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Message-ID: <5C4C569E8A4B9B42A84A977CF070A35B2C17497E04@USINDEVS01.corp.hds.com>
Date: Tue, 7 Jun 2011 11:47:38 -0400
From: Seiji Aguchi <seiji.aguchi@....com>
To: Matthew Garrett <mjg@...hat.com>,
"tony.luck@...el.com" <tony.luck@...el.com>
CC: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"Matt_Domsch@...l.com" <Matt_Domsch@...l.com>
Subject: RE: [PATCH 3/3] efi: Add support for using efivars as a pstore
backend
Hi,
Recently, I have suggested similar patches.
Does your patch satisfy my purpose?
[RFC][PATCH] kmsg_dumper for NVRAM
http://choon.net/forum/read.php?21,84718
[RFC][PATCH] pstore: EFI Support
http://choon.net/forum/read.php?21,84718,85162
Seiji
>-----Original Message-----
>From: linux-kernel-owner@...r.kernel.org [mailto:linux-kernel-owner@...r.kernel.org] On Behalf Of Matthew Garrett
>Sent: Monday, June 06, 2011 3:39 PM
>To: tony.luck@...el.com
>Cc: linux-kernel@...r.kernel.org; Matt_Domsch@...l.com; Matthew Garrett
>Subject: [PATCH 3/3] efi: Add support for using efivars as a pstore backend
>
>EFI provides an area of nonvolatile storage managed by the firmware. We
>can use this as a pstore backend to maintain copies of oopses, aiding
>diagnosis.
>
>Signed-off-by: Matthew Garrett <mjg@...hat.com>
>---
> drivers/firmware/efivars.c | 158 +++++++++++++++++++++++++++++++++++++++++++-
> include/linux/efi.h | 3 +
> 2 files changed, 159 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
>index 5f29aaf..89e6a3a 100644
>--- a/drivers/firmware/efivars.c
>+++ b/drivers/firmware/efivars.c
>@@ -78,6 +78,7 @@
> #include <linux/kobject.h>
> #include <linux/device.h>
> #include <linux/slab.h>
>+#include <linux/pstore.h>
>
> #include <asm/uaccess.h>
>
>@@ -89,6 +90,8 @@ MODULE_DESCRIPTION("sysfs interface to EFI Variables");
> MODULE_LICENSE("GPL");
> MODULE_VERSION(EFIVARS_VERSION);
>
>+#define DUMP_NAME_LEN 52
>+
> /*
> * The maximum size of VariableName + Data = 1024
> * Therefore, it's reasonable to save that much
>@@ -161,18 +164,28 @@ utf8_strsize(efi_char16_t *data, unsigned long maxlength)
> }
>
> static efi_status_t
>-get_var_data(struct efivars *efivars, struct efi_variable *var)
>+get_var_data_locked(struct efivars *efivars, struct efi_variable *var)
> {
> efi_status_t status;
>
>- spin_lock(&efivars->lock);
> var->DataSize = 1024;
> status = efivars->ops->get_variable(var->VariableName,
> &var->VendorGuid,
> &var->Attributes,
> &var->DataSize,
> var->Data);
>+ return status;
>+}
>+
>+static efi_status_t
>+get_var_data(struct efivars *efivars, struct efi_variable *var)
>+{
>+ efi_status_t status;
>+
>+ spin_lock(&efivars->lock);
>+ status = get_var_data_locked(efivars, var);
> spin_unlock(&efivars->lock);
>+
> if (status != EFI_SUCCESS) {
> printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
> status);
>@@ -387,12 +400,145 @@ static struct kobj_type efivar_ktype = {
> .default_attrs = def_attrs,
> };
>
>+static struct efivar_entry *walk_entry;
>+
>+static struct pstore_info efi_pstore_info;
>+
> static inline void
> efivar_unregister(struct efivar_entry *var)
> {
> kobject_put(&var->kobj);
> }
>
>+static int efi_pstore_open(struct pstore_info *psi)
>+{
>+ struct efivars *efivars = psi->data;
>+
>+ spin_lock(&efivars->lock);
>+ walk_entry = list_first_entry(&efivars->list, struct efivar_entry,
>+ list);
>+ return 0;
>+}
>+
>+static int efi_pstore_close(struct pstore_info *psi)
>+{
>+ struct efivars *efivars = psi->data;
>+
>+ spin_unlock(&efivars->lock);
>+ return 0;
>+}
>+
>+static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
>+ struct timespec *timespec, struct pstore_info *psi)
>+{
>+ efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
>+ struct efivars *efivars = psi->data;
>+ char name[DUMP_NAME_LEN];
>+ int i;
>+ unsigned int part, size;
>+ unsigned long time;
>+
>+ while (&walk_entry->list != &efivars->list) {
>+ if (!efi_guidcmp(walk_entry->var.VendorGuid, vendor)) {
>+ for (i = 0; i < DUMP_NAME_LEN; i++) {
>+ name[i] = walk_entry->var.VariableName[i];
>+ }
>+ if (sscanf(name, "dump-type%u-%u-%lu", type, &part, &time) == 3) {
>+ *id = part;
>+ timespec->tv_sec = time;
>+ timespec->tv_nsec = 0;
>+ get_var_data_locked(efivars, &walk_entry->var);
>+ size = walk_entry->var.DataSize;
>+ memcpy(psi->buf, walk_entry->var.Data, size);
>+ walk_entry = list_entry(walk_entry->list.next,
>+ struct efivar_entry, list);
>+ return size;
>+ }
>+ }
>+ walk_entry = list_entry(walk_entry->list.next,
>+ struct efivar_entry, list);
>+ }
>+ return 0;
>+}
>+
>+static u64 efi_pstore_write(enum pstore_type_id type, int part, size_t size,
>+ struct pstore_info *psi)
>+{
>+ char name[DUMP_NAME_LEN];
>+ char stub_name[DUMP_NAME_LEN];
>+ efi_char16_t efi_name[DUMP_NAME_LEN];
>+ efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
>+ struct efivars *efivars = psi->data;
>+ struct efivar_entry *entry, *found = NULL;
>+ int i;
>+
>+ sprintf(stub_name, "dump-type%u-%u-", type, part);
>+ sprintf(name, "%s%lu", stub_name, get_seconds());
>+
>+ spin_lock(&efivars->lock);
>+
>+ for (i = 0; i < DUMP_NAME_LEN; i++)
>+ efi_name[i] = stub_name[i];
>+
>+ /*
>+ * Clean up any entries with the same name
>+ */
>+
>+ list_for_each_entry(entry, &efivars->list, list) {
>+ get_var_data_locked(efivars, &entry->var);
>+
>+ for (i = 0; i < DUMP_NAME_LEN; i++) {
>+ if (efi_name[i] == 0) {
>+ found = entry;
>+ efi.set_variable(entry->var.VariableName, &entry->var.VendorGuid,
>+ EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS |
>EFI_VARIABLE_RUNTIME_ACCESS,
>+ 0, NULL);
>+ break;
>+ } else if (efi_name[i] != entry->var.VariableName[i]) {
>+ break;
>+ }
>+ }
>+ }
>+
>+ if (found)
>+ list_del(&found->list);
>+
>+ for (i = 0; i < DUMP_NAME_LEN; i++)
>+ efi_name[i] = name[i];
>+
>+ efi.set_variable(efi_name, &vendor,
>+ EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
>+ size, psi->buf);
>+
>+ spin_unlock(&efivars->lock);
>+
>+ if (found)
>+ efivar_unregister(found);
>+
>+ if (size)
>+ efivar_create_sysfs_entry(efivars, utf8_strsize(efi_name, DUMP_NAME_LEN * 2),
>+ efi_name, &vendor);
>+
>+ return part;
>+};
>+
>+static int efi_pstore_erase(enum pstore_type_id type, u64 id,
>+ struct pstore_info *psi)
>+{
>+ efi_pstore_write(type, id, 0, psi);
>+
>+ return 0;
>+}
>+
>+static struct pstore_info efi_pstore_info = {
>+ .owner = THIS_MODULE,
>+ .name = "efi",
>+ .open = efi_pstore_open,
>+ .close = efi_pstore_close,
>+ .read = efi_pstore_read,
>+ .write = efi_pstore_write,
>+ .erase = efi_pstore_erase,
>+};
>
> static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
> struct bin_attribute *bin_attr,
>@@ -763,6 +909,14 @@ int register_efivars(struct efivars *efivars,
> if (error)
> unregister_efivars(efivars);
>
>+ efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
>+ if (efi_pstore_info.buf) {
>+ efi_pstore_info.bufsize = 1024;
>+ efi_pstore_info.data = efivars;
>+ mutex_init(&efi_pstore_info.buf_mutex);
>+ pstore_register(&efi_pstore_info);
>+ }
>+
> out:
> kfree(variable_name);
>
>diff --git a/include/linux/efi.h b/include/linux/efi.h
>index ec25726..8dd9a01 100644
>--- a/include/linux/efi.h
>+++ b/include/linux/efi.h
>@@ -232,6 +232,9 @@ typedef efi_status_t efi_query_capsule_caps_t(efi_capsule_header_t **capsules,
> #define UV_SYSTEM_TABLE_GUID \
> EFI_GUID( 0x3b13a7d4, 0x633e, 0x11dd, 0x93, 0xec, 0xda, 0x25, 0x56, 0xd8, 0x95, 0x93 )
>
>+#define LINUX_EFI_CRASH_GUID \
>+ EFI_GUID( 0xcfc8fc79, 0xbe2e, 0x4ddc, 0x97, 0xf0, 0x9f, 0x98, 0xbf, 0xe2, 0x98, 0xa0 )
>+
> typedef struct {
> efi_guid_t guid;
> unsigned long table;
>--
>1.7.5.2
>
>--
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