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author | jhb <jhb@FreeBSD.org> | 2008-01-31 16:51:43 +0000 |
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committer | jhb <jhb@FreeBSD.org> | 2008-01-31 16:51:43 +0000 |
commit | 9c769565243961b07fe6ace665b47f5c6de6588d (patch) | |
tree | e79558f411fb99d94f5cb10284ba0d2713fa82db /sys/amd64/acpica | |
parent | 56d2c18f8e37bb0092ac85afbf4aa482b61b5be1 (diff) | |
download | FreeBSD-src-9c769565243961b07fe6ace665b47f5c6de6588d.zip FreeBSD-src-9c769565243961b07fe6ace665b47f5c6de6588d.tar.gz |
For no good reason I had assumed that ACPI table headers would be page
aligned (or at least not cross a page boundary). However, it turns out
that on at least one machine one table header does cross a page boundary.
This caused problems with the MADT early probe as it uses the crash dump
map to load ACPI tables by loading the RSDT/XSDT into pages 1 ... N and
loading the header of each ACPI table header into page 0 looking for the
MADT. However, if a table header crossed a page boundary, then page 1
would get trashed resulting in a panic. Fix this by reserving the first
2 pages for ACPI table headers (headers are less than a page in size,
so 2 pages will be sufficient) and use pages 2 .. N for the RSDT and XSDT.
Note: amd64 should probably be simplified to just use pmap_mapbios()
for all these tables which will use the direct map and not need the
crash dump hack.
MFC after: 5 days
Tested on: i386
Reported by: Pete French petefrench of ticketswitch.com
Diffstat (limited to 'sys/amd64/acpica')
-rw-r--r-- | sys/amd64/acpica/madt.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/sys/amd64/acpica/madt.c b/sys/amd64/acpica/madt.c index fcd40c8..3ed1ea7 100644 --- a/sys/amd64/acpica/madt.c +++ b/sys/amd64/acpica/madt.c @@ -109,9 +109,11 @@ static struct apic_enumerator madt_enumerator = { /* * Code to abuse the crashdump map to map in the tables for the early * probe. We cheat and make the following assumptions about how we - * use this KVA: page 0 is used to map in the first page of each table - * found via the RSDT or XSDT and pages 1 to n are used to map in the - * RSDT or XSDT. The offset is in pages; the length is in bytes. + * use this KVA: pages 0 and 1 are used to map in the header of each + * table found via the RSDT or XSDT and pages 2 to n are used to map + * in the RSDT or XSDT. We have to use 2 pages for the table headers + * in case a header spans a page boundary. The offset is in pages; + * the length is in bytes. */ static void * madt_map(vm_paddr_t pa, int offset, vm_offset_t length) @@ -232,7 +234,7 @@ madt_probe(void) printf("MADT: RSDP failed extended checksum\n"); return (ENXIO); } - xsdt = madt_map_table(rsdp->XsdtPhysicalAddress, 1, + xsdt = madt_map_table(rsdp->XsdtPhysicalAddress, 2, ACPI_SIG_XSDT); if (xsdt == NULL) { if (bootverbose) @@ -246,7 +248,7 @@ madt_probe(void) break; madt_unmap_table(xsdt); } else { - rsdt = madt_map_table(rsdp->RsdtPhysicalAddress, 1, + rsdt = madt_map_table(rsdp->RsdtPhysicalAddress, 2, ACPI_SIG_RSDT); if (rsdt == NULL) { if (bootverbose) |