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Diffstat (limited to 'arch/powerpc/platforms/powernv/idle.c')
-rw-r--r--arch/powerpc/platforms/powernv/idle.c188
1 files changed, 159 insertions, 29 deletions
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index fcc8b6861b63..479c25601612 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -27,9 +27,12 @@
#include "powernv.h"
#include "subcore.h"
+/* Power ISA 3.0 allows for stop states 0x0 - 0xF */
+#define MAX_STOP_STATE 0xF
+
static u32 supported_cpuidle_states;
-int pnv_save_sprs_for_winkle(void)
+static int pnv_save_sprs_for_deep_states(void)
{
int cpu;
int rc;
@@ -50,15 +53,19 @@ int pnv_save_sprs_for_winkle(void)
uint64_t pir = get_hard_smp_processor_id(cpu);
uint64_t hsprg0_val = (uint64_t)&paca[cpu];
- /*
- * HSPRG0 is used to store the cpu's pointer to paca. Hence last
- * 3 bits are guaranteed to be 0. Program slw to restore HSPRG0
- * with 63rd bit set, so that when a thread wakes up at 0x100 we
- * can use this bit to distinguish between fastsleep and
- * deep winkle.
- */
- hsprg0_val |= 1;
-
+ if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
+ /*
+ * HSPRG0 is used to store the cpu's pointer to paca.
+ * Hence last 3 bits are guaranteed to be 0. Program
+ * slw to restore HSPRG0 with 63rd bit set, so that
+ * when a thread wakes up at 0x100 we can use this bit
+ * to distinguish between fastsleep and deep winkle.
+ * This is not necessary with stop/psscr since PLS
+ * field of psscr indicates which state we are waking
+ * up from.
+ */
+ hsprg0_val |= 1;
+ }
rc = opal_slw_set_reg(pir, SPRN_HSPRG0, hsprg0_val);
if (rc != 0)
return rc;
@@ -130,8 +137,8 @@ static void pnv_alloc_idle_core_states(void)
update_subcore_sibling_mask();
- if (supported_cpuidle_states & OPAL_PM_WINKLE_ENABLED)
- pnv_save_sprs_for_winkle();
+ if (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT)
+ pnv_save_sprs_for_deep_states();
}
u32 pnv_get_supported_cpuidle_states(void)
@@ -230,43 +237,162 @@ static DEVICE_ATTR(fastsleep_workaround_applyonce, 0600,
show_fastsleep_workaround_applyonce,
store_fastsleep_workaround_applyonce);
-static int __init pnv_init_idle_states(void)
+
+/*
+ * Used for ppc_md.power_save which needs a function with no parameters
+ */
+static void power9_idle(void)
{
- struct device_node *power_mgt;
- int dt_idle_states;
- u32 *flags;
- int i;
+ /* Requesting stop state 0 */
+ power9_idle_stop(0);
+}
+/*
+ * First deep stop state. Used to figure out when to save/restore
+ * hypervisor context.
+ */
+u64 pnv_first_deep_stop_state = MAX_STOP_STATE;
- supported_cpuidle_states = 0;
+/*
+ * Deepest stop idle state. Used when a cpu is offlined
+ */
+u64 pnv_deepest_stop_state;
- if (cpuidle_disable != IDLE_NO_OVERRIDE)
- goto out;
+/*
+ * Power ISA 3.0 idle initialization.
+ *
+ * POWER ISA 3.0 defines a new SPR Processor stop Status and Control
+ * Register (PSSCR) to control idle behavior.
+ *
+ * PSSCR layout:
+ * ----------------------------------------------------------
+ * | PLS | /// | SD | ESL | EC | PSLL | /// | TR | MTL | RL |
+ * ----------------------------------------------------------
+ * 0 4 41 42 43 44 48 54 56 60
+ *
+ * PSSCR key fields:
+ * Bits 0:3 - Power-Saving Level Status (PLS). This field indicates the
+ * lowest power-saving state the thread entered since stop instruction was
+ * last executed.
+ *
+ * Bit 41 - Status Disable(SD)
+ * 0 - Shows PLS entries
+ * 1 - PLS entries are all 0
+ *
+ * Bit 42 - Enable State Loss
+ * 0 - No state is lost irrespective of other fields
+ * 1 - Allows state loss
+ *
+ * Bit 43 - Exit Criterion
+ * 0 - Exit from power-save mode on any interrupt
+ * 1 - Exit from power-save mode controlled by LPCR's PECE bits
+ *
+ * Bits 44:47 - Power-Saving Level Limit
+ * This limits the power-saving level that can be entered into.
+ *
+ * Bits 60:63 - Requested Level
+ * Used to specify which power-saving level must be entered on executing
+ * stop instruction
+ *
+ * @np: /ibm,opal/power-mgt device node
+ * @flags: cpu-idle-state-flags array
+ * @dt_idle_states: Number of idle state entries
+ * Returns 0 on success
+ */
+static int __init pnv_arch300_idle_init(struct device_node *np, u32 *flags,
+ int dt_idle_states)
+{
+ u64 *psscr_val = NULL;
+ int rc = 0, i;
- if (!firmware_has_feature(FW_FEATURE_OPAL))
+ psscr_val = kcalloc(dt_idle_states, sizeof(*psscr_val),
+ GFP_KERNEL);
+ if (!psscr_val) {
+ rc = -1;
+ goto out;
+ }
+ if (of_property_read_u64_array(np,
+ "ibm,cpu-idle-state-psscr",
+ psscr_val, dt_idle_states)) {
+ pr_warn("cpuidle-powernv: missing ibm,cpu-idle-states-psscr in DT\n");
+ rc = -1;
goto out;
+ }
- power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
- if (!power_mgt) {
+ /*
+ * Set pnv_first_deep_stop_state and pnv_deepest_stop_state.
+ * pnv_first_deep_stop_state should be set to the first stop
+ * level to cause hypervisor state loss.
+ * pnv_deepest_stop_state should be set to the deepest stop
+ * stop state.
+ */
+ pnv_first_deep_stop_state = MAX_STOP_STATE;
+ for (i = 0; i < dt_idle_states; i++) {
+ u64 psscr_rl = psscr_val[i] & PSSCR_RL_MASK;
+
+ if ((flags[i] & OPAL_PM_LOSE_FULL_CONTEXT) &&
+ (pnv_first_deep_stop_state > psscr_rl))
+ pnv_first_deep_stop_state = psscr_rl;
+
+ if (pnv_deepest_stop_state < psscr_rl)
+ pnv_deepest_stop_state = psscr_rl;
+ }
+
+out:
+ kfree(psscr_val);
+ return rc;
+}
+
+/*
+ * Probe device tree for supported idle states
+ */
+static void __init pnv_probe_idle_states(void)
+{
+ struct device_node *np;
+ int dt_idle_states;
+ u32 *flags = NULL;
+ int i;
+
+ np = of_find_node_by_path("/ibm,opal/power-mgt");
+ if (!np) {
pr_warn("opal: PowerMgmt Node not found\n");
goto out;
}
- dt_idle_states = of_property_count_u32_elems(power_mgt,
+ dt_idle_states = of_property_count_u32_elems(np,
"ibm,cpu-idle-state-flags");
if (dt_idle_states < 0) {
pr_warn("cpuidle-powernv: no idle states found in the DT\n");
goto out;
}
- flags = kzalloc(sizeof(*flags) * dt_idle_states, GFP_KERNEL);
- if (of_property_read_u32_array(power_mgt,
+ flags = kcalloc(dt_idle_states, sizeof(*flags), GFP_KERNEL);
+
+ if (of_property_read_u32_array(np,
"ibm,cpu-idle-state-flags", flags, dt_idle_states)) {
pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-flags in DT\n");
- goto out_free;
+ goto out;
+ }
+
+ if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+ if (pnv_arch300_idle_init(np, flags, dt_idle_states))
+ goto out;
}
for (i = 0; i < dt_idle_states; i++)
supported_cpuidle_states |= flags[i];
+out:
+ kfree(flags);
+}
+static int __init pnv_init_idle_states(void)
+{
+
+ supported_cpuidle_states = 0;
+
+ if (cpuidle_disable != IDLE_NO_OVERRIDE)
+ goto out;
+
+ pnv_probe_idle_states();
+
if (!(supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1)) {
patch_instruction(
(unsigned int *)pnv_fastsleep_workaround_at_entry,
@@ -285,8 +411,12 @@ static int __init pnv_init_idle_states(void)
}
pnv_alloc_idle_core_states();
-out_free:
- kfree(flags);
+
+ if (supported_cpuidle_states & OPAL_PM_NAP_ENABLED)
+ ppc_md.power_save = power7_idle;
+ else if (supported_cpuidle_states & OPAL_PM_STOP_INST_FAST)
+ ppc_md.power_save = power9_idle;
+
out:
return 0;
}