diff options
| author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2018-01-10 19:40:15 +0200 |
|---|---|---|
| committer | Bin Meng <bmeng.cn@gmail.com> | 2018-01-30 14:29:07 +0800 |
| commit | 3469bf4274540d1491d58e878a9edc0bdcba17ac (patch) | |
| tree | f174ac3c22a5d8535cf74ef86642a39dd8183155 /arch/x86/lib/acpi_table.c | |
| parent | 378960d8c2c72c5b6be2a6cd7787cab8c3ba5abc (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.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c index 7b33cd371eb..d3e5d2e104d 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 */ |