| Message ID | 1f5138b5080606804162b0a7cf20c134589b96b1.1581505210.git.psampat@linux.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Introduce Self-Save API for deep stop states | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (a5bc6e124219546a81ce334dc9b16483d55e9abf) |
| snowpatch_ozlabs/build-ppc64le | warning | Build succeeded but added 2 new sparse warnings |
| snowpatch_ozlabs/build-ppc64be | warning | Build succeeded but added 2 new sparse warnings |
| snowpatch_ozlabs/build-pmac32 | success | Build succeeded |
| snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 94 lines checked |
| snowpatch_ozlabs/needsstable | success | Patch has no Fixes tags |
Pratik Rajesh Sampat <psampat@linux.ibm.com> writes: > Parse the device tree for nodes self-save, self-restore and populate > support for the preferred SPRs based what was advertised by the device > tree. These should be documented in: Documentation/devicetree/bindings/powerpc/opal/power-mgt.txt > diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c > index 97aeb45e897b..27dfadf609e8 100644 > --- a/arch/powerpc/platforms/powernv/idle.c > +++ b/arch/powerpc/platforms/powernv/idle.c > @@ -1436,6 +1436,85 @@ static void __init pnv_probe_idle_states(void) > supported_cpuidle_states |= pnv_idle_states[i].flags; > } > > +/* > + * Extracts and populates the self save or restore capabilities > + * passed from the device tree node > + */ > +static int extract_save_restore_state_dt(struct device_node *np, int type) > +{ > + int nr_sprns = 0, i, bitmask_index; > + int rc = 0; > + u64 *temp_u64; > + u64 bit_pos; > + > + nr_sprns = of_property_count_u64_elems(np, "sprn-bitmask"); > + if (nr_sprns <= 0) > + return rc; Using <= 0 means zero SPRs is treated by success as the caller, is that intended? If so a comment would be appropriate. > + temp_u64 = kcalloc(nr_sprns, sizeof(u64), GFP_KERNEL); > + if (of_property_read_u64_array(np, "sprn-bitmask", > + temp_u64, nr_sprns)) { > + pr_warn("cpuidle-powernv: failed to find registers in DT\n"); > + kfree(temp_u64); > + return -EINVAL; > + } > + /* > + * Populate acknowledgment of support for the sprs in the global vector > + * gotten by the registers supplied by the firmware. > + * The registers are in a bitmask, bit index within > + * that specifies the SPR > + */ > + for (i = 0; i < nr_preferred_sprs; i++) { > + bitmask_index = preferred_sprs[i].spr / 64; > + bit_pos = preferred_sprs[i].spr % 64; This is basically a hand coded bitmap, see eg. BIT_WORD(), BIT_MASK() etc. I don't think there's an easy way to convert temp_u64 into a proper bitmap, so it's probably not worth doing that. But at least use the macros. > + if ((temp_u64[bitmask_index] & (1UL << bit_pos)) == 0) { > + if (type == SELF_RESTORE_TYPE) > + preferred_sprs[i].supported_mode &= > + ~SELF_RESTORE_STRICT; > + else > + preferred_sprs[i].supported_mode &= > + ~SELF_SAVE_STRICT; > + continue; > + } > + if (type == SELF_RESTORE_TYPE) { > + preferred_sprs[i].supported_mode |= > + SELF_RESTORE_STRICT; > + } else { > + preferred_sprs[i].supported_mode |= > + SELF_SAVE_STRICT; > + } > + } > + > + kfree(temp_u64); > + return rc; > +} > + > +static int pnv_parse_deepstate_dt(void) > +{ > + struct device_node *sr_np, *ss_np; You never use these concurrently AFAICS, so you could just have a single *np. > + int rc = 0, i; > + > + /* Self restore register population */ > + sr_np = of_find_node_by_path("/ibm,opal/power-mgt/self-restore"); I know the existing idle code uses of_find_node_by_path(), but that's because it's old and crufty. Please don't add new searches by path. You should be searching by compatible. > + if (!sr_np) { > + pr_warn("opal: self restore Node not found"); This warning and the others below will fire on all existing firmware versions, which is not OK. > + } else { > + rc = extract_save_restore_state_dt(sr_np, SELF_RESTORE_TYPE); > + if (rc != 0) > + return rc; > + } > + /* Self save register population */ > + ss_np = of_find_node_by_path("/ibm,opal/power-mgt/self-save"); > + if (!ss_np) { > + pr_warn("opal: self save Node not found"); > + pr_warn("Legacy firmware. Assuming default self-restore support"); > + for (i = 0; i < nr_preferred_sprs; i++) > + preferred_sprs[i].supported_mode &= ~SELF_SAVE_STRICT; > + } else { > + rc = extract_save_restore_state_dt(ss_np, SELF_SAVE_TYPE); > + } > + return rc; You're leaking references on all the device_nodes in here, you need of_node_put() before exiting. > +} cheers
Thank you Michael for the review. On 17/03/20 8:43 am, Michael Ellerman wrote: > Pratik Rajesh Sampat <psampat@linux.ibm.com> writes: >> Parse the device tree for nodes self-save, self-restore and populate >> support for the preferred SPRs based what was advertised by the device >> tree. > These should be documented in: > Documentation/devicetree/bindings/powerpc/opal/power-mgt.txt Sure thing I'll add them. >> diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c >> index 97aeb45e897b..27dfadf609e8 100644 >> --- a/arch/powerpc/platforms/powernv/idle.c >> +++ b/arch/powerpc/platforms/powernv/idle.c >> @@ -1436,6 +1436,85 @@ static void __init pnv_probe_idle_states(void) >> supported_cpuidle_states |= pnv_idle_states[i].flags; >> } >> >> +/* >> + * Extracts and populates the self save or restore capabilities >> + * passed from the device tree node >> + */ >> +static int extract_save_restore_state_dt(struct device_node *np, int type) >> +{ >> + int nr_sprns = 0, i, bitmask_index; >> + int rc = 0; >> + u64 *temp_u64; >> + u64 bit_pos; >> + >> + nr_sprns = of_property_count_u64_elems(np, "sprn-bitmask"); >> + if (nr_sprns <= 0) >> + return rc; > Using <= 0 means zero SPRs is treated by success as the caller, is that > intended? If so a comment would be appropriate. My bad, this is undesirable. This should be treated as a failure. I'll fix this. >> + temp_u64 = kcalloc(nr_sprns, sizeof(u64), GFP_KERNEL); >> + if (of_property_read_u64_array(np, "sprn-bitmask", >> + temp_u64, nr_sprns)) { >> + pr_warn("cpuidle-powernv: failed to find registers in DT\n"); >> + kfree(temp_u64); >> + return -EINVAL; >> + } >> + /* >> + * Populate acknowledgment of support for the sprs in the global vector >> + * gotten by the registers supplied by the firmware. >> + * The registers are in a bitmask, bit index within >> + * that specifies the SPR >> + */ >> + for (i = 0; i < nr_preferred_sprs; i++) { >> + bitmask_index = preferred_sprs[i].spr / 64; >> + bit_pos = preferred_sprs[i].spr % 64; > This is basically a hand coded bitmap, see eg. BIT_WORD(), BIT_MASK() etc. > > I don't think there's an easy way to convert temp_u64 into a proper > bitmap, so it's probably not worth doing that. But at least use the macros. Right. I'll use the macros for a cleaner abstraction. >> + if ((temp_u64[bitmask_index] & (1UL << bit_pos)) == 0) { >> + if (type == SELF_RESTORE_TYPE) >> + preferred_sprs[i].supported_mode &= >> + ~SELF_RESTORE_STRICT; >> + else >> + preferred_sprs[i].supported_mode &= >> + ~SELF_SAVE_STRICT; >> + continue; >> + } >> + if (type == SELF_RESTORE_TYPE) { >> + preferred_sprs[i].supported_mode |= >> + SELF_RESTORE_STRICT; >> + } else { >> + preferred_sprs[i].supported_mode |= >> + SELF_SAVE_STRICT; >> + } >> + } >> + >> + kfree(temp_u64); >> + return rc; >> +} >> + >> +static int pnv_parse_deepstate_dt(void) >> +{ >> + struct device_node *sr_np, *ss_np; > You never use these concurrently AFAICS, so you could just have a single *np. Sure, got rid of it. >> + int rc = 0, i; >> + >> + /* Self restore register population */ >> + sr_np = of_find_node_by_path("/ibm,opal/power-mgt/self-restore"); > I know the existing idle code uses of_find_node_by_path(), but that's > because it's old and crufty. Please don't add new searches by path. You > should be searching by compatible. > Alright, I'll replace of_find_node_by_path() calls with of_find_compatible_node() >> + if (!sr_np) { >> + pr_warn("opal: self restore Node not found"); > This warning and the others below will fire on all existing firmware > versions, which is not OK. I'll get rid of the warnings. They seem unnecessary to me also now. >> + } else { >> + rc = extract_save_restore_state_dt(sr_np, SELF_RESTORE_TYPE); >> + if (rc != 0) >> + return rc; >> + } >> + /* Self save register population */ >> + ss_np = of_find_node_by_path("/ibm,opal/power-mgt/self-save"); >> + if (!ss_np) { >> + pr_warn("opal: self save Node not found"); >> + pr_warn("Legacy firmware. Assuming default self-restore support"); >> + for (i = 0; i < nr_preferred_sprs; i++) >> + preferred_sprs[i].supported_mode &= ~SELF_SAVE_STRICT; >> + } else { >> + rc = extract_save_restore_state_dt(ss_np, SELF_SAVE_TYPE); >> + } >> + return rc; > You're leaking references on all the device_nodes in here, you need > of_node_put() before exiting. Got it. I'll clear the refcount before exitting. >> +} > > cheers Thanks! Pratik
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c index 97aeb45e897b..27dfadf609e8 100644 --- a/arch/powerpc/platforms/powernv/idle.c +++ b/arch/powerpc/platforms/powernv/idle.c @@ -1436,6 +1436,85 @@ static void __init pnv_probe_idle_states(void) supported_cpuidle_states |= pnv_idle_states[i].flags; } +/* + * Extracts and populates the self save or restore capabilities + * passed from the device tree node + */ +static int extract_save_restore_state_dt(struct device_node *np, int type) +{ + int nr_sprns = 0, i, bitmask_index; + int rc = 0; + u64 *temp_u64; + u64 bit_pos; + + nr_sprns = of_property_count_u64_elems(np, "sprn-bitmask"); + if (nr_sprns <= 0) + return rc; + temp_u64 = kcalloc(nr_sprns, sizeof(u64), GFP_KERNEL); + if (of_property_read_u64_array(np, "sprn-bitmask", + temp_u64, nr_sprns)) { + pr_warn("cpuidle-powernv: failed to find registers in DT\n"); + kfree(temp_u64); + return -EINVAL; + } + /* + * Populate acknowledgment of support for the sprs in the global vector + * gotten by the registers supplied by the firmware. + * The registers are in a bitmask, bit index within + * that specifies the SPR + */ + for (i = 0; i < nr_preferred_sprs; i++) { + bitmask_index = preferred_sprs[i].spr / 64; + bit_pos = preferred_sprs[i].spr % 64; + if ((temp_u64[bitmask_index] & (1UL << bit_pos)) == 0) { + if (type == SELF_RESTORE_TYPE) + preferred_sprs[i].supported_mode &= + ~SELF_RESTORE_STRICT; + else + preferred_sprs[i].supported_mode &= + ~SELF_SAVE_STRICT; + continue; + } + if (type == SELF_RESTORE_TYPE) { + preferred_sprs[i].supported_mode |= + SELF_RESTORE_STRICT; + } else { + preferred_sprs[i].supported_mode |= + SELF_SAVE_STRICT; + } + } + + kfree(temp_u64); + return rc; +} + +static int pnv_parse_deepstate_dt(void) +{ + struct device_node *sr_np, *ss_np; + int rc = 0, i; + + /* Self restore register population */ + sr_np = of_find_node_by_path("/ibm,opal/power-mgt/self-restore"); + if (!sr_np) { + pr_warn("opal: self restore Node not found"); + } else { + rc = extract_save_restore_state_dt(sr_np, SELF_RESTORE_TYPE); + if (rc != 0) + return rc; + } + /* Self save register population */ + ss_np = of_find_node_by_path("/ibm,opal/power-mgt/self-save"); + if (!ss_np) { + pr_warn("opal: self save Node not found"); + pr_warn("Legacy firmware. Assuming default self-restore support"); + for (i = 0; i < nr_preferred_sprs; i++) + preferred_sprs[i].supported_mode &= ~SELF_SAVE_STRICT; + } else { + rc = extract_save_restore_state_dt(ss_np, SELF_SAVE_TYPE); + } + return rc; +} + /* * This function parses device-tree and populates all the information * into pnv_idle_states structure. It also sets up nr_pnv_idle_states @@ -1584,6 +1663,9 @@ static int __init pnv_init_idle_states(void) return rc; pnv_probe_idle_states(); + rc = pnv_parse_deepstate_dt(); + if (rc) + return rc; if (!cpu_has_feature(CPU_FTR_ARCH_300)) { if (!(supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1)) { power7_fastsleep_workaround_entry = false;