Export fw_vendor, runtime and config tables physical addresses to /sys/firmware/efi/systab becaue kexec kernel will need them. >From EFI spec these 3 variables will be updated to virtual address after entering virtual mode. But kernel startup code will need the physical address. changelog: Greg: add standalone sysfs files instead of add lines to systab Document them as testing ABI Greg: use group attrs and is_visible Boris: align comments lines Signed-off-by: Dave Young --- Documentation/ABI/testing/sysfs-firmware-efi | 26 +++++++++++++++ arch/x86/platform/efi/efi.c | 4 ++ drivers/firmware/efi/efi.c | 44 +++++++++++++++++++++++++++ include/linux/efi.h | 3 + 4 files changed, 77 insertions(+) --- efi.orig/drivers/firmware/efi/efi.c +++ efi/drivers/firmware/efi/efi.c @@ -32,6 +32,9 @@ struct efi __read_mostly efi = { .hcdp = EFI_INVALID_TABLE_ADDR, .uga = EFI_INVALID_TABLE_ADDR, .uv_systab = EFI_INVALID_TABLE_ADDR, + .fw_vendor = EFI_INVALID_TABLE_ADDR, + .runtime = EFI_INVALID_TABLE_ADDR, + .config_table = EFI_INVALID_TABLE_ADDR, }; EXPORT_SYMBOL(efi); @@ -71,13 +74,54 @@ static ssize_t systab_show(struct kobjec static struct kobj_attribute efi_attr_systab = __ATTR(systab, 0400, systab_show, NULL); +static ssize_t fw_vendor_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "0x%lx\n", efi.fw_vendor); +} + +static ssize_t runtime_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "0x%lx\n", efi.runtime); +} + +static ssize_t config_table_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "0x%lx\n", efi.config_table); +} + +static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor); +static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime); +static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table); + static struct attribute *efi_subsys_attrs[] = { &efi_attr_systab.attr, + &efi_attr_fw_vendor.attr, + &efi_attr_runtime.attr, + &efi_attr_config_table.attr, NULL, /* maybe more in the future? */ }; +static umode_t efi_attr_is_visible(struct kobject *kobj, + struct attribute *attr, int n) +{ + umode_t mode = attr->mode; + + if (attr == &efi_attr_fw_vendor.attr) + return (efi.fw_vendor == EFI_INVALID_TABLE_ADDR) ? 0 : mode; + else if (attr == &efi_attr_runtime.attr) + return (efi.runtime == EFI_INVALID_TABLE_ADDR) ? 0 : mode; + else if (attr == &efi_attr_config_table.attr) + return (efi.config_table == EFI_INVALID_TABLE_ADDR) ? 0 : mode; + + return mode; +} + static struct attribute_group efi_subsys_attr_group = { .attrs = efi_subsys_attrs, + .is_visible = efi_attr_is_visible, }; static struct efivars generic_efivars; --- efi.orig/include/linux/efi.h +++ efi/include/linux/efi.h @@ -556,6 +556,9 @@ extern struct efi { unsigned long hcdp; /* HCDP table */ unsigned long uga; /* UGA table */ unsigned long uv_systab; /* UV system table */ + unsigned long fw_vendor; /* fw_vendor */ + unsigned long runtime; /* runtime table */ + unsigned long config_table; /* config tables */ efi_get_time_t *get_time; efi_set_time_t *set_time; efi_get_wakeup_time_t *get_wakeup_time; --- efi.orig/arch/x86/platform/efi/efi.c +++ efi/arch/x86/platform/efi/efi.c @@ -653,6 +653,10 @@ void __init efi_init(void) set_bit(EFI_SYSTEM_TABLES, &x86_efi_facility); + efi.config_table = (unsigned long)efi.systab->tables; + efi.fw_vendor = (unsigned long)efi.systab->fw_vendor; + efi.runtime = (unsigned long)efi.systab->runtime; + /* * Show what we know for posterity */ --- /dev/null +++ efi/Documentation/ABI/testing/sysfs-firmware-efi @@ -0,0 +1,26 @@ +What: /sys/firmware/efi/fw_vendor +Date: Nov 2013 +Contact: Dave Young +Description: + Shows the physical address of firmware vendor in the EFI + system table. +Users: + Kexec Mailing List + +What: /sys/firmware/efi/runtime +Date: Nov 2013 +Contact: Dave Young +Description: + Shows the physical address of runtime service table in the + EFI system table. +Users: + Kexec Mailing List + +What: /sys/firmware/efi/config_table +Date: Nov 2013 +Contact: Dave Young +Description: + Shows the physical address of config table in the EFI + system table. +Users: + Kexec Mailing List -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/