[PATCH v5 08/14] ARM: hisi: add hip04 SoC support

Nicolas Pitre nicolas.pitre at linaro.org
Wed May 7 10:44:54 PDT 2014


On Wed, 7 May 2014, Haojian Zhuang wrote:

> Hisilicon Hi3xxx is based on Cortex A9 Core. Now HiP04 SoC is based on
> Cortex A15 Core. Since multiple clusters is used in HiP04 SoC, it could
> be based on MCPM.
> 
> And HiP04 supports LPAE to support large memory.

This makes for a large patch with multiple things mixed together (DT 
bindings, MCPM backend, etc.)  That might help reviewing if split into 
separate patches.

> Signed-off-by: Haojian Zhuang <haojian.zhuang at linaro.org>
> ---
>  .../bindings/arm/hisilicon/hisilicon.txt           |  19 ++
>  .../devicetree/bindings/clock/hip04-clock.txt      |  20 ++
>  arch/arm/mach-hisi/Kconfig                         |  10 +-
>  arch/arm/mach-hisi/Makefile                        |   1 +
>  arch/arm/mach-hisi/core.h                          |   2 +
>  arch/arm/mach-hisi/hisilicon.c                     |  12 +
>  arch/arm/mach-hisi/platmcpm.c                      | 314 +++++++++++++++++++++
>  7 files changed, 377 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/clock/hip04-clock.txt
>  create mode 100644 arch/arm/mach-hisi/platmcpm.c

[...]

> diff --git a/arch/arm/mach-hisi/platmcpm.c b/arch/arm/mach-hisi/platmcpm.c
> new file mode 100644
> index 0000000..e0d7afd
> --- /dev/null
> +++ b/arch/arm/mach-hisi/platmcpm.c
> @@ -0,0 +1,314 @@
> +/*
> + * 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
> +
> +struct hip04_secondary_cpu_data {
> +	u32	bootwrapper_phys;
> +	u32	bootwrapper_size;
> +	u32	bootwrapper_magic;
> +	u32	relocation_entry;
> +	u32	relocation_size;
> +};
> +
> +static void __iomem *relocation, *sysctrl, *fabric;
> +static int hip04_cpu_table[HIP04_MAX_CLUSTERS][HIP04_MAX_CPUS_PER_CLUSTER];
> +static DEFINE_SPINLOCK(boot_lock);
> +static struct hip04_secondary_cpu_data hip04_boot;
> +
> +static bool hip04_cluster_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)
> +		return;
> +	data = readl_relaxed(fabric + FAB_SF_MODE);
> +	if (on)
> +		data |= 1 << cluster;
> +	else
> +		data &= ~(1 << cluster);
> +	writel_relaxed(data, fabric + FAB_SF_MODE);
> +	while (1) {
> +		if (data == readl_relaxed(fabric + FAB_SF_MODE))
> +			break;
> +	}
> +}
> +
> +static int hip04_mcpm_power_up(unsigned int cpu, unsigned int cluster)
> +{
> +	unsigned long data, mask;
> +
> +	if (!relocation || !sysctrl)
> +		return -ENODEV;
> +	if (cluster >= HIP04_MAX_CLUSTERS || cpu >= HIP04_MAX_CPUS_PER_CLUSTER)
> +		return -EINVAL;
> +
> +	spin_lock_irq(&boot_lock);
> +	writel_relaxed(hip04_boot.bootwrapper_phys, relocation);
> +	writel_relaxed(hip04_boot.bootwrapper_magic, relocation + 4);
> +	writel_relaxed(virt_to_phys(mcpm_entry_point), relocation + 8);
> +	writel_relaxed(0, relocation + 12);
> +
> +	if (hip04_cluster_down(cluster)) {
> +		data = CLUSTER_DEBUG_RESET_BIT;
> +		writel_relaxed(data, sysctrl + SC_CPU_RESET_DREQ(cluster));
> +		do {
> +			mask = CLUSTER_DEBUG_RESET_STATUS;
> +			data = readl_relaxed(sysctrl + \
> +					     SC_CPU_RESET_STATUS(cluster));
> +		} while (data & mask);
> +		hip04_set_snoop_filter(cluster, 1);
> +	}

Isn't this racy?  What if the new CPU starts executing code before 
snoops are enabled for it?

Normally we solve this race by letting the waking-up CPU turn on its 
snoops by itself from an assembly code callback provided as argument to 
mcpm_sync_init().  This is also the only way to eventually support deep 
C-states with cpuidle.

> +
> +	hip04_cpu_table[cluster][cpu]++;
> +
> +	data = CORE_RESET_BIT(cpu) | NEON_RESET_BIT(cpu) | \
> +	       CORE_DEBUG_RESET_BIT(cpu);
> +	writel_relaxed(data, sysctrl + SC_CPU_RESET_DREQ(cluster));
> +	spin_unlock_irq(&boot_lock);
> +	msleep(POLL_MSEC);

What is that msleep() for?

> +	return 0;
> +}
> +
> +static void hip04_mcpm_power_down(void)
> +{
> +	unsigned int mpidr, cpu, cluster;
> +	bool skip_wfi = 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 is still running\n", cluster, cpu);
> +		BUG();
> +	}
> +
> +	spin_unlock(&boot_lock);
> +
> +	v7_exit_coherency_flush(louis);

Don't you have to turn off snoop filters in the case of a complete 
cluster down as well?

> +
> +	__mcpm_cpu_down(cpu, cluster);
> +
> +	isb();
> +	dsb();

Those isb/dsb are redundant here.  They're implicit from 
__mcpm_cpu_down().

> +
> +	if (!skip_wfi)
> +		wfi();
> +}
> +
> +static int hip04_mcpm_wait_for_powerdown(unsigned int cpu, unsigned int cluster)
> +{
> +	unsigned int data, tries;
> +
> +	BUG_ON(cluster >= HIP04_MAX_CLUSTERS ||
> +	       cpu >= HIP04_MAX_CPUS_PER_CLUSTER);
> +
> +	for (tries = 0; tries < TIMEOUT_MSEC / POLL_MSEC; tries++) {
> +		data = readl_relaxed(sysctrl + SC_CPU_RESET_STATUS(cluster));
> +		if (!(data & CORE_WFI_STATUS(cpu))) {
> +			msleep(POLL_MSEC);
> +			continue;
> +		}
> +		data = CORE_RESET_BIT(cpu) | NEON_RESET_BIT(cpu) | \
> +		       CORE_DEBUG_RESET_BIT(cpu);
> +		writel_relaxed(data, sysctrl + SC_CPU_RESET_REQ(cluster));

You are not supposed to perform any changes here.  This method is there 
only to wait for given CPU to be down.  It is not guaranteed it will be 
called.  Furthermore this can race with the power_up method.

Normally you should perform this reset business from 
hip04_mcpm_power_down() while the lock is held.  Now... this assumes 
that any power/reset would be effective only when the CPU executes a 
WFI.  Is this the case on this hardware?  If not then we'll have to 
think about a different strategy.

> +		return 0;
> +	}
> +
> +	return -ETIMEDOUT;
> +}
> +
> +static void hip04_mcpm_powered_up(void)
> +{
> +	if (!relocation)
> +		return;
> +	spin_lock(&boot_lock);
> +	writel_relaxed(0, relocation);
> +	writel_relaxed(0, relocation + 4);
> +	writel_relaxed(0, relocation + 8);
> +	writel_relaxed(0, relocation + 12);
> +	spin_unlock(&boot_lock);
> +}
> +
> +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_fab;
> +	int ret = -ENODEV;
> +
> +	np = of_find_compatible_node(NULL, NULL, "hisilicon,sysctrl");
> +	if (!np)
> +		goto err;
> +	np_fab = of_find_compatible_node(NULL, NULL, "hisilicon,hip04-fabric");
> +	if (!np_fab)
> +		goto err;
> +
> +	if (of_property_read_u32(np, "bootwrapper-phys",
> +				 &hip04_boot.bootwrapper_phys)) {
> +		pr_err("failed to get bootwrapper-phys\n");
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +	if (of_property_read_u32(np, "bootwrapper-size",
> +				 &hip04_boot.bootwrapper_size)) {
> +		pr_err("failed to get bootwrapper-size\n");
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +	if (of_property_read_u32(np, "bootwrapper-magic",
> +				 &hip04_boot.bootwrapper_magic)) {
> +		pr_err("failed to get bootwrapper-magic\n");
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +	if (of_property_read_u32(np, "relocation-entry",
> +				 &hip04_boot.relocation_entry)) {
> +		pr_err("failed to get relocation-entry\n");
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +	if (of_property_read_u32(np, "relocation-size",
> +				 &hip04_boot.relocation_size)) {
> +		pr_err("failed to get relocation-size\n");
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +
> +	relocation = ioremap(hip04_boot.relocation_entry,
> +			     hip04_boot.relocation_size);
> +	if (!relocation) {
> +		pr_err("failed to map relocation space\n");
> +		ret = -ENOMEM;
> +		goto err;
> +	}
> +	sysctrl = of_iomap(np, 0);
> +	if (!sysctrl) {
> +		pr_err("failed to get sysctrl base\n");
> +		ret = -ENOMEM;
> +		goto err_sysctrl;
> +	}
> +	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())
> +		return -EINVAL;
> +	ret = mcpm_platform_register(&hip04_mcpm_ops);
> +	if (!ret) {
> +		mcpm_sync_init(NULL);
> +		pr_info("HiP04 MCPM initialized\n");
> +	}
> +	return ret;
> +err_fabric:
> +	iounmap(sysctrl);
> +err_sysctrl:
> +	iounmap(relocation);
> +err:
> +	return ret;
> +}
> +early_initcall(hip04_mcpm_init);
> +
> +bool __init hip04_smp_init_ops(void)
> +{
> +	mcpm_smp_set_ops();
> +	return true;
> +}

You should be able to call mcpm_smp_set_ops() directly from 
hip04_mcpm_init(), and only if there was no errors.


Nicolas



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