ACPI / tables: Move table override mechanisms to tables.c
This patch moves acpi_os_table_override() and
acpi_os_physical_table_override() to tables.c.
Along with the mechanisms, acpi_initrd_initialize_tables() is also moved to
tables.c to form a static function. The following functions are renamed
according to this change:
1. acpi_initrd_override() -> renamed to early_acpi_table_init(), which
invokes acpi_table_initrd_init()
2. acpi_os_physical_table_override() -> which invokes
acpi_table_initrd_override()
3. acpi_initialize_initrd_tables() -> renamed to acpi_table_initrd_scan()
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index f49c024..2e74dbf 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -32,6 +32,8 @@
#include <linux/errno.h>
#include <linux/acpi.h>
#include <linux/bootmem.h>
+#include <linux/earlycpio.h>
+#include <linux/memblock.h>
#include "internal.h"
#define ACPI_MAX_TABLES 128
@@ -433,6 +435,294 @@
return;
}
+static void acpi_table_taint(struct acpi_table_header *table)
+{
+ pr_warn("Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
+ table->signature, table->oem_table_id);
+ add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
+}
+
+#ifdef CONFIG_ACPI_INITRD_TABLE_OVERRIDE
+static u64 acpi_tables_addr;
+static int all_tables_size;
+
+/* Copied from acpica/tbutils.c:acpi_tb_checksum() */
+static 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 };
+
+#define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
+
+#define ACPI_OVERRIDE_TABLES 64
+static struct cpio_data __initdata acpi_initrd_files[ACPI_OVERRIDE_TABLES];
+static DECLARE_BITMAP(acpi_initrd_installed, ACPI_OVERRIDE_TABLES);
+
+#define MAP_CHUNK_SIZE (NR_FIX_BTMAPS << PAGE_SHIFT)
+
+static void __init acpi_table_initrd_init(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;
+
+ 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)) {
+ pr_err("ACPI OVERRIDE: Table smaller than ACPI header [%s%s]\n",
+ cpio_path, file.name);
+ continue;
+ }
+
+ table = file.data;
+
+ for (sig = 0; table_sigs[sig]; sig++)
+ if (!memcmp(table->signature, table_sigs[sig], 4))
+ break;
+
+ if (!table_sigs[sig]) {
+ pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
+ cpio_path, file.name);
+ continue;
+ }
+ if (file.size != table->length) {
+ pr_err("ACPI OVERRIDE: File length does not match table length [%s%s]\n",
+ cpio_path, file.name);
+ continue;
+ }
+ if (acpi_table_checksum(file.data, table->length)) {
+ pr_err("ACPI OVERRIDE: Bad table checksum [%s%s]\n",
+ cpio_path, file.name);
+ continue;
+ }
+
+ 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;
+ acpi_initrd_files[table_nr].data = file.data;
+ acpi_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, all_tables_size);
+ arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
+
+ /*
+ * early_ioremap only can remap 256k one time. If we map all
+ * tables one time, we will hit the limit. Need to map chunks
+ * one by one during copying the same as that in relocate_initrd().
+ */
+ for (no = 0; no < table_nr; no++) {
+ unsigned char *src_p = acpi_initrd_files[no].data;
+ phys_addr_t size = acpi_initrd_files[no].size;
+ phys_addr_t dest_addr = acpi_tables_addr + total_offset;
+ phys_addr_t slop, clen;
+ char *dest_p;
+
+ total_offset += size;
+
+ while (size) {
+ slop = dest_addr & ~PAGE_MASK;
+ clen = size;
+ if (clen > MAP_CHUNK_SIZE - slop)
+ clen = MAP_CHUNK_SIZE - slop;
+ dest_p = early_ioremap(dest_addr & PAGE_MASK,
+ clen + slop);
+ memcpy(dest_p + slop, src_p, clen);
+ early_iounmap(dest_p, clen + slop);
+ src_p += clen;
+ dest_addr += clen;
+ size -= clen;
+ }
+ }
+}
+
+static acpi_status
+acpi_table_initrd_override(struct acpi_table_header *existing_table,
+ acpi_physical_address *address, u32 *length)
+{
+ int table_offset = 0;
+ int table_index = 0;
+ struct acpi_table_header *table;
+ u32 table_length;
+
+ *length = 0;
+ *address = 0;
+ if (!acpi_tables_addr)
+ return AE_OK;
+
+ while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
+ 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_length = table->length;
+
+ /* Only override tables matched */
+ if (test_bit(table_index, acpi_initrd_installed) ||
+ memcmp(existing_table->signature, table->signature, 4) ||
+ memcmp(table->oem_table_id, existing_table->oem_table_id,
+ ACPI_OEM_TABLE_ID_SIZE)) {
+ acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
+ goto next_table;
+ }
+
+ *length = table_length;
+ *address = acpi_tables_addr + table_offset;
+ acpi_table_taint(existing_table);
+ acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
+ set_bit(table_index, acpi_initrd_installed);
+ break;
+
+next_table:
+ table_offset += table_length;
+ table_index++;
+ }
+ return AE_OK;
+}
+
+static void __init acpi_table_initrd_scan(void)
+{
+ int table_offset = 0;
+ int table_index = 0;
+ u32 table_length;
+ struct acpi_table_header *table;
+
+ if (!acpi_tables_addr)
+ return;
+
+ while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
+ 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;
+ }
+
+ table_length = table->length;
+
+ /* Skip RSDT/XSDT which should only be used for override */
+ if (test_bit(table_index, acpi_initrd_installed) ||
+ ACPI_COMPARE_NAME(table->signature, ACPI_SIG_RSDT) ||
+ ACPI_COMPARE_NAME(table->signature, ACPI_SIG_XSDT)) {
+ acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
+ goto next_table;
+ }
+
+ acpi_table_taint(table);
+ acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
+ acpi_install_table(acpi_tables_addr + table_offset, TRUE);
+ set_bit(table_index, acpi_initrd_installed);
+next_table:
+ table_offset += table_length;
+ table_index++;
+ }
+}
+#else
+static void __init acpi_table_initrd_init(void *data, size_t size)
+{
+}
+
+static acpi_status
+acpi_table_initrd_override(struct acpi_table_header *existing_table,
+ acpi_physical_address *address,
+ u32 *table_length)
+{
+ *table_length = 0;
+ *address = 0;
+ return AE_OK;
+}
+
+static void __init acpi_table_initrd_scan(void)
+{
+}
+#endif /* CONFIG_ACPI_INITRD_TABLE_OVERRIDE */
+
+acpi_status
+acpi_os_physical_table_override(struct acpi_table_header *existing_table,
+ acpi_physical_address *address,
+ u32 *table_length)
+{
+ return acpi_table_initrd_override(existing_table, address,
+ table_length);
+}
+
+acpi_status
+acpi_os_table_override(struct acpi_table_header *existing_table,
+ struct acpi_table_header **new_table)
+{
+ if (!existing_table || !new_table)
+ return AE_BAD_PARAMETER;
+
+ *new_table = NULL;
+
+#ifdef CONFIG_ACPI_CUSTOM_DSDT
+ if (strncmp(existing_table->signature, "DSDT", 4) == 0)
+ *new_table = (struct acpi_table_header *)AmlCode;
+#endif
+ if (*new_table != NULL)
+ acpi_table_taint(existing_table);
+ return AE_OK;
+}
+
+void __init early_acpi_table_init(void *data, size_t size)
+{
+ acpi_table_initrd_init(data, size);
+}
+
/*
* acpi_table_init()
*
@@ -457,7 +747,7 @@
status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
if (ACPI_FAILURE(status))
return -EINVAL;
- acpi_initrd_initialize_tables();
+ acpi_table_initrd_scan();
check_multiple_madt();
return 0;