x86: initial fixmap support

Needed to get fixed virtual address for USB debug and earlycon with mmio.

Signed-off-by: Eric W. Biderman <ebiderman@xmisson.com>
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Gerd Hoffmann <kraxel@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/i386/kernel/head.S b/arch/i386/kernel/head.S
index f74dfc419b56739f3cc7e854271f5106ef701911..82714668d43bb566ffbc56148bfa9e166d6081db 100644 (file)
--- a/arch/i386/kernel/head.S
+++ b/arch/i386/kernel/head.S
@@ -168,6 +168,12 @@ page_pde_offset = (__PAGE_OFFSET >> 20);
 .section .init.text,"ax",@progbits
 #endif
 
+       /* Do an early initialization of the fixmap area */
+       movl $(swapper_pg_dir - __PAGE_OFFSET), %edx
+       movl $(swapper_pg_pmd - __PAGE_OFFSET), %eax
+       addl $0x007, %eax                       /* 0x007 = PRESENT+RW+USER */
+       movl %eax, 4092(%edx)
+
 #ifdef CONFIG_SMP
 ENTRY(startup_32_smp)
        cld
@@ -507,6 +513,8 @@ ENTRY(_stext)
 .section ".bss.page_aligned","w"
 ENTRY(swapper_pg_dir)
        .fill 1024,4,0
+ENTRY(swapper_pg_pmd)
+       .fill 1024,4,0
 ENTRY(empty_zero_page)
        .fill 4096,1,0
 

diff --git a/arch/x86_64/kernel/head.S b/arch/x86_64/kernel/head.S
index 1fab487dee86d56dcf01f8a4976a7fdff2482c31..941c84baecc8da3fc4496d912216760a083e034a 100644 (file)
--- 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.