From b1c931e39327ef121797927d4b3198d370e75b9b Mon Sep 17 00:00:00 2001 From: "Eric W. Biderman" Date: Sun, 15 Jul 2007 23:37:28 -0700 Subject: x86: initial fixmap support Needed to get fixed virtual address for USB debug and earlycon with mmio. Signed-off-by: Eric W. Biderman Signed-off-by: Yinghai Lu Cc: Andi Kleen Cc: Bjorn Helgaas Cc: Russell King Cc: Gerd Hoffmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/head.S | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'arch/x86_64') diff --git a/arch/x86_64/kernel/head.S b/arch/x86_64/kernel/head.S index 1fab487dee86..941c84baecc8 100644 --- a/arch/x86_64/kernel/head.S +++ b/arch/x86_64/kernel/head.S @@ -73,7 +73,11 @@ startup_64: addq %rbp, init_level4_pgt + (511*8)(%rip) addq %rbp, level3_ident_pgt + 0(%rip) + addq %rbp, level3_kernel_pgt + (510*8)(%rip) + addq %rbp, level3_kernel_pgt + (511*8)(%rip) + + addq %rbp, level2_fixmap_pgt + (506*8)(%rip) /* Add an Identity mapping if I am above 1G */ leaq _text(%rip), %rdi @@ -314,7 +318,16 @@ NEXT_PAGE(level3_kernel_pgt) .fill 510,8,0 /* (2^48-(2*1024*1024*1024)-((2^39)*511))/(2^30) = 510 */ .quad level2_kernel_pgt - __START_KERNEL_map + _KERNPG_TABLE - .fill 1,8,0 + .quad level2_fixmap_pgt - __START_KERNEL_map + _PAGE_TABLE + +NEXT_PAGE(level2_fixmap_pgt) + .fill 506,8,0 + .quad level1_fixmap_pgt - __START_KERNEL_map + _PAGE_TABLE + /* 8MB reserved for vsyscalls + a 2MB hole = 4 + 1 entries */ + .fill 5,8,0 + +NEXT_PAGE(level1_fixmap_pgt) + .fill 512,8,0 NEXT_PAGE(level2_ident_pgt) /* Since I easily can, map the first 1G. -- cgit v1.2.3-58-ga151