From abc93f8eb6e46a480485f19256bdbda36ec78a84 Mon Sep 17 00:00:00 2001 From: Daniel Kiper Date: Mon, 30 Jun 2014 19:52:56 +0200 Subject: efi: Use early_mem*() instead of early_io*() Use early_mem*() instead of early_io*() because all mapped EFI regions are memory (usually RAM but they could also be ROM, EPROM, EEPROM, flash, etc.) not I/O regions. Additionally, I/O family calls do not work correctly under Xen in our case. early_ioremap() skips the PFN to MFN conversion when building the PTE. Using it for memory will attempt to map the wrong machine frame. However, all artificial EFI structures created under Xen live in dom0 memory and should be mapped/unmapped using early_mem*() family calls which map domain memory. Signed-off-by: Daniel Kiper Cc: Leif Lindholm Cc: Mark Salter Signed-off-by: Matt Fleming --- drivers/firmware/efi/efi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/firmware/efi/efi.c') diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index cd36deb619f..023937a63a4 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -298,7 +298,7 @@ int __init efi_config_init(efi_config_table_type_t *arch_tables) if (table64 >> 32) { pr_cont("\n"); pr_err("Table located above 4GB, disabling EFI.\n"); - early_iounmap(config_tables, + early_memunmap(config_tables, efi.systab->nr_tables * sz); return -EINVAL; } @@ -314,7 +314,7 @@ int __init efi_config_init(efi_config_table_type_t *arch_tables) tablep += sz; } pr_cont("\n"); - early_iounmap(config_tables, efi.systab->nr_tables * sz); + early_memunmap(config_tables, efi.systab->nr_tables * sz); set_bit(EFI_CONFIG_TABLES, &efi.flags); -- cgit v1.2.3-70-g09d2 From 9f27bc543bdf92e179927037e2ab8ed0261579a9 Mon Sep 17 00:00:00 2001 From: Daniel Kiper Date: Mon, 30 Jun 2014 19:52:58 +0200 Subject: efi: Introduce EFI_PARAVIRT flag Introduce EFI_PARAVIRT flag. If it is set then kernel runs on EFI platform but it has not direct control on EFI stuff like EFI runtime, tables, structures, etc. If not this means that Linux Kernel has direct access to EFI infrastructure and everything runs as usual. This functionality is used in Xen dom0 because hypervisor has full control on EFI stuff and all calls from dom0 to EFI must be requested via special hypercall which in turn executes relevant EFI code in behalf of dom0. Signed-off-by: Daniel Kiper Signed-off-by: Matt Fleming --- arch/x86/platform/efi/efi.c | 31 +++++++++++++++++++++++++------ drivers/firmware/efi/efi.c | 21 ++++++++++++--------- include/linux/efi.h | 3 ++- 3 files changed, 39 insertions(+), 16 deletions(-) (limited to 'drivers/firmware/efi/efi.c') diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 7d627a02ed8..d9026538cfd 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -210,6 +210,9 @@ int __init efi_memblock_x86_reserve_range(void) struct efi_info *e = &boot_params.efi_info; unsigned long pmap; + if (efi_enabled(EFI_PARAVIRT)) + return 0; + #ifdef CONFIG_X86_32 /* Can't handle data above 4GB at this time */ if (e->efi_memmap_hi) { @@ -422,14 +425,24 @@ static int __init efi_runtime_init(void) * the runtime services table so that we can grab the physical * address of several of the EFI runtime functions, needed to * set the firmware into virtual mode. + * + * When EFI_PARAVIRT is in force then we could not map runtime + * service memory region because we do not have direct access to it. + * However, runtime services are available through proxy functions + * (e.g. in case of Xen dom0 EFI implementation they call special + * hypercall which executes relevant EFI functions) and that is why + * they are always enabled. */ - if (efi_enabled(EFI_64BIT)) - rv = efi_runtime_init64(); - else - rv = efi_runtime_init32(); - if (rv) - return rv; + if (!efi_enabled(EFI_PARAVIRT)) { + if (efi_enabled(EFI_64BIT)) + rv = efi_runtime_init64(); + else + rv = efi_runtime_init32(); + + if (rv) + return rv; + } set_bit(EFI_RUNTIME_SERVICES, &efi.flags); @@ -438,6 +451,9 @@ static int __init efi_runtime_init(void) static int __init efi_memmap_init(void) { + if (efi_enabled(EFI_PARAVIRT)) + return 0; + /* Map the EFI memory map */ memmap.map = early_memremap((unsigned long)memmap.phys_map, memmap.nr_map * memmap.desc_size); @@ -914,6 +930,9 @@ static void __init __efi_enter_virtual_mode(void) void __init efi_enter_virtual_mode(void) { + if (efi_enabled(EFI_PARAVIRT)) + return; + if (efi_setup) kexec_enter_virtual_mode(); else diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 023937a63a4..ac88ec05eb7 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -104,16 +104,19 @@ static struct attribute *efi_subsys_attrs[] = { 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; + if (attr == &efi_attr_fw_vendor.attr) { + if (efi_enabled(EFI_PARAVIRT) || + efi.fw_vendor == EFI_INVALID_TABLE_ADDR) + return 0; + } else if (attr == &efi_attr_runtime.attr) { + if (efi.runtime == EFI_INVALID_TABLE_ADDR) + return 0; + } else if (attr == &efi_attr_config_table.attr) { + if (efi.config_table == EFI_INVALID_TABLE_ADDR) + return 0; + } - return mode; + return attr->mode; } static struct attribute_group efi_subsys_attr_group = { diff --git a/include/linux/efi.h b/include/linux/efi.h index bac0f93dc47..c7a29a26e90 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -922,7 +922,8 @@ extern int __init efi_setup_pcdp_console(char *); #define EFI_RUNTIME_SERVICES 3 /* Can we use runtime services? */ #define EFI_MEMMAP 4 /* Can we use EFI memory map? */ #define EFI_64BIT 5 /* Is the firmware 64-bit? */ -#define EFI_ARCH_1 6 /* First arch-specific bit */ +#define EFI_PARAVIRT 6 /* Access is via a paravirt interface */ +#define EFI_ARCH_1 7 /* First arch-specific bit */ #ifdef CONFIG_EFI /* -- cgit v1.2.3-70-g09d2 From 28d54022e6ff9c16bf4dacb5f64a97443a38caa9 Mon Sep 17 00:00:00 2001 From: "Lee, Chun-Yi" Date: Wed, 9 Jul 2014 18:39:29 +0800 Subject: efi: Autoload efivars The original patch is from Ben Hutchings's contribution to debian kernel. Got Ben's permission to remove the code of efi-pstore.c and send to linux-efi: https://github.com/BlankOn/linux-debian/blob/master/debian/patches/features/all/efi-autoload-efivars.patch efivars is generally useful to have on EFI systems, and in some cases it may be impossible to load it after a kernel upgrade in order to complete a boot loader update. At the same time we don't want to waste memory on non-EFI systems by making them built-in. Instead, give them module aliases as if they are platform drivers, and register a corresponding platform device whenever EFI runtime services are available. This should trigger udev to load them. Signed-off-by: Lee, Chun-Yi Cc: Ben Hutchings Tested-by: Ard Biesheuvel Signed-off-by: Matt Fleming --- drivers/firmware/efi/efi.c | 15 +++++++++++++++ drivers/firmware/efi/efivars.c | 1 + 2 files changed, 16 insertions(+) (limited to 'drivers/firmware/efi/efi.c') diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index ac88ec05eb7..36ffa1747e8 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -23,6 +23,7 @@ #include #include #include +#include struct efi __read_mostly efi = { .mps = EFI_INVALID_TABLE_ADDR, @@ -324,6 +325,20 @@ int __init efi_config_init(efi_config_table_type_t *arch_tables) return 0; } +#ifdef CONFIG_EFI_VARS_MODULE +static int __init efi_load_efivars(void) +{ + struct platform_device *pdev; + + if (!efi_enabled(EFI_RUNTIME_SERVICES)) + return 0; + + pdev = platform_device_register_simple("efivars", 0, NULL, 0); + return IS_ERR(pdev) ? PTR_ERR(pdev) : 0; +} +device_initcall(efi_load_efivars); +#endif + #ifdef CONFIG_EFI_PARAMS_FROM_FDT #define UEFI_PARAM(name, prop, field) \ diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c index 463c56545ae..f256ecd8a17 100644 --- a/drivers/firmware/efi/efivars.c +++ b/drivers/firmware/efi/efivars.c @@ -78,6 +78,7 @@ MODULE_AUTHOR("Matt Domsch "); MODULE_DESCRIPTION("sysfs interface to EFI Variables"); MODULE_LICENSE("GPL"); MODULE_VERSION(EFIVARS_VERSION); +MODULE_ALIAS("platform:efivars"); LIST_HEAD(efivar_sysfs_list); EXPORT_SYMBOL_GPL(efivar_sysfs_list); -- cgit v1.2.3-70-g09d2