From c50f13c672df758b59e026c15b9118f3ed46edc4 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 1 Dec 2014 23:50:16 +0100 Subject: [PATCH] ACPICA: Save current masks of enabled GPEs after enable register writes There is a race condition between acpi_hw_disable_all_gpes() or acpi_enable_all_wakeup_gpes() and acpi_ev_asynch_enable_gpe() such that if the latter wins the race, it may mistakenly enable a GPE disabled by the former. This may lead to premature system wakeups during system suspend and potentially to more serious consequences. The source of the problem is how acpi_hw_low_set_gpe() works when passed ACPI_GPE_CONDITIONAL_ENABLE as the second argument. In that case, the GPE will be enabled if the corresponding bit is set in the enable_for_run mask of the GPE enable register containing that bit. However, acpi_hw_disable_all_gpes() and acpi_enable_all_wakeup_gpes() don't modify the enable_for_run masks of GPE registers when writing to them. In consequence, if acpi_ev_asynch_enable_gpe(), which eventually calls acpi_hw_low_set_gpe() with the second argument equal to ACPI_GPE_CONDITIONAL_ENABLE, is executed in parallel with one of these functions, it may reverse changes made by them. To fix the problem, introduce a new enable_mask field in struct acpi_gpe_register_info in which to store the current mask of enabled GPEs and modify acpi_hw_low_set_gpe() to take this mask into account instead of enable_for_run when its second argument is equal to ACPI_GPE_CONDITIONAL_ENABLE. Also modify the low-level routines called by acpi_hw_disable_all_gpes(), acpi_enable_all_wakeup_gpes() and acpi_enable_all_runtime_gpes() to update the enable_mask masks of GPE registers after all (successful) writes to those registers. Acked-by: Lv Zheng Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpica/aclocal.h | 1 + drivers/acpi/acpica/evgpe.c | 6 ++-- drivers/acpi/acpica/hwgpe.c | 53 ++++++++++++++++++++++++++++------- include/acpi/actypes.h | 4 +++ 4 files changed, 51 insertions(+), 13 deletions(-) diff --git a/drivers/acpi/acpica/aclocal.h b/drivers/acpi/acpica/aclocal.h index 80c74e90f3cc..680d23bbae7c 100644 --- a/drivers/acpi/acpica/aclocal.h +++ b/drivers/acpi/acpica/aclocal.h @@ -454,6 +454,7 @@ struct acpi_gpe_register_info { u16 base_gpe_number; /* Base GPE number for this register */ u8 enable_for_wake; /* GPEs to keep enabled when sleeping */ u8 enable_for_run; /* GPEs to keep enabled when running */ + u8 enable_mask; /* Current mask of enabled GPEs */ }; /* diff --git a/drivers/acpi/acpica/evgpe.c b/drivers/acpi/acpica/evgpe.c index 2095dfb72bcb..81db932b15ee 100644 --- a/drivers/acpi/acpica/evgpe.c +++ b/drivers/acpi/acpica/evgpe.c @@ -134,7 +134,7 @@ acpi_status acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info) /* Enable the requested GPE */ - status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE); + status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE_SAVE); return_ACPI_STATUS(status); } @@ -213,7 +213,7 @@ acpi_ev_remove_gpe_reference(struct acpi_gpe_event_info *gpe_event_info) if (ACPI_SUCCESS(status)) { status = acpi_hw_low_set_gpe(gpe_event_info, - ACPI_GPE_DISABLE); + ACPI_GPE_DISABLE_SAVE); } if (ACPI_FAILURE(status)) { @@ -655,7 +655,7 @@ acpi_status acpi_ev_finish_gpe(struct acpi_gpe_event_info * gpe_event_info) /* * Enable this GPE, conditionally. This means that the GPE will - * only be physically enabled if the enable_for_run bit is set + * only be physically enabled if the enable_mask bit is set * in the event_info. */ (void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_CONDITIONAL_ENABLE); diff --git a/drivers/acpi/acpica/hwgpe.c b/drivers/acpi/acpica/hwgpe.c index 48ac7b7b59cd..494027f5c067 100644 --- a/drivers/acpi/acpica/hwgpe.c +++ b/drivers/acpi/acpica/hwgpe.c @@ -115,12 +115,12 @@ acpi_hw_low_set_gpe(struct acpi_gpe_event_info *gpe_event_info, u32 action) /* Set or clear just the bit that corresponds to this GPE */ register_bit = acpi_hw_get_gpe_register_bit(gpe_event_info); - switch (action) { + switch (action & ~ACPI_GPE_SAVE_MASK) { case ACPI_GPE_CONDITIONAL_ENABLE: - /* Only enable if the enable_for_run bit is set */ + /* Only enable if the corresponding enable_mask bit is set */ - if (!(register_bit & gpe_register_info->enable_for_run)) { + if (!(register_bit & gpe_register_info->enable_mask)) { return (AE_BAD_PARAMETER); } @@ -145,6 +145,9 @@ acpi_hw_low_set_gpe(struct acpi_gpe_event_info *gpe_event_info, u32 action) /* Write the updated enable mask */ status = acpi_hw_write(enable_mask, &gpe_register_info->enable_address); + if (ACPI_SUCCESS(status) && (action & ACPI_GPE_SAVE_MASK)) { + gpe_register_info->enable_mask = enable_mask; + } return (status); } @@ -260,6 +263,32 @@ acpi_hw_get_gpe_status(struct acpi_gpe_event_info * gpe_event_info, return (AE_OK); } +/****************************************************************************** + * + * FUNCTION: acpi_hw_gpe_enable_write + * + * PARAMETERS: enable_mask - Bit mask to write to the GPE register + * gpe_register_info - Gpe Register info + * + * RETURN: Status + * + * DESCRIPTION: Write the enable mask byte to the given GPE register. + * + ******************************************************************************/ + +static acpi_status +acpi_hw_gpe_enable_write(u8 enable_mask, + struct acpi_gpe_register_info *gpe_register_info) +{ + acpi_status status; + + status = acpi_hw_write(enable_mask, &gpe_register_info->enable_address); + if (ACPI_SUCCESS(status)) { + gpe_register_info->enable_mask = enable_mask; + } + return (status); +} + /****************************************************************************** * * FUNCTION: acpi_hw_disable_gpe_block @@ -287,8 +316,8 @@ acpi_hw_disable_gpe_block(struct acpi_gpe_xrupt_info *gpe_xrupt_info, /* Disable all GPEs in this register */ status = - acpi_hw_write(0x00, - &gpe_block->register_info[i].enable_address); + acpi_hw_gpe_enable_write(0x00, + &gpe_block->register_info[i]); if (ACPI_FAILURE(status)) { return (status); } @@ -355,21 +384,23 @@ acpi_hw_enable_runtime_gpe_block(struct acpi_gpe_xrupt_info *gpe_xrupt_info, { u32 i; acpi_status status; + struct acpi_gpe_register_info *gpe_register_info; /* NOTE: assumes that all GPEs are currently disabled */ /* Examine each GPE Register within the block */ for (i = 0; i < gpe_block->register_count; i++) { - if (!gpe_block->register_info[i].enable_for_run) { + gpe_register_info = &gpe_block->register_info[i]; + if (!gpe_register_info->enable_for_run) { continue; } /* Enable all "runtime" GPEs in this register */ status = - acpi_hw_write(gpe_block->register_info[i].enable_for_run, - &gpe_block->register_info[i].enable_address); + acpi_hw_gpe_enable_write(gpe_register_info->enable_for_run, + gpe_register_info); if (ACPI_FAILURE(status)) { return (status); } @@ -399,10 +430,12 @@ acpi_hw_enable_wakeup_gpe_block(struct acpi_gpe_xrupt_info *gpe_xrupt_info, { u32 i; acpi_status status; + struct acpi_gpe_register_info *gpe_register_info; /* Examine each GPE Register within the block */ for (i = 0; i < gpe_block->register_count; i++) { + gpe_register_info = &gpe_block->register_info[i]; /* * Enable all "wake" GPEs in this register and disable the @@ -410,8 +443,8 @@ acpi_hw_enable_wakeup_gpe_block(struct acpi_gpe_xrupt_info *gpe_xrupt_info, */ status = - acpi_hw_write(gpe_block->register_info[i].enable_for_wake, - &gpe_block->register_info[i].enable_address); + acpi_hw_gpe_enable_write(gpe_register_info->enable_for_wake, + gpe_register_info); if (ACPI_FAILURE(status)) { return (status); } diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h index 7000e66f768e..bbef17368e49 100644 --- a/include/acpi/actypes.h +++ b/include/acpi/actypes.h @@ -736,6 +736,10 @@ typedef u32 acpi_event_status; #define ACPI_GPE_ENABLE 0 #define ACPI_GPE_DISABLE 1 #define ACPI_GPE_CONDITIONAL_ENABLE 2 +#define ACPI_GPE_SAVE_MASK 4 + +#define ACPI_GPE_ENABLE_SAVE (ACPI_GPE_ENABLE | ACPI_GPE_SAVE_MASK) +#define ACPI_GPE_DISABLE_SAVE (ACPI_GPE_DISABLE | ACPI_GPE_SAVE_MASK) /* * GPE info flags - Per GPE -- 2.20.1