diff options
Diffstat (limited to 'arch/x86/include/asm/highmem.h')
| -rw-r--r-- | arch/x86/include/asm/highmem.h | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/arch/x86/include/asm/highmem.h b/arch/x86/include/asm/highmem.h index 302a323b3f67..04e9d023168f 100644 --- a/arch/x86/include/asm/highmem.h +++ b/arch/x86/include/asm/highmem.h @@ -38,17 +38,20 @@ extern unsigned long highstart_pfn, highend_pfn; /* * Ordering is: * - * FIXADDR_TOP - * fixed_addresses - * FIXADDR_START - * temp fixed addresses - * FIXADDR_BOOT_START - * Persistent kmap area - * PKMAP_BASE - * VMALLOC_END - * Vmalloc area - * VMALLOC_START - * high_memory + * high memory on: high_memory off: + * FIXADDR_TOP FIXADDR_TOP + * fixed addresses fixed addresses + * FIXADDR_START FIXADDR_START + * temp fixed addresses/persistent kmap area VMALLOC_END + * PKMAP_BASE temp fixed addresses/vmalloc area + * VMALLOC_END VMALLOC_START + * vmalloc area high_memory + * VMALLOC_START + * high_memory + * + * The temp fixed area is only used during boot for early_ioremap(), and + * it is unused when the ioremap() is functional. vmalloc/pkmap area become + * available after early boot so the temp fixed area is available for re-use. */ #define LAST_PKMAP_MASK (LAST_PKMAP-1) #define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) |