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Diffstat (limited to 'arch/arm/mach-vexpress/tc2_pm.c')
-rw-r--r--arch/arm/mach-vexpress/tc2_pm.c132
1 files changed, 78 insertions, 54 deletions
diff --git a/arch/arm/mach-vexpress/tc2_pm.c b/arch/arm/mach-vexpress/tc2_pm.c
index 7aeb5d60e48..b743a0ae02c 100644
--- a/arch/arm/mach-vexpress/tc2_pm.c
+++ b/arch/arm/mach-vexpress/tc2_pm.c
@@ -12,10 +12,12 @@
* published by the Free Software Foundation.
*/
+#include <linux/delay.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/of_address.h>
+#include <linux/of_irq.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/irqchip/arm-gic.h>
@@ -31,11 +33,17 @@
#include "spc.h"
/* SCC conf registers */
+#define RESET_CTRL 0x018
+#define RESET_A15_NCORERESET(cpu) (1 << (2 + (cpu)))
+#define RESET_A7_NCORERESET(cpu) (1 << (16 + (cpu)))
+
#define A15_CONF 0x400
#define A7_CONF 0x500
#define SYS_INFO 0x700
#define SPC_BASE 0xb00
+static void __iomem *scc;
+
/*
* We can't use regular spinlocks. In the switcher case, it is possible
* for an outbound CPU to call power_down() after its inbound counterpart
@@ -131,6 +139,16 @@ static void tc2_pm_down(u64 residency)
} else
BUG();
+ /*
+ * If the CPU is committed to power down, make sure
+ * the power controller will be in charge of waking it
+ * up upon IRQ, ie IRQ lines are cut from GIC CPU IF
+ * to the CPU by disabling the GIC CPU IF to prevent wfi
+ * from completing execution behind power controller back
+ */
+ if (!skip_wfi)
+ gic_cpu_if_down();
+
if (last_man && __mcpm_outbound_enter_critical(cpu, cluster)) {
arch_spin_unlock(&tc2_pm_lock);
@@ -146,32 +164,7 @@ static void tc2_pm_down(u64 residency)
: : "r" (0x400) );
}
- /*
- * We need to disable and flush the whole (L1 and L2) cache.
- * Let's do it in the safest possible way i.e. with
- * no memory access within the following sequence
- * including the stack.
- *
- * Note: fp is preserved to the stack explicitly prior doing
- * this since adding it to the clobber list is incompatible
- * with having CONFIG_FRAME_POINTER=y.
- */
- asm volatile(
- "str fp, [sp, #-4]! \n\t"
- "mrc p15, 0, r0, c1, c0, 0 @ get CR \n\t"
- "bic r0, r0, #"__stringify(CR_C)" \n\t"
- "mcr p15, 0, r0, c1, c0, 0 @ set CR \n\t"
- "isb \n\t"
- "bl v7_flush_dcache_all \n\t"
- "clrex \n\t"
- "mrc p15, 0, r0, c1, c0, 1 @ get AUXCR \n\t"
- "bic r0, r0, #(1 << 6) @ disable local coherency \n\t"
- "mcr p15, 0, r0, c1, c0, 1 @ set AUXCR \n\t"
- "isb \n\t"
- "dsb \n\t"
- "ldr fp, [sp], #4"
- : : : "r0","r1","r2","r3","r4","r5","r6","r7",
- "r9","r10","lr","memory");
+ v7_exit_coherency_flush(all);
cci_disable_port_by_cpu(mpidr);
@@ -187,26 +180,7 @@ static void tc2_pm_down(u64 residency)
arch_spin_unlock(&tc2_pm_lock);
- /*
- * We need to disable and flush only the L1 cache.
- * Let's do it in the safest possible way as above.
- */
- asm volatile(
- "str fp, [sp, #-4]! \n\t"
- "mrc p15, 0, r0, c1, c0, 0 @ get CR \n\t"
- "bic r0, r0, #"__stringify(CR_C)" \n\t"
- "mcr p15, 0, r0, c1, c0, 0 @ set CR \n\t"
- "isb \n\t"
- "bl v7_flush_dcache_louis \n\t"
- "clrex \n\t"
- "mrc p15, 0, r0, c1, c0, 1 @ get AUXCR \n\t"
- "bic r0, r0, #(1 << 6) @ disable local coherency \n\t"
- "mcr p15, 0, r0, c1, c0, 1 @ set AUXCR \n\t"
- "isb \n\t"
- "dsb \n\t"
- "ldr fp, [sp], #4"
- : : : "r0","r1","r2","r3","r4","r5","r6","r7",
- "r9","r10","lr","memory");
+ v7_exit_coherency_flush(louis);
}
__mcpm_cpu_down(cpu, cluster);
@@ -223,6 +197,55 @@ static void tc2_pm_power_down(void)
tc2_pm_down(0);
}
+static int tc2_core_in_reset(unsigned int cpu, unsigned int cluster)
+{
+ u32 mask = cluster ?
+ RESET_A7_NCORERESET(cpu)
+ : RESET_A15_NCORERESET(cpu);
+
+ return !(readl_relaxed(scc + RESET_CTRL) & mask);
+}
+
+#define POLL_MSEC 10
+#define TIMEOUT_MSEC 1000
+
+static int tc2_pm_wait_for_powerdown(unsigned int cpu, unsigned int cluster)
+{
+ unsigned tries;
+
+ pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
+ BUG_ON(cluster >= TC2_CLUSTERS || cpu >= TC2_MAX_CPUS_PER_CLUSTER);
+
+ for (tries = 0; tries < TIMEOUT_MSEC / POLL_MSEC; ++tries) {
+ /*
+ * Only examine the hardware state if the target CPU has
+ * caught up at least as far as tc2_pm_down():
+ */
+ if (ACCESS_ONCE(tc2_pm_use_count[cpu][cluster]) == 0) {
+ pr_debug("%s(cpu=%u, cluster=%u): RESET_CTRL = 0x%08X\n",
+ __func__, cpu, cluster,
+ readl_relaxed(scc + RESET_CTRL));
+
+ /*
+ * We need the CPU to reach WFI, but the power
+ * controller may put the cluster in reset and
+ * power it off as soon as that happens, before
+ * we have a chance to see STANDBYWFI.
+ *
+ * So we need to check for both conditions:
+ */
+ if (tc2_core_in_reset(cpu, cluster) ||
+ ve_spc_cpu_in_wfi(cpu, cluster))
+ return 0; /* success: the CPU is halted */
+ }
+
+ /* Otherwise, wait and retry: */
+ msleep(POLL_MSEC);
+ }
+
+ return -ETIMEDOUT; /* timeout */
+}
+
static void tc2_pm_suspend(u64 residency)
{
unsigned int mpidr, cpu, cluster;
@@ -231,7 +254,6 @@ static void tc2_pm_suspend(u64 residency)
cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
ve_spc_set_resume_addr(cluster, cpu, virt_to_phys(mcpm_entry_point));
- gic_cpu_if_down();
tc2_pm_down(residency);
}
@@ -266,10 +288,11 @@ static void tc2_pm_powered_up(void)
}
static const struct mcpm_platform_ops tc2_pm_power_ops = {
- .power_up = tc2_pm_power_up,
- .power_down = tc2_pm_power_down,
- .suspend = tc2_pm_suspend,
- .powered_up = tc2_pm_powered_up,
+ .power_up = tc2_pm_power_up,
+ .power_down = tc2_pm_power_down,
+ .wait_for_powerdown = tc2_pm_wait_for_powerdown,
+ .suspend = tc2_pm_suspend,
+ .powered_up = tc2_pm_powered_up,
};
static bool __init tc2_pm_usage_count_init(void)
@@ -302,8 +325,7 @@ static void __naked tc2_pm_power_up_setup(unsigned int affinity_level)
static int __init tc2_pm_init(void)
{
- int ret;
- void __iomem *scc;
+ int ret, irq;
u32 a15_cluster_id, a7_cluster_id, sys_info;
struct device_node *np;
@@ -327,13 +349,15 @@ static int __init tc2_pm_init(void)
tc2_nr_cpus[a15_cluster_id] = (sys_info >> 16) & 0xf;
tc2_nr_cpus[a7_cluster_id] = (sys_info >> 20) & 0xf;
+ irq = irq_of_parse_and_map(np, 0);
+
/*
* A subset of the SCC registers is also used to communicate
* with the SPC (power controller). We need to be able to
* drive it very early in the boot process to power up
* processors, so we initialize the SPC driver here.
*/
- ret = ve_spc_init(scc + SPC_BASE, a15_cluster_id);
+ ret = ve_spc_init(scc + SPC_BASE, a15_cluster_id, irq);
if (ret)
return ret;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-04 11:23:08 +0000