aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorNicolas Pitre <nicolas.pitre@linaro.org>2013-05-16 03:25:39 -0400
committerAndrey Konovalov <andrey.konovalov@linaro.org>2013-05-25 13:31:47 +0400
commit82d931619b0843d88ff2dea3f50b0b00b4d0bc3d (patch)
treed65dffd8dabc1fd23f1fc8a129a34c23c1e3f4bb
parentaacbeb9c9fabd1156a2de3e36817ee3c9a90d2ca (diff)
downloadvexpress-lsk-tracking-lsk-vexpress-iks-lsk-20130525.1.tar.gz
Up to now, the logical CPU was somehow tied to the physical CPU number within a cluster which caused problems when forcing the boot on an A7. The pairing is completely independent from physical CPU numbers now. Signed-off-by: Nicolas Pitre <nico@linaro.org>
-rw-r--r--arch/arm/common/bL_switcher.c203
1 files changed, 114 insertions, 89 deletions
diff --git a/arch/arm/common/bL_switcher.c b/arch/arm/common/bL_switcher.c
index e6b1157742f..914b90345df 100644
--- a/arch/arm/common/bL_switcher.c
+++ b/arch/arm/common/bL_switcher.c
@@ -53,7 +53,7 @@ static int read_mpidr(void)
{
unsigned int id;
asm volatile ("mrc\tp15, 0, %0, c0, c0, 5" : "=r" (id));
- return id;
+ return id & MPIDR_HWID_BITMASK;
}
/*
@@ -72,16 +72,14 @@ static s64 get_ns(void)
static void bL_do_switch(void *_arg)
{
- unsigned mpidr, cpuid, clusterid, ob_cluster, ib_cluster;
+ unsigned ib_mpidr, ib_cpu, ib_cluster;
long volatile handshake, **handshake_ptr = _arg;
pr_debug("%s\n", __func__);
- mpidr = read_mpidr();
- cpuid = MPIDR_AFFINITY_LEVEL(mpidr, 0);
- clusterid = MPIDR_AFFINITY_LEVEL(mpidr, 1);
- ob_cluster = clusterid;
- ib_cluster = clusterid ^ 1;
+ ib_mpidr = cpu_logical_map(smp_processor_id());
+ ib_cpu = MPIDR_AFFINITY_LEVEL(ib_mpidr, 0);
+ ib_cluster = MPIDR_AFFINITY_LEVEL(ib_mpidr, 1);
/* Advertise our handshake location */
if (handshake_ptr) {
@@ -94,7 +92,7 @@ static void bL_do_switch(void *_arg)
* Our state has been saved at this point. Let's release our
* inbound CPU.
*/
- mcpm_set_entry_vector(cpuid, ib_cluster, cpu_resume);
+ mcpm_set_entry_vector(ib_cpu, ib_cluster, cpu_resume);
sev();
/*
@@ -148,6 +146,7 @@ static int bL_switchpoint(unsigned long _arg)
*/
static unsigned int bL_gic_id[MAX_CPUS_PER_CLUSTER][MAX_NR_CLUSTERS];
+static int bL_switcher_cpu_pairing[NR_CPUS];
/*
* bL_switch_to - Switch to a specific cluster for the current CPU
@@ -158,41 +157,46 @@ static unsigned int bL_gic_id[MAX_CPUS_PER_CLUSTER][MAX_NR_CLUSTERS];
*/
static int bL_switch_to(unsigned int new_cluster_id)
{
- unsigned int mpidr, cpuid, clusterid, ob_cluster, ib_cluster, this_cpu;
+ unsigned int mpidr, this_cpu, that_cpu;
+ unsigned int ob_mpidr, ob_cpu, ob_cluster, ib_mpidr, ib_cpu, ib_cluster;
struct completion inbound_alive;
struct tick_device *tdev;
enum clock_event_mode tdev_mode;
long volatile *handshake_ptr;
int ipi_nr, ret;
- mpidr = read_mpidr();
- cpuid = MPIDR_AFFINITY_LEVEL(mpidr, 0);
- clusterid = MPIDR_AFFINITY_LEVEL(mpidr, 1);
- ob_cluster = clusterid;
- ib_cluster = clusterid ^ 1;
+ this_cpu = smp_processor_id();
+ ob_mpidr = read_mpidr();
+ ob_cpu = MPIDR_AFFINITY_LEVEL(ob_mpidr, 0);
+ ob_cluster = MPIDR_AFFINITY_LEVEL(ob_mpidr, 1);
+ BUG_ON(cpu_logical_map(this_cpu) != ob_mpidr);
- if (new_cluster_id == clusterid)
+ if (new_cluster_id == ob_cluster)
return 0;
- pr_debug("before switch: CPU %d in cluster %d\n", cpuid, clusterid);
+ that_cpu = bL_switcher_cpu_pairing[this_cpu];
+ ib_mpidr = cpu_logical_map(that_cpu);
+ ib_cpu = MPIDR_AFFINITY_LEVEL(ib_mpidr, 0);
+ ib_cluster = MPIDR_AFFINITY_LEVEL(ib_mpidr, 1);
- this_cpu = smp_processor_id();
+ pr_debug("before switch: CPU %d MPIDR %#x -> %#x\n",
+ this_cpu, ob_mpidr, ib_mpidr);
/* Close the gate for our entry vectors */
- mcpm_set_entry_vector(cpuid, ob_cluster, NULL);
- mcpm_set_entry_vector(cpuid, ib_cluster, NULL);
+ mcpm_set_entry_vector(ob_cpu, ob_cluster, NULL);
+ mcpm_set_entry_vector(ib_cpu, ib_cluster, NULL);
/* Install our "inbound alive" notifier. */
init_completion(&inbound_alive);
ipi_nr = register_ipi_completion(&inbound_alive, this_cpu);
- ipi_nr |= ((1 << 16) << bL_gic_id[cpuid][ob_cluster]);
- mcpm_set_early_poke(cpuid, ib_cluster, gic_get_sgir_physaddr(), ipi_nr);
+ ipi_nr |= ((1 << 16) << bL_gic_id[ob_cpu][ob_cluster]);
+ mcpm_set_early_poke(ib_cpu, ib_cluster, gic_get_sgir_physaddr(), ipi_nr);
/*
* Let's wake up the inbound CPU now in case it requires some delay
* to come online, but leave it gated in our entry vector code.
*/
- ret = mcpm_cpu_power_up(cpuid, ib_cluster);
+ ret = mcpm_cpu_power_up(ib_cpu, ib_cluster);
if (ret) {
pr_err("%s: mcpm_cpu_power_up() returned %d\n", __func__, ret);
return ret;
@@ -202,14 +206,14 @@ static int bL_switch_to(unsigned int new_cluster_id)
* Raise a SGI on the inbound CPU to make sure it doesn't stall
* in a possible WFI, such as in bL_power_down().
*/
- gic_send_sgi(bL_gic_id[cpuid][ib_cluster], 0);
+ gic_send_sgi(bL_gic_id[ib_cpu][ib_cluster], 0);
/*
* Wait for the inbound to come up. This allows for other
* tasks to be scheduled in the mean time.
*/
wait_for_completion(&inbound_alive);
- mcpm_set_early_poke(cpuid, ib_cluster, 0, 0);
+ mcpm_set_early_poke(ib_cpu, ib_cluster, 0, 0);
/*
* From this point we are entering the switch critical zone
@@ -217,10 +221,10 @@ static int bL_switch_to(unsigned int new_cluster_id)
*/
local_irq_disable();
local_fiq_disable();
- trace_cpu_migrate_begin(get_ns(), mpidr & MPIDR_HWID_BITMASK);
+ trace_cpu_migrate_begin(get_ns(), ob_mpidr);
/* redirect GIC's SGIs to our counterpart */
- gic_migrate_target(bL_gic_id[cpuid][ib_cluster]);
+ gic_migrate_target(bL_gic_id[ib_cpu][ib_cluster]);
tdev = tick_get_device(this_cpu);
if (tdev && !cpumask_equal(tdev->evtdev->cpumask, cpumask_of(this_cpu)))
@@ -237,13 +241,13 @@ static int bL_switch_to(unsigned int new_cluster_id)
panic("%s: cpu_pm_enter() returned %d\n", __func__, ret);
/*
- * Flip the cluster in the CPU logical map for this CPU.
+ * Swap the physical CPUs in the logical map for this logical CPU.
* This must be flushed to RAM as the resume code
* needs to access it while the caches are still disabled.
*/
- cpu_logical_map(this_cpu) ^= (1 << 8);
- __cpuc_flush_dcache_area(&cpu_logical_map(this_cpu),
- sizeof(cpu_logical_map(this_cpu)));
+ cpu_logical_map(this_cpu) = ib_mpidr;
+ cpu_logical_map(that_cpu) = ob_mpidr;
+ sync_cache_w(&cpu_logical_map(this_cpu));
/* Let's do the actual CPU switch. */
ret = cpu_suspend((unsigned long)&handshake_ptr, bL_switchpoint);
@@ -252,10 +256,8 @@ static int bL_switch_to(unsigned int new_cluster_id)
/* We are executing on the inbound CPU at this point */
mpidr = read_mpidr();
- cpuid = MPIDR_AFFINITY_LEVEL(mpidr, 0);
- clusterid = MPIDR_AFFINITY_LEVEL(mpidr, 1);
- pr_debug("after switch: CPU %d in cluster %d\n", cpuid, clusterid);
- BUG_ON(clusterid != ib_cluster);
+ pr_debug("after switch: CPU %d MPIDR %#x\n", this_cpu, mpidr);
+ BUG_ON(mpidr != ib_mpidr);
mcpm_cpu_powered_up();
@@ -267,7 +269,7 @@ static int bL_switch_to(unsigned int new_cluster_id)
tdev->evtdev->next_event, 1);
}
- trace_cpu_migrate_finish(get_ns(), mpidr & MPIDR_HWID_BITMASK);
+ trace_cpu_migrate_finish(get_ns(), ib_mpidr);
local_fiq_enable();
local_irq_enable();
@@ -400,52 +402,74 @@ static void bL_switcher_restore_cpus(void)
static int bL_switcher_halve_cpus(void)
{
- int cpu, cluster, i, ret;
- cpumask_t cluster_mask[2], common_mask;
-
- cpumask_clear(&bL_switcher_removed_logical_cpus);
- cpumask_clear(&cluster_mask[0]);
- cpumask_clear(&cluster_mask[1]);
+ int i, j, gic_id, ret;
+ unsigned int cpu, cluster, cntpart, mask;
+ cpumask_t available_cpus;
+ /* First pass to validate what we have */
+ mask = 0;
for_each_online_cpu(i) {
- cpu = cpu_logical_map(i) & 0xff;
- cluster = (cpu_logical_map(i) >> 8) & 0xff;
+ cpu = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 0);
+ cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 1);
if (cluster >= 2) {
pr_err("%s: only dual cluster systems are supported\n", __func__);
return -EINVAL;
}
- cpumask_set_cpu(cpu, &cluster_mask[cluster]);
+ if (WARN_ON(cpu >= MAX_CPUS_PER_CLUSTER))
+ return -EINVAL;
+ mask |= (1 << cluster);
}
-
- if (!cpumask_and(&common_mask, &cluster_mask[0], &cluster_mask[1])) {
- pr_err("%s: no common set of CPUs\n", __func__);
+ if (mask != 3) {
+ pr_err("%s: no CPU pairing possible\n", __func__);
return -EINVAL;
}
+ /*
+ * Now let's do the pairing. We match each CPU with another CPU
+ * from a different cluster. To keep the logical CPUs contiguous,
+ * the pairing is done backward from the end of the CPU list.
+ */
+ memset(bL_switcher_cpu_pairing, -1, sizeof(bL_switcher_cpu_pairing));
+ cpumask_copy(&available_cpus, cpu_online_mask);
+ for_each_cpu(i, &available_cpus) {
+ int match = -1;
+ cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 1);
+ cpumask_clear_cpu(i, &available_cpus);
+ for_each_cpu(j, &available_cpus) {
+ cntpart = MPIDR_AFFINITY_LEVEL(cpu_logical_map(j), 1);
+ if (cntpart != cluster)
+ match = j;
+ }
+ if (match != -1) {
+ bL_switcher_cpu_pairing[i] = match;
+ cpumask_clear_cpu(match, &available_cpus);
+ pr_info("CPU%d paired with CPU%d\n", i, match);
+ }
+ }
+
+ /*
+ * Now we disable the unwanted CPUs i.e. everything that has no
+ * pairing information (that includes the pairing counterparts).
+ */
+ cpumask_clear(&bL_switcher_removed_logical_cpus);
for_each_online_cpu(i) {
- cpu = cpu_logical_map(i) & 0xff;
- cluster = (cpu_logical_map(i) >> 8) & 0xff;
-
- if (cpumask_test_cpu(cpu, &common_mask)) {
- /* Let's take note of the GIC ID for this CPU */
- int gic_id = gic_get_cpu_id(i);
- if (gic_id < 0) {
- pr_err("%s: bad GIC ID for CPU %d\n", __func__, i);
- return -EINVAL;
- }
- bL_gic_id[cpu][cluster] = gic_id;
- pr_info("GIC ID for CPU %u cluster %u is %u\n",
- cpu, cluster, gic_id);
-
- /*
- * We keep only those logical CPUs which number
- * is equal to their physical CPU number. This is
- * not perfect but good enough in most cases.
- */
- if (cpu == i) {
- bL_switcher_cpu_original_cluster[cpu] = cluster;
- continue;
- }
+ cpu = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 0);
+ cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 1);
+
+ /* Let's take note of the GIC ID for this CPU */
+ gic_id = gic_get_cpu_id(i);
+ if (gic_id < 0) {
+ pr_err("%s: bad GIC ID for CPU %d\n", __func__, i);
+ bL_switcher_restore_cpus();
+ return -EINVAL;
+ }
+ bL_gic_id[cpu][cluster] = gic_id;
+ pr_info("GIC ID for CPU %u cluster %u is %u\n",
+ cpu, cluster, gic_id);
+
+ if (bL_switcher_cpu_pairing[i] != -1) {
+ bL_switcher_cpu_original_cluster[i] = cluster;
+ continue;
}
ret = cpu_down(i);
@@ -462,20 +486,26 @@ static int bL_switcher_halve_cpus(void)
/* Determine the logical CPU a given physical CPU is grouped on. */
int bL_switcher_get_logical_index(u32 mpidr)
{
- int cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+ int cpu;
if (!bL_switcher_active)
return -EUNATCH;
- if (cpumask_test_cpu(cpu, &bL_switcher_removed_logical_cpus))
- return -EINVAL;
-
- return cpu;
+ mpidr &= MPIDR_HWID_BITMASK;
+ for_each_online_cpu(cpu) {
+ int pairing = bL_switcher_cpu_pairing[cpu];
+ if (pairing == -1)
+ continue;
+ if ((mpidr == cpu_logical_map(cpu)) ||
+ (mpidr == cpu_logical_map(pairing)))
+ return cpu;
+ }
+ return -EINVAL;
}
static void bL_switcher_trace_trigger_cpu(void *__always_unused info)
{
- trace_cpu_migrate_current(get_ns(), read_mpidr() & MPIDR_HWID_BITMASK);
+ trace_cpu_migrate_current(get_ns(), read_mpidr());
}
int bL_switcher_trace_trigger(void)
@@ -544,7 +574,7 @@ out:
static void bL_switcher_disable(void)
{
- unsigned int cpu, cluster, i;
+ unsigned int cpu, cluster;
struct bL_thread *t;
struct task_struct *task;
@@ -570,15 +600,14 @@ static void bL_switcher_disable(void)
* possibility for interference from external requests.
*/
for_each_online_cpu(cpu) {
- BUG_ON(cpu != (cpu_logical_map(cpu) & 0xff));
t = &bL_threads[cpu];
task = t->task;
t->task = NULL;
- if (IS_ERR_OR_NULL(task))
+ if (!task || IS_ERR(task))
continue;
kthread_stop(task);
/* no more switch may happen on this CPU at this point */
- cluster = (cpu_logical_map(cpu) >> 8) & 0xff;
+ cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1);
if (cluster == bL_switcher_cpu_original_cluster[cpu])
continue;
init_completion(&t->started);
@@ -587,21 +616,17 @@ static void bL_switcher_disable(void)
if (!IS_ERR(task)) {
wait_for_completion(&t->started);
kthread_stop(task);
- cluster = (cpu_logical_map(cpu) >> 8) & 0xff;
+ cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1);
if (cluster == bL_switcher_cpu_original_cluster[cpu])
continue;
}
/* If execution gets here, we're in trouble. */
pr_crit("%s: unable to restore original cluster for CPU %d\n",
__func__, cpu);
- for_each_cpu(i, &bL_switcher_removed_logical_cpus) {
- if ((cpu_logical_map(i) & 0xff) != cpu)
- continue;
- pr_crit("%s: CPU %d can't be restored\n",
- __func__, i);
- cpumask_clear_cpu(i, &bL_switcher_removed_logical_cpus);
- break;
- }
+ pr_crit("%s: CPU %d can't be restored\n",
+ __func__, bL_switcher_cpu_pairing[cpu]);
+ cpumask_clear_cpu(bL_switcher_cpu_pairing[cpu],
+ &bL_switcher_removed_logical_cpus);
}
bL_switcher_restore_cpus();