Commit-ID: e6e094e053af75cbc164e950814d3d084fb1e698
Gitweb: https://git.kernel.org/tip/e6e094e053af75cbc164e950814d3d084fb1e698
Author: Juergen Gross <jgross@xxxxxxxx>
AuthorDate: Tue, 20 Nov 2018 08:25:29 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 20 Nov 2018 09:43:11 +0100
x86/acpi, x86/boot: Take RSDP address from boot params if available
In case the RSDP address in struct boot_params is specified don't try
to find the table by searching, but take the address directly as set
by the boot loader.
Suggested-by: "H. Peter Anvin" <hpa@xxxxxxxxx>
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: boris.ostrovsky@xxxxxxxxxx
Cc: bp@xxxxxxxxx
Cc: daniel.kiper@xxxxxxxxxx
Cc: sstabellini@xxxxxxxxxx
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20181120072529.5489-3-jgross@xxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/uapi/asm/bootparam.h | 3 ++-
arch/x86/kernel/acpi/boot.c | 2 +-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
index a06cbf019744..60733f137e9a 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/arch/x86/include/uapi/asm/bootparam.h
@@ -155,7 +155,8 @@ struct boot_params {
__u8 _pad2[4]; /* 0x054 */
__u64 tboot_addr; /* 0x058 */
struct ist_info ist_info; /* 0x060 */
- __u8 _pad3[16]; /* 0x070 */
+ __u64 acpi_rsdp_addr; /* 0x070 */
+ __u8 _pad3[8]; /* 0x078 */
__u8 hd0_info[16]; /* obsolete! */ /* 0x080 */
__u8 hd1_info[16]; /* obsolete! */ /* 0x090 */
struct sys_desc_table sys_desc_table; /* obsolete! */ /* 0x0a0 */
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index fb3b1f3a5aba..06635fbca81c 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1776,5 +1776,5 @@ void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size)
u64 x86_default_get_root_pointer(void)
{
- return 0;
+ return boot_params.acpi_rsdp_addr;
}
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