[PATCH 4/6] ARM: mach-omap2: clean up debug-macro.S
Tony Lindgren
tony at atomide.com
Mon Sep 5 05:51:06 EDT 2011
Here's this one too updated to use 99f. Other than that:
Tested-by: Tony Lindgren <tony at atomide.com>
From: Nicolas Pitre <nico at fluxnic.net>
Date: Thu, 1 Sep 2011 22:59:11 -0400
Subject: [PATCH] ARM: mach-omap2: clean up debug-macro.S
This achieves two goals:
1) Get rid of omap_uart_v2p() and omap_uart_p2v() which were the last users
of PLAT_PHYS_OFFSET.
2) Remove the probing of the M bit in the CP15 control reg and make
the access to the .data variables completely position independent.
There is a catch though: the busyuart macro needs to know where the LSR
register is which might be at a different offset depending on the hardware.
Given that this macro is given only two registers and that one of them
must be preserved, the trick is to always pass the LSR register address
around, and deduce the base address for the THR register by masking out
the LSR offset in senduart instead.
Signed-off-by: Nicolas Pitre <nicolas.pitre at linaro.org>
diff --git a/arch/arm/mach-omap2/include/mach/debug-macro.S b/arch/arm/mach-omap2/include/mach/debug-macro.S
index d48e485..13f98e5 100644
--- a/arch/arm/mach-omap2/include/mach/debug-macro.S
+++ b/arch/arm/mach-omap2/include/mach/debug-macro.S
@@ -13,15 +13,10 @@
#include <linux/serial_reg.h>
-#include <asm/memory.h>
-
#include <plat/serial.h>
#define UART_OFFSET(addr) ((addr) & 0x00ffffff)
-#define omap_uart_v2p(x) ((x) - PAGE_OFFSET + PLAT_PHYS_OFFSET)
-#define omap_uart_p2v(x) ((x) - PLAT_PHYS_OFFSET + PAGE_OFFSET)
-
.pushsection .data
omap_uart_phys: .word 0
omap_uart_virt: .word 0
@@ -37,13 +32,13 @@ omap_uart_lsr: .word 0
.macro addruart, rp, rv, tmp
/* Use omap_uart_phys/virt if already configured */
-10: mrc p15, 0, \rp, c1, c0
- tst \rp, #1 @ MMU enabled?
- ldreq \rp, =omap_uart_v2p(omap_uart_phys) @ MMU disabled
- ldrne \rp, =omap_uart_phys @ MMU enabled
- add \rv, \rp, #4 @ omap_uart_virt
- ldr \rp, [\rp, #0]
- ldr \rv, [\rv, #0]
+10: adr \rp, 99f @ get effective addr of 99f
+ ldr \rv, [\rp] @ get absolute addr of 99f
+ sub \rv, \rv, \rp @ offset between the two
+ ldr \rp, [\rp, #4] @ abs addr of omap_uart_phys
+ sub \tmp, \rp, \rv @ make it effective
+ ldr \rp, [\tmp, #0] @ omap_uart_phys
+ ldr \rv, [\tmp, #4] @ omap_uart_virt
cmp \rp, #0 @ is port configured?
cmpne \rv, #0
bne 100f @ already configured
@@ -105,50 +100,47 @@ omap_uart_lsr: .word 0
b 98f
83: mov \rp, #UART_OFFSET(TI816X_UART3_BASE)
b 98f
+
95: ldr \rp, =ZOOM_UART_BASE
- mrc p15, 0, \rv, c1, c0
- tst \rv, #1 @ MMU enabled?
- ldreq \rv, =omap_uart_v2p(omap_uart_phys) @ MMU disabled
- ldrne \rv, =omap_uart_phys @ MMU enabled
- str \rp, [\rv, #0]
+ str \rp, [\tmp, #0] @ omap_uart_phys
ldr \rp, =ZOOM_UART_VIRT
- add \rv, \rv, #4 @ omap_uart_virt
- str \rp, [\rv, #0]
+ str \rp, [\tmp, #4] @ omap_uart_virt
mov \rp, #(UART_LSR << ZOOM_PORT_SHIFT)
- add \rv, \rv, #4 @ omap_uart_lsr
- str \rp, [\rv, #0]
+ str \rp, [\tmp, #8] @ omap_uart_lsr
b 10b
/* Store both phys and virt address for the uart */
98: add \rp, \rp, #0x48000000 @ phys base
- mrc p15, 0, \rv, c1, c0
- tst \rv, #1 @ MMU enabled?
- ldreq \rv, =omap_uart_v2p(omap_uart_phys) @ MMU disabled
- ldrne \rv, =omap_uart_phys @ MMU enabled
- str \rp, [\rv, #0]
+ str \rp, [\tmp, #0] @ omap_uart_phys
sub \rp, \rp, #0x48000000 @ phys base
add \rp, \rp, #0xfa000000 @ virt base
- add \rv, \rv, #4 @ omap_uart_virt
- str \rp, [\rv, #0]
+ str \rp, [\tmp, #4] @ omap_uart_virt
mov \rp, #(UART_LSR << OMAP_PORT_SHIFT)
- add \rv, \rv, #4 @ omap_uart_lsr
- str \rp, [\rv, #0]
+ str \rp, [\tmp, #8] @ omap_uart_lsr
b 10b
-100:
+
+ .align
+99: .word .
+ .word omap_uart_phys
+ .ltorg
+
+100: /* Pass the UART_LSR reg address */
+ ldr \tmp, [\tmp, #8] @ omap_uart_lsr
+ add \rp, \rp, \tmp
+ add \rv, \rv, \tmp
.endm
.macro senduart,rd,rx
- strb \rd, [\rx]
+ orr \rd, \rd, \rx, lsl #24 @ preserve LSR reg offset
+ bic \rx, \rx, #0xff @ get base (THR) reg address
+ strb \rd, [\rx] @ send lower byte of rd
+ orr \rx, \rx, \rd, lsr #24 @ restore original rx (LSR)
+ bic \rd, \rd, #(0xff << 24) @ restore original rd
.endm
.macro busyuart,rd,rx
-1001: mrc p15, 0, \rd, c1, c0
- tst \rd, #1 @ MMU enabled?
- ldreq \rd, =omap_uart_v2p(omap_uart_lsr) @ MMU disabled
- ldrne \rd, =omap_uart_lsr @ MMU enabled
- ldr \rd, [\rd, #0]
- ldrb \rd, [\rx, \rd]
+1001: ldrb \rd, [\rx] @ rx contains UART_LSR address
and \rd, \rd, #(UART_LSR_TEMT | UART_LSR_THRE)
teq \rd, #(UART_LSR_TEMT | UART_LSR_THRE)
bne 1001b
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