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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2018-01-10 19:40:15 +0200
committerBin Meng <bmeng.cn@gmail.com>2018-01-30 14:29:07 +0800
commit3469bf4274540d1491d58e878a9edc0bdcba17ac (patch)
treef174ac3c22a5d8535cf74ef86642a39dd8183155 /arch/x86/lib/acpi_table.c
parent378960d8c2c72c5b6be2a6cd7787cab8c3ba5abc (diff)
x86: zImage: Propagate acpi_rsdp_addr to kernel via boot parameters
New field acpi_rsdp_addr, which has been introduced in boot protocol v2.14 [1], in boot parameters tells kernel the exact address of RDSP ACPI table. Knowing it increases robustness of the kernel by avoiding in some cases traversal through a part of physical memory. It will slightly reduce boot time by the same reason. [1] See Linux kernel commit 2f74cbf ("x86/boot: Add the ACPI RSDP address to struct setup_header::acpi_rdsp_addr") @ https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=2f74cbf for the details. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> [bmeng: updated the kernel commit git URL and fixed one style issue] Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Diffstat (limited to 'arch/x86/lib/acpi_table.c')
-rw-r--r--arch/x86/lib/acpi_table.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c
index 7b33cd371e..d3e5d2e104 100644
--- a/arch/x86/lib/acpi_table.c
+++ b/arch/x86/lib/acpi_table.c
@@ -20,6 +20,7 @@
#include <asm/mpspec.h>
#include <asm/tables.h>
#include <asm/arch/global_nvs.h>
+#include "acpi_table.h"
/*
* IASL compiles the dsdt entries and writes the hex values
@@ -27,6 +28,9 @@
*/
extern const unsigned char AmlCode[];
+/* ACPI RSDP address to be used in boot parameters */
+unsigned long acpi_rsdp_addr;
+
static void acpi_write_rsdp(struct acpi_rsdp *rsdp, struct acpi_rsdt *rsdt,
struct acpi_xsdt *xsdt)
{
@@ -460,6 +464,7 @@ ulong write_acpi_tables(ulong start)
debug("current = %x\n", current);
+ acpi_rsdp_addr = (unsigned long)rsdp;
debug("ACPI: done\n");
/* Don't touch ACPI hardware on HW reduced platforms */