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Subject[PATCH v6 1/3] powerpc/powernv: Introduce interface for self-restore support
Date
Introduces an interface that helps determine support for the
self-restore API. The commit is isomorphic to the original interface of
declaring SPRs to self-restore.

Signed-off-by: Pratik Rajesh Sampat <psampat@linux.ibm.com>
---
arch/powerpc/platforms/powernv/idle.c | 200 +++++++++++++++++++-------
1 file changed, 152 insertions(+), 48 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index 78599bca66c2..858ceb86394d 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -32,10 +32,67 @@
#define P9_STOP_SPR_MSR 2000
#define P9_STOP_SPR_PSSCR 855

+/*
+ * Type of support for each SPR
+ * FIRMWARE_RESTORE: firmware restoration supported: calls self-restore OPAL API
+ */
+#define UNSUPPORTED 0x0
+#define FIRMWARE_RESTORE 0x1
+
static u32 supported_cpuidle_states;
struct pnv_idle_states_t *pnv_idle_states;
int nr_pnv_idle_states;

+struct preferred_sprs {
+ u64 spr;
+ u32 supported_mode;
+};
+
+/*
+ * Supported mode: Default support. Can be overwritten during system
+ * initialization
+ */
+struct preferred_sprs preferred_sprs[] = {
+ {
+ .spr = SPRN_HSPRG0,
+ .supported_mode = FIRMWARE_RESTORE,
+ },
+ {
+ .spr = SPRN_LPCR,
+ .supported_mode = FIRMWARE_RESTORE,
+ },
+ {
+ .spr = SPRN_HMEER,
+ .supported_mode = FIRMWARE_RESTORE,
+ },
+ {
+ .spr = SPRN_HID0,
+ .supported_mode = FIRMWARE_RESTORE,
+ },
+ {
+ .spr = P9_STOP_SPR_MSR,
+ .supported_mode = FIRMWARE_RESTORE,
+ },
+ {
+ .spr = P9_STOP_SPR_PSSCR,
+ .supported_mode = FIRMWARE_RESTORE,
+ },
+ {
+ .spr = SPRN_HID1,
+ .supported_mode = FIRMWARE_RESTORE,
+ },
+ {
+ .spr = SPRN_HID4,
+ .supported_mode = FIRMWARE_RESTORE,
+ },
+ {
+ .spr = SPRN_HID5,
+ .supported_mode = FIRMWARE_RESTORE,
+ }
+};
+
+const int nr_preferred_sprs = ARRAY_SIZE(preferred_sprs);
+
/*
* The default stop state that will be used by ppc_md.power_save
* function on platforms that support stop instruction.
@@ -61,78 +118,125 @@ static bool deepest_stop_found;

static unsigned long power7_offline_type;

-static int pnv_save_sprs_for_deep_states(void)
+static int pnv_self_restore_sprs(u64 pir, int cpu, u64 spr)
{
- int cpu;
+ u64 reg_val;
int rc;

- /*
- * hid0, hid1, hid4, hid5, hmeer and lpcr values are symmetric across
- * all cpus at boot. Get these reg values of current cpu and use the
- * same across all cpus.
- */
- uint64_t lpcr_val = mfspr(SPRN_LPCR);
- uint64_t hid0_val = mfspr(SPRN_HID0);
- uint64_t hid1_val = mfspr(SPRN_HID1);
- uint64_t hid4_val = mfspr(SPRN_HID4);
- uint64_t hid5_val = mfspr(SPRN_HID5);
- uint64_t hmeer_val = mfspr(SPRN_HMEER);
- uint64_t msr_val = MSR_IDLE;
- uint64_t psscr_val = pnv_deepest_stop_psscr_val;
-
- for_each_present_cpu(cpu) {
- uint64_t pir = get_hard_smp_processor_id(cpu);
- uint64_t hsprg0_val = (uint64_t)paca_ptrs[cpu];
-
- rc = opal_slw_set_reg(pir, SPRN_HSPRG0, hsprg0_val);
+ switch (spr) {
+ case SPRN_HSPRG0:
+ reg_val = (uint64_t)paca_ptrs[cpu];
+ rc = opal_slw_set_reg(pir, SPRN_HSPRG0, reg_val);
if (rc != 0)
return rc;
-
- rc = opal_slw_set_reg(pir, SPRN_LPCR, lpcr_val);
+ break;
+ case SPRN_LPCR:
+ reg_val = mfspr(SPRN_LPCR);
+ rc = opal_slw_set_reg(pir, SPRN_LPCR, reg_val);
if (rc != 0)
return rc;
-
+ break;
+ case P9_STOP_SPR_MSR:
+ reg_val = MSR_IDLE;
if (cpu_has_feature(CPU_FTR_ARCH_300)) {
- rc = opal_slw_set_reg(pir, P9_STOP_SPR_MSR, msr_val);
+ rc = opal_slw_set_reg(pir, P9_STOP_SPR_MSR, reg_val);
if (rc)
return rc;
-
- rc = opal_slw_set_reg(pir,
- P9_STOP_SPR_PSSCR, psscr_val);
-
+ }
+ break;
+ case P9_STOP_SPR_PSSCR:
+ reg_val = pnv_deepest_stop_psscr_val;
+ if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+ rc = opal_slw_set_reg(pir, P9_STOP_SPR_PSSCR, reg_val);
if (rc)
return rc;
}
-
- /* HIDs are per core registers */
+ break;
+ case SPRN_HMEER:
+ reg_val = mfspr(SPRN_HMEER);
if (cpu_thread_in_core(cpu) == 0) {
-
- rc = opal_slw_set_reg(pir, SPRN_HMEER, hmeer_val);
- if (rc != 0)
+ rc = opal_slw_set_reg(pir, SPRN_HMEER, reg_val);
+ if (rc)
return rc;
-
- rc = opal_slw_set_reg(pir, SPRN_HID0, hid0_val);
- if (rc != 0)
+ }
+ break;
+ case SPRN_HID0:
+ reg_val = mfspr(SPRN_HID0);
+ if (cpu_thread_in_core(cpu) == 0) {
+ rc = opal_slw_set_reg(pir, SPRN_HID0, reg_val);
+ if (rc)
return rc;
+ }
+ break;
+ case SPRN_HID1:
+ reg_val = mfspr(SPRN_HID1);
+ if (!cpu_has_feature(CPU_FTR_ARCH_300) &&
+ cpu_thread_in_core(cpu) == 0) {
+ rc = opal_slw_set_reg(pir, SPRN_HID1, reg_val);
+ if (rc)
+ return rc;
+ }
+ break;
+ case SPRN_HID4:
+ reg_val = mfspr(SPRN_HID4);
+ if (!cpu_has_feature(CPU_FTR_ARCH_300) &&
+ cpu_thread_in_core(cpu) == 0) {
+ rc = opal_slw_set_reg(pir, SPRN_HID4, reg_val);
+ if (rc)
+ return rc;
+ }
+ break;
+ case SPRN_HID5:
+ reg_val = mfspr(SPRN_HID5);
+ if (!cpu_has_feature(CPU_FTR_ARCH_300) &&
+ cpu_thread_in_core(cpu) == 0) {
+ rc = opal_slw_set_reg(pir, SPRN_HID5, reg_val);
+ if (rc)
+ return rc;
+ }
+ break;
+ default:
+ return -EINVAL;
+ }
+ return 0;
+}

- /* Only p8 needs to set extra HID regiters */
- if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
-
- rc = opal_slw_set_reg(pir, SPRN_HID1, hid1_val);
- if (rc != 0)
- return rc;
-
- rc = opal_slw_set_reg(pir, SPRN_HID4, hid4_val);
- if (rc != 0)
- return rc;
+static int pnv_self_save_restore_sprs(void)
+{
+ int rc, index, cpu;
+ u64 pir;
+ struct preferred_sprs curr_spr;

- rc = opal_slw_set_reg(pir, SPRN_HID5, hid5_val);
+ for_each_present_cpu(cpu) {
+ pir = get_hard_smp_processor_id(cpu);
+ for (index = 0; index < nr_preferred_sprs; index++) {
+ curr_spr = preferred_sprs[index];
+ /* HIDs are per core register */
+ if (cpu_thread_in_core(cpu) != 0 &&
+ (curr_spr.spr == SPRN_HMEER ||
+ curr_spr.spr == SPRN_HID0 ||
+ curr_spr.spr == SPRN_HID1 ||
+ curr_spr.spr == SPRN_HID4 ||
+ curr_spr.spr == SPRN_HID5))
+ continue;
+ if (curr_spr.supported_mode & FIRMWARE_RESTORE) {
+ rc = pnv_self_restore_sprs(pir, cpu,
+ curr_spr.spr);
if (rc != 0)
return rc;
}
}
}
+ return 0;
+}

+static int pnv_save_sprs_for_deep_states(void)
+{
+ int rc;
+
+ rc = pnv_self_save_restore_sprs();
+ if (rc != 0)
+ return rc;
return 0;
}

--
2.17.1
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