Re: [PATCH v5 3/7] acpi: apei: Add SEI notification type support for ARMv8

Jonathan Cameron
2017-08-22T07:56:32Z

On Fri, 18 Aug 2017 22:11:53 +0800
Dongjiu Geng <gengdongjiu@huawei.com> wrote:

> ARMV8.2 requires implementation of the RAS extension, in
> this extension it adds SEI(SError Interrupt) notification
> type, this patch addes a new GHES error source handling
> function for SEI. Because this error source parse and handling
> method are similar with the SEA. so use one function to handle
> them.

Because the error source parsing and handling methods are similar
to that for the SEA, use one function to handle both.

>
> In current code logic, The two functions ghes_sea_add() and

No capital after ,

> ghes_sea_remove() are only called when CONFIG_ACPI_APEI_SEA
> and CONFIG_ACPI_APEI_SEI are defined. If not, it will return
> errors in the ghes_probe() and do not continue, so remove the
> useless code that handling CONFIG_ACPI_APEI_SEA and
> CONFIG_ACPI_APEI_SEI do not defined.

If not, it will return errors in the ghes_probe() and not contiue.
Hence, remove the unnecessary handling when CONFIG_ACPI_APEI_SEA
and CONFIG_ACPI_APEI_SEI are not defined.

>
> Expose one API ghes_notify_sex() to external, external modules
> can call this exposed APIs to parse and handling the SEA/SEI.

Expose one API ghes_notify_sec() to external users. External modules...
>
> Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>

Some really trivial suggestions inline. Feel free to ignore them as
they are a matter of personal taste.

Jonathan

> ---
> arch/arm64/mm/fault.c | 21 +++++++++++++++--
> drivers/acpi/apei/Kconfig | 15 ++++++++++++
> drivers/acpi/apei/ghes.c | 60 ++++++++++++++++++++++++++++++-----------------
> include/acpi/ghes.h | 2 +-
> 4 files changed, 74 insertions(+), 24 deletions(-)
>
> diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
> index 2509e4fe6992..0aa92a69c280 100644
> --- a/arch/arm64/mm/fault.c
> +++ b/arch/arm64/mm/fault.c
> @@ -585,7 +585,7 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
> if (interrupts_enabled(regs))
> nmi_enter();
>
> - ret = ghes_notify_sea();
> + ret = ghes_notify_sex(ACPI_HEST_NOTIFY_SEA);
>
> if (interrupts_enabled(regs))
> nmi_exit();
> @@ -682,7 +682,24 @@ int handle_guest_sea(phys_addr_t addr, unsigned int esr)
> int ret = -ENOENT;
>
> if (IS_ENABLED(CONFIG_ACPI_APEI_SEA))
> - ret = ghes_notify_sea();
> + ret = ghes_notify_sex(ACPI_HEST_NOTIFY_SEA);
> +
> + return ret;
> +}
> +
> +/*
> + * Handle SError interrupt that occur in a guest kernel.
> + *
> + * The return value will be zero if the SEI was successfully handled
> + * and non-zero if there was an error processing the error or there was
> + * no error to process.
> + */
> +int handle_guest_sei(phys_addr_t addr, unsigned int esr)
> +{
> + int ret = -ENOENT;
> +
> + if (IS_ENABLED(CONFIG_ACPI_APEI_SEI))
> + ret = ghes_notify_sex(ACPI_HEST_NOTIFY_SEI);
>
> return ret;
> }
> diff --git a/drivers/acpi/apei/Kconfig b/drivers/acpi/apei/Kconfig
> index de14d49a5c90..556370c763ec 100644
> --- a/drivers/acpi/apei/Kconfig
> +++ b/drivers/acpi/apei/Kconfig
> @@ -54,6 +54,21 @@ config ACPI_APEI_SEA
> option allows the OS to look for such hardware error record, and
> take appropriate action.
>
> +config ACPI_APEI_SEI
> + bool "APEI Asynchronous SError Interrupt logging/recovering support"
> + depends on ARM64 && ACPI_APEI_GHES
> + default y
> + help
> + This option should be enabled if the system supports
> + firmware first handling of SEI (asynchronous SError interrupt).
> +
> + SEI happens with invalid instruction access or asynchronous exceptions
> + on ARMv8 systems. If a system supports firmware first handling of SEI,
> + the platform analyzes and handles hardware error notifications from
> + SEI, and it may then form a HW error record for the OS to parse and
> + handle. This option allows the OS to look for such hardware error
> + record, and take appropriate action.
> +
> config ACPI_APEI_MEMORY_FAILURE
> bool "APEI memory error recovering support"
> depends on ACPI_APEI && MEMORY_FAILURE
> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> index d661d452b238..705738aa48b8 100644
> --- a/drivers/acpi/apei/ghes.c
> +++ b/drivers/acpi/apei/ghes.c
> @@ -813,20 +813,21 @@ static struct notifier_block ghes_notifier_hed = {
> .notifier_call = ghes_notify_hed,
> };
>
> -#ifdef CONFIG_ACPI_APEI_SEA
> static LIST_HEAD(ghes_sea);
> +static LIST_HEAD(ghes_sei);
>
> /*
> * Return 0 only if one of the SEA error sources successfully reported an error
> * record sent from the firmware.
> */
> -int ghes_notify_sea(void)
> +
> +int ghes_handle_sex(struct list_head *head)
> {
> struct ghes *ghes;
> int ret = -ENOENT;
>
> rcu_read_lock();
> - list_for_each_entry_rcu(ghes, &ghes_sea, list) {
> + list_for_each_entry_rcu(ghes, head, list) {
> if (!ghes_proc(ghes))
> ret = 0;
> }
> @@ -834,33 +835,41 @@ int ghes_notify_sea(void)
> return ret;
> }
>
> -static void ghes_sea_add(struct ghes *ghes)
> +int ghes_notify_sex(u8 type)
> +{
> + if (type == ACPI_HEST_NOTIFY_SEA)
> + return ghes_handle_sex(&ghes_sea);
> + else if (type == ACPI_HEST_NOTIFY_SEI)

No real need for the else. If there is potential that additional
elements may be added in here in future, it might be best to go
straight to a switch statement.

> + return ghes_handle_sex(&ghes_sei);
> +
> + return -ENOENT;
> +}
> +
> +/*
> + * This function is only called when the CONFIG_HAVE_ACPI_APEI_SEA or
> + * CONFIG_HAVE_ACPI_APEI_SEA is enabled. when disabled, it will return
> + * error in the ghes_probe
> + */
> +static void ghes_sex_add(struct ghes *ghes)
> {
> + u8 notify_type = ghes->generic->notify.type;
> +
> mutex_lock(&ghes_list_mutex);
> - list_add_rcu(&ghes->list, &ghes_sea);
> + if (notify_type == ACPI_HEST_NOTIFY_SEA)
> + list_add_rcu(&ghes->list, &ghes_sea);
> + else if (notify_type == ACPI_HEST_NOTIFY_SEI)
> + list_add_rcu(&ghes->list, &ghes_sei);

Again, perhaps a switch statement would be slightly cleaner?

> +
> mutex_unlock(&ghes_list_mutex);
> }
>
> -static void ghes_sea_remove(struct ghes *ghes)
> +static void ghes_sex_remove(struct ghes *ghes)
> {
> mutex_lock(&ghes_list_mutex);
> list_del_rcu(&ghes->list);
> mutex_unlock(&ghes_list_mutex);
> synchronize_rcu();
> }
> -#else /* CONFIG_ACPI_APEI_SEA */
> -static inline void ghes_sea_add(struct ghes *ghes)
> -{
> - pr_err(GHES_PFX "ID: %d, trying to add SEA notification which is not supported\n",
> - ghes->generic->header.source_id);
> -}
> -
> -static inline void ghes_sea_remove(struct ghes *ghes)
> -{
> - pr_err(GHES_PFX "ID: %d, trying to remove SEA notification which is not supported\n",
> - ghes->generic->header.source_id);
> -}
> -#endif /* CONFIG_ACPI_APEI_SEA */
>
> #ifdef CONFIG_HAVE_ACPI_APEI_NMI
> /*
> @@ -1107,6 +1116,13 @@ static int ghes_probe(struct platform_device *ghes_dev)
> goto err;
> }
> break;
> + case ACPI_HEST_NOTIFY_SEI:
> + if (!IS_ENABLED(CONFIG_ACPI_APEI_SEI)) {
> + pr_warn(GHES_PFX "Generic hardware error source: %d notified via SEI is not supported!\n",
> + generic->header.source_id);
> + goto err;
> + }
> + break;
> case ACPI_HEST_NOTIFY_NMI:
> if (!IS_ENABLED(CONFIG_HAVE_ACPI_APEI_NMI)) {
> pr_warn(GHES_PFX "Generic hardware error source: %d notified via NMI interrupt is not supported!\n",
> @@ -1176,7 +1192,8 @@ static int ghes_probe(struct platform_device *ghes_dev)
> break;
>
> case ACPI_HEST_NOTIFY_SEA:
> - ghes_sea_add(ghes);
> + case ACPI_HEST_NOTIFY_SEI:
> + ghes_sex_add(ghes);
> break;
> case ACPI_HEST_NOTIFY_NMI:
> ghes_nmi_add(ghes);
> @@ -1229,7 +1246,8 @@ static int ghes_remove(struct platform_device *ghes_dev)
> break;
>
> case ACPI_HEST_NOTIFY_SEA:
> - ghes_sea_remove(ghes);
> + case ACPI_HEST_NOTIFY_SEI:
> + ghes_sex_remove(ghes);
> break;
> case ACPI_HEST_NOTIFY_NMI:
> ghes_nmi_remove(ghes);
> diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h
> index 9061c5c743b3..41cbce1bc926 100644
> --- a/include/acpi/ghes.h
> +++ b/include/acpi/ghes.h
> @@ -118,6 +118,6 @@ static inline void *acpi_hest_get_next(struct acpi_hest_generic_data *gdata)
> (void *)section - (void *)(estatus + 1) < estatus->data_length; \
> section = acpi_hest_get_next(section))
>
> -int ghes_notify_sea(void);
> +int ghes_notify_sex(u8 type);
>
> #endif /* GHES_H */