Re: [PATCH v2 03/28] ACPICA: Hardware: Enable 64-bit firmware waking vector for selected FACS.

Rafael J. Wysocki
2015-06-24T13:39:45Z

On Wednesday, June 24, 2015 11:02:10 AM Lv Zheng wrote:
> ACPICA commit 7aa598d711644ab0de5f70ad88f1e2de253115e4
>
> The following commit is reported to have broken s2ram on some platforms:
> Commit: 0249ed2444d65d65fc3f3f64f398f1ad0b7e54cd
> ACPICA: Add option to favor 32-bit FADT addresses.
> The platform reports 2 FACS tables (which is not allowed by ACPI
> specification) and the new 32-bit address favor rule forces OSPMs to use
> the FACS table reported via FADT's X_FIRMWARE_CTRL field.
>
> The root cause of the reported bug might be one of the followings:
> 1. BIOS may favor the 64-bit firmware waking vector address when the
> version of the FACS is greater than 0 and Linux currently only supports
> resuming from the real mode, so the 64-bit firmware waking vector has
> never been set and might be invalid to BIOS while the commit enables
> higher version FACS.
> 2. BIOS may favor the FACS reported via the "FIRMWARE_CTRL" field in the
> FADT while the commit doesn't set the firmware waking vector address of
> the FACS reported by "FIRMWARE_CTRL", it only sets the firware waking
> vector address of the FACS reported by "X_FIRMWARE_CTRL".
>
> This patch excludes the cases that can trigger the bugs caused by the root
> cause 1.
>
> ACPI specification says:
> A. 32-bit FACS address (FIRMWARE_CTRL field in FADT):
> Physical memory address of the FACS, where OSPM and firmware exchange
> control information.
> If the X_FIRMWARE_CTRL field contains a non zero value then this field
> must be zero.
> A zero value indicates that no FACS is specified by this field.
> B. 64-bit FACS address (X_FIRMWARE_CTRL field in FADT):
> 64bit physical memory address of the FACS.
> This field is used when the physical address of the FACS is above 4GB.
> If the FIRMWARE_CTRL field contains a non zero value then this field
> must be zero.
> A zero value indicates that no FACS is specified by this field.
> Thus the 32bit and 64bit firmware waking vector should indicate completely
> different resuming environment - real mode (1MB addressable) and non real
> mode (4GB+ addressable) and currently Linux only supports resuming from
> real mode.
>
> This patch enables 64-bit firmware waking vector for selected FACS via
> acpi_set_firmware_waking_vector() so that it's up to OSPMs to determine which
> resuming mode should be used by BIOS and ACPICA changes won't trigger the
> bugs caused by the root cause 1. For example, Linux can pass
> physical_address64=0 as the parameter of acpi_set_firmware_waking_vector() to
> indicate no 64bit waking vector support. Lv Zheng.
>
> This patch also updates acpi_set_firmware_waking_vector() invocations in
> order to keep 32-bit firmware waking vector favor for Linux. 64-bit
> firmware waking vector has never been enabled by Linux. The
> (acpi_physical_address)0 for 64-bit address can be used to force ACPICA to
> set only 32-bit firmware waking vector for Linux.
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=74021
> Link: https://github.com/acpica/acpica/commit/7aa598d7
> Cc: 3.14.1+ <stable@vger.kernel.org> # 3.14.1+
> Reported-and-tested-by: Oswald Buddenhagen <ossi@kde.org>
> Signed-off-by: Lv Zheng <lv.zheng@intel.com>
> Signed-off-by: Bob Moore <robert.moore@intel.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: x86@kernel.org
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Fenghua Yu <fenghua.yu@intel.com>
> Cc: linux-ia64@vger.kernel.org
> ---
> arch/ia64/include/asm/acpi.h | 3 +-
> arch/ia64/kernel/acpi.c | 2 --
> arch/x86/include/asm/acpi.h | 3 +-
> drivers/acpi/acpica/hwxfsleep.c | 61 ++++++++++++---------------------------
> drivers/acpi/sleep.c | 8 +++--
> include/acpi/acpixf.h | 11 +++----
> 6 files changed, 33 insertions(+), 55 deletions(-)
>
> diff --git a/arch/ia64/include/asm/acpi.h b/arch/ia64/include/asm/acpi.h
> index aa0fdf1..0ac4fab 100644
> --- a/arch/ia64/include/asm/acpi.h
> +++ b/arch/ia64/include/asm/acpi.h
> @@ -79,7 +79,8 @@ int acpi_gsi_to_irq (u32 gsi, unsigned int *irq);
> /* Low-level suspend routine. */
> extern int acpi_suspend_lowlevel(void);
>
> -extern unsigned long acpi_wakeup_address;
> +#define acpi_wakeup_address ((acpi_physical_address)0)
> +#define acpi_wakeup_address64 ((acpi_physical_address)0)
>
> /*
> * Record the cpei override flag and current logical cpu. This is
> diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
> index b1698bc..1b08d6f 100644
> --- a/arch/ia64/kernel/acpi.c
> +++ b/arch/ia64/kernel/acpi.c
> @@ -60,8 +60,6 @@ int acpi_lapic;
> unsigned int acpi_cpei_override;
> unsigned int acpi_cpei_phys_cpuid;
>
> -unsigned long acpi_wakeup_address = 0;
> -
> #ifdef CONFIG_IA64_GENERIC
> static unsigned long __init acpi_find_rsdp(void)
> {
> diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
> index 3a45668..fc9608d 100644
> --- a/arch/x86/include/asm/acpi.h
> +++ b/arch/x86/include/asm/acpi.h
> @@ -72,7 +72,8 @@ static inline void acpi_disable_pci(void)
> extern int (*acpi_suspend_lowlevel)(void);
>
> /* Physical address to resume after wakeup */
> -#define acpi_wakeup_address ((unsigned long)(real_mode_header->wakeup_start))
> +#define acpi_wakeup_address ((acpi_physical_address)(real_mode_header->wakeup_start))
> +#define acpi_wakeup_address64 ((acpi_physical_address)(0))

Do we need this?

Why don't we define

static inline void acpi_set_wakeup_address(void)
{
acpi_set_firmware_waking_vector((unsigned long)real_mode_header->wakeup_start, 0);
}

and

static inline void acpi_clear_wakeup_address(void)
{
acpi_set_firmware_waking_vector(0, 0);
}

instead?

Which may be defined as empty stubs on ia64?

>
> /*
> * Check if the CPU can handle C2 and deeper
> diff --git a/drivers/acpi/acpica/hwxfsleep.c b/drivers/acpi/acpica/hwxfsleep.c
> index 82e310b..c67cd32 100644
> --- a/drivers/acpi/acpica/hwxfsleep.c
> +++ b/drivers/acpi/acpica/hwxfsleep.c
> @@ -73,7 +73,6 @@ static struct acpi_sleep_functions acpi_sleep_dispatch[] = {
> /*
> * These functions are removed for the ACPI_REDUCED_HARDWARE case:
> * acpi_set_firmware_waking_vector
> - * acpi_set_firmware_waking_vector64
> * acpi_enter_sleep_state_s4bios
> */
>
> @@ -83,15 +82,19 @@ static struct acpi_sleep_functions acpi_sleep_dispatch[] = {
> * FUNCTION: acpi_set_firmware_waking_vector
> *
> * PARAMETERS: physical_address - 32-bit physical address of ACPI real mode
> - * entry point.
> + * entry point
> + * physical_address64 - 64-bit physical address of ACPI protected
> + * entry point
> *
> * RETURN: Status
> *
> - * DESCRIPTION: Sets the 32-bit firmware_waking_vector field of the FACS
> + * DESCRIPTION: Sets the firmware_waking_vector fields of the FACS
> *
> ******************************************************************************/
>
> -acpi_status acpi_set_firmware_waking_vector(u32 physical_address)
> +acpi_status
> +acpi_set_firmware_waking_vector(acpi_physical_address physical_address,
> + acpi_physical_address physical_address64)
> {
> ACPI_FUNCTION_TRACE(acpi_set_firmware_waking_vector);
>
> @@ -106,53 +109,27 @@ acpi_status acpi_set_firmware_waking_vector(u32 physical_address)
>
> /* Set the 32-bit vector */
>
> - acpi_gbl_FACS->firmware_waking_vector = physical_address;
> + acpi_gbl_FACS->firmware_waking_vector = (u32)physical_address;
>
> - /* Clear the 64-bit vector if it exists */
> + if (acpi_gbl_FACS->length > 32) {
> + if (acpi_gbl_FACS->version >= 1) {
>
> - if ((acpi_gbl_FACS->length > 32) && (acpi_gbl_FACS->version >= 1)) {
> - acpi_gbl_FACS->xfirmware_waking_vector = 0;
> - }
> -
> - return_ACPI_STATUS(AE_OK);
> -}
> -
> -ACPI_EXPORT_SYMBOL(acpi_set_firmware_waking_vector)
> -
> -#if ACPI_MACHINE_WIDTH == 64
> -/*******************************************************************************
> - *
> - * FUNCTION: acpi_set_firmware_waking_vector64
> - *
> - * PARAMETERS: physical_address - 64-bit physical address of ACPI protected
> - * mode entry point.
> - *
> - * RETURN: Status
> - *
> - * DESCRIPTION: Sets the 64-bit X_firmware_waking_vector field of the FACS, if
> - * it exists in the table. This function is intended for use with
> - * 64-bit host operating systems.
> - *
> - ******************************************************************************/
> -acpi_status acpi_set_firmware_waking_vector64(u64 physical_address)
> -{
> - ACPI_FUNCTION_TRACE(acpi_set_firmware_waking_vector64);
> + /* Set the 64-bit vector */
>
> - /* Determine if the 64-bit vector actually exists */
> + acpi_gbl_FACS->xfirmware_waking_vector =
> + physical_address64;
> + } else {
> + /* Clear the 64-bit vector if it exists */
>
> - if ((acpi_gbl_FACS->length <= 32) || (acpi_gbl_FACS->version < 1)) {
> - return_ACPI_STATUS(AE_NOT_EXIST);
> + acpi_gbl_FACS->xfirmware_waking_vector = 0;
> + }
> }
>
> - /* Clear 32-bit vector, set the 64-bit X_ vector */
> -
> - acpi_gbl_FACS->firmware_waking_vector = 0;
> - acpi_gbl_FACS->xfirmware_waking_vector = physical_address;
> return_ACPI_STATUS(AE_OK);
> }
>
> -ACPI_EXPORT_SYMBOL(acpi_set_firmware_waking_vector64)
> -#endif
> +ACPI_EXPORT_SYMBOL(acpi_set_firmware_waking_vector)
> +
> /*******************************************************************************
> *
> * FUNCTION: acpi_enter_sleep_state_s4bios
> diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
> index 2f0d4db..3a6a2eb 100644
> --- a/drivers/acpi/sleep.c
> +++ b/drivers/acpi/sleep.c
> @@ -25,6 +25,8 @@
> #include "internal.h"
> #include "sleep.h"
>
> +#define ACPI_NO_WAKING_VECTOR ((acpi_physical_address)0)

Do we need this too?

> +
> static u8 sleep_states[ACPI_S_STATE_COUNT];
>
> static void acpi_sleep_tts_switch(u32 acpi_state)
> @@ -61,7 +63,8 @@ static int acpi_sleep_prepare(u32 acpi_state)
> if (acpi_state == ACPI_STATE_S3) {
> if (!acpi_wakeup_address)
> return -EFAULT;
> - acpi_set_firmware_waking_vector(acpi_wakeup_address);
> + acpi_set_firmware_waking_vector(acpi_wakeup_address,
> + acpi_wakeup_address64);
>
> }
> ACPI_FLUSH_CPU_CACHE();
> @@ -410,7 +413,8 @@ static void acpi_pm_finish(void)
> acpi_leave_sleep_state(acpi_state);
>
> /* reset firmware waking vector */
> - acpi_set_firmware_waking_vector((acpi_physical_address) 0);
> + acpi_set_firmware_waking_vector(ACPI_NO_WAKING_VECTOR,
> + ACPI_NO_WAKING_VECTOR);
>
> acpi_target_sleep_state = ACPI_STATE_S0;
>
> diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
> index d68f1cd..a68e4b9 100644
> --- a/include/acpi/acpixf.h
> +++ b/include/acpi/acpixf.h
> @@ -814,13 +814,10 @@ ACPI_EXTERNAL_RETURN_STATUS(acpi_status
> ACPI_EXTERNAL_RETURN_STATUS(acpi_status acpi_leave_sleep_state(u8 sleep_state))
>
> ACPI_HW_DEPENDENT_RETURN_STATUS(acpi_status
> - acpi_set_firmware_waking_vector(u32
> - physical_address))
> -#if ACPI_MACHINE_WIDTH == 64
> -ACPI_HW_DEPENDENT_RETURN_STATUS(acpi_status
> - acpi_set_firmware_waking_vector64(u64
> - physical_address))
> -#endif
> + acpi_set_firmware_waking_vector
> + (acpi_physical_address physical_address,
> + acpi_physical_address physical_address64))
> +
> /*
> * ACPI Timer interfaces
> */
>

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.