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

[nicolas.pitre@linaro.org (Nicolas Pitre)]

On Fri, 9 Jan 2015, Vincent Yang wrote:

> 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>

Once the initcall issue raised by Russell is fixed you can add:

Reviewed-by: Nicolas Pitre <nico@linaro.org>


> ---
>  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
> 
>