ARM: hisi: enable MCPM implementation

Multiple CPU clusters are used in Hisilicon HiP04 SoC. Now use MCPM
framework to manage power on HiP04 SoC.

Changelog:
v20:
  * Disable L2 prefetch when the whole cluster is down.
  * Move disabling snoop filter into power_down() after L2 prefetch
    disabled.
  * Remove delay in wait_for_power_down() after L2 prefetch disabled.
  * Add the sleep polling in wait_for_power_down() again since we
    need to wait L2 when the cluster is down.
v19:
  * Add comments on those delay hacks.
  * Update on checking core enabled counts in wait_for_power_down().
v18:
  * Fix to release resource in probe().
  * Check whether cpu is already up in the process of making cpu down.
  * Add udelay in power up/down sequence.
  * Optimize on setting relocation entry.
  * Optimize on polling status in wait_for_power_down().
  * Add mcpm critical operations.
v17:
  * Parse bootwrapper parameters in DTS file.
  * Fix to use msleep() in spinlock region.
v16:
  * Parse bootwrapper parameters in command line instead.
v13:
  * Restore power down operation in MCPM.
  * Fix disabling snoop filter issue in MCPM.
v12:
  * Use wfi as power down state in MCPM.
  * Remove wait_for_powerdown() in MCPM because wfi is used now.
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>

arch/arm/mach-hisi/Makefile

@@ -3,4 +3,5 @@
 #
 
 obj-y	+= hisilicon.o
+obj-$(CONFIG_MCPM)		+= platmcpm.o
 obj-$(CONFIG_SMP)		+= platsmp.o hotplug.o headsmp.o

arch/arm/mach-hisi/platmcpm.c

+/*
+ * Copyright (c) 2013-2014 Linaro Ltd.
+ * Copyright (c) 2013-2014 Hisilicon Limited.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/memblock.h>
+#include <linux/of_address.h>
+
+#include <asm/cputype.h>
+#include <asm/cp15.h>
+#include <asm/mcpm.h>
+
+#include "core.h"
+
+/* bits definition in SC_CPU_RESET_REQ[x]/SC_CPU_RESET_DREQ[x]
+ * 1 -- unreset; 0 -- reset
+ */
+#define CORE_RESET_BIT(x)		(1 << x)
+#define NEON_RESET_BIT(x)		(1 << (x + 4))
+#define CORE_DEBUG_RESET_BIT(x)		(1 << (x + 9))
+#define CLUSTER_L2_RESET_BIT		(1 << 8)
+#define CLUSTER_DEBUG_RESET_BIT		(1 << 13)
+
+/*
+ * bits definition in SC_CPU_RESET_STATUS[x]
+ * 1 -- reset status; 0 -- unreset status
+ */
+#define CORE_RESET_STATUS(x)		(1 << x)
+#define NEON_RESET_STATUS(x)		(1 << (x + 4))
+#define CORE_DEBUG_RESET_STATUS(x)	(1 << (x + 9))
+#define CLUSTER_L2_RESET_STATUS		(1 << 8)
+#define CLUSTER_DEBUG_RESET_STATUS	(1 << 13)
+#define CORE_WFI_STATUS(x)		(1 << (x + 16))
+#define CORE_WFE_STATUS(x)		(1 << (x + 20))
+#define CORE_DEBUG_ACK(x)		(1 << (x + 24))
+
+#define SC_CPU_RESET_REQ(x)		(0x520 + (x << 3))	/* reset */
+#define SC_CPU_RESET_DREQ(x)		(0x524 + (x << 3))	/* unreset */
+#define SC_CPU_RESET_STATUS(x)		(0x1520 + (x << 3))
+
+#define FAB_SF_MODE			0x0c
+#define FAB_SF_INVLD			0x10
+
+/* bits definition in FB_SF_INVLD */
+#define FB_SF_INVLD_START		(1 << 8)
+
+#define HIP04_MAX_CLUSTERS		4
+#define HIP04_MAX_CPUS_PER_CLUSTER	4
+
+#define POLL_MSEC	10
+#define TIMEOUT_MSEC	1000
+
+static void __iomem *sysctrl, *fabric;
+static int hip04_cpu_table[HIP04_MAX_CLUSTERS][HIP04_MAX_CPUS_PER_CLUSTER];
+static DEFINE_SPINLOCK(boot_lock);
+static u32 fabric_phys_addr;
+/*
+ * [0]: bootwrapper physical address
+ * [1]: bootwrapper size
+ * [2]: relocation address
+ * [3]: relocation size
+ */
+static u32 hip04_boot_method[4];
+
+static bool hip04_cluster_is_down(unsigned int cluster)
+{
+	int i;
+
+	for (i = 0; i < HIP04_MAX_CPUS_PER_CLUSTER; i++)
+		if (hip04_cpu_table[cluster][i])
+			return false;
+	return true;
+}
+
+static void hip04_set_snoop_filter(unsigned int cluster, unsigned int on)
+{
+	unsigned long data;
+
+	if (!fabric)
+		BUG();
+	data = readl_relaxed(fabric + FAB_SF_MODE);
+	if (on)
+		data |= 1 << cluster;
+	else
+		data &= ~(1 << cluster);
+	writel_relaxed(data, fabric + FAB_SF_MODE);
+	do {
+		cpu_relax();
+	} while (data != readl_relaxed(fabric + FAB_SF_MODE));
+}
+
+static int hip04_mcpm_power_up(unsigned int cpu, unsigned int cluster)
+{
+	unsigned long data;
+	void __iomem *sys_dreq, *sys_status;
+
+	if (!sysctrl)
+		return -ENODEV;
+	if (cluster >= HIP04_MAX_CLUSTERS || cpu >= HIP04_MAX_CPUS_PER_CLUSTER)
+		return -EINVAL;
+
+	spin_lock_irq(&boot_lock);
+
+	if (hip04_cpu_table[cluster][cpu])
+		goto out;
+
+	sys_dreq = sysctrl + SC_CPU_RESET_DREQ(cluster);
+	sys_status = sysctrl + SC_CPU_RESET_STATUS(cluster);
+	if (hip04_cluster_is_down(cluster)) {
+		data = CLUSTER_DEBUG_RESET_BIT;
+		writel_relaxed(data, sys_dreq);
+		do {
+			cpu_relax();
+			data = readl_relaxed(sys_status);
+		} while (data & CLUSTER_DEBUG_RESET_STATUS);
+	}
+
+	data = CORE_RESET_BIT(cpu) | NEON_RESET_BIT(cpu) | \
+	       CORE_DEBUG_RESET_BIT(cpu);
+	writel_relaxed(data, sys_dreq);
+	do {
+		cpu_relax();
+	} while (data == readl_relaxed(sys_status));
+	/*
+	 * We may fail to power up core again without this delay.
+	 * It's not mentioned in document. It's found by test.
+	 */
+	udelay(20);
+out:
+	hip04_cpu_table[cluster][cpu]++;
+	spin_unlock_irq(&boot_lock);
+
+	return 0;
+}
+
+static void hip04_mcpm_power_down(void)
+{
+	unsigned int mpidr, cpu, cluster;
+	bool skip_wfi = false, last_man = false;
+
+	mpidr = read_cpuid_mpidr();
+	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+
+	__mcpm_cpu_going_down(cpu, cluster);
+
+	spin_lock(&boot_lock);
+	BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP);
+	hip04_cpu_table[cluster][cpu]--;
+	if (hip04_cpu_table[cluster][cpu] == 1) {
+		/* A power_up request went ahead of us. */
+		skip_wfi = true;
+	} else if (hip04_cpu_table[cluster][cpu] > 1) {
+		pr_err("Cluster %d CPU%d boots multiple times\n", cluster, cpu);
+		BUG();
+	}
+
+	last_man = hip04_cluster_is_down(cluster);
+	if (last_man && __mcpm_outbound_enter_critical(cpu, cluster)) {
+		spin_unlock(&boot_lock);
+		/* Since it's Cortex A15, disable L2 prefetching. */
+		asm volatile(
+		"mcr	p15, 1, %0, c15, c0, 3 \n\t"
+		"isb	\n\t"
+		"dsb	"
+		: : "r" (0x400) );
+		v7_exit_coherency_flush(all);
+		hip04_set_snoop_filter(cluster, 0);
+		__mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN);
+	} else {
+		spin_unlock(&boot_lock);
+		v7_exit_coherency_flush(louis);
+	}
+
+	__mcpm_cpu_down(cpu, cluster);
+
+	if (!skip_wfi)
+		wfi();
+}
+
+static int hip04_mcpm_wait_for_powerdown(unsigned int cpu, unsigned int cluster)
+{
+	unsigned int data, tries, count;
+	int ret = -ETIMEDOUT;
+
+	BUG_ON(cluster >= HIP04_MAX_CLUSTERS ||
+	       cpu >= HIP04_MAX_CPUS_PER_CLUSTER);
+
+	count = TIMEOUT_MSEC / POLL_MSEC;
+	spin_lock_irq(&boot_lock);
+	for (tries = 0; tries < count; tries++) {
+		if (hip04_cpu_table[cluster][cpu]) {
+			ret = -EBUSY;
+			goto err;
+		}
+		cpu_relax();
+		data = readl_relaxed(sysctrl + SC_CPU_RESET_STATUS(cluster));
+		if (data & CORE_WFI_STATUS(cpu))
+			break;
+		spin_unlock_irq(&boot_lock);
+		/* Wait for clean L2 when the whole cluster is down. */
+		msleep(POLL_MSEC);
+		spin_lock_irq(&boot_lock);
+	}
+	if (tries >= count)
+		goto err;
+	data = CORE_RESET_BIT(cpu) | NEON_RESET_BIT(cpu) | \
+	       CORE_DEBUG_RESET_BIT(cpu);
+	writel_relaxed(data, sysctrl + SC_CPU_RESET_REQ(cluster));
+	for (tries = 0; tries < count; tries++) {
+		cpu_relax();
+		data = readl_relaxed(sysctrl + SC_CPU_RESET_STATUS(cluster));
+		if (data & CORE_RESET_STATUS(cpu))
+			break;
+	}
+	if (tries >= count)
+		goto err;
+	spin_unlock_irq(&boot_lock);
+	return 0;
+err:
+	spin_unlock_irq(&boot_lock);
+	return ret;
+}
+
+static void hip04_mcpm_powered_up(void)
+{
+	unsigned int mpidr, cpu, cluster;
+
+	mpidr = read_cpuid_mpidr();
+	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+
+	spin_lock(&boot_lock);
+	if (!hip04_cpu_table[cluster][cpu])
+		hip04_cpu_table[cluster][cpu] = 1;
+	spin_unlock(&boot_lock);
+}
+
+static void __naked hip04_mcpm_power_up_setup(unsigned int affinity_level)
+{
+	asm volatile ("			\n"
+"	cmp	r0, #0			\n"
+"	bxeq	lr			\n"
+	/* calculate fabric phys address */
+"	adr	r2, 2f			\n"
+"	ldmia	r2, {r1, r3}		\n"
+"	sub	r0, r2, r1		\n"
+"	ldr	r2, [r0, r3]		\n"
+	/* get cluster id from MPIDR */
+"	mrc	p15, 0, r0, c0, c0, 5	\n"
+"	ubfx	r1, r0, #8, #8		\n"
+	/* 1 << cluster id */
+"	mov	r0, #1			\n"
+"	mov	r3, r0, lsl r1		\n"
+"	ldr	r0, [r2, #"__stringify(FAB_SF_MODE)"]	\n"
+"	tst	r0, r3			\n"
+"	bxne	lr			\n"
+"	orr	r1, r0, r3		\n"
+"	str	r1, [r2, #"__stringify(FAB_SF_MODE)"]	\n"
+"1:	ldr	r0, [r2, #"__stringify(FAB_SF_MODE)"]	\n"
+"	tst	r0, r3			\n"
+"	beq	1b			\n"
+"	bx	lr			\n"
+
+"	.align	2			\n"
+"2:	.word	.			\n"
+"	.word	fabric_phys_addr	\n"
+	);
+}
+
+static const struct mcpm_platform_ops hip04_mcpm_ops = {
+	.power_up		= hip04_mcpm_power_up,
+	.power_down		= hip04_mcpm_power_down,
+	.wait_for_powerdown	= hip04_mcpm_wait_for_powerdown,
+	.powered_up		= hip04_mcpm_powered_up,
+};
+
+static bool __init hip04_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 >= HIP04_MAX_CLUSTERS ||
+	    cpu >= HIP04_MAX_CPUS_PER_CLUSTER) {
+		pr_err("%s: boot CPU is out of bound!\n", __func__);
+		return false;
+	}
+	hip04_set_snoop_filter(cluster, 1);
+	hip04_cpu_table[cluster][cpu] = 1;
+	return true;
+}
+
+static int __init hip04_mcpm_init(void)
+{
+	struct device_node *np, *np_sctl, *np_fab;
+	struct resource fab_res;
+	void __iomem *relocation;
+	int ret = -ENODEV;
+
+	np = of_find_compatible_node(NULL, NULL, "hisilicon,hip04-bootwrapper");
+	if (!np)
+		goto err;
+	ret = of_property_read_u32_array(np, "boot-method",
+					 &hip04_boot_method[0], 4);
+	if (ret)
+		goto err;
+	np_sctl = of_find_compatible_node(NULL, NULL, "hisilicon,sysctrl");
+	if (!np_sctl)
+		goto err;
+	np_fab = of_find_compatible_node(NULL, NULL, "hisilicon,hip04-fabric");
+	if (!np_fab)
+		goto err;
+
+	ret = memblock_reserve(hip04_boot_method[0], hip04_boot_method[1]);
+	if (ret)
+		goto err;
+
+	relocation = ioremap(hip04_boot_method[2], hip04_boot_method[3]);
+	if (!relocation) {
+		pr_err("failed to map relocation space\n");
+		ret = -ENOMEM;
+		goto err_reloc;
+	}
+	sysctrl = of_iomap(np_sctl, 0);
+	if (!sysctrl) {
+		pr_err("failed to get sysctrl base\n");
+		ret = -ENOMEM;
+		goto err_sysctrl;
+	}
+	ret = of_address_to_resource(np_fab, 0, &fab_res);
+	if (ret) {
+		pr_err("failed to get fabric base phys\n");
+		goto err_fabric;
+	}
+	fabric_phys_addr = fab_res.start;
+	sync_cache_w(&fabric_phys_addr);
+	fabric = of_iomap(np_fab, 0);
+	if (!fabric) {
+		pr_err("failed to get fabric base\n");
+		ret = -ENOMEM;
+		goto err_fabric;
+	}
+
+	if (!hip04_cpu_table_init()) {
+		ret = -EINVAL;
+		goto err_table;
+	}
+	ret = mcpm_platform_register(&hip04_mcpm_ops);
+	if (ret) {
+		goto err_table;
+	}
+
+	/*
+	 * Fill the instruction address that is used after secondary core
+	 * out of reset.
+	 */
+	writel_relaxed(hip04_boot_method[0], relocation);
+	writel_relaxed(0xa5a5a5a5, relocation + 4);	/* magic number */
+	writel_relaxed(virt_to_phys(mcpm_entry_point), relocation + 8);
+	writel_relaxed(0, relocation + 12);
+	iounmap(relocation);
+
+	mcpm_sync_init(hip04_mcpm_power_up_setup);
+	mcpm_smp_set_ops();
+	pr_info("HiP04 MCPM initialized\n");
+	return ret;
+err_table:
+	iounmap(fabric);
+err_fabric:
+	iounmap(sysctrl);
+err_sysctrl:
+	iounmap(relocation);
+err_reloc:
+	memblock_free(hip04_boot_method[0], hip04_boot_method[1]);
+err:
+	return ret;
+}
+early_initcall(hip04_mcpm_init);