[PATCH 1/2] ACPI / OSL: Cleanup initrd table override code

Lv Zheng
2016-03-02T06:16:31Z

This patch cleans up initrd table override code, merging redundant logics
and re-ordering code blocks. No functional changes.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
---
drivers/acpi/osl.c | 114 ++++++++++++++++++++++++----------------------------
1 file changed, 52 insertions(+), 62 deletions(-)

diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 67da6fb..a8c417c 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -602,6 +602,14 @@ acpi_os_predefined_override(const struct acpi_predefined_names *init_val,
return AE_OK;
}

+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, LOCKDEP_NOW_UNRELIABLE);
+}
+
#ifdef CONFIG_ACPI_INITRD_TABLE_OVERRIDE
#include <linux/earlycpio.h>
#include <linux/memblock.h>
@@ -746,96 +754,78 @@ void __init acpi_initrd_override(void *data, size_t 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, LOCKDEP_NOW_UNRELIABLE);
-}
-
-
-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;
-}

acpi_status
acpi_os_physical_table_override(struct acpi_table_header *existing_table,
- acpi_physical_address *address,
- u32 *table_length)
+ acpi_physical_address *address, u32 *length)
{
-#ifndef CONFIG_ACPI_INITRD_TABLE_OVERRIDE
- *table_length = 0;
- *address = 0;
- return AE_OK;
-#else
int table_offset = 0;
struct acpi_table_header *table;
+ u32 table_length;

- *table_length = 0;
+ *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;
- }
-
+ 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_offset += table->length;
+ table_length = 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,
+ /* Only override tables matched */
+ if (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);
- continue;
+ acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
+ goto next_table;
}

- table_offset -= table->length;
- *table_length = table->length;
- acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
+ *length = table_length;
*address = acpi_tables_addr + table_offset;
+ acpi_table_taint(existing_table);
+ acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
break;
- } while (table_offset + ACPI_HEADER_SIZE < all_tables_size);

- if (*address != 0)
- acpi_table_taint(existing_table);
+next_table:
+ table_offset += table_length;
+ }
return AE_OK;
+}
+#else
+acpi_status
+acpi_os_physical_table_override(struct acpi_table_header *existing_table,
+ acpi_physical_address *address,
+ u32 *table_length)
+{
+ *table_length = 0;
+ *address = 0;
+ return AE_OK;
+}
+#endif /* CONFIG_ACPI_INITRD_TABLE_OVERRIDE */
+
+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;
}

static irqreturn_t acpi_irq(int irq, void *dev_id)
--
1.7.10