From 945661d581c50cb67fc04291d374156f4d807fe3 Mon Sep 17 00:00:00 2001 From: Huisong Li Date: Mon, 29 Sep 2025 17:37:49 +0800 Subject: [PATCH 1/3] ACPI: processor: idle: Relocate state flags initialization Since acpi_processor_setup_cstates() is a more logical place for setting idle state flags than acpi_processor_setup_cpuidle_cx(), move that code from the latter to the former. It also allows direct references to acpi_idle_driver in acpi_processor_setup_cpuidle_cx() to be avoided. No intentional functional impact. Signed-off-by: Huisong Li [ rjw: Subject and changelog rewrite ] Link: https://patch.msgid.link/20250929093754.3998136-5-lihuisong@huawei.com Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_idle.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 22b051b94a86..341825e8ac63 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -737,13 +737,11 @@ static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, { int i, count = ACPI_IDLE_STATE_START; struct acpi_processor_cx *cx; - struct cpuidle_state *state; if (max_cstate == 0) max_cstate = 1; for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { - state = &acpi_idle_driver.states[count]; cx = &pr->power.states[i]; if (!cx->valid) @@ -751,15 +749,6 @@ static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, per_cpu(acpi_cstate[count], dev->cpu) = cx; - if (lapic_timer_needs_broadcast(pr, cx)) - state->flags |= CPUIDLE_FLAG_TIMER_STOP; - - if (cx->type == ACPI_STATE_C3) { - state->flags |= CPUIDLE_FLAG_TLB_FLUSHED; - if (pr->flags.bm_check) - state->flags |= CPUIDLE_FLAG_RCU_IDLE; - } - count++; if (count == CPUIDLE_STATE_MAX) break; @@ -818,6 +807,15 @@ static int acpi_processor_setup_cstates(struct acpi_processor *pr) if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr)) state->enter_s2idle = acpi_idle_enter_s2idle; + if (lapic_timer_needs_broadcast(pr, cx)) + state->flags |= CPUIDLE_FLAG_TIMER_STOP; + + if (cx->type == ACPI_STATE_C3) { + state->flags |= CPUIDLE_FLAG_TLB_FLUSHED; + if (pr->flags.bm_check) + state->flags |= CPUIDLE_FLAG_RCU_IDLE; + } + count++; if (count == CPUIDLE_STATE_MAX) break; From 77ca1612b80154c62d4002a3e303bc2c2999aac7 Mon Sep 17 00:00:00 2001 From: Huisong Li Date: Wed, 5 Nov 2025 17:36:47 +0800 Subject: [PATCH 2/3] ACPI: processor: idle: Drop redundant C-state count checks acpi_processor_setup_cstates() and acpi_processor_setup_cpuidle_cx() are called after successfully obtaining power information. Among other things, these setup functions check the C-state count against zero. However, that check is done by acpi_processor_get_power_info_cst() which will cause acpi_processor_get_power_info() to fail if it does no pass, so the checks in the two functions mentioned above are redundant. Drop those redundant checks. No intentional functional impact. Signed-off-by: Huisong Li [ rjw: Subject and changelog rewrite ] Link: https://patch.msgid.link/20251105093647.3557248-1-lihuisong@huawei.com Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_idle.c | 22 +++++++--------------- 1 file changed, 7 insertions(+), 15 deletions(-) diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 341825e8ac63..22909fccf0b1 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -732,8 +732,8 @@ static int __cpuidle acpi_idle_enter_s2idle(struct cpuidle_device *dev, return 0; } -static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, - struct cpuidle_device *dev) +static void acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, + struct cpuidle_device *dev) { int i, count = ACPI_IDLE_STATE_START; struct acpi_processor_cx *cx; @@ -753,14 +753,9 @@ static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, if (count == CPUIDLE_STATE_MAX) break; } - - if (!count) - return -EINVAL; - - return 0; } -static int acpi_processor_setup_cstates(struct acpi_processor *pr) +static void acpi_processor_setup_cstates(struct acpi_processor *pr) { int i, count; struct acpi_processor_cx *cx; @@ -822,11 +817,6 @@ static int acpi_processor_setup_cstates(struct acpi_processor *pr) } drv->state_count = count; - - if (!count) - return -EINVAL; - - return 0; } static inline void acpi_processor_cstate_first_run_checks(void) @@ -1241,7 +1231,8 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) if (pr->flags.has_lpi) return acpi_processor_setup_lpi_states(pr); - return acpi_processor_setup_cstates(pr); + acpi_processor_setup_cstates(pr); + return 0; } /** @@ -1261,7 +1252,8 @@ static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr, if (pr->flags.has_lpi) return acpi_processor_ffh_lpi_probe(pr->id); - return acpi_processor_setup_cpuidle_cx(pr, dev); + acpi_processor_setup_cpuidle_cx(pr, dev); + return 0; } static int acpi_processor_get_power_info(struct acpi_processor *pr) From 17e7972979e147cc51d4a165e6b6b0f93273ca68 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ren=C3=A9=20Rebe?= Date: Wed, 26 Nov 2025 16:55:13 +0100 Subject: [PATCH 3/3] ACPI: processor_core: fix map_x2apic_id for amd-pstate on am4 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On all AMD AM4 systems I have seen, e.g ASUS X470-i, Pro WS X570 Ace and equivalent Gigabyte, amd-pstate does not initialize when the x2apic is enabled in the BIOS. Kernel debug messages include: [ 0.315438] acpi LNXCPU:00: Failed to get CPU physical ID. [ 0.354756] ACPI CPPC: No CPC descriptor for CPU:0 [ 0.714951] amd_pstate: the _CPC object is not present in SBIOS or ACPI disabled I tracked this down to map_x2apic_id() checking device_declaration passed in via the type argument of acpi_get_phys_id() via map_madt_entry() while map_lapic_id() does not. It appears these BIOSes use Processor statements for declaring the CPUs in the ACPI namespace instead of processor device objects (which should have been used). CPU declarations via Processor statements were deprecated in ACPI 6.0 that was released 10 years ago. They should not be used any more in any contemporary platform firmware. I tried to contact Asus support multiple times, but never received a reply nor did any BIOS update ever change this. Fix amd-pstate w/ x2apic on am4 by allowing map_x2apic_id() to work with CPUs declared via Processor statements for IDs less than 255, which is consistent with ACPI 5.0 that still allowed Processor statements to be used for declaring CPUs. Fixes: 7237d3de78ff ("x86, ACPI: add support for x2apic ACPI extensions") Signed-off-by: René Rebe [ rjw: Changelog edits ] Link: https://patch.msgid.link/20251126.165513.1373131139292726554.rene@exactco.de Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c index 9b6b71a2ffb5..a4498357bd16 100644 --- a/drivers/acpi/processor_core.c +++ b/drivers/acpi/processor_core.c @@ -54,7 +54,7 @@ static int map_x2apic_id(struct acpi_subtable_header *entry, if (!(apic->lapic_flags & ACPI_MADT_ENABLED)) return -ENODEV; - if (device_declaration && (apic->uid == acpi_id)) { + if (apic->uid == acpi_id && (device_declaration || acpi_id < 255)) { *apic_id = apic->local_apic_id; return 0; }