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x86: acpi: Add one API to find OS wakeup vector

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This adds one API acpi_find_wakeup_vector() to locate OS wakeup
vector from the ACPI FACS table, to be used in the S3 boot path.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Stefan Roese <sr@denx.de>
This commit is contained in:
Bin Meng 2017-04-21 07:24:36 -07:00
parent 2b2d666f9c
commit e76bf38f18
3 changed files with 83 additions and 0 deletions
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10
arch/x86/include/asm/acpi_table.h
View File

@ -317,3 +317,13 @@ int acpi_create_madt_lapic_nmi(struct acpi_madt_lapic_nmi *lapic_nmi,
u32 acpi_fill_madt(u32 current);
void acpi_create_gnvs(struct acpi_global_nvs *gnvs);
ulong write_acpi_tables(ulong start);
/**
* acpi_find_wakeup_vector() - find OS installed wake up vector address
*
* This routine parses the ACPI table to locate the wake up vector installed
* by the OS previously.
*
* @return: wake up vector address installed by the OS
*/
void *acpi_find_wakeup_vector(void);

1
arch/x86/include/asm/tables.h
View File

@ -15,6 +15,7 @@
* PIRQ routing table, Multi-Processor table and ACPI table.
*/
#define ROM_TABLE_ADDR 0xf0000
#define ROM_TABLE_END 0xfffff
#define ROM_TABLE_ALIGN 1024

72
arch/x86/lib/acpi_table.c
View File

@ -438,3 +438,75 @@ ulong write_acpi_tables(ulong start)
return current;
}
static struct acpi_rsdp *acpi_valid_rsdp(struct acpi_rsdp *rsdp)
{
if (strncmp((char *)rsdp, RSDP_SIG, sizeof(RSDP_SIG) - 1) != 0)
return NULL;
debug("Looking on %p for valid checksum\n", rsdp);
if (table_compute_checksum((void *)rsdp, 20) != 0)
return NULL;
debug("acpi rsdp checksum 1 passed\n");
if ((rsdp->revision > 1) &&
(table_compute_checksum((void *)rsdp, rsdp->length) != 0))
return NULL;
debug("acpi rsdp checksum 2 passed\n");
return rsdp;
}
void *acpi_find_wakeup_vector(void)
{
char *p, *end;
struct acpi_rsdp *rsdp = NULL;
struct acpi_rsdt *rsdt;
struct acpi_fadt *fadt = NULL;
struct acpi_facs *facs;
void *wake_vec;
int i;
debug("Trying to find the wakeup vector...\n");
/* Find RSDP */
for (p = (char *)ROM_TABLE_ADDR; p < (char *)ROM_TABLE_END; p += 16) {
rsdp = acpi_valid_rsdp((struct acpi_rsdp *)p);
if (rsdp)
break;
}
if (rsdp == NULL)
return NULL;
debug("RSDP found at %p\n", rsdp);
rsdt = (struct acpi_rsdt *)rsdp->rsdt_address;
end = (char *)rsdt + rsdt->header.length;
debug("RSDT found at %p ends at %p\n", rsdt, end);
for (i = 0; ((char *)&rsdt->entry[i]) < end; i++) {
fadt = (struct acpi_fadt *)rsdt->entry[i];
if (strncmp((char *)fadt, "FACP", 4) == 0)
break;
fadt = NULL;
}
if (fadt == NULL)
return NULL;
debug("FADT found at %p\n", fadt);
facs = (struct acpi_facs *)fadt->firmware_ctrl;
if (facs == NULL) {
debug("No FACS found, wake up from S3 not possible.\n");
return NULL;
}
debug("FACS found at %p\n", facs);
wake_vec = (void *)facs->firmware_waking_vector;
debug("OS waking vector is %p\n", wake_vec);
return wake_vec;
}