[ARM] 4226/1: initial .data and .bss mappings of XIP kernel should be TEXT_OFFSET

 aware

Since TEXT_OFFSET is meant to determine RAM location for kernel use,
itshould affect .data and .bss initial mapping in the XIP case.
Otherwise a XIP kernel would crash if TEXT_OFFSET gets somewhat larger
than 2MB.

Corresponding code is also moved up a bit to be near the similar .text
mapping code making the whole a bit more straight forward to understand.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index c5f0c52..66db0a9 100644 (file)
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -252,6 +252,23 @@ __create_page_tables:
        strls   r3, [r0], #4
        bls     1b
 
+#ifdef CONFIG_XIP_KERNEL
+       /*
+        * Map some ram to cover our .data and .bss areas.
+        */
+       orr     r3, r7, #(KERNEL_RAM_PADDR & 0xff000000)
+       orr     r3, r3, #(KERNEL_RAM_PADDR & 0x00f00000)
+       add     r0, r4,  #(KERNEL_RAM_VADDR & 0xff000000) >> 18
+       str     r3, [r0, #(KERNEL_RAM_VADDR & 0x00f00000) >> 18]!
+       ldr     r6, =(_end - 1)
+       add     r0, r0, #4
+       add     r6, r4, r6, lsr #18
+1:     cmp     r0, r6
+       add     r3, r3, #1 << 20
+       strls   r3, [r0], #4
+       bls     1b
+#endif
+
        /*
         * Then map first 1MB of ram in case it contains our boot params.
         */
@@ -260,22 +277,6 @@ __create_page_tables:
        orr     r6, r6, #(PHYS_OFFSET & 0x00e00000)
        str     r6, [r0]
 
-#ifdef CONFIG_XIP_KERNEL
-       /*
-        * Map some ram to cover our .data and .bss areas.
-        * Mapping 3MB should be plenty.
-        */
-       sub     r3, r4, #PHYS_OFFSET
-       mov     r3, r3, lsr #20
-       add     r0, r0, r3, lsl #2
-       add     r6, r6, r3, lsl #20
-       str     r6, [r0], #4
-       add     r6, r6, #(1 << 20)
-       str     r6, [r0], #4
-       add     r6, r6, #(1 << 20)
-       str     r6, [r0]
-#endif
-
 #ifdef CONFIG_DEBUG_LL
        ldr     r7, [r10, #PROCINFO_IO_MMUFLAGS] @ io_mmuflags
        /*