Re: 回复: [PATCH] ACPI: APEI: move edac_init ahead of ghes platform drv register

Borislav Petkov
2022-08-09T19:07:36Z

On Tue, Aug 09, 2022 at 07:15:43PM +0200, Borislav Petkov wrote:
> Yes, I think you do. Lemme write something and you can finish it/test
> it.

Here's something to only show what I'm thinking of. It doesn't build
because of:

drivers/acpi/apei/ghes.c: In function ‘ghes_do_proc’:
drivers/acpi/apei/ghes.c:651:25: error: implicit declaration of function ‘ghes_edac_report_mem_error’; did you mean ‘arch_apei_report_mem_error’? [-Werror=implicit-function-declaration]
651 | ghes_edac_report_mem_error(sev, mem_err);

and that needs more thinking what to do. My idea currently is to do a
notifier like we do for MCA...

And I'm not really happy about returning a list of ghes devices just so
ghes_edac instances can get their struct device * pointers. Maybe we'll
think of something better.

But this is the general goal: not call module code from builtin code -
i.e., call ghes_edac.c code from ghes.c. It works now because ghes_edac
is forced builtin which is ugly as hell.

Anyway, enough for today...

---
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index d91ad378c00d..0919317b8313 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -118,6 +118,9 @@ module_param_named(disable, ghes_disable, bool, 0);
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
@@ -1376,7 +1379,11 @@ 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);

/* Handle any pending errors right away */
spin_lock_irqsave(&ghes_notify_lock_irq, flags);
@@ -1440,8 +1447,6 @@ static int ghes_remove(struct platform_device *ghes_dev)

ghes_fini(ghes);

- ghes_edac_unregister(ghes);
-
kfree(ghes);

platform_set_drvdata(ghes_dev, NULL);
@@ -1497,3 +1502,25 @@ void __init acpi_ghes_init(void)
else
pr_info(GHES_PFX "Failed to enable APEI firmware first mode.\n");
}
+
+/*
+ * Known x86 systems that prefer GHES error reporting:
+ */
+static struct acpi_platform_list plat_list[] = {
+ {"HPE ", "Server ", 0, ACPI_SIG_FADT, all_versions},
+ { } /* End */
+};
+
+struct list_head *ghes_get_devices(bool force)
+{
+ int idx = -1;
+
+ if (IS_ENABLED(CONFIG_X86)) {
+ idx = acpi_match_platform_list(plat_list);
+ if (idx < 0 && !force)
+ return NULL;
+ }
+
+ return &ghes_devs;
+}
+EXPORT_SYMBOL_GPL(ghes_get_devices);
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 c8fa7dcfdbd0..da6d1a9e107d 100644
--- a/drivers/edac/ghes_edac.c
+++ b/drivers/edac/ghes_edac.c
@@ -59,6 +59,8 @@ module_param(force_load, bool, 0);

static bool system_scanned;

+static struct list_head *ghes_devs;
+
/* Memory Device - Type 17 of SMBIOS spec */
struct memdev_dmi_entry {
u8 type;
@@ -376,34 +378,15 @@ void ghes_edac_report_mem_error(int sev, struct cper_sec_mem_err *mem_err)
spin_unlock_irqrestore(&ghes_lock, flags);
}

-/*
- * 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 (!force_load && idx < 0)
- return -ENODEV;
- } else {
- force_load = true;
- idx = 0;
- }
-
/* finish another registration/unregistration instance first */
mutex_lock(&ghes_reg_mutex);

@@ -447,7 +430,7 @@ 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 (force_load) {
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");
@@ -517,7 +500,7 @@ 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;
@@ -551,3 +534,30 @@ 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(force_load);
+ 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);
diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h
index 34fb3431a8f3..f39b75c3f9c6 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 {
@@ -69,35 +71,13 @@ 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);
+struct list_head *ghes_get_devices(bool force);
+#else
+static inline struct list_head *ghes_get_devices(bool force) { return NULL; }
#endif

int ghes_estatus_pool_init(int num_ghes);

-/* From drivers/edac/ghes_edac.c */
-
-#ifdef CONFIG_EDAC_GHES
-void ghes_edac_report_mem_error(int sev, struct cper_sec_mem_err *mem_err);
-
-int ghes_edac_register(struct ghes *ghes, struct device *dev);
-
-void ghes_edac_unregister(struct ghes *ghes);
-
-#else
-static inline void ghes_edac_report_mem_error(int sev,
- struct cper_sec_mem_err *mem_err)
-{
-}
-
-static inline int ghes_edac_register(struct ghes *ghes, struct device *dev)
-{
- return -ENODEV;
-}
-
-static inline void ghes_edac_unregister(struct ghes *ghes)
-{
-}
-#endif
-
static inline int acpi_hest_get_version(struct acpi_hest_generic_data *gdata)
{
return gdata->revision >> 8;

--
Regards/Gruss,
Boris.