diff options
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 9 | ||||
| -rw-r--r-- | drivers/firmware/efi/Kconfig | 21 | ||||
| -rw-r--r-- | drivers/firmware/efi/efi.c | 8 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/efi-stub-helper.c | 19 | ||||
| -rw-r--r-- | include/linux/efi.h | 14 |
5 files changed, 70 insertions, 1 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index a84a83f8881e..2359dc56d82c 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1168,7 +1168,8 @@ Format: {"off" | "on" | "skip[mbr]"} efi= [EFI] - Format: { "old_map", "nochunk", "noruntime", "debug" } + Format: { "old_map", "nochunk", "noruntime", "debug", + "nosoftreserve" } old_map [X86-64]: switch to the old ioremap-based EFI runtime services mapping. 32-bit still uses this one by default. @@ -1177,6 +1178,12 @@ firmware implementations. noruntime : disable EFI runtime services support debug: enable misc debug output + nosoftreserve: The EFI_MEMORY_SP (Specific Purpose) + attribute may cause the kernel to reserve the + memory range for a memory mapping driver to + claim. Specify efi=nosoftreserve to disable this + reservation and treat the memory by its base type + (i.e. EFI_CONVENTIONAL_MEMORY / "System RAM"). efi_no_storage_paranoia [EFI; X86] Using this parameter you can use more than 50% of diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index b248870a9806..bcc378c19ebe 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -75,6 +75,27 @@ config EFI_MAX_FAKE_MEM Ranges can be set up to this value using comma-separated list. The default value is 8. +config EFI_SOFT_RESERVE + bool "Reserve EFI Specific Purpose Memory" + depends on EFI && EFI_STUB && ACPI_HMAT + default ACPI_HMAT + help + On systems that have mixed performance classes of memory EFI + may indicate specific purpose memory with an attribute (See + EFI_MEMORY_SP in UEFI 2.8). A memory range tagged with this + attribute may have unique performance characteristics compared + to the system's general purpose "System RAM" pool. On the + expectation that such memory has application specific usage, + and its base EFI memory type is "conventional" answer Y to + arrange for the kernel to reserve it as a "Soft Reserved" + resource, and set aside for direct-access (device-dax) by + default. The memory range can later be optionally assigned to + the page allocator by system administrator policy via the + device-dax kmem facility. Say N to have the kernel treat this + memory as "System RAM" by default. + + If unsure, say Y. + config EFI_PARAMS_FROM_FDT bool help diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index f8f8e273d809..e1cb915b45c6 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -81,6 +81,11 @@ bool efi_runtime_disabled(void) return disable_runtime; } +bool __pure __efi_soft_reserve_enabled(void) +{ + return !efi_enabled(EFI_MEM_NO_SOFT_RESERVE); +} + static int __init parse_efi_cmdline(char *str) { if (!str) { @@ -94,6 +99,9 @@ static int __init parse_efi_cmdline(char *str) if (parse_option_str(str, "noruntime")) disable_runtime = true; + if (parse_option_str(str, "nosoftreserve")) + set_bit(EFI_MEM_NO_SOFT_RESERVE, &efi.flags); + return 0; } early_param("efi", parse_efi_cmdline); diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c index 35dbc2791c97..e02579907f2e 100644 --- a/drivers/firmware/efi/libstub/efi-stub-helper.c +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -32,6 +32,7 @@ static unsigned long __chunk_size = EFI_READ_CHUNK_SIZE; static int __section(.data) __nokaslr; static int __section(.data) __quiet; static int __section(.data) __novamap; +static bool __section(.data) efi_nosoftreserve; int __pure nokaslr(void) { @@ -45,6 +46,10 @@ int __pure novamap(void) { return __novamap; } +bool __pure __efi_soft_reserve_enabled(void) +{ + return !efi_nosoftreserve; +} #define EFI_MMAP_NR_SLACK_SLOTS 8 @@ -211,6 +216,10 @@ again: if (desc->type != EFI_CONVENTIONAL_MEMORY) continue; + if (efi_soft_reserve_enabled() && + (desc->attribute & EFI_MEMORY_SP)) + continue; + if (desc->num_pages < nr_pages) continue; @@ -305,6 +314,10 @@ efi_status_t efi_low_alloc_above(efi_system_table_t *sys_table_arg, if (desc->type != EFI_CONVENTIONAL_MEMORY) continue; + if (efi_soft_reserve_enabled() && + (desc->attribute & EFI_MEMORY_SP)) + continue; + if (desc->num_pages < nr_pages) continue; @@ -484,6 +497,12 @@ efi_status_t efi_parse_options(char const *cmdline) __novamap = 1; } + if (IS_ENABLED(CONFIG_EFI_SOFT_RESERVE) && + !strncmp(str, "nosoftreserve", 7)) { + str += strlen("nosoftreserve"); + efi_nosoftreserve = 1; + } + /* Group words together, delimited by "," */ while (*str && *str != ' ' && *str != ',') str++; diff --git a/include/linux/efi.h b/include/linux/efi.h index 44c85b559e15..88654910ce29 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -1202,6 +1202,7 @@ extern int __init efi_setup_pcdp_console(char *); #define EFI_DBG 8 /* Print additional debug info at runtime */ #define EFI_NX_PE_DATA 9 /* Can runtime data regions be mapped non-executable? */ #define EFI_MEM_ATTR 10 /* Did firmware publish an EFI_MEMORY_ATTRIBUTES table? */ +#define EFI_MEM_NO_SOFT_RESERVE 11 /* Is the kernel configured to ignore soft reservations? */ #ifdef CONFIG_EFI /* @@ -1212,6 +1213,14 @@ static inline bool efi_enabled(int feature) return test_bit(feature, &efi.flags) != 0; } extern void efi_reboot(enum reboot_mode reboot_mode, const char *__unused); + +bool __pure __efi_soft_reserve_enabled(void); + +static inline bool __pure efi_soft_reserve_enabled(void) +{ + return IS_ENABLED(CONFIG_EFI_SOFT_RESERVE) + && __efi_soft_reserve_enabled(); +} #else static inline bool efi_enabled(int feature) { @@ -1225,6 +1234,11 @@ efi_capsule_pending(int *reset_type) { return false; } + +static inline bool efi_soft_reserve_enabled(void) +{ + return false; +} #endif extern int efi_status_to_err(efi_status_t status); |