[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>

1 files changed, 17 insertions, 16 deletions

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index c5f0c52660b2..66db0a9bf0bc 100644
--- 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
         /*