ARM: mach-davinci: make DAVINCI_UART_INFO into a relative offset

This is the first step to remove PLAT_PHYS_OFFSET usage from the debug
UART code.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>

3 files changed, 18 insertions, 13 deletions

diff --git a/arch/arm/mach-davinci/include/mach/debug-macro.S b/arch/arm/mach-davinci/include/mach/debug-macro.S
index 3cf4c1b4f33a..45fff2c61f48 100644
--- a/arch/arm/mach-davinci/include/mach/debug-macro.S
+++ b/arch/arm/mach-davinci/include/mach/debug-macro.S
@@ -50,21 +50,20 @@ davinci_uart_virt:	.word	0
                 mrc     p15, 0, \rp, c1, c0
                 tst     \rp, #1                 @ MMU enabled?
 
-                /* Copy uart phys address from decompressor uart info */
+                and     \rp, pc, #0xff000000
+                ldr     \rv, =DAVINCI_UART_INFO_OFS
+                add     \rp, \rp, \rv
+
                 ldreq   \rv, =davinci_uart_v2p(davinci_uart_phys)
                 ldrne   \rv, =davinci_uart_phys
-                ldreq   \rp, =DAVINCI_UART_INFO
-                ldrne   \rp, =davinci_uart_p2v(DAVINCI_UART_INFO)
-                ldr     \rp, [\rp, #0]
-                str     \rp, [\rv]
+
+                /* Copy uart phys address from decompressor uart info */
+                ldr     \tmp, [\rp, #0]
+                str     \tmp, [\rv, #0]
 
                 /* Copy uart virt address from decompressor uart info */
-                ldreq   \rv, =davinci_uart_v2p(davinci_uart_virt)
-                ldrne   \rv, =davinci_uart_virt
-                ldreq   \rp, =DAVINCI_UART_INFO
-                ldrne   \rp, =davinci_uart_p2v(DAVINCI_UART_INFO)
-                ldr     \rp, [\rp, #4]
-                str     \rp, [\rv]
+                ldr     \tmp, [\rp, #4]
+                str     \tmp, [\rv, #4]
 
                 b       10b
 99:
diff --git a/arch/arm/mach-davinci/include/mach/serial.h b/arch/arm/mach-davinci/include/mach/serial.h
index c9e6ce185a66..e347d88fef91 100644
--- a/arch/arm/mach-davinci/include/mach/serial.h
+++ b/arch/arm/mach-davinci/include/mach/serial.h
@@ -21,8 +21,9 @@
  * macros in debug-macro.S.
  *
  * This area sits just below the page tables (see arch/arm/kernel/head.S).
+ * We define it as a relative offset from start of usable RAM.
  */
-#define DAVINCI_UART_INFO       (PLAT_PHYS_OFFSET + 0x3ff8)
+#define DAVINCI_UART_INFO_OFS   0x3ff8
 
 #define DAVINCI_UART0_BASE      (IO_PHYS + 0x20000)
 #define DAVINCI_UART1_BASE      (IO_PHYS + 0x20400)
diff --git a/arch/arm/mach-davinci/include/mach/uncompress.h b/arch/arm/mach-davinci/include/mach/uncompress.h
index 78d80683cdc2..9dc7cf9664fe 100644
--- a/arch/arm/mach-davinci/include/mach/uncompress.h
+++ b/arch/arm/mach-davinci/include/mach/uncompress.h
@@ -43,7 +43,12 @@ static inline void flush(void)
 
 static inline void set_uart_info(u32 phys, void * __iomem virt)
 {
-        u32 *uart_info = (u32 *)(DAVINCI_UART_INFO);
+        /*
+         * Get address of some.bss variable and round it down
+         * a la CONFIG_AUTO_ZRELADDR.
+         */
+        u32 ram_start = (u32)&uart & 0xf8000000;
+        u32 *uart_info = (u32 *)(ram_start + DAVINCI_UART_INFO_OFS);
 
         uart = (u32 *)phys;
         uart_info[0] = phys;