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authorLinus Torvalds <torvalds@linux-foundation.org>2012-12-14 10:03:23 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-14 10:03:23 -0800
commit18dd0bf22b6f0c1bd5e4e813a42245ed86ec57b6 (patch)
treea4794b6041b44fa94f5d9438cdb5bbfc58b35f05 /drivers/acpi
parent2d9c8b5d6a5f5f7a6111cc68a050b5b44729376b (diff)
parent385ddeac7ed99cf7dc62d76274d55fbd7cae1b5a (diff)
Merge branch 'x86-acpi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 ACPI update from Peter Anvin: "This is a patchset which didn't make the last merge window. It adds a debugging capability to feed ACPI tables via the initramfs. On a grander scope, it formalizes using the initramfs protocol for feeding arbitrary blobs which need to be accessed early to the kernel: they are fed first in the initramfs blob (lots of bootloaders can concatenate this at boot time, others can use a single file) in an uncompressed cpio archive using filenames starting with "kernel/". The ACPI maintainers requested that this patchset be fed via the x86 tree rather than the ACPI tree as the footprint in the general x86 code is much bigger than in the ACPI code proper." * 'x86-acpi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: X86 ACPI: Use #ifdef not #if for CONFIG_X86 check ACPI: Fix build when disabled ACPI: Document ACPI table overriding via initrd ACPI: Create acpi_table_taint() function to avoid code duplication ACPI: Implement physical address table override ACPI: Store valid ACPI tables passed via early initrd in reserved memblock areas x86, acpi: Introduce x86 arch specific arch_reserve_mem_area() for e820 handling lib: Add early cpio decoder
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/Kconfig9
-rw-r--r--drivers/acpi/osl.c202
2 files changed, 200 insertions, 11 deletions
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 0300bf61294..38c5078da11 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -267,6 +267,15 @@ config ACPI_CUSTOM_DSDT
bool
default ACPI_CUSTOM_DSDT_FILE != ""
+config ACPI_INITRD_TABLE_OVERRIDE
+ bool "ACPI tables can be passed via uncompressed cpio in initrd"
+ default n
+ 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 6dc4a2b1e95..3ff26786154 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -534,6 +534,137 @@ 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 */
+
+static void acpi_table_taint(struct acpi_table_header *table)
+{
+ pr_warn(PREFIX
+ "Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
+ table->signature, table->oem_table_id);
+ add_taint(TAINT_OVERRIDDEN_ACPI_TABLE);
+}
+
+
acpi_status
acpi_os_table_override(struct acpi_table_header * existing_table,
struct acpi_table_header ** new_table)
@@ -547,24 +678,73 @@ acpi_os_table_override(struct acpi_table_header * existing_table,
if (strncmp(existing_table->signature, "DSDT", 4) == 0)
*new_table = (struct acpi_table_header *)AmlCode;
#endif
- if (*new_table != NULL) {
- printk(KERN_WARNING PREFIX "Override [%4.4s-%8.8s], "
- "this is unsafe: tainting kernel\n",
- existing_table->signature,
- existing_table->oem_table_id);
- add_taint(TAINT_OVERRIDDEN_ACPI_TABLE);
- }
+ if (*new_table != NULL)
+ acpi_table_taint(existing_table);
return AE_OK;
}
acpi_status
acpi_os_physical_table_override(struct acpi_table_header *existing_table,
- acpi_physical_address * new_address,
- u32 *new_table_length)
+ acpi_physical_address *address,
+ u32 *table_length)
{
- return AE_SUPPORT;
-}
+#ifndef CONFIG_ACPI_INITRD_TABLE_OVERRIDE
+ *table_length = 0;
+ *address = 0;
+ return AE_OK;
+#else
+ int table_offset = 0;
+ struct acpi_table_header *table;
+
+ *table_length = 0;
+ *address = 0;
+
+ if (!acpi_tables_addr)
+ return AE_OK;
+
+ do {
+ if (table_offset + ACPI_HEADER_SIZE > all_tables_size) {
+ WARN_ON(1);
+ return AE_OK;
+ }
+ table = acpi_os_map_memory(acpi_tables_addr + table_offset,
+ ACPI_HEADER_SIZE);
+
+ if (table_offset + table->length > all_tables_size) {
+ acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
+ WARN_ON(1);
+ return AE_OK;
+ }
+
+ table_offset += table->length;
+
+ if (memcmp(existing_table->signature, table->signature, 4)) {
+ acpi_os_unmap_memory(table,
+ ACPI_HEADER_SIZE);
+ continue;
+ }
+
+ /* Only override tables with matching oem id */
+ if (memcmp(table->oem_table_id, existing_table->oem_table_id,
+ ACPI_OEM_TABLE_ID_SIZE)) {
+ acpi_os_unmap_memory(table,
+ ACPI_HEADER_SIZE);
+ continue;
+ }
+
+ table_offset -= table->length;
+ *table_length = table->length;
+ acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
+ *address = acpi_tables_addr + table_offset;
+ break;
+ } while (table_offset + ACPI_HEADER_SIZE < all_tables_size);
+
+ if (*address != 0)
+ acpi_table_taint(existing_table);
+ return AE_OK;
+#endif
+}
static irqreturn_t acpi_irq(int irq, void *dev_id)
{