[ARM] Feroceon: Feroceon-specific WA-cache compatible {copy,clear}_user_page()

This patch implements a set of Feroceon-specific
{copy,clear}_user_page() routines that perform more optimally than
the generic implementations.  This also deals with write-allocate
caches (Feroceon can run L1 D in WA mode) which otherwise prevents
Linux from booting.

[nico: optimized the code even further]

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Tested-by: Sylver Bruneau <sylver.bruneau@googlemail.com>
Tested-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>

1 files changed, 95 insertions, 0 deletions

diff --git a/arch/arm/mm/copypage-feroceon.S b/arch/arm/mm/copypage-feroceon.S
new file mode 100644
index 000000000000..7eb0d320d240
--- /dev/null
+++ b/arch/arm/mm/copypage-feroceon.S
@@ -0,0 +1,95 @@
+/*
+ *  linux/arch/arm/lib/copypage-feroceon.S
+ *
+ *  Copyright (C) 2008 Marvell Semiconductors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This handles copy_user_page and clear_user_page on Feroceon
+ * more optimally than the generic implementations.
+ */
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/asm-offsets.h>
+
+        .text
+        .align  5
+
+ENTRY(feroceon_copy_user_page)
+        stmfd   sp!, {r4-r9, lr}
+        mov     ip, #PAGE_SZ
+1:      mov     lr, r1
+        ldmia   r1!, {r2 - r9}
+        pld     [lr, #32]
+        pld     [lr, #64]
+        pld     [lr, #96]
+        pld     [lr, #128]
+        pld     [lr, #160]
+        pld     [lr, #192]
+        pld     [lr, #224]
+        stmia   r0, {r2 - r9}
+        ldmia   r1!, {r2 - r9}
+        mcr     p15, 0, r0, c7, c14, 1          @ clean and invalidate D line
+        add     r0, r0, #32
+        stmia   r0, {r2 - r9}
+        ldmia   r1!, {r2 - r9}
+        mcr     p15, 0, r0, c7, c14, 1          @ clean and invalidate D line
+        add     r0, r0, #32
+        stmia   r0, {r2 - r9}
+        ldmia   r1!, {r2 - r9}
+        mcr     p15, 0, r0, c7, c14, 1          @ clean and invalidate D line
+        add     r0, r0, #32
+        stmia   r0, {r2 - r9}
+        ldmia   r1!, {r2 - r9}
+        mcr     p15, 0, r0, c7, c14, 1          @ clean and invalidate D line
+        add     r0, r0, #32
+        stmia   r0, {r2 - r9}
+        ldmia   r1!, {r2 - r9}
+        mcr     p15, 0, r0, c7, c14, 1          @ clean and invalidate D line
+        add     r0, r0, #32
+        stmia   r0, {r2 - r9}
+        ldmia   r1!, {r2 - r9}
+        mcr     p15, 0, r0, c7, c14, 1          @ clean and invalidate D line
+        add     r0, r0, #32
+        stmia   r0, {r2 - r9}
+        ldmia   r1!, {r2 - r9}
+        mcr     p15, 0, r0, c7, c14, 1          @ clean and invalidate D line
+        add     r0, r0, #32
+        stmia   r0, {r2 - r9}
+        subs    ip, ip, #(32 * 8)
+        mcr     p15, 0, r0, c7, c14, 1          @ clean and invalidate D line
+        add     r0, r0, #32
+        bne     1b
+        mcr     p15, 0, ip, c7, c10, 4          @ drain WB
+        ldmfd   sp!, {r4-r9, pc}
+
+        .align  5
+
+ENTRY(feroceon_clear_user_page)
+        stmfd   sp!, {r4-r7, lr}
+        mov     r1, #PAGE_SZ/32
+        mov     r2, #0
+        mov     r3, #0
+        mov     r4, #0
+        mov     r5, #0
+        mov     r6, #0
+        mov     r7, #0
+        mov     ip, #0
+        mov     lr, #0
+1:      stmia   r0, {r2-r7, ip, lr}
+        subs    r1, r1, #1
+        mcr     p15, 0, r0, c7, c14, 1          @ clean and invalidate D line
+        add     r0, r0, #32
+        bne     1b
+        mcr     p15, 0, r1, c7, c10, 4          @ drain WB
+        ldmfd   sp!, {r4-r7, pc}
+
+        __INITDATA
+
+        .type   feroceon_user_fns, #object
+ENTRY(feroceon_user_fns)
+        .long   feroceon_clear_user_page
+        .long   feroceon_copy_user_page
+        .size   feroceon_user_fns, . - feroceon_user_fns