ARM: brcmstb: reintroduce SMP support

obj-$(CONFIG_ARCH_BCM_63XX)	:= bcm63xx.o

ifeq ($(CONFIG_ARCH_BRCMSTB),y)

CFLAGS_platsmp-brcmstb.o	+= -march=armv7-a

obj-y				+= brcmstb.o

obj-$(CONFIG_SMP)		+= headsmp-brcmstb.o platsmp-brcmstb.o

endif

/*

 * Copyright (C) 2013-2014 Broadcom Corporation

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License as

 * published by the Free Software Foundation version 2.

 *

 * This program is distributed "as is" WITHOUT ANY WARRANTY of any

 * kind, whether express or implied; without even the implied warranty

 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

#ifndef __BRCMSTB_H__

#define __BRCMSTB_H__

void brcmstb_secondary_startup(void);

#endif /* __BRCMSTB_H__ */

/*

 * SMP boot code for secondary CPUs

 * Based on arch/arm/mach-tegra/headsmp.S

 *

 * Copyright (C) 2010 NVIDIA, Inc.

 * Copyright (C) 2013-2014 Broadcom Corporation

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License as

 * published by the Free Software Foundation version 2.

 *

 * This program is distributed "as is" WITHOUT ANY WARRANTY of any

 * kind, whether express or implied; without even the implied warranty

 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

#include <asm/assembler.h>

#include <linux/linkage.h>

#include <linux/init.h>

        .section ".text.head", "ax"

ENTRY(brcmstb_secondary_startup)

        /*

         * Ensure CPU is in a sane state by disabling all IRQs and switching

         * into SVC mode.

         */

        setmode	PSR_I_BIT | PSR_F_BIT | SVC_MODE, r0

        bl      v7_invalidate_l1

        b       secondary_startup

ENDPROC(brcmstb_secondary_startup)

/*

 * Broadcom STB CPU SMP and hotplug support for ARM

 *

 * Copyright (C) 2013-2014 Broadcom Corporation

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License as

 * published by the Free Software Foundation version 2.

 *

 * This program is distributed "as is" WITHOUT ANY WARRANTY of any

 * kind, whether express or implied; without even the implied warranty

 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

#include <linux/delay.h>

#include <linux/errno.h>

#include <linux/init.h>

#include <linux/io.h>

#include <linux/of_address.h>

#include <linux/of_platform.h>

#include <linux/printk.h>

#include <linux/regmap.h>

#include <linux/smp.h>

#include <linux/mfd/syscon.h>

#include <asm/cacheflush.h>

#include <asm/cp15.h>

#include <asm/mach-types.h>

#include <asm/smp_plat.h>

#include "brcmstb.h"

enum {

	ZONE_MAN_CLKEN_MASK		= BIT(0),

	ZONE_MAN_RESET_CNTL_MASK	= BIT(1),

	ZONE_MAN_MEM_PWR_MASK		= BIT(4),

	ZONE_RESERVED_1_MASK		= BIT(5),

	ZONE_MAN_ISO_CNTL_MASK		= BIT(6),

	ZONE_MANUAL_CONTROL_MASK	= BIT(7),

	ZONE_PWR_DN_REQ_MASK		= BIT(9),

	ZONE_PWR_UP_REQ_MASK		= BIT(10),

	ZONE_BLK_RST_ASSERT_MASK	= BIT(12),

	ZONE_PWR_OFF_STATE_MASK		= BIT(25),

	ZONE_PWR_ON_STATE_MASK		= BIT(26),

	ZONE_DPG_PWR_STATE_MASK		= BIT(28),

	ZONE_MEM_PWR_STATE_MASK		= BIT(29),

	ZONE_RESET_STATE_MASK		= BIT(31),

	CPU0_PWR_ZONE_CTRL_REG		= 1,

	CPU_RESET_CONFIG_REG		= 2,

};

static void __iomem *cpubiuctrl_block;

static void __iomem *hif_cont_block;

static u32 cpu0_pwr_zone_ctrl_reg;

static u32 cpu_rst_cfg_reg;

static u32 hif_cont_reg;

#ifdef CONFIG_HOTPLUG_CPU

/*

 * We must quiesce a dying CPU before it can be killed by the boot CPU. Because

 * one or more cache may be disabled, we must flush to ensure coherency. We

 * cannot use traditionl completion structures or spinlocks as they rely on

 * coherency.

 */

static DEFINE_PER_CPU_ALIGNED(int, per_cpu_sw_state);

static int per_cpu_sw_state_rd(u32 cpu)

{

	sync_cache_r(SHIFT_PERCPU_PTR(&per_cpu_sw_state, per_cpu_offset(cpu)));

	return per_cpu(per_cpu_sw_state, cpu);

}

static void per_cpu_sw_state_wr(u32 cpu, int val)

{

	dmb();

	per_cpu(per_cpu_sw_state, cpu) = val;

	sync_cache_w(SHIFT_PERCPU_PTR(&per_cpu_sw_state, per_cpu_offset(cpu)));

}

#else

static inline void per_cpu_sw_state_wr(u32 cpu, int val) { }

#endif

static void __iomem *pwr_ctrl_get_base(u32 cpu)

{

	void __iomem *base = cpubiuctrl_block + cpu0_pwr_zone_ctrl_reg;

	base += (cpu_logical_map(cpu) * 4);

	return base;

}

static u32 pwr_ctrl_rd(u32 cpu)

{

	void __iomem *base = pwr_ctrl_get_base(cpu);

	return readl_relaxed(base);

}

static void pwr_ctrl_wr(u32 cpu, u32 val)

{

	void __iomem *base = pwr_ctrl_get_base(cpu);

	writel(val, base);

}

static void cpu_rst_cfg_set(u32 cpu, int set)

{

	u32 val;

	val = readl_relaxed(cpubiuctrl_block + cpu_rst_cfg_reg);

	if (set)

		val |= BIT(cpu_logical_map(cpu));

	else

		val &= ~BIT(cpu_logical_map(cpu));

	writel_relaxed(val, cpubiuctrl_block + cpu_rst_cfg_reg);

}

static void cpu_set_boot_addr(u32 cpu, unsigned long boot_addr)

{

	const int reg_ofs = cpu_logical_map(cpu) * 8;

	writel_relaxed(0, hif_cont_block + hif_cont_reg + reg_ofs);

	writel_relaxed(boot_addr, hif_cont_block + hif_cont_reg + 4 + reg_ofs);

}

static void brcmstb_cpu_boot(u32 cpu)

{

	/* Mark this CPU as "up" */

	per_cpu_sw_state_wr(cpu, 1);

	/*

	 * Set the reset vector to point to the secondary_startup

	 * routine

	 */

	cpu_set_boot_addr(cpu, virt_to_phys(brcmstb_secondary_startup));

	/* Unhalt the cpu */

	cpu_rst_cfg_set(cpu, 0);

}

static void brcmstb_cpu_power_on(u32 cpu)

{

	/*

	 * The secondary cores power was cut, so we must go through

	 * power-on initialization.

	 */

	u32 tmp;

	/* Request zone power up */

	pwr_ctrl_wr(cpu, ZONE_PWR_UP_REQ_MASK);

	/* Wait for the power up FSM to complete */

	do {

		tmp = pwr_ctrl_rd(cpu);

	} while (!(tmp & ZONE_PWR_ON_STATE_MASK));

}

static int brcmstb_cpu_get_power_state(u32 cpu)

{

	int tmp = pwr_ctrl_rd(cpu);

	return (tmp & ZONE_RESET_STATE_MASK) ? 0 : 1;

}

#ifdef CONFIG_HOTPLUG_CPU

static void brcmstb_cpu_die(u32 cpu)

{

	v7_exit_coherency_flush(all);

	per_cpu_sw_state_wr(cpu, 0);

	/* Sit and wait to die */

	wfi();

	/* We should never get here... */

	while (1)

		;

}

static int brcmstb_cpu_kill(u32 cpu)

{

	u32 tmp;

	while (per_cpu_sw_state_rd(cpu))

		;

	/* Program zone reset */

	pwr_ctrl_wr(cpu, ZONE_RESET_STATE_MASK | ZONE_BLK_RST_ASSERT_MASK |

			      ZONE_PWR_DN_REQ_MASK);

	/* Verify zone reset */

	tmp = pwr_ctrl_rd(cpu);

	if (!(tmp & ZONE_RESET_STATE_MASK))

		pr_err("%s: Zone reset bit for CPU %d not asserted!\n",

			__func__, cpu);

	/* Wait for power down */

	do {

		tmp = pwr_ctrl_rd(cpu);

	} while (!(tmp & ZONE_PWR_OFF_STATE_MASK));

	/* Flush pipeline before resetting CPU */

	mb();

	/* Assert reset on the CPU */

	cpu_rst_cfg_set(cpu, 1);

	return 1;

}

#endif /* CONFIG_HOTPLUG_CPU */

static int __init setup_hifcpubiuctrl_regs(struct device_node *np)

{

	int rc = 0;

	char *name;

	struct device_node *syscon_np = NULL;

	name = "syscon-cpu";

	syscon_np = of_parse_phandle(np, name, 0);

	if (!syscon_np) {

		pr_err("can't find phandle %s\n", name);

		rc = -EINVAL;

		goto cleanup;

	}

	cpubiuctrl_block = of_iomap(syscon_np, 0);

	if (!cpubiuctrl_block) {

		pr_err("iomap failed for cpubiuctrl_block\n");

		rc = -EINVAL;

		goto cleanup;

	}

	rc = of_property_read_u32_index(np, name, CPU0_PWR_ZONE_CTRL_REG,

					&cpu0_pwr_zone_ctrl_reg);

	if (rc) {

		pr_err("failed to read 1st entry from %s property (%d)\n", name,

			rc);

		rc = -EINVAL;

		goto cleanup;

	}

	rc = of_property_read_u32_index(np, name, CPU_RESET_CONFIG_REG,

					&cpu_rst_cfg_reg);

	if (rc) {

		pr_err("failed to read 2nd entry from %s property (%d)\n", name,

			rc);

		rc = -EINVAL;

		goto cleanup;

	}

cleanup:

	of_node_put(syscon_np);

	return rc;

}

static int __init setup_hifcont_regs(struct device_node *np)

{

	int rc = 0;

	char *name;

	struct device_node *syscon_np = NULL;

	name = "syscon-cont";

	syscon_np = of_parse_phandle(np, name, 0);

	if (!syscon_np) {

		pr_err("can't find phandle %s\n", name);

		rc = -EINVAL;

		goto cleanup;

	}

	hif_cont_block = of_iomap(syscon_np, 0);

	if (!hif_cont_block) {

		pr_err("iomap failed for hif_cont_block\n");

		rc = -EINVAL;

		goto cleanup;

	}

	/* Offset is at top of hif_cont_block */

	hif_cont_reg = 0;

cleanup:

	of_node_put(syscon_np);

	return rc;

}

static void __init brcmstb_cpu_ctrl_setup(unsigned int max_cpus)

{

	int rc;

	struct device_node *np;

	char *name;

	name = "brcm,brcmstb-smpboot";

	np = of_find_compatible_node(NULL, NULL, name);

	if (!np) {

		pr_err("can't find compatible node %s\n", name);

		return;

	}

	rc = setup_hifcpubiuctrl_regs(np);

	if (rc)

		return;

	rc = setup_hifcont_regs(np);

	if (rc)

		return;

}

static int brcmstb_boot_secondary(unsigned int cpu, struct task_struct *idle)

{

	/* Missing the brcm,brcmstb-smpboot DT node? */

	if (!cpubiuctrl_block || !hif_cont_block)

		return -ENODEV;

	/* Bring up power to the core if necessary */

	if (brcmstb_cpu_get_power_state(cpu) == 0)

		brcmstb_cpu_power_on(cpu);

	brcmstb_cpu_boot(cpu);

	return 0;

}

static struct smp_operations brcmstb_smp_ops __initdata = {

	.smp_prepare_cpus	= brcmstb_cpu_ctrl_setup,

	.smp_boot_secondary	= brcmstb_boot_secondary,

#ifdef CONFIG_HOTPLUG_CPU

	.cpu_kill		= brcmstb_cpu_kill,

	.cpu_die		= brcmstb_cpu_die,

#endif

};

CPU_METHOD_OF_DECLARE(brcmstb_smp, "brcm,brahma-b15", &brcmstb_smp_ops);