[PATCH v2 3/8] ARM: MB86S7X: Add MCPM support
Nicolas Pitre
nicolas.pitre at linaro.org
Mon Dec 15 12:15:07 PST 2014
On Mon, 15 Dec 2014, Vincent Yang wrote:
> 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 at linaro.org>
> Signed-off-by: Jassi Brar <jaswinder.singh at linaro.org>
> Signed-off-by: Vincent Yang <Vincent.Yang at tw.fujitsu.com>
> Signed-off-by: Tetsuya Nuriya <nuriya.tetsuya at jp.fujitsu.com>
Minor issues below.
> ---
> arch/arm/mach-mb86s7x/Makefile | 4 +-
> arch/arm/mach-mb86s7x/mcpm.c | 311 +++++++++++++++++++++++++++++++++++++++++
> arch/arm/mach-mb86s7x/smc.S | 27 ++++
> drivers/soc/mb86s7x/scb_mhu.c | 20 ++-
> include/soc/mb86s7x/scb_mhu.h | 8 ++
> 5 files changed, 365 insertions(+), 5 deletions(-)
> 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..ee79dd3
> --- /dev/null
> +++ b/arch/arm/mach-mb86s7x/mcpm.c
> @@ -0,0 +1,311 @@
> +/*
> + * arch/arm/mach-mb86s7x/mcpm.c
> + * Copyright: (C) 2013-2014 Fujitsu Semiconductor Limited
> + * Copyright: (C) 2014 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) {
> + /*
> + * 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;
It is well possible for mb86s7x_pm_use_count[cluster][cpu] to be 2 here.
In which case you are returning with mb86s7x_pm_lock still locked and
IRQs disabled.
> +}
> +
> +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)
> + pr_err("%s:%d failed to get SCB version\n",
> + __func__, __LINE__);
Wouldn't it be better to return an error here as well rather than
continuing with potentially bad data?
> +
> + pr_info("MB86S7x MCPM initialized: 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 */
> + mcpm_smp_set_ops();
You should call mcpm_smp_set_ops() only if none of the precedent calls
returned an error.
> +
> + 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..a14330b
> --- /dev/null
> +++ b/arch/arm/mach-mb86s7x/smc.S
> @@ -0,0 +1,27 @@
> +/*
> + * SMC command interface to set secondary entry point
> + * Copyright: (C) 2013-2014 Fujitsu Semiconductor Limited
> + * Copyright: (C) 2014 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 72070f1..f4276d7 100644
> --- a/drivers/soc/mb86s7x/scb_mhu.c
> +++ b/drivers/soc/mb86s7x/scb_mhu.c
> @@ -35,7 +35,7 @@ static struct mbox_client mhu_cl;
> static struct mbox_chan *mhu_chan;
> static mb86s7x_mhu_handler_t handler[MHU_NUM_CMDS];
>
> -void __iomem *mhu_base, *mb86s7x_shm_base;
> +static void __iomem *mhu_base, *mb86s7x_shm_base;
This should probably be done in the patch that introduced it instead.
> static void __iomem *cmd_to_scb, *rsp_to_scb;
> static void __iomem *cmd_from_scb, *rsp_from_scb;
>
> @@ -81,15 +81,27 @@ static int mhu_fsm[4][4] = {
> },
> };
>
> -struct mhu_xfer {
> +static struct mhu_xfer {
> int code;
> int len;
> void *buf;
> struct completion *c;
> struct list_head node;
> -};
> +} *ax; /* stages of xfer */
Ditto for the above.
> +
> +#define WFI_COLOR_OFFSET 0x3f00
>
> -static struct mhu_xfer *ax; /* stages of xfer */
> +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)
> {
> diff --git a/include/soc/mb86s7x/scb_mhu.h b/include/soc/mb86s7x/scb_mhu.h
> index a7e3484..1268640 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
>
>
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