[PATCH v2 11/18] x86, acpi: Try to find SRAT in firmware earlier.

Tang Chen
2013-08-01T07:11:02Z

This patch introduce early_acpi_firmware_srat() to find the
phys addr of SRAT provided by firmware. And call it in
find_hotpluggable_memory().

Since we have initialized acpi_gbl_root_table_list earlier,
and store all the tables' phys addrs and signatures in it,
it is easy to find the SRAT.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
---
drivers/acpi/acpica/tbxface.c | 32 ++++++++++++++++++++++++++++++++
drivers/acpi/osl.c | 22 ++++++++++++++++++++++
include/acpi/acpixf.h | 4 ++++
include/linux/acpi.h | 4 ++++
mm/memory_hotplug.c | 8 ++++++--
5 files changed, 68 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/acpica/tbxface.c b/drivers/acpi/acpica/tbxface.c
index ad11162..6a92f12 100644
--- a/drivers/acpi/acpica/tbxface.c
+++ b/drivers/acpi/acpica/tbxface.c
@@ -181,6 +181,38 @@ acpi_status acpi_reallocate_root_table(void)
return_ACPI_STATUS(status);
}

+/**
+ * acpi_get_table_desc - Get the acpi table descriptor of a specific table.
+ * @signature: The signature of the table to be found.
+ * @out_desc: The out returned descriptor.
+ *
+ * Iterate over acpi_gbl_root_table_list to find a specific table and then
+ * return its phys addr.
+ *
+ * NOTE: The caller has the responsibility to allocate memory for @out_desc.
+ *
+ * Return AE_OK on success, AE_NOT_FOUND if the table is not found.
+ */
+acpi_status acpi_get_table_desc(char *signature,
+ struct acpi_table_desc *out_desc)
+{
+ struct acpi_table_desc *desc;
+ int pos, count = acpi_gbl_root_table_list.current_table_count;
+
+ for (pos = 0; pos < count; pos++) {
+ desc = &acpi_gbl_root_table_list.tables[pos];
+
+ if (!ACPI_COMPARE_NAME(&desc->signature, signature))
+ continue;
+
+ memcpy(out_desc, desc, sizeof(struct acpi_table_desc));
+
+ return_ACPI_STATUS(AE_OK);
+ }
+
+ return_ACPI_STATUS(AE_NOT_FOUND);
+}
+
/*******************************************************************************
*
* FUNCTION: acpi_get_table_header
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index d0b687c..319a274 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -53,6 +53,7 @@
#include <acpi/acpi.h>
#include <acpi/acpi_bus.h>
#include <acpi/processor.h>
+#include <acpi/acpixf.h>

#define _COMPONENT ACPI_OS_SERVICES
ACPI_MODULE_NAME("osl");
@@ -757,6 +758,27 @@ void __init acpi_initrd_override(void *data, size_t size)
}
#endif /* CONFIG_ACPI_INITRD_TABLE_OVERRIDE */

+#ifdef CONFIG_ACPI_NUMA
+/*******************************************************************************
+ *
+ * FUNCTION: early_acpi_firmware_srat
+ *
+ * RETURN: Phys addr of SRAT on success, 0 on error.
+ *
+ * DESCRIPTION: Get the phys addr of SRAT provided by firmware.
+ *
+ ******************************************************************************/
+phys_addr_t __init early_acpi_firmware_srat(void)
+{
+ struct acpi_table_desc table_desc;
+
+ if (acpi_get_table_desc(ACPI_SIG_SRAT, &table_desc))
+ return 0;
+
+ return table_desc.address;
+}
+#endif /* CONFIG_ACPI_NUMA */
+
static void acpi_table_taint(struct acpi_table_header *table)
{
pr_warn(PREFIX
diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
index f5549b5..1d94f89 100644
--- a/include/acpi/acpixf.h
+++ b/include/acpi/acpixf.h
@@ -184,6 +184,10 @@ acpi_status acpi_find_root_pointer(acpi_size *rsdp_address);
acpi_status acpi_unload_table_id(acpi_owner_id id);

acpi_status
+acpi_get_table_desc(char *signature,
+ struct acpi_table_desc *out_desc);
+
+acpi_status
acpi_get_table_header(acpi_string signature,
u32 instance, struct acpi_table_header *out_table_header);

diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 17155bc..6fa7543 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -97,6 +97,10 @@ static inline phys_addr_t early_acpi_override_srat(void)
}
#endif /* CONFIG_ACPI_INITRD_TABLE_OVERRIDE */

+#ifdef CONFIG_ACPI_NUMA
+phys_addr_t early_acpi_firmware_srat(void);
+#endif /* CONFIG_ACPI_NUMA */
+
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);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 48964bf..4ccffe6 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -107,8 +107,12 @@ void __init find_hotpluggable_memory(void)

/* Try to find if SRAT is overridden */
srat_paddr = early_acpi_override_srat();
- if (!srat_paddr)
- return;
+ if (!srat_paddr) {
+ /* Try to find SRAT from firmware if it wasn't overridden */
+ srat_paddr = early_acpi_firmware_srat();
+ if (!srat_paddr)
+ return;
+ }

/* Will parse SRAT and find out hotpluggable memory here */
}
--
1.7.1