LinuxLists.cc - [PATCH v5 0/8] Make ghes

2022-09-05 16:23:15

Subject: [PATCH v5 0/8] Make ghes_edac a proper module

2022-09-05 16:24:17

Subject: [PATCH v5 5/8] EDAC/ghes: Make ghes_edac a proper module to remove the dependency on ghes

Commit dc4e8c07e9e2 ("ACPI: APEI: explicit init of HEST and GHES in
apci_init()") introduced a bug that ghes_edac_register() would be invoked
before edac_init(). Because at that time, the bus "edac" hadn't been even
registered, this created sysfs /devices/mc0 instead of
/sys/devices/system/edac/mc/mc0 on an Ampere eMag server.

To remove the dependency of ghes_edac on ghes, make it a proper module. Use
a list to save the probing devices in ghes_probe(), and defer the
ghes_edac_register() to module_init() of the new ghes_edac module by
iterating over the devices list.

Co-developed-by: Borislav Petkov <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Signed-off-by: Jia He <[email protected]>
Fixes: dc4e8c07e9e2 ("ACPI: APEI: explicit init of HEST and GHES in apci_init()")
Cc: Shuai Xue <[email protected]>
---
drivers/acpi/apei/ghes.c | 22 +++++++++++++--
drivers/edac/Kconfig | 4 +--
drivers/edac/ghes_edac.c | 59 +++++++++++++++++++++++-----------------
include/acpi/ghes.h | 24 ++++------------
4 files changed, 62 insertions(+), 47 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 0c2dbfffe22a..4af269b22bd4 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -130,6 +130,9 @@ static bool ghes_present;
static LIST_HEAD(ghes_hed);
static DEFINE_MUTEX(ghes_list_mutex);

+static LIST_HEAD(ghes_devs);
+static DEFINE_MUTEX(ghes_devs_mutex);
+
/*
* Because the memory area used to transfer hardware error information
* from BIOS to Linux can be determined only in NMI, IRQ or timer
@@ -1388,7 +1391,11 @@ static int ghes_probe(struct platform_device *ghes_dev)

platform_set_drvdata(ghes_dev, ghes);

- ghes_edac_register(ghes, &ghes_dev->dev);
+ ghes->dev = &ghes_dev->dev;
+
+ mutex_lock(&ghes_devs_mutex);
+ list_add_tail(&ghes->elist, &ghes_devs);
+ mutex_unlock(&ghes_devs_mutex);

ghes_present = true;

@@ -1454,7 +1461,9 @@ static int ghes_remove(struct platform_device *ghes_dev)

ghes_fini(ghes);

- ghes_edac_unregister(ghes);
+ mutex_lock(&ghes_devs_mutex);
+ list_del(&ghes->elist);
+ mutex_unlock(&ghes_devs_mutex);

kfree(ghes);

@@ -1537,6 +1546,15 @@ bool ghes_edac_preferred(void)
}
EXPORT_SYMBOL_GPL(ghes_edac_preferred);

+struct list_head *ghes_get_devices(void)
+{
+ if (!ghes_edac_preferred())
+ return NULL;
+
+ return &ghes_devs;
+}
+EXPORT_SYMBOL_GPL(ghes_get_devices);
+
void ghes_register_report_chain(struct notifier_block *nb)
{
atomic_notifier_chain_register(&ghes_report_chain, nb);
diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
index 17562cf1fe97..df45db81858b 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -53,8 +53,8 @@ config EDAC_DECODE_MCE
has been initialized.

config EDAC_GHES
- bool "Output ACPI APEI/GHES BIOS detected errors via EDAC"
- depends on ACPI_APEI_GHES && (EDAC=y)
+ tristate "Output ACPI APEI/GHES BIOS detected errors via EDAC"
+ depends on ACPI_APEI_GHES
select UEFI_CPER
help
Not all machines support hardware-driven error report. Some of those
diff --git a/drivers/edac/ghes_edac.c b/drivers/edac/ghes_edac.c
index 11a1b5e7e484..129665896a80 100644
--- a/drivers/edac/ghes_edac.c
+++ b/drivers/edac/ghes_edac.c
@@ -56,6 +56,8 @@ static DEFINE_SPINLOCK(ghes_lock);

static bool system_scanned;

+static struct list_head *ghes_devs;
+
/* Memory Device - Type 17 of SMBIOS spec */
struct memdev_dmi_entry {
u8 type;
@@ -383,34 +385,15 @@ static struct notifier_block ghes_edac_mem_err_nb = {
.priority = 0,
};

-/*
- * Known systems that are safe to enable this module.
- */
-static struct acpi_platform_list plat_list[] = {
- {"HPE ", "Server ", 0, ACPI_SIG_FADT, all_versions},
- { } /* End */
-};
-
-int ghes_edac_register(struct ghes *ghes, struct device *dev)
+static int ghes_edac_register(struct device *dev)
{
bool fake = false;
struct mem_ctl_info *mci;
struct ghes_pvt *pvt;
struct edac_mc_layer layers[1];
unsigned long flags;
- int idx = -1;
int rc = 0;

- if (IS_ENABLED(CONFIG_X86)) {
- /* Check if safe to enable on this system */
- idx = acpi_match_platform_list(plat_list);
- if (!ghes_edac_force_enable && idx < 0)
- return -ENODEV;
- } else {
- ghes_edac_force_enable = true;
- idx = 0;
- }
-
/* finish another registration/unregistration instance first */
mutex_lock(&ghes_reg_mutex);

@@ -454,7 +437,7 @@ int ghes_edac_register(struct ghes *ghes, struct device *dev)
pr_info("This system has a very crappy BIOS: It doesn't even list the DIMMS.\n");
pr_info("Its SMBIOS info is wrong. It is doubtful that the error report would\n");
pr_info("work on such system. Use this driver with caution\n");
- } else if (idx < 0) {
+ } else if (ghes_edac_force_enable) {
pr_info("This EDAC driver relies on BIOS to enumerate memory and get error reports.\n");
pr_info("Unfortunately, not all BIOSes reflect the memory layout correctly.\n");
pr_info("So, the end result of using this driver varies from vendor to vendor.\n");
@@ -526,14 +509,11 @@ int ghes_edac_register(struct ghes *ghes, struct device *dev)
return rc;
}

-void ghes_edac_unregister(struct ghes *ghes)
+static void ghes_edac_unregister(struct ghes *ghes)
{
struct mem_ctl_info *mci;
unsigned long flags;

- if (!ghes_edac_force_enable)
- return;
-
mutex_lock(&ghes_reg_mutex);

system_scanned = false;
@@ -562,3 +542,32 @@ void ghes_edac_unregister(struct ghes *ghes)
unlock:
mutex_unlock(&ghes_reg_mutex);
}
+
+static int __init ghes_edac_init(void)
+{
+ struct ghes *g, *g_tmp;
+
+ ghes_devs = ghes_get_devices();
+ if (!ghes_devs)
+ return -ENODEV;
+
+ list_for_each_entry_safe(g, g_tmp, ghes_devs, elist) {
+ ghes_edac_register(g->dev);
+ }
+
+ return 0;
+}
+module_init(ghes_edac_init);
+
+static void __exit ghes_edac_exit(void)
+{
+ struct ghes *g, *g_tmp;
+
+ list_for_each_entry_safe(g, g_tmp, ghes_devs, elist) {
+ ghes_edac_unregister(g);
+ }
+}
+module_exit(ghes_edac_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Output ACPI APEI/GHES BIOS detected errors module via EDAC");
diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h
index 7ce91c0ff3eb..08f12dde99ae 100644
--- a/include/acpi/ghes.h
+++ b/include/acpi/ghes.h
@@ -27,6 +27,8 @@ struct ghes {
struct timer_list timer;
unsigned int irq;
};
+ struct device *dev;
+ struct list_head elist;
};

struct ghes_estatus_node {
@@ -69,30 +71,16 @@ int ghes_register_vendor_record_notifier(struct notifier_block *nb);
* @nb: pointer to the notifier_block structure of the vendor record handler.
*/
void ghes_unregister_vendor_record_notifier(struct notifier_block *nb);
-#endif
-
-int ghes_estatus_pool_init(int num_ghes);
-
-/* From drivers/edac/ghes_edac.c */
-
-#ifdef CONFIG_EDAC_GHES
-int ghes_edac_register(struct ghes *ghes, struct device *dev);
-
-void ghes_edac_unregister(struct ghes *ghes);

+struct list_head *ghes_get_devices(void);
bool ghes_edac_preferred(void);
#else
-static inline int ghes_edac_register(struct ghes *ghes, struct device *dev)
-{
- return -ENODEV;
-}
-
-static inline void ghes_edac_unregister(struct ghes *ghes)
-{
-}
+static inline struct list_head *ghes_get_devices(void) { return NULL; }
static bool ghes_edac_preferred(void) { return false; }
#endif

+int ghes_estatus_pool_init(int num_ghes);
+
static inline int acpi_hest_get_version(struct acpi_hest_generic_data *gdata)
{
return gdata->revision >> 8;
--
2.25.1

2022-09-05 16:24:42

by Justin He

[permalink] [raw]

Subject: [PATCH v5 8/8] EDAC/igen6: Return consistent errno when another edac driver is enabled

Only a single edac driver can be enabled for EDAC MC. The igen6_init()
should be returned with EBUSY instead of ENODEV, which is consistent with
other edac drivers.

Signed-off-by: Jia He <[email protected]>
---
drivers/edac/igen6_edac.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/edac/igen6_edac.c b/drivers/edac/igen6_edac.c
index 4ac6d0c533ec..4646cb72b9f8 100644
--- a/drivers/edac/igen6_edac.c
+++ b/drivers/edac/igen6_edac.c
@@ -1276,7 +1276,7 @@ static int __init igen6_init(void)

owner = edac_get_owner();
if (owner && strncmp(owner, EDAC_MOD_STR, sizeof(EDAC_MOD_STR)))
- return -ENODEV;
+ return -EBUSY;

edac_op_state = EDAC_OPSTATE_NMI;

--
2.25.1

2022-09-08 01:24:12

by Justin He

[permalink] [raw]

Subject: RE: [PATCH v5 5/8] EDAC/ghes: Make ghes_edac a proper module to remove the dependency on ghes

Hi Kani

> -----Original Message-----
> From: Kani, Toshi <[email protected]>
> Sent: Thursday, September 8, 2022 8:31 AM
> To: Justin He <[email protected]>; Len Brown <[email protected]>; James
> Morse <[email protected]>; Tony Luck <[email protected]>; Borislav
> Petkov <[email protected]>; Mauro Carvalho Chehab <[email protected]>;
> Robert Richter <[email protected]>; Robert Moore <[email protected]>;
> Qiuxu Zhuo <[email protected]>; Yazen Ghannam
> <[email protected]>; Jan Luebbe <[email protected]>; Khuong
> Dinh <[email protected]>
> Cc: Ard Biesheuvel <[email protected]>; [email protected];
> [email protected]; [email protected]; [email protected];
> Rafael J . Wysocki <[email protected]>; Shuai Xue
> <[email protected]>; Jarkko Sakkinen <[email protected]>;
> [email protected]; nd <[email protected]>
> Subject: RE: [PATCH v5 5/8] EDAC/ghes: Make ghes_edac a proper module to
> remove the dependency on ghes
>
> On Monday, September 5, 2022 9:25 AM, Jia He wrote:
> > -void ghes_edac_unregister(struct ghes *ghes)
> > +static void ghes_edac_unregister(struct ghes *ghes)
> > {
> > struct mem_ctl_info *mci;
> > unsigned long flags;
> >
> > - if (!ghes_edac_force_enable)
> > - return;
> > -
>
> I am not familiar with this original check. Assuming it is safe to delete it now
> (as you mentioned in other email w/o description), I suggest adding some
> description to the commit log.
>
Thanks, will do
I've tested the insmod/rmmod multiple times on Arm host.

I will wait for others' comments for a while before sending the new version.
> At high-level, the patch looks good to me.
> Acked-by: Toshi Kani <[email protected]>

Thanks a lot for the help ????

--
Cheers,
Justin (Jia He)

2022-09-08 01:26:22

by Kani, Toshimitsu

[permalink] [raw]

Subject: RE: [PATCH v5 5/8] EDAC/ghes: Make ghes_edac a proper module to remove the dependency on ghes

On Monday, September 5, 2022 9:25 AM, Jia He wrote:
> -void ghes_edac_unregister(struct ghes *ghes)
> +static void ghes_edac_unregister(struct ghes *ghes)
> {
> struct mem_ctl_info *mci;
> unsigned long flags;
>
> - if (!ghes_edac_force_enable)
> - return;
> -

I am not familiar with this original check. Assuming it is safe to
delete it now (as you mentioned in other email w/o description),
I suggest adding some description to the commit log.

At high-level, the patch looks good to me.
Acked-by: Toshi Kani <[email protected]>

Toshi