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authorHyok S. Choi <hyok.choi@samsung.com>2006-06-28 15:10:01 +0200
committerRussell King <rmk+kernel@arm.linux.org.uk>2006-06-28 18:59:56 +0200
commitd090dddaba7c8da6401bb259340dce05ca32f564 (patch)
treec35d9e22dc09d40144b4a672962269ff60c9ad07 /arch/arm/mm/proc-arm920.S
parent[ARM] nommu: prevent Xscale-based machines being selected (diff)
downloadlinux-d090dddaba7c8da6401bb259340dce05ca32f564.tar.xz
linux-d090dddaba7c8da6401bb259340dce05ca32f564.zip
[ARM] nommu: Initial uCLinux support for MMU-based CPUs
In noMMU mode, various of functions which are defined in mm/proc-*.S is not valid or needed to be avoided. i.g. switch_mm is not needed, just returns and this makes the I & D caches are valid which shows great improvement of performance including task switching and IPC. Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/proc-arm920.S')
-rw-r--r--arch/arm/mm/proc-arm920.S9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/arm/mm/proc-arm920.S b/arch/arm/mm/proc-arm920.S
index a17f79e0199c..31dc839ba07c 100644
--- a/arch/arm/mm/proc-arm920.S
+++ b/arch/arm/mm/proc-arm920.S
@@ -3,6 +3,7 @@
*
* Copyright (C) 1999,2000 ARM Limited
* Copyright (C) 2000 Deep Blue Solutions Ltd.
+ * hacked for non-paged-MM by Hyok S. Choi, 2003.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -97,7 +98,9 @@ ENTRY(cpu_arm920_reset)
mov ip, #0
mcr p15, 0, ip, c7, c7, 0 @ invalidate I,D caches
mcr p15, 0, ip, c7, c10, 4 @ drain WB
+#ifdef CONFIG_MMU
mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs
+#endif
mrc p15, 0, ip, c1, c0, 0 @ ctrl register
bic ip, ip, #0x000f @ ............wcam
bic ip, ip, #0x1100 @ ...i...s........
@@ -317,6 +320,7 @@ ENTRY(cpu_arm920_dcache_clean_area)
*/
.align 5
ENTRY(cpu_arm920_switch_mm)
+#ifdef CONFIG_MMU
mov ip, #0
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
@@ -337,6 +341,7 @@ ENTRY(cpu_arm920_switch_mm)
mcr p15, 0, ip, c7, c10, 4 @ drain WB
mcr p15, 0, r0, c2, c0, 0 @ load page table pointer
mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs
+#endif
mov pc, lr
/*
@@ -346,6 +351,7 @@ ENTRY(cpu_arm920_switch_mm)
*/
.align 5
ENTRY(cpu_arm920_set_pte)
+#ifdef CONFIG_MMU
str r1, [r0], #-2048 @ linux version
eor r1, r1, #L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_WRITE | L_PTE_DIRTY
@@ -372,6 +378,7 @@ ENTRY(cpu_arm920_set_pte)
mov r0, r0
mcr p15, 0, r0, c7, c10, 1 @ clean D entry
mcr p15, 0, r0, c7, c10, 4 @ drain WB
+#endif /* CONFIG_MMU */
mov pc, lr
__INIT
@@ -381,7 +388,9 @@ __arm920_setup:
mov r0, #0
mcr p15, 0, r0, c7, c7 @ invalidate I,D caches on v4
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer on v4
+#ifdef CONFIG_MMU
mcr p15, 0, r0, c8, c7 @ invalidate I,D TLBs on v4
+#endif
mrc p15, 0, r0, c1, c0 @ get control register v4
ldr r5, arm920_cr1_clear
bic r0, r0, r5