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Commit 323ab953 authored by Nicolas Pitre's avatar Nicolas Pitre Committed by Olof Johansson
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ARM: vexpress: migrate DCSCB to the new MCPM backend abstraction 

Signed-off-by: default avatarNicolas Pitre <nico@linaro.org>
Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
parent 03fd5db7
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Showing with 66 additions and 129 deletions
arch/arm/mach-vexpress/dcscb.c
View file @ 323ab953
......@@ -12,7 +12,6 @@
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/of_address.h>
#include <linux/vexpress.h>
......@@ -36,163 +35,102 @@
#define KFC_CFG_W 0x2c
#define DCS_CFG_R 0x30
/*
* We can't use regular spinlocks. In the switcher case, it is possible
* for an outbound CPU to call power_down() while its inbound counterpart
* is already live using the same logical CPU number which trips lockdep
* debugging.
*/
static arch_spinlock_t dcscb_lock = __ARCH_SPIN_LOCK_UNLOCKED;
static void __iomem *dcscb_base;
static int dcscb_use_count[4][2];
static int dcscb_allcpus_mask[2];
static int dcscb_power_up(unsigned int cpu, unsigned int cluster)
static int dcscb_cpu_powerup(unsigned int cpu, unsigned int cluster)
{
unsigned int rst_hold, cpumask = (1 << cpu);
unsigned int all_mask;
pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
if (cluster >= 2 || !(cpumask & dcscb_allcpus_mask[cluster]))
return -EINVAL;
all_mask = dcscb_allcpus_mask[cluster];
rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4);
rst_hold &= ~(cpumask | (cpumask << 4));
writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4);
return 0;
}
/*
* Since this is called with IRQs enabled, and no arch_spin_lock_irq
* variant exists, we need to disable IRQs manually here.
*/
local_irq_disable();
arch_spin_lock(&dcscb_lock);
dcscb_use_count[cpu][cluster]++;
if (dcscb_use_count[cpu][cluster] == 1) {
rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4);
if (rst_hold & (1 << 8)) {
/* remove cluster reset and add individual CPU's reset */
rst_hold &= ~(1 << 8);
rst_hold |= all_mask;
}
rst_hold &= ~(cpumask | (cpumask << 4));
writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4);
} else if (dcscb_use_count[cpu][cluster] != 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();
}
static int dcscb_cluster_powerup(unsigned int cluster)
{
unsigned int rst_hold;
arch_spin_unlock(&dcscb_lock);
local_irq_enable();
pr_debug("%s: cluster %u\n", __func__, cluster);
if (cluster >= 2)
return -EINVAL;
/* remove cluster reset and add individual CPU's reset */
rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4);
rst_hold &= ~(1 << 8);
rst_hold |= dcscb_allcpus_mask[cluster];
writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4);
return 0;
}
static void dcscb_power_down(void)
static void dcscb_cpu_powerdown_prepare(unsigned int cpu, unsigned int cluster)
{
unsigned int mpidr, cpu, cluster, rst_hold, cpumask, all_mask;
bool last_man = false, skip_wfi = false;
mpidr = read_cpuid_mpidr();
cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
cpumask = (1 << cpu);
unsigned int rst_hold;
pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
BUG_ON(cluster >= 2 || !(cpumask & dcscb_allcpus_mask[cluster]));
all_mask = dcscb_allcpus_mask[cluster];
__mcpm_cpu_going_down(cpu, cluster);
arch_spin_lock(&dcscb_lock);
BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP);
dcscb_use_count[cpu][cluster]--;
if (dcscb_use_count[cpu][cluster] == 0) {
rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4);
rst_hold |= cpumask;
if (((rst_hold | (rst_hold >> 4)) & all_mask) == all_mask) {
rst_hold |= (1 << 8);
last_man = true;
}
writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4);
} else if (dcscb_use_count[cpu][cluster] == 1) {
/*
* A power_up request went ahead of us.
* Even if we do not want to shut this CPU down,
* the caller expects a certain state as if the WFI
* was aborted. So let's continue with cache cleaning.
*/
skip_wfi = true;
} else
BUG();
if (last_man && __mcpm_outbound_enter_critical(cpu, cluster)) {
arch_spin_unlock(&dcscb_lock);
/* Flush all cache levels for this cluster. */
v7_exit_coherency_flush(all);
/*
* A full outer cache flush could be needed at this point
* on platforms with such a cache, depending on where the
* outer cache sits. In some cases the notion of a "last
* cluster standing" would need to be implemented if the
* outer cache is shared across clusters. In any case, when
* the outer cache needs flushing, there is no concurrent
* access to the cache controller to worry about and no
* special locking besides what is already provided by the
* MCPM state machinery is needed.
*/
/*
* Disable cluster-level coherency by masking
* incoming snoops and DVM messages:
*/
cci_disable_port_by_cpu(mpidr);
__mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN);
} else {
arch_spin_unlock(&dcscb_lock);
/* Disable and flush the local CPU cache. */
v7_exit_coherency_flush(louis);
}
BUG_ON(cluster >= 2 || !((1 << cpu) & dcscb_allcpus_mask[cluster]));
__mcpm_cpu_down(cpu, cluster);
rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4);
rst_hold |= (1 << cpu);
writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4);
}
/* Now we are prepared for power-down, do it: */
dsb();
if (!skip_wfi)
wfi();
static void dcscb_cluster_powerdown_prepare(unsigned int cluster)
{
unsigned int rst_hold;
/* Not dead at this point? Let our caller cope. */
pr_debug("%s: cluster %u\n", __func__, cluster);
BUG_ON(cluster >= 2);
rst_hold = readl_relaxed(dcscb_base + RST_HOLD0 + cluster * 4);
rst_hold |= (1 << 8);
writel_relaxed(rst_hold, dcscb_base + RST_HOLD0 + cluster * 4);
}
static const struct mcpm_platform_ops dcscb_power_ops = {
.power_up = dcscb_power_up,
.power_down = dcscb_power_down,
};
static void dcscb_cpu_cache_disable(void)
{
/* Disable and flush the local CPU cache. */
v7_exit_coherency_flush(louis);
}
static void __init dcscb_usage_count_init(void)
static void dcscb_cluster_cache_disable(void)
{
unsigned int mpidr, cpu, cluster;
/* Flush all cache levels for this cluster. */
v7_exit_coherency_flush(all);
mpidr = read_cpuid_mpidr();
cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
/*
* A full outer cache flush could be needed at this point
* on platforms with such a cache, depending on where the
* outer cache sits. In some cases the notion of a "last
* cluster standing" would need to be implemented if the
* outer cache is shared across clusters. In any case, when
* the outer cache needs flushing, there is no concurrent
* access to the cache controller to worry about and no
* special locking besides what is already provided by the
* MCPM state machinery is needed.
*/
pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
BUG_ON(cluster >= 2 || !((1 << cpu) & dcscb_allcpus_mask[cluster]));
dcscb_use_count[cpu][cluster] = 1;
/*
* Disable cluster-level coherency by masking
* incoming snoops and DVM messages:
*/
cci_disable_port_by_cpu(read_cpuid_mpidr());
}
static const struct mcpm_platform_ops dcscb_power_ops = {
.cpu_powerup = dcscb_cpu_powerup,
.cluster_powerup = dcscb_cluster_powerup,
.cpu_powerdown_prepare = dcscb_cpu_powerdown_prepare,
.cluster_powerdown_prepare = dcscb_cluster_powerdown_prepare,
.cpu_cache_disable = dcscb_cpu_cache_disable,
.cluster_cache_disable = dcscb_cluster_cache_disable,
};
extern void dcscb_power_up_setup(unsigned int affinity_level);
static int __init dcscb_init(void)
......@@ -213,7 +151,6 @@ static int __init dcscb_init(void)
cfg = readl_relaxed(dcscb_base + DCS_CFG_R);
dcscb_allcpus_mask[0] = (1 << (((cfg >> 16) >> (0 << 2)) & 0xf)) - 1;
dcscb_allcpus_mask[1] = (1 << (((cfg >> 16) >> (1 << 2)) & 0xf)) - 1;
dcscb_usage_count_init();
ret = mcpm_platform_register(&dcscb_power_ops);
if (!ret)
......
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