--- /dev/null
+// 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/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 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_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
+
+static void __iomem *cpucfg_base;
+static void __iomem *prcm_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 int sunxi_cpu_powerup(unsigned int cpu, unsigned int cluster)
+{
+ u32 reg;
+
+ pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
+ if (cpu >= SUNXI_CPUS_PER_CLUSTER || cluster >= SUNXI_NR_CLUSTERS)
+ return -EINVAL;
+
+ /* 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 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;
+}
+
+static const struct smp_operations sunxi_mc_smp_smp_ops __initconst = {
+ .smp_boot_secondary = sunxi_mc_smp_boot_secondary,
+};
+
+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_lookback(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;
+}
+
+static int __init sunxi_mc_smp_init(void)
+{
+ struct device_node *cpucfg_node, *node;
+ struct resource res;
+ int ret;
+
+ if (!of_machine_is_compatible("allwinner,sun9i-a80"))
+ 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;
+ }
+
+ node = of_find_compatible_node(NULL, NULL, "allwinner,sun9i-a80-prcm");
+ if (!node) {
+ pr_err("%s: PRCM not available\n", __func__);
+ return -ENODEV;
+ }
+
+ /*
+ * Unfortunately we can not request the I/O region for the PRCM.
+ * It is shared with the PRCM clock.
+ */
+ prcm_base = of_iomap(node, 0);
+ of_node_put(node);
+ if (!prcm_base) {
+ pr_err("%s: failed to map PRCM registers\n", __func__);
+ return -ENOMEM;
+ }
+
+ cpucfg_node = of_find_compatible_node(NULL, NULL,
+ "allwinner,sun9i-a80-cpucfg");
+ if (!cpucfg_node) {
+ ret = -ENODEV;
+ pr_err("%s: CPUCFG not available\n", __func__);
+ goto err_unmap_prcm;
+ }
+
+ cpucfg_base = of_io_request_and_map(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_put_cpucfg_node;
+ }
+
+ /* Configure CCI-400 for boot cluster */
+ ret = sunxi_mc_smp_lookback();
+ if (ret) {
+ pr_err("%s: failed to configure boot cluster: %d\n",
+ __func__, ret);
+ goto err_unmap_release_cpucfg;
+ }
+
+ /* We don't need the CPUCFG device node anymore */
+ of_node_put(cpucfg_node);
+
+ /* 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_cpucfg:
+ iounmap(cpucfg_base);
+ of_address_to_resource(cpucfg_node, 0, &res);
+ release_mem_region(res.start, resource_size(&res));
+err_put_cpucfg_node:
+ of_node_put(cpucfg_node);
+err_unmap_prcm:
+ iounmap(prcm_base);
+ return ret;
+}
+
+early_initcall(sunxi_mc_smp_init);
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