[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>
diff --git a/arch/arm/mm/proc-arm925.S b/arch/arm/mm/proc-arm925.S
index 224ce22..8d47c9f 100644
--- a/arch/arm/mm/proc-arm925.S
+++ b/arch/arm/mm/proc-arm925.S
@@ -9,6 +9,8 @@
* Update for Linux-2.6 and cache flush improvements
* Copyright (C) 2004 Nokia Corporation by Tony Lindgren <tony@atomide.com>
*
+ * hacked for non-paged-MM by Hyok S. Choi, 2004.
+ *
* 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
* the Free Software Foundation; either version 2 of the License, or
@@ -122,7 +124,9 @@
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........
@@ -369,6 +373,7 @@
*/
.align 5
ENTRY(cpu_arm925_switch_mm)
+#ifdef CONFIG_MMU
mov ip, #0
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
@@ -383,6 +388,7 @@
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
/*
@@ -392,6 +398,7 @@
*/
.align 5
ENTRY(cpu_arm925_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
@@ -420,6 +427,7 @@
mcr p15, 0, r0, c7, c10, 1 @ clean D entry
#endif
mcr p15, 0, r0, c7, c10, 4 @ drain WB
+#endif /* CONFIG_MMU */
mov pc, lr
__INIT
@@ -438,7 +446,9 @@
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
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
mov r0, #4 @ disable write-back on caches explicitly