[PATCH x86 for review II] [35/39] x86_64: Don't reserve ROMs

Andi Kleen
2007-02-12T07:42:32Z

We trust the e820 table, so explicitely reserving ROMs shouldn't
be needed.

Signed-off-by: Andi Kleen <ak@suse.de>

---
arch/x86_64/kernel/setup.c | 130 ---------------------------------------------
1 file changed, 2 insertions(+), 128 deletions(-)

Index: linux/arch/x86_64/kernel/setup.c
===================================================================
--- linux.orig/arch/x86_64/kernel/setup.c
+++ linux/arch/x86_64/kernel/setup.c
@@ -138,128 +138,6 @@ struct resource code_resource = {
.flags = IORESOURCE_RAM,
};

-#define IORESOURCE_ROM (IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM)
-
-static struct resource system_rom_resource = {
- .name = "System ROM",
- .start = 0xf0000,
- .end = 0xfffff,
- .flags = IORESOURCE_ROM,
-};
-
-static struct resource extension_rom_resource = {
- .name = "Extension ROM",
- .start = 0xe0000,
- .end = 0xeffff,
- .flags = IORESOURCE_ROM,
-};
-
-static struct resource adapter_rom_resources[] = {
- { .name = "Adapter ROM", .start = 0xc8000, .end = 0,
- .flags = IORESOURCE_ROM },
- { .name = "Adapter ROM", .start = 0, .end = 0,
- .flags = IORESOURCE_ROM },
- { .name = "Adapter ROM", .start = 0, .end = 0,
- .flags = IORESOURCE_ROM },
- { .name = "Adapter ROM", .start = 0, .end = 0,
- .flags = IORESOURCE_ROM },
- { .name = "Adapter ROM", .start = 0, .end = 0,
- .flags = IORESOURCE_ROM },
- { .name = "Adapter ROM", .start = 0, .end = 0,
- .flags = IORESOURCE_ROM }
-};
-
-static struct resource video_rom_resource = {
- .name = "Video ROM",
- .start = 0xc0000,
- .end = 0xc7fff,
- .flags = IORESOURCE_ROM,
-};
-
-static struct resource video_ram_resource = {
- .name = "Video RAM area",
- .start = 0xa0000,
- .end = 0xbffff,
- .flags = IORESOURCE_RAM,
-};
-
-#define romsignature(x) (*(unsigned short *)(x) == 0xaa55)
-
-static int __init romchecksum(unsigned char *rom, unsigned long length)
-{
- unsigned char *p, sum = 0;
-
- for (p = rom; p < rom + length; p++)
- sum += *p;
- return sum == 0;
-}
-
-static void __init probe_roms(void)
-{
- unsigned long start, length, upper;
- unsigned char *rom;
- int i;
-
- /* video rom */
- upper = adapter_rom_resources[0].start;
- for (start = video_rom_resource.start; start < upper; start += 2048) {
- rom = isa_bus_to_virt(start);
- if (!romsignature(rom))
- continue;
-
- video_rom_resource.start = start;
-
- /* 0 < length <= 0x7f * 512, historically */
- length = rom[2] * 512;
-
- /* if checksum okay, trust length byte */
- if (length && romchecksum(rom, length))
- video_rom_resource.end = start + length - 1;
-
- request_resource(&iomem_resource, &video_rom_resource);
- break;
- }
-
- start = (video_rom_resource.end + 1 + 2047) & ~2047UL;
- if (start < upper)
- start = upper;
-
- /* system rom */
- request_resource(&iomem_resource, &system_rom_resource);
- upper = system_rom_resource.start;
-
- /* check for extension rom (ignore length byte!) */
- rom = isa_bus_to_virt(extension_rom_resource.start);
- if (romsignature(rom)) {
- length = extension_rom_resource.end - extension_rom_resource.start + 1;
- if (romchecksum(rom, length)) {
- request_resource(&iomem_resource, &extension_rom_resource);
- upper = extension_rom_resource.start;
- }
- }
-
- /* check for adapter roms on 2k boundaries */
- for (i = 0; i < ARRAY_SIZE(adapter_rom_resources) && start < upper;
- start += 2048) {
- rom = isa_bus_to_virt(start);
- if (!romsignature(rom))
- continue;
-
- /* 0 < length <= 0x7f * 512, historically */
- length = rom[2] * 512;
-
- /* but accept any length that fits if checksum okay */
- if (!length || start + length > upper || !romchecksum(rom, length))
- continue;
-
- adapter_rom_resources[i].start = start;
- adapter_rom_resources[i].end = start + length - 1;
- request_resource(&iomem_resource, &adapter_rom_resources[i]);
-
- start = adapter_rom_resources[i++].end & ~2047UL;
- }
-}
-
#ifdef CONFIG_PROC_VMCORE
/* elfcorehdr= specifies the location of elf core header
* stored by the crashed kernel. This option will be passed
@@ -524,15 +402,11 @@ void __init setup_arch(char **cmdline_p)
init_apic_mappings();

/*
- * Request address space for all standard RAM and ROM resources
- * and also for regions reported as reserved by the e820.
- */
- probe_roms();
+ * We trust e820 completely. No explicit ROM probing in memory.
+ */
e820_reserve_resources();
e820_mark_nosave_regions();

- request_resource(&iomem_resource, &video_ram_resource);
-
{
unsigned i;
/* request I/O space for devices used on all i[345]86 PCs */