From mboxrd@z Thu Jan 1 00:00:00 1970 From: Artur Paszkiewicz Subject: [PATCH v2 5/5] imsm: use efivarfs interface for reading UEFI variables Date: Thu, 20 Nov 2014 18:56:13 +0100 Message-ID: <1416506173-15879-1-git-send-email-artur.paszkiewicz@intel.com> Return-path: Sender: linux-raid-owner@vger.kernel.org To: neilb@suse.de Cc: linux-raid@vger.kernel.org, pawel.baldysiak@intel.com, Artur Paszkiewicz List-Id: linux-raid.ids Read UEFI variables using the new efivarfs interface, fallback to sysfs-efivars if that fails. Signed-off-by: Artur Paszkiewicz --- platform-intel.c | 37 ++++++++++++++++++++++++++++++++++++- 1 file changed, 36 insertions(+), 1 deletion(-) diff --git a/platform-intel.c b/platform-intel.c index 54ef37f..37274da 100644 --- a/platform-intel.c +++ b/platform-intel.c @@ -416,6 +416,7 @@ static const struct imsm_orom *find_imsm_hba_orom(struct sys_dev *hba) (d0), (d1), (d2), (d3), (d4), (d5), (d6), (d7) }}) #define SYS_EFI_VAR_PATH "/sys/firmware/efi/vars" +#define SYS_EFIVARS_PATH "/sys/firmware/efi/efivars" #define SCU_PROP "RstScuV" #define AHCI_PROP "RstSataV" #define AHCI_SSATA_PROP "RstsSatV" @@ -426,13 +427,47 @@ static const struct imsm_orom *find_imsm_hba_orom(struct sys_dev *hba) #define PCI_CLASS_RAID_CNTRL 0x010400 -int read_efi_variable(void *buffer, ssize_t buf_size, char *variable_name, struct efi_guid guid) +static int read_efi_var(void *buffer, ssize_t buf_size, char *variable_name, struct efi_guid guid) +{ + char path[PATH_MAX]; + char buf[GUID_STR_MAX]; + int fd; + ssize_t n; + + snprintf(path, PATH_MAX, "%s/%s-%s", SYS_EFIVARS_PATH, variable_name, guid_str(buf, guid)); + + fd = open(path, O_RDONLY); + if (fd < 0) + return 1; + + /* read the variable attributes and ignore it */ + n = read(fd, buf, sizeof(__u32)); + if (n < 0) { + close(fd); + return 1; + } + + /* read the variable data */ + n = read(fd, buffer, buf_size); + close(fd); + if (n < buf_size) + return 1; + + return 0; +} + +static int read_efi_variable(void *buffer, ssize_t buf_size, char *variable_name, struct efi_guid guid) { char path[PATH_MAX]; char buf[GUID_STR_MAX]; int dfd; ssize_t n, var_data_len; + /* Try to read the variable using the new efivarfs interface first. + * If that fails, fall back to the old sysfs-efivars interface. */ + if (!read_efi_var(buffer, buf_size, variable_name, guid)) + return 0; + snprintf(path, PATH_MAX, "%s/%s-%s/size", SYS_EFI_VAR_PATH, variable_name, guid_str(buf, guid)); dprintf("EFI VAR: path=%s\n", path); -- 1.8.4.5