[PATCH v3 3/8] ARM: MB86S7X: Add MCPM support

Vincent Yang
2015-01-09T11:28:54Z

From: Jassi Brar <jaswinder.singh@linaro.org>

The remote firmware(SCB) owns the SMP control. This MCPM driver gets
CPU/CLUSTER power up/down done by SCB over mailbox.

Signed-off-by: Andy Green <andy.green@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Vincent Yang <Vincent.Yang@tw.fujitsu.com>
Signed-off-by: Tetsuya Nuriya <nuriya.tetsuya@jp.fujitsu.com>
---
arch/arm/mach-mb86s7x/Makefile | 4 +-
arch/arm/mach-mb86s7x/mcpm.c | 315 +++++++++++++++++++++++++++++++++++++++++
arch/arm/mach-mb86s7x/smc.S | 27 ++++
drivers/soc/mb86s7x/scb_mhu.c | 14 ++
include/soc/mb86s7x/scb_mhu.h | 8 ++
5 files changed, 367 insertions(+), 1 deletion(-)
create mode 100644 arch/arm/mach-mb86s7x/mcpm.c
create mode 100644 arch/arm/mach-mb86s7x/smc.S

diff --git a/arch/arm/mach-mb86s7x/Makefile b/arch/arm/mach-mb86s7x/Makefile
index 97640b6..00e843c 100644
--- a/arch/arm/mach-mb86s7x/Makefile
+++ b/arch/arm/mach-mb86s7x/Makefile
@@ -1 +1,3 @@
-obj-$(CONFIG_ARCH_MB86S7X) += board.o
+obj-$(CONFIG_ARCH_MB86S7X) += board.o mcpm.o smc.o
+CFLAGS_smc.o += -march=armv7-a
+CFLAGS_mcpm.o += -march=armv7-a
diff --git a/arch/arm/mach-mb86s7x/mcpm.c b/arch/arm/mach-mb86s7x/mcpm.c
new file mode 100644
index 0000000..c278c6e
--- /dev/null
+++ b/arch/arm/mach-mb86s7x/mcpm.c
@@ -0,0 +1,315 @@
+/*
+ * arch/arm/mach-mb86s7x/mcpm.c
+ * Copyright: (C) 2013-2015 Fujitsu Semiconductor Limited
+ * Copyright: (C) 2015 Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/io.h>
+#include <linux/pm.h>
+#include <linux/delay.h>
+#include <linux/cpu_pm.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/arm-cci.h>
+#include <linux/spinlock.h>
+#include <linux/suspend.h>
+#include <linux/of_device.h>
+#include <linux/irqchip/arm-gic.h>
+#include <linux/platform_device.h>
+
+#include <soc/mb86s7x/scb_mhu.h>
+
+#include <asm/mcpm.h>
+#include <asm/cp15.h>
+#include <asm/cputype.h>
+#include <asm/suspend.h>
+#include <asm/idmap.h>
+
+#define S7X_MAX_CLUSTER 2
+#define S7X_MAX_CPU 2
+
+#define MHU_SHM_OFFSET 0x3800
+#define TRAMPOLINE_OFFSET 0x3c00
+#define RESET_OFFSET (TRAMPOLINE_OFFSET + 0x3fc)
+
+static arch_spinlock_t mb86s7x_pm_lock = __ARCH_SPIN_LOCK_UNLOCKED;
+static int mb86s7x_pm_use_count[S7X_MAX_CLUSTER][S7X_MAX_CPU];
+
+struct mb86s7x_cpu_gate {
+ u32 payload_size;
+ u32 cluster_class;
+ u32 cluster_id;
+ u32 cpu_id;
+#define SCB_CPU_STATE_OFF 0x0
+#define SCB_CPU_STATE_ON 0x1
+#define SCB_CPU_STATE_SUSP 0x2
+ u32 cpu_state;
+};
+
+static int mb86s7x_pm_power_up(unsigned int cpu, unsigned int cluster)
+{
+ int ret = 0;
+
+ if (cluster >= S7X_MAX_CLUSTER || cpu >= S7X_MAX_CPU)
+ return -EINVAL;
+
+ pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
+
+ local_irq_disable();
+ arch_spin_lock(&mb86s7x_pm_lock);
+
+ mb86s7x_pm_use_count[cluster][cpu]++;
+
+ if (mb86s7x_pm_use_count[cluster][cpu] == 1) {
+ struct mb86s7x_cpu_gate cmd;
+
+ mb86s7x_set_wficolor(cluster, cpu, AT_WFI_DO_NOTHING);
+ arch_spin_unlock(&mb86s7x_pm_lock);
+ local_irq_enable();
+
+ cmd.payload_size = sizeof(cmd);
+ cmd.cluster_class = 0;
+ cmd.cluster_id = cluster;
+ cmd.cpu_id = cpu;
+ cmd.cpu_state = SCB_CPU_STATE_ON;
+
+ pr_debug("%s:%d CMD Cl_Class-%u CL_ID-%u CPU_ID-%u STATE-%u}\n",
+ __func__, __LINE__, cmd.cluster_class,
+ cmd.cluster_id, cmd.cpu_id, cmd.cpu_state);
+
+ ret = mb86s7x_send_packet(CMD_CPU_CLOCK_GATE_SET_REQ,
+ &cmd, sizeof(cmd));
+ if (ret < 0) {
+ pr_err("%s:%d failed!\n", __func__, __LINE__);
+ return ret;
+ }
+
+ pr_debug("%s:%d REP Cl_Class-%u CL_ID-%u CPU_ID-%u STATE-%u}\n",
+ __func__, __LINE__, cmd.cluster_class,
+ cmd.cluster_id, cmd.cpu_id, cmd.cpu_state);
+
+ if (cmd.cpu_state != SCB_CPU_STATE_ON)
+ return -ENODEV;
+ } else if (mb86s7x_pm_use_count[cluster][cpu] == 2) {
+ arch_spin_unlock(&mb86s7x_pm_lock);
+ local_irq_enable();
+ } else {
+ /*
+ * The only possible values are:
+ * 0 = CPU down
+ * 1 = CPU (still) up
+ * 2 = CPU requested to be up before it had a chance
+ * to actually make itself down.
+ * Any other value is a bug.
+ */
+ BUG();
+ }
+
+ return 0;
+}
+
+static void mb86s7x_pm_suspend(u64 ignored)
+{
+ unsigned int mpidr, cpu, cluster;
+ bool last_man = false, skip_wfi = false;
+
+ mpidr = read_cpuid_mpidr();
+ cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+ cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+
+ pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
+ __mcpm_cpu_going_down(cpu, cluster);
+
+ arch_spin_lock(&mb86s7x_pm_lock);
+ BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP);
+
+ mb86s7x_pm_use_count[cluster][cpu]--;
+
+ if (mb86s7x_pm_use_count[cluster][cpu] == 0) {
+ if (!mb86s7x_pm_use_count[cluster][0] &&
+ !mb86s7x_pm_use_count[cluster][1])
+ last_man = true;
+ mb86s7x_set_wficolor(cluster, cpu, AT_WFI_DO_POWEROFF);
+ } else if (mb86s7x_pm_use_count[cluster][cpu] == 1) {
+ skip_wfi = true; /* Overtaken by a power up */
+ } else {
+ BUG();
+ }
+
+ if (!skip_wfi)
+ gic_cpu_if_down();
+
+ if (last_man && __mcpm_outbound_enter_critical(cpu, cluster)) {
+ arch_spin_unlock(&mb86s7x_pm_lock);
+
+ 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\t"
+ "isb\n\t"
+ "dsb"
+ : : "r" (0x400));
+ }
+
+ v7_exit_coherency_flush(all);
+
+ cci_disable_port_by_cpu(mpidr);
+
+ __mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN);
+ } else {
+ arch_spin_unlock(&mb86s7x_pm_lock);
+ v7_exit_coherency_flush(louis);
+ }
+
+ __mcpm_cpu_down(cpu, cluster);
+
+ /* Now we are prepared for power-down, do it: */
+ if (!skip_wfi)
+ wfi();
+}
+
+static void mb86s7x_pm_power_down(void)
+{
+ mb86s7x_pm_suspend(0);
+}
+
+static int mb86s7x_wait_for_powerdown(unsigned int cpu, unsigned int cluster)
+{
+ struct mb86s7x_cpu_gate cmd;
+ int i, ret;
+
+ BUG_ON(cluster >= S7X_MAX_CLUSTER || cpu >= S7X_MAX_CPU);
+
+ cmd.payload_size = sizeof(cmd);
+ cmd.cluster_class = 0;
+ cmd.cluster_id = cluster;
+ cmd.cpu_id = cpu;
+ cmd.cpu_state = SCB_CPU_STATE_ON;
+
+ for (i = 0; i < 50; i++) {
+ ret = mb86s7x_send_packet(CMD_CPU_CLOCK_GATE_GET_REQ,
+ &cmd, sizeof(cmd));
+ if (ret < 0) {
+ pr_err("%s:%d failed to get CPU status\n",
+ __func__, __LINE__);
+ return ret;
+ }
+
+ pr_debug("%s:%d Cl_Class-%u CL_ID-%u CPU_ID-%u STATE-%u\n",
+ __func__, __LINE__,
+ cmd.cluster_class, cmd.cluster_id,
+ cmd.cpu_id, cmd.cpu_state);
+
+ if (cmd.cpu_state == SCB_CPU_STATE_OFF)
+ return 0;
+
+ msleep(20);
+ }
+
+ return -ETIMEDOUT;
+}
+
+static void mb86s7x_pm_powered_up(void)
+{
+ unsigned int mpidr, cpu, cluster;
+
+ mpidr = read_cpuid_mpidr();
+ cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+ cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+
+ arch_spin_lock(&mb86s7x_pm_lock);
+ if (!mb86s7x_pm_use_count[cluster][cpu])
+ mb86s7x_pm_use_count[cluster][cpu] = 1;
+ arch_spin_unlock(&mb86s7x_pm_lock);
+}
+
+static const struct mcpm_platform_ops mb86s7x_pm_power_ops = {
+ .power_up = mb86s7x_pm_power_up,
+ .power_down = mb86s7x_pm_power_down,
+ .wait_for_powerdown = mb86s7x_wait_for_powerdown,
+ .suspend = mb86s7x_pm_suspend,
+ .powered_up = mb86s7x_pm_powered_up,
+};
+
+/*
+ * Enable cluster-level coherency, in preparation for turning on the MMU.
+ */
+static void __naked mb86s7x_pm_power_up_setup(unsigned int affinity_level)
+{
+ asm volatile ("\n"
+" cmp r0, #1\n"
+" bxne lr\n"
+" b cci_enable_port_for_self");
+}
+
+static void __init mb86s7x_cache_off(void)
+{
+ if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A15) {
+ /* disable L2 prefetching on the Cortex-A15 */
+ asm volatile(
+ "mcr p15, 1, %0, c15, c0, 3\n\t"
+ "isb\n\t"
+ "dsb"
+ : : "r" (0x400));
+ }
+ v7_exit_coherency_flush(all);
+}
+
+struct mb86s7x_scb_version {
+ u32 payload_size;
+ u32 version;
+ u32 config_version;
+};
+
+static int __init mb86s7x_mcpm_init(void)
+{
+ unsigned int mpidr, cpu, cluster;
+ struct mb86s7x_scb_version cmd;
+ int ret;
+
+ if (!cci_probed())
+ return -ENODEV;
+
+ mpidr = read_cpuid_mpidr();
+ cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+ cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+
+ pr_info("Booting on cpu_%u cluster_%u\n", cpu, cluster);
+ mb86s7x_pm_use_count[cluster][cpu] = 1;
+
+ /* reset the wfi 'color' for primary cpu */
+ mb86s7x_set_wficolor(cluster, cpu, AT_WFI_DO_NOTHING);
+
+ /* Do SMC to set entry address for CPUs coming online */
+ mb86s7x_cpu_entry(virt_to_phys(mcpm_entry_point));
+
+ cmd.payload_size = sizeof(cmd);
+ cmd.version = 0;
+ cmd.config_version = 0;
+ ret = mb86s7x_send_packet(CMD_SCB_CAPABILITY_GET_REQ,
+ &cmd, sizeof(cmd));
+ if (ret < 0) /* non fatal */
+ pr_err("%s:%d failed to get SCB version\n",
+ __func__, __LINE__);
+ else
+ pr_err("MB86S7x SCB version 0x%x:0x%x\n",
+ cmd.version, cmd.config_version);
+
+ ret = mcpm_platform_register(&mb86s7x_pm_power_ops);
+ if (!ret)
+ ret = mcpm_sync_init(mb86s7x_pm_power_up_setup);
+ if (!ret)
+ ret = mcpm_loopback(mb86s7x_cache_off); /* turn on the CCI */
+ if (!ret)
+ mcpm_smp_set_ops();
+
+ return ret;
+}
+early_initcall(mb86s7x_mcpm_init);
diff --git a/arch/arm/mach-mb86s7x/smc.S b/arch/arm/mach-mb86s7x/smc.S
new file mode 100644
index 0000000..3ffe4f7
--- /dev/null
+++ b/arch/arm/mach-mb86s7x/smc.S
@@ -0,0 +1,27 @@
+/*
+ * SMC command interface to set secondary entry point
+ * Copyright: (C) 2013-2015 Fujitsu Semiconductor Limited
+ * Copyright: (C) 2015 Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+
+.arch_extension sec
+
+/* void mb86s7x_cpu_entry(unsigned long secondary_entry); */
+ENTRY(mb86s7x_cpu_entry)
+ stmfd sp!, {r1-r11, lr}
+ mov r1, r0
+ ldr r0, =1
+ mrc p15, 0, r3, c1, c0, 0
+ mov r4, r3
+ and r3, #0xbfffffff
+ mcr p15, 0, r3, c1, c0, 0
+ smc #0
+ mcr p15, 0, r4, c1, c0, 0
+ ldmfd sp!, {r1-r11, pc}
+ENDPROC(mb86s7x_cpu_entry)
diff --git a/drivers/soc/mb86s7x/scb_mhu.c b/drivers/soc/mb86s7x/scb_mhu.c
index 08a3c88..a86ed0a 100644
--- a/drivers/soc/mb86s7x/scb_mhu.c
+++ b/drivers/soc/mb86s7x/scb_mhu.c
@@ -89,6 +89,20 @@ static struct mhu_xfer {
struct list_head node;
} *ax; /* stages of xfer */

+#define WFI_COLOR_OFFSET 0x3f00
+
+void mb86s7x_set_wficolor(unsigned clstr, unsigned cpu, unsigned clr)
+{
+ u8 val;
+
+ val = readb_relaxed(mb86s7x_shm_base
+ + WFI_COLOR_OFFSET + clstr * 2 + cpu);
+ val &= ~AT_WFI_COLOR_MASK;
+ val |= clr;
+ writeb_relaxed(val, mb86s7x_shm_base
+ + WFI_COLOR_OFFSET + clstr * 2 + cpu);
+}
+
static int mhu_alloc_xfers(int n, struct list_head *list)
{
struct mhu_xfer *x = kcalloc(n, sizeof(struct mhu_xfer), GFP_ATOMIC);
diff --git a/include/soc/mb86s7x/scb_mhu.h b/include/soc/mb86s7x/scb_mhu.h
index 334fa9f..f792950 100644
--- a/include/soc/mb86s7x/scb_mhu.h
+++ b/include/soc/mb86s7x/scb_mhu.h
@@ -87,6 +87,14 @@ enum {
#define CMD_POWERDOMAIN_SET_REP ENC_REP(CMD_POWERDOMAIN_SET_REQ)
#define CMD_STG_BLOCK_ERASE_REP ENC_REP(CMD_STG_BLOCK_ERASE_REQ)

+#define AT_WFI_DO_NOTHING 0x0
+#define AT_WFI_DO_SUSPEND 0x1
+#define AT_WFI_DO_POWEROFF 0x2
+#define AT_WFI_COLOR_MASK 0x3
+
+void mb86s7x_set_wficolor(unsigned clstr, unsigned cpu, unsigned clr);
+void mb86s7x_cpu_entry(unsigned long secondary_entry);
+
/* Helper functions to talk to remote */
int mb86s7x_send_packet(int cmd, void *buf, int len);

--
1.9.0