[ARM] 3061/1: cleanup the XIP link address mess

Patch from Nicolas Pitre

Since vmlinux.lds.S is preprocessed, we can use the defines already
present in asm/memory.h (allowed by patch #3060) for the XIP kernel link
address instead of relying on a duplicated Makefile hardcoded value, and
also get rid of its dependency on awk to handle it at the same time.

While at it let's clean XIP stuff even further and make things clearer
in head.S with a nice code reduction.

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

1 files changed, 15 insertions, 39 deletions

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index dd5d0f07d358..8d8748407cbe 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -34,52 +34,28 @@
 #define MACHINFO_PGOFFIO        12
 #define MACHINFO_NAME           16
 
-#ifndef CONFIG_XIP_KERNEL
 /*
- * We place the page tables 16K below TEXTADDR.  Therefore, we must make sure
- * that TEXTADDR is correctly set.  Currently, we expect the least significant
- * 16 bits to be 0x8000, but we could probably relax this restriction to
- * TEXTADDR >= PAGE_OFFSET + 0x4000
- *
- * Note that swapper_pg_dir is the virtual address of the page tables, and
- * pgtbl gives us a position-independent reference to these tables.  We can
- * do this because stext == TEXTADDR
+ * swapper_pg_dir is the virtual address of the initial page table.
+ * We place the page tables 16K below KERNEL_RAM_ADDR.  Therefore, we must
+ * make sure that KERNEL_RAM_ADDR is correctly set.  Currently, we expect
+ * the least significant 16 bits to be 0x8000, but we could probably
+ * relax this restriction to KERNEL_RAM_ADDR >= PAGE_OFFSET + 0x4000.
  */
-#if (TEXTADDR & 0xffff) != 0x8000
-#error TEXTADDR must start at 0xXXXX8000
+#if (KERNEL_RAM_ADDR & 0xffff) != 0x8000
+#error KERNEL_RAM_ADDR must start at 0xXXXX8000
 #endif
 
         .globl  swapper_pg_dir
-        .equ    swapper_pg_dir, TEXTADDR - 0x4000
+        .equ    swapper_pg_dir, KERNEL_RAM_ADDR - 0x4000
 
-        .macro  pgtbl, rd, phys
-        adr     \rd, stext
-        sub     \rd, \rd, #0x4000
+        .macro  pgtbl, rd
+        ldr     \rd, =(__virt_to_phys(KERNEL_RAM_ADDR - 0x4000))
         .endm
-#else
-/*
- * XIP Kernel:
- *
- * We place the page tables 16K below DATAADDR.  Therefore, we must make sure
- * that DATAADDR is correctly set.  Currently, we expect the least significant
- * 16 bits to be 0x8000, but we could probably relax this restriction to
- * DATAADDR >= PAGE_OFFSET + 0x4000
- *
- * Note that pgtbl is meant to return the physical address of swapper_pg_dir.
- * We can't make it relative to the kernel position in this case since
- * the kernel can physically be anywhere.
- */
-#if (DATAADDR & 0xffff) != 0x8000
-#error DATAADDR must start at 0xXXXX8000
-#endif
-
-        .globl  swapper_pg_dir
-        .equ    swapper_pg_dir, DATAADDR - 0x4000
 
-        .macro  pgtbl, rd, phys
-        ldr     \rd, =((DATAADDR - 0x4000) - PAGE_OFFSET)
-        add     \rd, \rd, \phys
-        .endm
+#ifdef CONFIG_XIP_KERNEL
+#define TEXTADDR  XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR)
+#else
+#define TEXTADDR  KERNEL_RAM_ADDR
 #endif
 
 /*
@@ -280,7 +256,7 @@ __turn_mmu_on:
         .type   __create_page_tables, %function
 __create_page_tables:
         ldr     r5, [r8, #MACHINFO_PHYSRAM]     @ physram
-        pgtbl   r4, r5                          @ page table address
+        pgtbl   r4                              @ page table address
 
         /*
          * Clear the 16K level 1 swapper page table