM_CPU_PO_RST_CTRL(cluster)); + reg &= ~PRCM_CPU_PO_RST_CTRL_CORE_ALL; + writel(reg, prcm_base + PRCM_CPU_PO_RST_CTRL(cluster)); + + /* assert cluster resets */ + reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster)); + reg &= ~CPUCFG_CX_RST_CTRL_DBG_SOC_RST; + reg &= ~CPUCFG_CX_RST_CTRL_DBG_RST_ALL; + reg &= ~CPUCFG_CX_RST_CTRL_H_RST; + reg &= ~CPUCFG_CX_RST_CTRL_L2_RST; + + /* + * Allwinner code also asserts resets for NEON on A15. According + * to ARM manuals, asserting power-on reset is sufficient. + */ + if (!sunxi_core_is_cortex_a15(0, cluster)) + reg &= ~CPUCFG_CX_RST_CTRL_ETM_RST_ALL; + + writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster)); + + /* hold L1/L2 reset disable signals low */ + reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG0(cluster)); + if (sunxi_core_is_cortex_a15(0, cluster)) { + /* Cortex-A15: hold L2RSTDISABLE low */ + reg &= ~CPUCFG_CX_CTRL_REG0_L2_RST_DISABLE_A15; + } else { + /* Cortex-A7: hold L1RSTDISABLE and L2RSTDISABLE low */ + reg &= ~CPUCFG_CX_CTRL_REG0_L1_RST_DISABLE_ALL; + reg &= ~CPUCFG_CX_CTRL_REG0_L2_RST_DISABLE_A7; + } + writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG0(cluster)); + + /* clear cluster power gate */ + reg = readl(prcm_base + PRCM_PWROFF_GATING_REG(cluster)); + reg &= ~PRCM_PWROFF_GATING_REG_CLUSTER; + writel(reg, prcm_base + PRCM_PWROFF_GATING_REG(cluster)); + udelay(20); + + /* de-assert cluster resets */ + reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster)); + reg |= CPUCFG_CX_RST_CTRL_DBG_SOC_RST; + reg |= CPUCFG_CX_RST_CTRL_H_RST; + reg |= CPUCFG_CX_RST_CTRL_L2_RST; + writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster)); + + /* de-assert ACINACTM */ + reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster)); + reg &= ~CPUCFG_CX_CTRL_REG1_ACINACTM; + writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster)); + + return 0; +} + +/* + * This bit is shared between the initial nocache_trampoline call to + * enable CCI-400 and proper cluster cache disable before power down. + */ +static void sunxi_cluster_cache_disable_without_axi(void) +{ + if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A15) { + /* + * On the Cortex-A15 we need to disable + * L2 prefetching before flushing the cache. + */ + asm volatile( + "mcr p15, 1, %0, c15, c0, 3\n" + "isb\n" + "dsb" + : : "r" (0x400)); + } + + /* Flush all cache levels for this cluster. */ + v7_exit_coherency_flush(all); + + /* + * Disable cluster-level coherency by masking + * incoming snoops and DVM messages: + */ + cci_disable_port_by_cpu(read_cpuid_mpidr()); +} + +static int sunxi_mc_smp_cpu_table[SUNXI_NR_CLUSTERS][SUNXI_CPUS_PER_CLUSTER]; +static int sunxi_mc_smp_first_comer; + +/* + * Enable cluster-level coherency, in preparation for turning on the MMU. + * + * Also enable regional clock gating and L2 data latency settings for + * Cortex-A15. These settings are from the vendor kernel. + */ +static void __naked sunxi_mc_smp_cluster_cache_enable(void) +{ + asm volatile ( + "mrc p15, 0, r1, c0, c0, 0\n" + "movw r2, #" __stringify(ARM_CPU_PART_MASK & 0xffff) "\n" + "movt r2, #" __stringify(ARM_CPU_PART_MASK >> 16) "\n" + "and r1, r1, r2\n" + "movw r2, #" __stringify(ARM_CPU_PART_CORTEX_A15 & 0xffff) "\n" + "movt r2, #" __stringify(ARM_CPU_PART_CORTEX_A15 >> 16) "\n" + "cmp r1, r2\n" + "bne not_a15\n" + + /* The following is Cortex-A15 specific */ + + /* ACTLR2: Enable CPU regional clock gates */ + "mrc p15, 1, r1, c15, c0, 4\n" + "orr r1, r1, #(0x1<<31)\n" + "mcr p15, 1, r1, c15, c0, 4\n" + + /* L2ACTLR */ + "mrc p15, 1, r1, c15, c0, 0\n" + /* Enable L2, GIC, and Timer regional clock gates */ + "orr r1, r1, #(0x1<<26)\n" + /* Disable clean/evict from being pushed to external */ + "orr r1, r1, #(0x1<<3)\n" + "mcr p15, 1, r1, c15, c0, 0\n" + + /* L2CTRL: L2 data RAM latency */ + "mrc p15, 1, r1, c9, c0, 2\n" + "bic r1, r1, #(0x7<<0)\n" + "orr r1, r1, #(0x3<<0)\n" + "mcr p15, 1, r1, c9, c0, 2\n" + + /* End of Cortex-A15 specific setup */ + "not_a15:\n" + + /* Get value of sunxi_mc_smp_first_comer */ + "adr r1, first\n" + "ldr r0, [r1]\n" + "ldr r0, [r1, r0]\n" + + /* Skip cci_enable_port_for_self if not first comer */ + "cmp r0, #0\n" + "bxeq lr\n" + "b cci_enable_port_for_self\n" + + ".align 2\n" + "first: .word sunxi_mc_smp_first_comer - .\n" + ); +} + +static void __naked sunxi_mc_smp_secondary_startup(void) +{ + asm volatile( + "bl sunxi_mc_smp_cluster_cache_enable\n" + "b secondary_startup" + /* Let compiler know about sunxi_mc_smp_cluster_cache_enable */ + :: "i" (sunxi_mc_smp_cluster_cache_enable) + ); +} + +static DEFINE_SPINLOCK(boot_lock); + +static bool sunxi_mc_smp_cluster_is_down(unsigned int cluster) +{ + int i; + + for (i = 0; i < SUNXI_CPUS_PER_CLUSTER; i++) + if (sunxi_mc_smp_cpu_table[cluster][i]) + return false; + return true; +} + +static void sunxi_mc_smp_secondary_init(unsigned int cpu) +{ + /* Clear hotplug support magic flags for cpu0 */ + if (cpu == 0) + sunxi_cpu0_hotplug_support_set(false); +} + +static int sunxi_mc_smp_boot_secondary(unsigned int l_cpu, struct task_struct *idle) +{ + unsigned int mpidr, cpu, cluster; + + mpidr = cpu_logical_map(l_cpu); + cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0); + cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1); + + if (!cpucfg_base) + return -ENODEV; + if (cluster >= SUNXI_NR_CLUSTERS || cpu >= SUNXI_CPUS_PER_CLUSTER) + return -EINVAL; + + spin_lock_irq(&boot_lock); + + if (sunxi_mc_smp_cpu_table[cluster][cpu]) + goto out; + + if (sunxi_mc_smp_cluster_is_down(cluster)) { + sunxi_mc_smp_first_comer = true; + sunxi_cluster_powerup(cluster); + } else { + sunxi_mc_smp_first_comer = false; + } + + /* This is read by incoming CPUs with their cache and MMU disabled */ + sync_cache_w(&sunxi_mc_smp_first_comer); + sunxi_cpu_powerup(cpu, cluster); + +out: + sunxi_mc_smp_cpu_table[cluster][cpu]++; + spin_unlock_irq(&boot_lock); + + return 0; +} + +#ifdef CONFIG_HOTPLUG_CPU +static void sunxi_cluster_cache_disable(void) +{ + unsigned int cluster = MPIDR_AFFINITY_LEVEL(read_cpuid_mpidr(), 1); + u32 reg; + + pr_debug("%s: cluster %u\n", __func__, cluster); + + sunxi_cluster_cache_disable_without_axi(); + + /* last man standing, assert ACINACTM */ + reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster)); + reg |= CPUCFG_CX_CTRL_REG1_ACINACTM; + writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster)); +} + +static void sunxi_mc_smp_cpu_die(unsigned int l_cpu) +{ + unsigned int mpidr, cpu, cluster; + bool last_man; + + mpidr = cpu_logical_map(l_cpu); + cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0); + cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1); + pr_debug("%s: cluster %u cpu %u\n", __func__, cluster, cpu); + + spin_lock(&boot_lock); + sunxi_mc_smp_cpu_table[cluster][cpu]--; + if (sunxi_mc_smp_cpu_table[cluster][cpu] == 1) { + /* A power_up request went ahead of us. */ + pr_debug("%s: aborting due to a power up request\n", + __func__); + spin_unlock(&boot_lock); + return; + } else if (sunxi_mc_smp_cpu_table[cluster][cpu] > 1) { + pr_err("Cluster %d CPU%d boots multiple times\n", + cluster, cpu); + BUG(); + } + + last_man = sunxi_mc_smp_cluster_is_down(cluster); + spin_unlock(&boot_lock); + + gic_cpu_if_down(0); + if (last_man) + sunxi_cluster_cache_disable(); + else + v7_exit_coherency_flush(louis); + + for (;;) + wfi(); +} + +static int sunxi_cpu_powerdown(unsigned int cpu, unsigned int cluster) +{ + u32 reg; + + pr_debug("%s: cluster %u cpu %u\n", __func__, cluster, cpu); + if (cpu >= SUNXI_CPUS_PER_CLUSTER || cluster >= SUNXI_NR_CLUSTERS) + return -EINVAL; + + /* gate processor power */ + reg = readl(prcm_base + PRCM_PWROFF_GATING_REG(cluster)); + reg |= PRCM_PWROFF_GATING_REG_CORE(cpu); + writel(reg, prcm_base + PRCM_PWROFF_GATING_REG(cluster)); + udelay(20); + + /* close power switch */ + sunxi_cpu_power_switch_set(cpu, cluster, false); + + return 0; +} + +static int sunxi_cluster_powerdown(unsigned int cluster) +{ + u32 reg; + + pr_debug("%s: cluster %u\n", __func__, cluster); + if (cluster >= SUNXI_NR_CLUSTERS) + return -EINVAL; + + /* assert cluster resets or system will hang */ + pr_debug("%s: assert cluster reset\n", __func__); + reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster)); + reg &= ~CPUCFG_CX_RST_CTRL_DBG_SOC_RST; + reg &= ~CPUCFG_CX_RST_CTRL_H_RST; + reg &= ~CPUCFG_CX_RST_CTRL_L2_RST; + writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster)); + + /* gate cluster power */ + pr_debug("%s: gate cluster power\n", __func__); + reg = readl(prcm_base + PRCM_PWROFF_GATING_REG(cluster)); + reg |= PRCM_PWROFF_GATING_REG_CLUSTER; + writel(reg, prcm_base + PRCM_PWROFF_GATING_REG(cluster)); + udelay(20); + + return 0; +} + +static int sunxi_mc_smp_cpu_kill(unsigned int l_cpu) +{ + unsigned int mpidr, cpu, cluster; + unsigned int tries, count; + int ret = 0; + u32 reg; + + mpidr = cpu_logical_map(l_cpu); + cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0); + cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1); + + /* This should never happen */ + if (WARN_ON(cluster >= SUNXI_NR_CLUSTERS || + cpu >= SUNXI_CPUS_PER_CLUSTER)) + return 0; + + /* wait for CPU core to die and enter WFI */ + count = TIMEOUT_USEC / POLL_USEC; + spin_lock_irq(&boot_lock); + for (tries = 0; tries < count; tries++) { + spin_unlock_irq(&boot_lock); + usleep_range(POLL_USEC / 2, POLL_USEC); + spin_lock_irq(&boot_lock); + + /* + * If the user turns off a bunch of cores at the same + * time, the kernel might call cpu_kill before some of + * them are ready. This is because boot_lock serializes + * both cpu_die and cpu_kill callbacks. Either one could + * run first. We should wait for cpu_die to complete. + */ + if (sunxi_mc_smp_cpu_table[cluster][cpu]) + continue; + + reg = readl(cpucfg_base + CPUCFG_CX_STATUS(cluster)); + if (reg & CPUCFG_CX_STATUS_STANDBYWFI(cpu)) + break; + } + + if (tries >= count) { + ret = ETIMEDOUT; + goto out; + } + + /* power down CPU core */ + sunxi_cpu_powerdown(cpu, cluster); + + if (!sunxi_mc_smp_cluster_is_down(cluster)) + goto out; + + /* wait for cluster L2 WFI */ + ret = readl_poll_timeout(cpucfg_base + CPUCFG_CX_STATUS(cluster), reg, + reg & CPUCFG_CX_STATUS_STANDBYWFIL2, + POLL_USEC, TIMEOUT_USEC); + if (ret) { + /* + * Ignore timeout on the cluster. Leaving the cluster on + * will not affect system execution, just use a bit more + * power. But returning an error here will only confuse + * the user as the CPU has already been shutdown. + */ + ret = 0; + goto out; + } + + /* Power down cluster */ + sunxi_cluster_powerdown(cluster); + +out: + spin_unlock_irq(&boot_lock); + pr_debug("%s: cluster %u cpu %u powerdown: %d\n", + __func__, cluster, cpu, ret); + return !ret; +} + +static bool sunxi_mc_smp_cpu_can_disable(unsigned int __unused) +{ + return true; +} +#endif + +static const struct smp_operations sunxi_mc_smp_smp_ops __initconst = { + .smp_secondary_init = sunxi_mc_smp_secondary_init, + .smp_boot_secondary = sunxi_mc_smp_boot_secondary, +#ifdef CONFIG_HOTPLUG_CPU + .cpu_die = sunxi_mc_smp_cpu_die, + .cpu_kill = sunxi_mc_smp_cpu_kill, + .cpu_can_disable = sunxi_mc_smp_cpu_can_disable, +#endif +}; + +static bool __init sunxi_mc_smp_cpu_table_init(void) +{ + unsigned int mpidr, cpu, cluster; + + mpidr = read_cpuid_mpidr(); + cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0); + cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1); + + if (cluster >= SUNXI_NR_CLUSTERS || cpu >= SUNXI_CPUS_PER_CLUSTER) { + pr_err("%s: boot CPU is out of bounds!\n", __func__); + return false; + } + sunxi_mc_smp_cpu_table[cluster][cpu] = 1; + return true; +} + +/* + * Adapted from arch/arm/common/mc_smp_entry.c + * + * We need the trampoline code to enable CCI-400 on the first cluster + */ +typedef typeof(cpu_reset) phys_reset_t; + +static void __init __naked sunxi_mc_smp_resume(void) +{ + asm volatile( + "bl sunxi_mc_smp_cluster_cache_enable\n" + "b cpu_resume" + /* Let compiler know about sunxi_mc_smp_cluster_cache_enable */ + :: "i" (sunxi_mc_smp_cluster_cache_enable) + ); +} + +static int __init nocache_trampoline(unsigned long __unused) +{ + phys_reset_t phys_reset; + + setup_mm_for_reboot(); + sunxi_cluster_cache_disable_without_axi(); + + phys_reset = (phys_reset_t)(unsigned long)__pa_symbol(cpu_reset); + phys_reset(__pa_symbol(sunxi_mc_smp_resume), false); + BUG(); +} + +static int __init sunxi_mc_smp_loopback(void) +{ + int ret; + + /* + * We're going to soft-restart the current CPU through the + * low-level MCPM code by leveraging the suspend/resume + * infrastructure. Let's play it safe by using cpu_pm_enter() + * in case the CPU init code path resets the VFP or similar. + */ + sunxi_mc_smp_first_comer = true; + local_irq_disable(); + local_fiq_disable(); + ret = cpu_pm_enter(); + if (!ret) { + ret = cpu_suspend(0, nocache_trampoline); + cpu_pm_exit(); + } + local_fiq_enable(); + local_irq_enable(); + sunxi_mc_smp_first_comer = false; + + return ret; +} + +/* + * This holds any device nodes that we requested resources for, + * so that we may easily release resources in the error path. + */ +struct sunxi_mc_smp_nodes { + struct device_node *prcm_node; + struct device_node *cpucfg_node; + struct device_node *sram_node; +}; + +/* This structure holds SoC-specific bits tied to an enable-method string. */ +struct sunxi_mc_smp_data { + const char *enable_method; + int (*get_smp_nodes)(struct sunxi_mc_smp_nodes *nodes); +}; + +static void __init sunxi_mc_smp_put_nodes(struct sunxi_mc_smp_nodes *nodes) +{ + of_node_put(nodes->prcm_node); + of_node_put(nodes->cpucfg_node); + of_node_put(nodes->sram_node); + memset(nodes, 0, sizeof(*nodes)); +} + +static int __init sun9i_a80_get_smp_nodes(struct sunxi_mc_smp_nodes *nodes) +{ + nodes->prcm_node = of_find_compatible_node(NULL, NULL, + "allwinner,sun9i-a80-prcm"); + if (!nodes->prcm_node) { + pr_err("%s: PRCM not available\n", __func__); + return -ENODEV; + } + + nodes->cpucfg_node = of_find_compatible_node(NULL, NULL, + "allwinner,sun9i-a80-cpucfg"); + if (!nodes->cpucfg_node) { + pr_err("%s: CPUCFG not available\n", __func__); + return -ENODEV; + } + + nodes->sram_node = of_find_compatible_node(NULL, NULL, + "allwinner,sun9i-a80-smp-sram"); + if (!nodes->sram_node) { + pr_err("%s: Secure SRAM not available\n", __func__); + return -ENODEV; + } + + return 0; +} + +static const struct sunxi_mc_smp_data sunxi_mc_smp_data[] __initconst = { + { + .enable_method = "allwinner,sun9i-a80-smp", + .get_smp_nodes = sun9i_a80_get_smp_nodes, + }, +}; + +static int __init sunxi_mc_smp_init(void) +{ + struct sunxi_mc_smp_nodes nodes = { 0 }; + struct device_node *node; + struct resource res; + int i, ret; + + /* + * Don't bother checking the "cpus" node, as an enable-method + * property in that node is undocumented. + */ + node = of_cpu_device_node_get(0); + if (!node) + return -ENODEV; + + /* + * We can't actually use the enable-method magic in the kernel. + * Our loopback / trampoline code uses the CPU suspend framework, + * which requires the identity mapping be available. It would not + * yet be available if we used the .init_cpus or .prepare_cpus + * callbacks in smp_operations, which we would use if we were to + * use CPU_METHOD_OF_DECLARE + */ + for (i = 0; i < ARRAY_SIZE(sunxi_mc_smp_data); i++) { + ret = of_property_match_string(node, "enable-method", + sunxi_mc_smp_data[i].enable_method); + if (!ret) + break; + } + + of_node_put(node); + if (ret) + return -ENODEV; + + if (!sunxi_mc_smp_cpu_table_init()) + return -EINVAL; + + if (!cci_probed()) { + pr_err("%s: CCI-400 not available\n", __func__); + return -ENODEV; + } + + /* Get needed device tree nodes */ + ret = sunxi_mc_smp_data[i].get_smp_nodes(&nodes); + if (ret) + goto err_put_nodes; + + /* + * Unfortunately we can not request the I/O region for the PRCM. + * It is shared with the PRCM clock. + */ + prcm_base = of_iomap(nodes.prcm_node, 0); + if (!prcm_base) { + pr_err("%s: failed to map PRCM registers\n", __func__); + ret = -ENOMEM; + goto err_put_nodes; + } + + cpucfg_base = of_io_request_and_map(nodes.cpucfg_node, 0, + "sunxi-mc-smp"); + if (IS_ERR(cpucfg_base)) { + ret = PTR_ERR(cpucfg_base); + pr_err("%s: failed to map CPUCFG registers: %d\n", + __func__, ret); + goto err_unmap_prcm; + } + + sram_b_smp_base = of_io_request_and_map(nodes.sram_node, 0, + "sunxi-mc-smp"); + if (IS_ERR(sram_b_smp_base)) { + ret = PTR_ERR(sram_b_smp_base); + pr_err("%s: failed to map secure SRAM\n", __func__); + goto err_unmap_release_cpucfg; + } + + /* Configure CCI-400 for boot cluster */ + ret = sunxi_mc_smp_loopback(); + if (ret) { + pr_err("%s: failed to configure boot cluster: %d\n", + __func__, ret); + goto err_unmap_release_secure_sram; + } + + /* We don't need the device nodes anymore */ + sunxi_mc_smp_put_nodes(&nodes); + + /* Set the hardware entry point address */ + writel(__pa_symbol(sunxi_mc_smp_secondary_startup), + prcm_base + PRCM_CPU_SOFT_ENTRY_REG); + + /* Actually enable multi cluster SMP */ + smp_set_ops(&sunxi_mc_smp_smp_ops); + + pr_info("sunxi multi cluster SMP support installed\n"); + + return 0; + +err_unmap_release_secure_sram: + iounmap(sram_b_smp_base); + of_address_to_resource(nodes.sram_node, 0, &res); + release_mem_region(res.start, resource_size(&res)); +err_unmap_release_cpucfg: + iounmap(cpucfg_base); + of_address_to_resource(nodes.cpucfg_node, 0, &res); + release_mem_region(res.start, resource_size(&res)); +err_unmap_prcm: + iounmap(prcm_base); +err_put_nodes: + sunxi_mc_smp_put_nodes(&nodes); + return ret; +} + +early_initcall(sunxi_mc_smp_init); |