[PATCH 2/2] ACPI / OSL: Add support to install tables via initrd

Lv Zheng
2016-03-02T06:16:33Z

This patch adds support to install tables from initrd.

If a table in the initrd wasn't used by the override mechanism, the table
would be installed after initializing all RSDT/XSDT tables.

Reference: https://lkml.org/lkml/2014/2/28/368
Reported-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
---
drivers/acpi/internal.h | 1 +
drivers/acpi/osl.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++-
drivers/acpi/tables.c | 2 ++
3 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 9860df0..a37508e 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -20,6 +20,7 @@

#define PREFIX "ACPI: "

+void acpi_initrd_initialize_tables(void);
acpi_status acpi_os_initialize1(void);
void init_acpi_device_notify(void);
int acpi_scan_init(void);
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index a8c417c..814d5f8 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -644,6 +644,7 @@ static const char * const table_sigs[] = {

#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)

@@ -760,6 +761,7 @@ acpi_os_physical_table_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;

@@ -780,7 +782,8 @@ acpi_os_physical_table_override(struct acpi_table_header *existing_table,
table_length = table->length;

/* Only override tables matched */
- if (memcmp(existing_table->signature, table->signature, 4) ||
+ 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);
@@ -791,13 +794,54 @@ acpi_os_physical_table_override(struct acpi_table_header *existing_table,
*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;
}
+
+void __init acpi_initrd_initialize_tables(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
acpi_status
acpi_os_physical_table_override(struct acpi_table_header *existing_table,
@@ -808,6 +852,10 @@ acpi_os_physical_table_override(struct acpi_table_header *existing_table,
*address = 0;
return AE_OK;
}
+
+void __init acpi_initrd_initialize_tables(void)
+{
+}
#endif /* CONFIG_ACPI_INITRD_TABLE_OVERRIDE */

acpi_status
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index ebdf564..f49c024 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -32,6 +32,7 @@
#include <linux/errno.h>
#include <linux/acpi.h>
#include <linux/bootmem.h>
+#include "internal.h"

#define ACPI_MAX_TABLES 128

@@ -456,6 +457,7 @@ int __init acpi_table_init(void)
status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
if (ACPI_FAILURE(status))
return -EINVAL;
+ acpi_initrd_initialize_tables();

check_multiple_madt();
return 0;
--
1.7.10