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From:   Shiju Jose <shiju.jose@huawei.com>
To:     <linux-acpi@vger.kernel.org>, <linux-pci@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <rjw@rjwysocki.net>,
        <helgaas@kernel.org>, <bp@alien8.de>, <james.morse@arm.com>,
        <lenb@kernel.org>, <tony.luck@intel.com>,
        <dan.carpenter@oracle.com>, <zhangliguang@linux.alibaba.com>,
        <andriy.shevchenko@linux.intel.com>, <wangkefeng.wang@huawei.com>,
        <jroedel@suse.de>
CC:     <linuxarm@huawei.com>, <yangyicong@hisilicon.com>,
        <jonathan.cameron@huawei.com>, <tanxiaofei@huawei.com>
Subject: [PATCH v10 1/2] ACPI / APEI: Add support to notify the vendor specific HW errors
Date:   Thu, 18 Jun 2020 16:38:22 +0100
Message-ID: <20200618153823.588-2-shiju.jose@huawei.com>
In-Reply-To: <20200618153823.588-1-shiju.jose@huawei.com>
References: <20200618153823.588-1-shiju.jose@huawei.com>
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Add support to report the vendor specific non-fatal HW errors
to the drivers for the error recovery.

The interface functions ghes_register_event_notifier() and
ghes_unregister_event_notifier() enables the drivers to register and
unregister the vendor specific error handlers. The interface uses
work queue for queuing each vendor-specific error record and uses
blocking notifier chain, in the work function, to report the error to
the registered drivers.
The drivers should match the section type of the error record before
processing the error data.

Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
Reviewed-by: Bjorn Helgaas <helgaas@kernel.org>
---
 drivers/acpi/apei/ghes.c | 123 +++++++++++++++++++++++++++++++++++++++
 include/acpi/ghes.h      |  29 +++++++++
 2 files changed, 152 insertions(+)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 81bf71b10d44..b6dc4eaa6345 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -33,6 +33,7 @@
 #include <linux/irq_work.h>
 #include <linux/llist.h>
 #include <linux/genalloc.h>
+#include <linux/kfifo.h>
 #include <linux/pci.h>
 #include <linux/pfn.h>
 #include <linux/aer.h>
@@ -64,6 +65,7 @@
 #define GHES_ESTATUS_CACHES_SIZE	4
 
 #define GHES_ESTATUS_IN_CACHE_MAX_NSEC	10000000000ULL
+
 /* Prevent too many caches are allocated because of RCU */
 #define GHES_ESTATUS_CACHE_ALLOCED_MAX	(GHES_ESTATUS_CACHES_SIZE * 3 / 2)
 
@@ -88,6 +90,10 @@
 #define FIX_APEI_GHES_SDEI_CRITICAL	__end_of_fixed_addresses
 #endif
 
+#define GHES_EVENT_RING_SIZE	256
+#define GHES_EVENT_GDATA_POOL_MIN_ALLOC_ORDER	3
+#define GHES_EVENT_GDATA_POOL_MIN_SIZE	65536
+
 static inline bool is_hest_type_generic_v2(struct ghes *ghes)
 {
 	return ghes->generic->header.type == ACPI_HEST_TYPE_GENERIC_ERROR_V2;
@@ -123,6 +129,19 @@ static DEFINE_MUTEX(ghes_list_mutex);
  */
 static DEFINE_SPINLOCK(ghes_notify_lock_irq);
 
+struct ghes_event_entry {
+	struct acpi_hest_generic_data *gdata;
+	int error_severity;
+};
+
+static DEFINE_KFIFO(ghes_event_ring, struct ghes_event_entry,
+		    GHES_EVENT_RING_SIZE);
+
+static DEFINE_SPINLOCK(ghes_event_ring_lock);
+
+static struct gen_pool *ghes_event_gdata_pool;
+static unsigned long ghes_event_gdata_pool_size_request;
+
 static struct gen_pool *ghes_estatus_pool;
 static unsigned long ghes_estatus_pool_size_request;
 
@@ -183,6 +202,38 @@ int ghes_estatus_pool_init(int num_ghes)
 	return -ENOMEM;
 }
 
+static int ghes_event_gdata_pool_init(void)
+{
+	unsigned long addr, len;
+	int rc;
+
+	ghes_event_gdata_pool = gen_pool_create(GHES_EVENT_GDATA_POOL_MIN_ALLOC_ORDER, -1);
+	if (!ghes_event_gdata_pool)
+		return -ENOMEM;
+
+	if (ghes_event_gdata_pool_size_request < GHES_EVENT_GDATA_POOL_MIN_SIZE)
+		ghes_event_gdata_pool_size_request = GHES_EVENT_GDATA_POOL_MIN_SIZE;
+
+	len = ghes_event_gdata_pool_size_request;
+	addr = (unsigned long)vmalloc(PAGE_ALIGN(len));
+	if (!addr)
+		goto err_pool_alloc;
+
+	rc = gen_pool_add(ghes_event_gdata_pool, addr, PAGE_ALIGN(len), -1);
+	if (rc)
+		goto err_pool_add;
+
+	return 0;
+
+err_pool_add:
+	vfree((void *)addr);
+
+err_pool_alloc:
+	gen_pool_destroy(ghes_event_gdata_pool);
+
+	return -ENOMEM;
+}
+
 static int map_gen_v2(struct ghes *ghes)
 {
 	return apei_map_generic_address(&ghes->generic_v2->read_ack_register);
@@ -242,6 +293,10 @@ static struct ghes *ghes_new(struct acpi_hest_generic *generic)
 		goto err_unmap_status_addr;
 	}
 
+	ghes_event_gdata_pool_size_request += generic->records_to_preallocate *
+					      generic->max_sections_per_record *
+					      generic->max_raw_data_length;
+
 	return ghes;
 
 err_unmap_status_addr:
@@ -511,6 +566,69 @@ static void ghes_handle_aer(struct acpi_hest_generic_data *gdata)
 #endif
 }
 
+static BLOCKING_NOTIFIER_HEAD(ghes_event_notify_list);
+
+/**
+ * ghes_register_event_notifier - register an event notifier
+ * for the non-fatal HW errors.Presently supported to notify
+ * the vendor-specific HW errors only, though it can be used to
+ * notify the standard errors also.
+ * @nb: pointer to the notifier_block structure of the event handler.
+ *
+ * return 0 : SUCCESS, non-zero : FAIL
+ */
+int ghes_register_event_notifier(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&ghes_event_notify_list, nb);
+}
+EXPORT_SYMBOL_GPL(ghes_register_event_notifier);
+
+/**
+ * ghes_unregister_event_notifier - unregister the previously
+ * registered event notifier.
+ * @nb: pointer to the notifier_block structure of the event handler.
+ */
+void ghes_unregister_event_notifier(struct notifier_block *nb)
+{
+	blocking_notifier_chain_unregister(&ghes_event_notify_list, nb);
+}
+EXPORT_SYMBOL_GPL(ghes_unregister_event_notifier);
+
+static void ghes_event_work_func(struct work_struct *work)
+{
+	struct ghes_event_entry entry;
+	u32 len;
+
+	while (kfifo_get(&ghes_event_ring, &entry)) {
+		blocking_notifier_call_chain(&ghes_event_notify_list,
+					     entry.error_severity,
+					     entry.gdata);
+		len = acpi_hest_get_record_size(entry.gdata);
+		gen_pool_free(ghes_event_gdata_pool, (unsigned long)entry.gdata, len);
+	}
+}
+
+static DECLARE_WORK(ghes_event_work, ghes_event_work_func);
+
+static void ghes_handle_non_standard_event(struct acpi_hest_generic_data *gdata,
+					   int sev)
+{
+	u32 len;
+	struct ghes_event_entry event_entry;
+
+	len = acpi_hest_get_record_size(gdata);
+	event_entry.gdata = (void *)gen_pool_alloc(ghes_event_gdata_pool, len);
+	if (!event_entry.gdata)
+		return;
+
+	memcpy(event_entry.gdata, gdata, len);
+	event_entry.error_severity = sev;
+	if (kfifo_in_spinlocked(&ghes_event_ring, &event_entry, 1, &ghes_event_ring_lock))
+		schedule_work(&ghes_event_work);
+	else
+		pr_warn(GHES_PFX "event notify queue full\n");
+}
+
 static bool ghes_do_proc(struct ghes *ghes,
 			 const struct acpi_hest_generic_status *estatus)
 {
@@ -549,6 +667,7 @@ static bool ghes_do_proc(struct ghes *ghes,
 		} else {
 			void *err = acpi_hest_get_payload(gdata);
 
+			ghes_handle_non_standard_event(gdata, sev);
 			log_non_standard_event(sec_type, fru_id, fru_text,
 					       sec_sev, err,
 					       gdata->error_data_length);
@@ -1385,6 +1504,10 @@ static int __init ghes_init(void)
 	else
 		pr_info(GHES_PFX "Failed to enable APEI firmware first mode.\n");
 
+	rc = ghes_event_gdata_pool_init();
+	if (rc)
+		pr_warn(GHES_PFX "non-fatal vendor-specific errors not being notified\n");
+
 	return 0;
 err:
 	return rc;
diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h
index 517a5231cc1b..37a48ce13499 100644
--- a/include/acpi/ghes.h
+++ b/include/acpi/ghes.h
@@ -53,6 +53,35 @@ enum {
 	GHES_SEV_PANIC = 0x3,
 };
 
+#ifdef CONFIG_ACPI_APEI_GHES
+/**
+ * ghes_register_event_notifier - register an event notifier
+ * for the non-fatal HW errors.Presently supported to notify
+ * the vendor-specific HW errors only, though it can be used to notify
+ * the standard errors also.
+ * @nb: pointer to the notifier_block structure of the event notifier.
+ *
+ * Return : 0 - SUCCESS, non-zero - FAIL.
+ */
+int ghes_register_event_notifier(struct notifier_block *nb);
+
+/**
+ * ghes_unregister_event_notifier - unregister the previously
+ * registered event notifier.
+ * @nb: pointer to the notifier_block structure of the event notifier.
+ */
+void ghes_unregister_event_notifier(struct notifier_block *nb);
+#else
+static inline int ghes_register_event_notifier(struct notifier_block *nb)
+{
+	return -ENODEV;
+}
+
+static inline void ghes_unregister_event_notifier(struct notifier_block *nb)
+{
+}
+#endif
+
 int ghes_estatus_pool_init(int num_ghes);
 
 /* From drivers/edac/ghes_edac.c */
-- 
2.17.1