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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/powerpc/platforms/powernv/opal-dump.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/platforms/powernv/opal-dump.c')
-rw-r--r--arch/powerpc/platforms/powernv/opal-dump.c459
1 files changed, 459 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-dump.c b/arch/powerpc/platforms/powernv/opal-dump.c
new file mode 100644
index 000000000..16c5860f1
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-dump.c
@@ -0,0 +1,459 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PowerNV OPAL Dump Interface
+ *
+ * Copyright 2013,2014 IBM Corp.
+ */
+
+#include <linux/kobject.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/pagemap.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+
+#include <asm/opal.h>
+
+#define DUMP_TYPE_FSP 0x01
+
+struct dump_obj {
+ struct kobject kobj;
+ struct bin_attribute dump_attr;
+ uint32_t id; /* becomes object name */
+ uint32_t type;
+ uint32_t size;
+ char *buffer;
+};
+#define to_dump_obj(x) container_of(x, struct dump_obj, kobj)
+
+struct dump_attribute {
+ struct attribute attr;
+ ssize_t (*show)(struct dump_obj *dump, struct dump_attribute *attr,
+ char *buf);
+ ssize_t (*store)(struct dump_obj *dump, struct dump_attribute *attr,
+ const char *buf, size_t count);
+};
+#define to_dump_attr(x) container_of(x, struct dump_attribute, attr)
+
+static ssize_t dump_id_show(struct dump_obj *dump_obj,
+ struct dump_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "0x%x\n", dump_obj->id);
+}
+
+static const char* dump_type_to_string(uint32_t type)
+{
+ switch (type) {
+ case 0x01: return "SP Dump";
+ case 0x02: return "System/Platform Dump";
+ case 0x03: return "SMA Dump";
+ default: return "unknown";
+ }
+}
+
+static ssize_t dump_type_show(struct dump_obj *dump_obj,
+ struct dump_attribute *attr,
+ char *buf)
+{
+
+ return sprintf(buf, "0x%x %s\n", dump_obj->type,
+ dump_type_to_string(dump_obj->type));
+}
+
+static ssize_t dump_ack_show(struct dump_obj *dump_obj,
+ struct dump_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "ack - acknowledge dump\n");
+}
+
+/*
+ * Send acknowledgement to OPAL
+ */
+static int64_t dump_send_ack(uint32_t dump_id)
+{
+ int rc;
+
+ rc = opal_dump_ack(dump_id);
+ if (rc)
+ pr_warn("%s: Failed to send ack to Dump ID 0x%x (%d)\n",
+ __func__, dump_id, rc);
+ return rc;
+}
+
+static ssize_t dump_ack_store(struct dump_obj *dump_obj,
+ struct dump_attribute *attr,
+ const char *buf,
+ size_t count)
+{
+ /*
+ * Try to self remove this attribute. If we are successful,
+ * delete the kobject itself.
+ */
+ if (sysfs_remove_file_self(&dump_obj->kobj, &attr->attr)) {
+ dump_send_ack(dump_obj->id);
+ kobject_put(&dump_obj->kobj);
+ }
+ return count;
+}
+
+/* Attributes of a dump
+ * The binary attribute of the dump itself is dynamic
+ * due to the dynamic size of the dump
+ */
+static struct dump_attribute id_attribute =
+ __ATTR(id, 0444, dump_id_show, NULL);
+static struct dump_attribute type_attribute =
+ __ATTR(type, 0444, dump_type_show, NULL);
+static struct dump_attribute ack_attribute =
+ __ATTR(acknowledge, 0660, dump_ack_show, dump_ack_store);
+
+static ssize_t init_dump_show(struct dump_obj *dump_obj,
+ struct dump_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "1 - initiate Service Processor(FSP) dump\n");
+}
+
+static int64_t dump_fips_init(uint8_t type)
+{
+ int rc;
+
+ rc = opal_dump_init(type);
+ if (rc)
+ pr_warn("%s: Failed to initiate FSP dump (%d)\n",
+ __func__, rc);
+ return rc;
+}
+
+static ssize_t init_dump_store(struct dump_obj *dump_obj,
+ struct dump_attribute *attr,
+ const char *buf,
+ size_t count)
+{
+ int rc;
+
+ rc = dump_fips_init(DUMP_TYPE_FSP);
+ if (rc == OPAL_SUCCESS)
+ pr_info("%s: Initiated FSP dump\n", __func__);
+
+ return count;
+}
+
+static struct dump_attribute initiate_attribute =
+ __ATTR(initiate_dump, 0600, init_dump_show, init_dump_store);
+
+static struct attribute *initiate_attrs[] = {
+ &initiate_attribute.attr,
+ NULL,
+};
+
+static const struct attribute_group initiate_attr_group = {
+ .attrs = initiate_attrs,
+};
+
+static struct kset *dump_kset;
+
+static ssize_t dump_attr_show(struct kobject *kobj,
+ struct attribute *attr,
+ char *buf)
+{
+ struct dump_attribute *attribute;
+ struct dump_obj *dump;
+
+ attribute = to_dump_attr(attr);
+ dump = to_dump_obj(kobj);
+
+ if (!attribute->show)
+ return -EIO;
+
+ return attribute->show(dump, attribute, buf);
+}
+
+static ssize_t dump_attr_store(struct kobject *kobj,
+ struct attribute *attr,
+ const char *buf, size_t len)
+{
+ struct dump_attribute *attribute;
+ struct dump_obj *dump;
+
+ attribute = to_dump_attr(attr);
+ dump = to_dump_obj(kobj);
+
+ if (!attribute->store)
+ return -EIO;
+
+ return attribute->store(dump, attribute, buf, len);
+}
+
+static const struct sysfs_ops dump_sysfs_ops = {
+ .show = dump_attr_show,
+ .store = dump_attr_store,
+};
+
+static void dump_release(struct kobject *kobj)
+{
+ struct dump_obj *dump;
+
+ dump = to_dump_obj(kobj);
+ vfree(dump->buffer);
+ kfree(dump);
+}
+
+static struct attribute *dump_default_attrs[] = {
+ &id_attribute.attr,
+ &type_attribute.attr,
+ &ack_attribute.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(dump_default);
+
+static struct kobj_type dump_ktype = {
+ .sysfs_ops = &dump_sysfs_ops,
+ .release = &dump_release,
+ .default_groups = dump_default_groups,
+};
+
+static int64_t dump_read_info(uint32_t *dump_id, uint32_t *dump_size, uint32_t *dump_type)
+{
+ __be32 id, size, type;
+ int rc;
+
+ type = cpu_to_be32(0xffffffff);
+
+ rc = opal_dump_info2(&id, &size, &type);
+ if (rc == OPAL_PARAMETER)
+ rc = opal_dump_info(&id, &size);
+
+ if (rc) {
+ pr_warn("%s: Failed to get dump info (%d)\n",
+ __func__, rc);
+ return rc;
+ }
+
+ *dump_id = be32_to_cpu(id);
+ *dump_size = be32_to_cpu(size);
+ *dump_type = be32_to_cpu(type);
+
+ return rc;
+}
+
+static int64_t dump_read_data(struct dump_obj *dump)
+{
+ struct opal_sg_list *list;
+ uint64_t addr;
+ int64_t rc;
+
+ /* Allocate memory */
+ dump->buffer = vzalloc(PAGE_ALIGN(dump->size));
+ if (!dump->buffer) {
+ pr_err("%s : Failed to allocate memory\n", __func__);
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ /* Generate SG list */
+ list = opal_vmalloc_to_sg_list(dump->buffer, dump->size);
+ if (!list) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ /* First entry address */
+ addr = __pa(list);
+
+ /* Fetch data */
+ rc = OPAL_BUSY_EVENT;
+ while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
+ rc = opal_dump_read(dump->id, addr);
+ if (rc == OPAL_BUSY_EVENT) {
+ opal_poll_events(NULL);
+ msleep(20);
+ }
+ }
+
+ if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL)
+ pr_warn("%s: Extract dump failed for ID 0x%x\n",
+ __func__, dump->id);
+
+ /* Free SG list */
+ opal_free_sg_list(list);
+
+out:
+ return rc;
+}
+
+static ssize_t dump_attr_read(struct file *filep, struct kobject *kobj,
+ struct bin_attribute *bin_attr,
+ char *buffer, loff_t pos, size_t count)
+{
+ ssize_t rc;
+
+ struct dump_obj *dump = to_dump_obj(kobj);
+
+ if (!dump->buffer) {
+ rc = dump_read_data(dump);
+
+ if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL) {
+ vfree(dump->buffer);
+ dump->buffer = NULL;
+
+ return -EIO;
+ }
+ if (rc == OPAL_PARTIAL) {
+ /* On a partial read, we just return EIO
+ * and rely on userspace to ask us to try
+ * again.
+ */
+ pr_info("%s: Platform dump partially read. ID = 0x%x\n",
+ __func__, dump->id);
+ return -EIO;
+ }
+ }
+
+ memcpy(buffer, dump->buffer + pos, count);
+
+ /* You may think we could free the dump buffer now and retrieve
+ * it again later if needed, but due to current firmware limitation,
+ * that's not the case. So, once read into userspace once,
+ * we keep the dump around until it's acknowledged by userspace.
+ */
+
+ return count;
+}
+
+static void create_dump_obj(uint32_t id, size_t size, uint32_t type)
+{
+ struct dump_obj *dump;
+ int rc;
+
+ dump = kzalloc(sizeof(*dump), GFP_KERNEL);
+ if (!dump)
+ return;
+
+ dump->kobj.kset = dump_kset;
+
+ kobject_init(&dump->kobj, &dump_ktype);
+
+ sysfs_bin_attr_init(&dump->dump_attr);
+
+ dump->dump_attr.attr.name = "dump";
+ dump->dump_attr.attr.mode = 0400;
+ dump->dump_attr.size = size;
+ dump->dump_attr.read = dump_attr_read;
+
+ dump->id = id;
+ dump->size = size;
+ dump->type = type;
+
+ rc = kobject_add(&dump->kobj, NULL, "0x%x-0x%x", type, id);
+ if (rc) {
+ kobject_put(&dump->kobj);
+ return;
+ }
+
+ /*
+ * As soon as the sysfs file for this dump is created/activated there is
+ * a chance the opal_errd daemon (or any userspace) might read and
+ * acknowledge the dump before kobject_uevent() is called. If that
+ * happens then there is a potential race between
+ * dump_ack_store->kobject_put() and kobject_uevent() which leads to a
+ * use-after-free of a kernfs object resulting in a kernel crash.
+ *
+ * To avoid that, we need to take a reference on behalf of the bin file,
+ * so that our reference remains valid while we call kobject_uevent().
+ * We then drop our reference before exiting the function, leaving the
+ * bin file to drop the last reference (if it hasn't already).
+ */
+
+ /* Take a reference for the bin file */
+ kobject_get(&dump->kobj);
+ rc = sysfs_create_bin_file(&dump->kobj, &dump->dump_attr);
+ if (rc == 0) {
+ kobject_uevent(&dump->kobj, KOBJ_ADD);
+
+ pr_info("%s: New platform dump. ID = 0x%x Size %u\n",
+ __func__, dump->id, dump->size);
+ } else {
+ /* Drop reference count taken for bin file */
+ kobject_put(&dump->kobj);
+ }
+
+ /* Drop our reference */
+ kobject_put(&dump->kobj);
+ return;
+}
+
+static irqreturn_t process_dump(int irq, void *data)
+{
+ int rc;
+ uint32_t dump_id, dump_size, dump_type;
+ char name[22];
+ struct kobject *kobj;
+
+ rc = dump_read_info(&dump_id, &dump_size, &dump_type);
+ if (rc != OPAL_SUCCESS)
+ return IRQ_HANDLED;
+
+ sprintf(name, "0x%x-0x%x", dump_type, dump_id);
+
+ /* we may get notified twice, let's handle
+ * that gracefully and not create two conflicting
+ * entries.
+ */
+ kobj = kset_find_obj(dump_kset, name);
+ if (kobj) {
+ /* Drop reference added by kset_find_obj() */
+ kobject_put(kobj);
+ return IRQ_HANDLED;
+ }
+
+ create_dump_obj(dump_id, dump_size, dump_type);
+
+ return IRQ_HANDLED;
+}
+
+void __init opal_platform_dump_init(void)
+{
+ int rc;
+ int dump_irq;
+
+ /* Dump not supported by firmware */
+ if (!opal_check_token(OPAL_DUMP_READ))
+ return;
+
+ dump_kset = kset_create_and_add("dump", NULL, opal_kobj);
+ if (!dump_kset) {
+ pr_warn("%s: Failed to create dump kset\n", __func__);
+ return;
+ }
+
+ rc = sysfs_create_group(&dump_kset->kobj, &initiate_attr_group);
+ if (rc) {
+ pr_warn("%s: Failed to create initiate dump attr group\n",
+ __func__);
+ kobject_put(&dump_kset->kobj);
+ return;
+ }
+
+ dump_irq = opal_event_request(ilog2(OPAL_EVENT_DUMP_AVAIL));
+ if (!dump_irq) {
+ pr_err("%s: Can't register OPAL event irq (%d)\n",
+ __func__, dump_irq);
+ return;
+ }
+
+ rc = request_threaded_irq(dump_irq, NULL, process_dump,
+ IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
+ "opal-dump", NULL);
+ if (rc) {
+ pr_err("%s: Can't request OPAL event irq (%d)\n",
+ __func__, rc);
+ return;
+ }
+
+ if (opal_check_token(OPAL_DUMP_RESEND))
+ opal_dump_resend_notification();
+}