--- v5
+++ v1
@@ -1,133 +1,364 @@
From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
-Balbir pointed out that in idle_book3s.S and powernv/idle.c some
-functions and variables had power9 in their names while some others
-had arch300.
-
-This patch uniformly renames all instances of "power9" in the
-variables/function/comments occuring in these files to "arch300" in
-order to make them consistent.
+The power9_idle_stop method currently takes only the requested stop
+level as a parameter and picks up the rest of the PSSCR bits from a
+hand-coded macro. This is not a very flexible design, especially when
+the firmware has the capability to communicate the psscr value and the
+mask associated with a particular stop state via device tree.
+
+This patch modifies the power9_idle_stop API to take as parameters the
+PSSCR value and the PSSCR mask corresponding to the stop state that
+needs to be set. These PSSCR value and mask are respectively obtained
+by parsing the "ibm,cpu-idle-state-psscr" and
+"ibm,cpu-idle-state-psscr-mask" fields from the device tree.
+
+In addition to this, the patch adds support for handling stop states
+for which ESL and EC bits in the PSSCR are zero. As per the
+architecture, a wakeup from these stop states resumes execution from
+the subsequent instruction as opposed to waking up at the System
+Vector.
+
+This patch depends on the following skiboot patch that exports the
+PSSCR values and the mask for all the stop states:
+https://lists.ozlabs.org/pipermail/skiboot/2016-September/004869.html
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
---
-New patch in v5
-
- arch/powerpc/include/asm/processor.h | 2 +-
- arch/powerpc/kernel/idle_book3s.S | 13 +++++++------
- arch/powerpc/platforms/powernv/idle.c | 6 +++---
- arch/powerpc/platforms/powernv/smp.c | 2 +-
- drivers/cpuidle/cpuidle-powernv.c | 2 +-
- 5 files changed, 13 insertions(+), 12 deletions(-)
+ arch/powerpc/include/asm/processor.h | 3 +-
+ arch/powerpc/kernel/idle_book3s.S | 31 ++++++++-----
+ arch/powerpc/platforms/powernv/idle.c | 76 +++++++++++++++++++++++++++-----
+ arch/powerpc/platforms/powernv/powernv.h | 3 +-
+ arch/powerpc/platforms/powernv/smp.c | 7 +--
+ drivers/cpuidle/cpuidle-powernv.c | 30 ++++++++++---
+ 6 files changed, 115 insertions(+), 35 deletions(-)
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
-index c07c31b..4b47308 100644
+index 68e3bf5..4ead497 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
-@@ -458,7 +458,7 @@ static inline unsigned long get_clean_sp(unsigned long sp, int is_32)
+@@ -460,7 +460,8 @@ extern int powersave_nap; /* set if nap mode can be used in idle loop */
extern unsigned long power7_nap(int check_irq);
extern unsigned long power7_sleep(void);
extern unsigned long power7_winkle(void);
-extern unsigned long power9_idle_stop(unsigned long stop_level);
-+extern unsigned long arch300_idle_stop(unsigned long stop_level);
++extern unsigned long power9_idle_stop(unsigned long stop_psscr_val,
++ unsigned long stop_psscr_mask);
extern void flush_instruction_cache(void);
extern void hard_reset_now(void);
diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
-index be90e2f..7f6657f 100644
+index 32d666b..9f77cd4 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
-@@ -106,8 +106,9 @@ core_idle_lock_held:
-
- /*
- * Pass requested state in r3:
-- * r3 - PNV_THREAD_NAP/SLEEP/WINKLE in POWER8
-- * - Requested STOP state in POWER9
-+ * r3 - PNV_THREAD_NAP/SLEEP/WINKLE on ISA 2.07 or less
-+ (POWER7,POWER8)
-+ * - Requested STOP state on ISA 3.0 CPUs
- *
- * To check IRQ_HAPPENED in r4
- * 0 - don't check
-@@ -357,7 +358,7 @@ ALT_FTR_SECTION_END_NESTED_IFSET(CPU_FTR_ARCH_207S, 66); \
- /*
- * r3 - requested stop state
- */
--_GLOBAL(power9_idle_stop)
-+_GLOBAL(arch300_idle_stop)
- LOAD_REG_IMMEDIATE(r4, PSSCR_HV_TEMPLATE)
- or r4,r4,r3
- mtspr SPRN_PSSCR, r4
-@@ -377,7 +378,7 @@ _GLOBAL(pnv_restore_hyp_resource)
- BEGIN_FTR_SECTION
- ld r2,PACATOC(r13);
- /*
-- * POWER ISA 3. Use PSSCR to determine if we
-+ * POWER ISA 3.0. Use PSSCR to determine if we
- * are waking up from deep idle state
- */
- LOAD_REG_ADDRBASE(r5,pnv_first_deep_stop_state)
-@@ -429,8 +430,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
- /*
- * Called if waking up from idle state which can cause either partial or
- * complete hyp state loss.
-- * In POWER8, called if waking up from fastsleep or winkle
-- * In POWER9, called if waking up from stop state >= pnv_first_deep_stop_state
-+ * In ISA 2.07 (POWER8),called if waking up from fastsleep or winkle
-+ * In ISA 3.0, called if waking up from stop state >= pnv_first_deep_stop_state
- *
- * r13 - PACA
- * cr3 - gt if waking up with partial/complete hypervisor state loss
+@@ -40,9 +40,7 @@
+ #define _WORC GPR11
+ #define _PTCR GPR12
+
+-#define PSSCR_HV_TEMPLATE PSSCR_ESL | PSSCR_EC | \
+- PSSCR_PSLL_MASK | PSSCR_TR_MASK | \
+- PSSCR_MTL_MASK
++#define PSSCR_EC_ESL_MASK_SHIFTED (PSSCR_EC | PSSCR_ESL) >> 16
+
+ .text
+
+@@ -247,13 +245,23 @@ enter_winkle:
+ IDLE_STATE_ENTER_SEQ_NORET(PPC_WINKLE)
+
+ /*
+- * r3 - requested stop state
++ * r3 - PSSCR value corresponding to the requested stop state.
+ */
+ power_enter_stop:
+ /*
++ * Check if we are executing the lite variant with ESL=EC=0
++ */
++ andis. r4, r3, PSSCR_EC_ESL_MASK_SHIFTED
++ andi. r3, r3, PSSCR_RL_MASK /* r3 = requested stop state */
++ cmpdi r4, 0
++ bne 1f
++ IDLE_STATE_ENTER_SEQ(PPC_STOP)
++ li r3,0 /* Since we didn't lose state, return 0 */
++ b pnv_wakeup_noloss
++/*
+ * Check if the requested state is a deep idle state.
+ */
+- LOAD_REG_ADDRBASE(r5,pnv_first_deep_stop_state)
++1: LOAD_REG_ADDRBASE(r5,pnv_first_deep_stop_state)
+ ld r4,ADDROFF(pnv_first_deep_stop_state)(r5)
+ cmpd r3,r4
+ bge 2f
+@@ -330,16 +338,17 @@ ALT_FTR_SECTION_END_NESTED_IFSET(CPU_FTR_ARCH_207S, 66); \
+ ld r3,ORIG_GPR3(r1); /* Restore original r3 */ \
+ 20: nop;
+
+-
+ /*
+- * r3 - requested stop state
++ * r3 - The PSSCR value corresponding to the stop state.
++ * r4 - The PSSCR mask corrresonding to the stop state.
+ */
+ _GLOBAL(power9_idle_stop)
+- LOAD_REG_IMMEDIATE(r4, PSSCR_HV_TEMPLATE)
+- or r4,r4,r3
+- mtspr SPRN_PSSCR, r4
+- li r4, 1
++ mfspr r5, SPRN_PSSCR
++ andc r5, r5, r4
++ or r3, r3, r5
++ mtspr SPRN_PSSCR, r3
+ LOAD_REG_ADDR(r5,power_enter_stop)
++ li r4, 1
+ b pnv_powersave_common
+ /* No return */
+ /*
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
-index 479c256..c3a2fac 100644
+index 479c256..575f2aa 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
-@@ -241,10 +241,10 @@ static DEVICE_ATTR(fastsleep_workaround_applyonce, 0600,
+@@ -237,15 +237,21 @@ static DEVICE_ATTR(fastsleep_workaround_applyonce, 0600,
+ show_fastsleep_workaround_applyonce,
+ store_fastsleep_workaround_applyonce);
+
++/*
++ * The default stop state that will be used by ppc_md.power_save
++ * function on platforms that support stop instruction.
++ */
++u64 pnv_default_stop_val;
++u64 pnv_default_stop_mask;
+
/*
* Used for ppc_md.power_save which needs a function with no parameters
*/
--static void power9_idle(void)
-+static void arch300_idle(void)
+ static void power9_idle(void)
{
- /* Requesting stop state 0 */
+- /* Requesting stop state 0 */
- power9_idle_stop(0);
-+ arch300_idle_stop(0);
++ power9_idle_stop(pnv_default_stop_val, pnv_default_stop_mask);
}
++
/*
* First deep stop state. Used to figure out when to save/restore
-@@ -415,7 +415,7 @@ static int __init pnv_init_idle_states(void)
- 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;
-+ ppc_md.power_save = arch300_idle;
-
+ * hypervisor context.
+@@ -253,9 +259,11 @@ static void power9_idle(void)
+ u64 pnv_first_deep_stop_state = MAX_STOP_STATE;
+
+ /*
+- * Deepest stop idle state. Used when a cpu is offlined
++ * psscr value and mask of the deepest stop idle state.
++ * Used when a cpu is offlined.
+ */
+-u64 pnv_deepest_stop_state;
++u64 pnv_deepest_stop_psscr_val;
++u64 pnv_deepest_stop_psscr_mask;
+
+ /*
+ * Power ISA 3.0 idle initialization.
+@@ -302,28 +310,61 @@ static int __init pnv_arch300_idle_init(struct device_node *np, u32 *flags,
+ int dt_idle_states)
+ {
+ u64 *psscr_val = NULL;
++ u64 *psscr_mask = NULL;
++ u32 *residency_ns = NULL;
++ u64 max_residency_ns = 0;
+ int rc = 0, i;
++ bool default_stop_found = false;
+
+ psscr_val = kcalloc(dt_idle_states, sizeof(*psscr_val),
+ GFP_KERNEL);
+- if (!psscr_val) {
++ psscr_mask = kcalloc(dt_idle_states, sizeof(*psscr_mask),
++ GFP_KERNEL);
++ residency_ns = kcalloc(dt_idle_states, sizeof(*residency_ns),
++ GFP_KERNEL);
++
++ if (!psscr_val || !psscr_mask || !residency_ns) {
+ 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");
++ pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-psscr in DT\n");
++ rc = -1;
++ goto out;
++ }
++
++ if (of_property_read_u64_array(np,
++ "ibm,cpu-idle-state-psscr-mask",
++ psscr_mask, dt_idle_states)) {
++ pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-psscr-mask in DT\n");
+ rc = -1;
+ goto out;
+ }
+
++ if (of_property_read_u32_array(np,
++ "ibm,cpu-idle-state-residency-ns",
++ residency_ns, dt_idle_states)) {
++ pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-residency-ns in DT\n");
++ rc = -1;
++ goto out;
++
++ }
++
+ /*
+- * Set pnv_first_deep_stop_state and pnv_deepest_stop_state.
++ * Set pnv_first_deep_stop_state, pnv_deepest_stop_psscr_{val,mask},
++ * and the pnv_default_stop_{val,mask}.
++ *
+ * 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_deepest_stop_{val,mask} should be set to values corresponding to
++ * the deepest stop state.
++ *
++ * pnv_default_stop_{val,mask} should be set to values corresponding to
++ * the shallowest (OPAL_PM_STOP_INST_FAST) loss-less stop state.
+ */
+ pnv_first_deep_stop_state = MAX_STOP_STATE;
+ for (i = 0; i < dt_idle_states; i++) {
+@@ -333,12 +374,23 @@ static int __init pnv_arch300_idle_init(struct device_node *np, u32 *flags,
+ (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;
+- }
++ if (max_residency_ns < residency_ns[i]) {
++ max_residency_ns = residency_ns[i];
++ pnv_deepest_stop_psscr_val = psscr_val[i];
++ pnv_deepest_stop_psscr_mask = psscr_mask[i];
++ }
+
++ if (!default_stop_found &&
++ (flags[i] & OPAL_PM_STOP_INST_FAST)) {
++ pnv_default_stop_val = psscr_val[i];
++ pnv_default_stop_mask = psscr_mask[i];
++ default_stop_found = true;
++ }
++ }
out:
- return 0;
+ kfree(psscr_val);
++ kfree(psscr_mask);
++ kfree(residency_ns);
+ return rc;
+ }
+
+diff --git a/arch/powerpc/platforms/powernv/powernv.h b/arch/powerpc/platforms/powernv/powernv.h
+index da7c843..6130522 100644
+--- a/arch/powerpc/platforms/powernv/powernv.h
++++ b/arch/powerpc/platforms/powernv/powernv.h
+@@ -18,7 +18,8 @@ static inline void pnv_pci_shutdown(void) { }
+ #endif
+
+ extern u32 pnv_get_supported_cpuidle_states(void);
+-extern u64 pnv_deepest_stop_state;
++extern u64 pnv_deepest_stop_psscr_val;
++extern u64 pnv_deepest_stop_psscr_mask;
+
+ extern void pnv_lpc_init(void);
+
diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c
-index c789258..c931bb2 100644
+index c789258..55c4aaa 100644
--- a/arch/powerpc/platforms/powernv/smp.c
+++ b/arch/powerpc/platforms/powernv/smp.c
-@@ -183,7 +183,7 @@ static void pnv_smp_cpu_kill_self(void)
+@@ -182,9 +182,10 @@ static void pnv_smp_cpu_kill_self(void)
+
ppc64_runlatch_off();
- if (cpu_has_feature(CPU_FTR_ARCH_300))
+- if (cpu_has_feature(CPU_FTR_ARCH_300))
- srr1 = power9_idle_stop(pnv_deepest_stop_state);
-+ srr1 = arch300_idle_stop(pnv_deepest_stop_state);
- else if (idle_states & OPAL_PM_WINKLE_ENABLED)
+- else if (idle_states & OPAL_PM_WINKLE_ENABLED)
++ if (cpu_has_feature(CPU_FTR_ARCH_300)) {
++ srr1 = power9_idle_stop(pnv_deepest_stop_psscr_val,
++ pnv_deepest_stop_psscr_mask);
++ } else if (idle_states & OPAL_PM_WINKLE_ENABLED)
srr1 = power7_winkle();
else if ((idle_states & OPAL_PM_SLEEP_ENABLED) ||
+ (idle_states & OPAL_PM_SLEEP_ENABLED_ER1))
diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
-index 7fe442c..a7f6528 100644
+index f7ca891..6f2bee0 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
-@@ -102,7 +102,7 @@ static int stop_loop(struct cpuidle_device *dev,
+@@ -30,7 +30,11 @@ struct cpuidle_driver powernv_idle_driver = {
+ static int max_idle_state;
+ static struct cpuidle_state *cpuidle_state_table;
+
+-static u64 stop_psscr_table[CPUIDLE_STATE_MAX];
++struct stop_psscr_table {
++ u64 val;
++ u64 mask;
++};
++static struct stop_psscr_table stop_psscr_table[CPUIDLE_STATE_MAX];
+
+ static u64 snooze_timeout;
+ static bool snooze_timeout_en;
+@@ -102,7 +106,8 @@ static int stop_loop(struct cpuidle_device *dev,
int index)
{
ppc64_runlatch_off();
- power9_idle_stop(stop_psscr_table[index]);
-+ arch300_idle_stop(stop_psscr_table[index]);
++ power9_idle_stop(stop_psscr_table[index].val,
++ stop_psscr_table[index].mask);
ppc64_runlatch_on();
return index;
}
+@@ -186,6 +191,7 @@ static int powernv_add_idle_states(void)
+ u32 residency_ns[CPUIDLE_STATE_MAX];
+ u32 flags[CPUIDLE_STATE_MAX];
+ u64 psscr_val[CPUIDLE_STATE_MAX];
++ u64 psscr_mask[CPUIDLE_STATE_MAX];
+ const char *names[CPUIDLE_STATE_MAX];
+ int i, rc;
+
+@@ -233,14 +239,22 @@ static int powernv_add_idle_states(void)
+
+ /*
+ * If the idle states use stop instruction, probe for psscr values
+- * which are necessary to specify required stop level.
++ * and psscr mask which are necessary to specify required stop level.
+ */
+- if (flags[0] & (OPAL_PM_STOP_INST_FAST | OPAL_PM_STOP_INST_DEEP))
++ if (flags[0] & (OPAL_PM_STOP_INST_FAST | OPAL_PM_STOP_INST_DEEP)) {
+ if (of_property_read_u64_array(power_mgt,
+ "ibm,cpu-idle-state-psscr", psscr_val, dt_idle_states)) {
+- pr_warn("cpuidle-powernv: missing ibm,cpu-idle-states-psscr in DT\n");
++ pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-psscr in DT\n");
++ goto out;
++ }
++
++ if (of_property_read_u64_array(power_mgt,
++ "ibm,cpu-idle-state-psscr-mask", psscr_mask,
++ dt_idle_states)) {
++ pr_warn("cpuidle-powernv:Missing ibm,cpu-idle-state-psscr-mask in DT\n");
+ goto out;
+ }
++ }
+
+ rc = of_property_read_u32_array(power_mgt,
+ "ibm,cpu-idle-state-residency-ns", residency_ns, dt_idle_states);
+@@ -274,7 +288,8 @@ static int powernv_add_idle_states(void)
+ powernv_states[nr_idle_states].flags = 0;
+
+ powernv_states[nr_idle_states].enter = stop_loop;
+- stop_psscr_table[nr_idle_states] = psscr_val[i];
++ stop_psscr_table[nr_idle_states].val = psscr_val[i];
++ stop_psscr_table[nr_idle_states].mask = psscr_mask[i];
+ }
+
+ /*
+@@ -299,7 +314,8 @@ static int powernv_add_idle_states(void)
+
+ powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
+ powernv_states[nr_idle_states].enter = stop_loop;
+- stop_psscr_table[nr_idle_states] = psscr_val[i];
++ stop_psscr_table[nr_idle_states].val = psscr_val[i];
++ stop_psscr_table[nr_idle_states].mask = psscr_mask[i];
+ }
+ #endif
+ powernv_states[nr_idle_states].exit_latency =
--
1.9.4