A later patch will compare them with ACPI tables that get loaded at boot or
runtime and if criteria match, a stored one is loaded.
Signed-off-by: Thomas Renninger <trenn@xxxxxxx>
---
arch/x86/kernel/setup.c | 2 +
drivers/acpi/Kconfig | 9 ++++
drivers/acpi/osl.c | 122 +++++++++++++++++++++++++++++++++++++++++++++++
include/linux/acpi.h | 8 +++
4 files changed, 141 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index f4b9b80..764e543 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -941,6 +941,8 @@ void __init setup_arch(char **cmdline_p)
reserve_initrd();
+ acpi_initrd_override((void *)initrd_start, initrd_end - initrd_start);
+
reserve_crashkernel();
vsmp_init();
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 8099895..a508f77 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -261,6 +261,15 @@ config ACPI_CUSTOM_DSDT
bool
default ACPI_CUSTOM_DSDT_FILE != ""
+config ACPI_INITRD_TABLE_OVERRIDE
+ bool
+ default y
+ help
+ This option provides functionality to override arbitrary ACPI tables
+ via initrd. No functional change if no ACPI tables are passed via
+ initrd, therefore it's safe to say Y.
+ See Documentation/acpi/initrd_table_override.txt for details
+
config ACPI_BLACKLIST_YEAR
int "Disable ACPI for systems before Jan 1st this year" if X86_32
default 0
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 9eaf708..b20b079 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -534,6 +534,128 @@ acpi_os_predefined_override(const struct acpi_predefined_names *init_val,
return AE_OK;
}
+#ifdef CONFIG_ACPI_INITRD_TABLE_OVERRIDE
+#include <linux/earlycpio.h>
+#include <linux/memblock.h>
+
+static u64 acpi_tables_addr;
+static int all_tables_size;
+
+/* Copied from acpica/tbutils.c:acpi_tb_checksum() */
+u8 __init acpi_table_checksum(u8 *buffer, u32 length)
+{
+ u8 sum = 0;
+ u8 *end = buffer + length;
+
+ while (buffer < end)
+ sum = (u8) (sum + *(buffer++));
+ return sum;
+}
+
+/* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
+static const char * const table_sigs[] = {
+ ACPI_SIG_BERT, ACPI_SIG_CPEP, ACPI_SIG_ECDT, ACPI_SIG_EINJ,
+ ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT, ACPI_SIG_MSCT,
+ ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT, ACPI_SIG_ASF,
+ ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR, ACPI_SIG_HPET,
+ ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG, ACPI_SIG_MCHI,
+ ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI, ACPI_SIG_TCPA,
+ ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT, ACPI_SIG_WDDT,
+ ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT, ACPI_SIG_PSDT,
+ ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT, NULL };
+
+/* Non-fatal errors: Affected tables/files are ignored */
+#define INVALID_TABLE(x, path, name) \
+ { pr_err("ACPI OVERRIDE: " x " [%s%s]\n", path, name); continue; }
+
+#define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
+
+/* Must not increase 10 or needs code modification below */
+#define ACPI_OVERRIDE_TABLES 10
+
+void __init acpi_initrd_override(void *data, size_t size)
+{
+ int sig, no, table_nr = 0, total_offset = 0;
+ long offset = 0;
+ struct acpi_table_header *table;
+ char cpio_path[32] = "kernel/firmware/acpi/";
+ struct cpio_data file;
+ struct cpio_data early_initrd_files[ACPI_OVERRIDE_TABLES];
+ char *p;
+
+ if (data == NULL || size == 0)
+ return;
+
+ for (no = 0; no < ACPI_OVERRIDE_TABLES; no++) {
+ file = find_cpio_data(cpio_path, data, size, &offset);
+ if (!file.data)
+ break;
+
+ data += offset;
+ size -= offset;
+
+ if (file.size < sizeof(struct acpi_table_header))
+ INVALID_TABLE("Table smaller than ACPI header",
+ cpio_path, file.name);
+
+ table = file.data;
+
+ for (sig = 0; table_sigs[sig]; sig++)
+ if (!memcmp(table->signature, table_sigs[sig], 4))
+ break;
+
+ if (!table_sigs[sig])
+ INVALID_TABLE("Unknown signature",
+ cpio_path, file.name);
+ if (file.size != table->length)
+ INVALID_TABLE("File length does not match table length",
+ cpio_path, file.name);
+ if (acpi_table_checksum(file.data, table->length))
+ INVALID_TABLE("Bad table checksum",
+ cpio_path, file.name);
+
+ pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n",
+ table->signature, cpio_path, file.name, table->length);
+
+ all_tables_size += table->length;
+ early_initrd_files[table_nr].data = file.data;
+ early_initrd_files[table_nr].size = file.size;
+ table_nr++;
+ }
+ if (table_nr == 0)
+ return;
+
+ acpi_tables_addr =
+ memblock_find_in_range(0, max_low_pfn_mapped << PAGE_SHIFT,
+ all_tables_size, PAGE_SIZE);
+ if (!acpi_tables_addr) {
+ WARN_ON(1);
+ return;
+ }
+ /*
+ * Only calling e820_add_reserve does not work and the
+ * tables are invalid (memory got used) later.
+ * memblock_reserve works as expected and the tables won't get modified.
+ * But it's not enough on X86 because ioremap will
+ * complain later (used by acpi_os_map_memory) that the pages
+ * that should get mapped are not marked "reserved".
+ * Both memblock_reserve and e820_add_region (via arch_reserve_mem_area)
+ * works fine.
+ */
+ memblock_reserve(acpi_tables_addr, acpi_tables_addr + all_tables_size);
+ arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
+
+ p = early_ioremap(acpi_tables_addr, all_tables_size);
+
+ for (no = 0; no < table_nr; no++) {
+ memcpy(p + total_offset, early_initrd_files[no].data,
+ early_initrd_files[no].size);
+ total_offset += early_initrd_files[no].size;
+ }
+ early_iounmap(p, all_tables_size);
+}
+#endif /* CONFIG_ACPI_INITRD_TABLE_OVERRIDE */
+
acpi_status
acpi_os_table_override(struct acpi_table_header * existing_table,
struct acpi_table_header ** new_table)
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index bf6a0ad..ee81cdc 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -76,6 +76,14 @@ typedef int (*acpi_table_handler) (struct acpi_table_header *table);
typedef int (*acpi_table_entry_handler) (struct acpi_subtable_header *header, const unsigned long end);
+#ifdef CONFIG_ACPI_INITRD_TABLE_OVERRIDE
+void acpi_initrd_override(void *data, size_t size);
+#else
+static inline void acpi_initrd_override(void *data, size_t size)
+{
+}
+#endif
+
char * __acpi_map_table (unsigned long phys_addr, unsigned long size);
void __acpi_unmap_table(char *map, unsigned long size);
int early_acpi_boot_init(void);
--
1.7.6.1
--
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