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authorRussell King <rmk@dyn-67.arm.linux.org.uk>2005-06-08 10:28:24 -0400
committerRussell King <rmk@dyn-67.arm.linux.org.uk>2005-06-08 10:28:24 -0400
commitf8f98a9335db4a7d6285b785180fad720bf22864 (patch)
tree201cf5ce682812b0ed15544269930c0d45e1a42f /arch
parent17d82fcc6a15887b7138d35802ab8fc5f249794f (diff)
[PATCH] ARM: Fix Xscale copy_page implementation
The ARM copypage changes in 2.6.12-rc4-git1 removed the preempt locking from the copypage functions which broke the XScale implementation. This patch fixes the locking on XScale and removes the now unneeded minicache code. Signed-off-by: Russell King <rmk@arm.linux.org.uk> Checked-by: Richard Purdie
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/mm/Kconfig7
-rw-r--r--arch/arm/mm/Makefile2
-rw-r--r--arch/arm/mm/copypage-xscale.S113
-rw-r--r--arch/arm/mm/copypage-xscale.c131
-rw-r--r--arch/arm/mm/minicache.c73
5 files changed, 131 insertions, 195 deletions
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 48bac7da8c70..ade0e2222f59 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -228,7 +228,6 @@ config CPU_SA1100
228 select CPU_CACHE_V4WB 228 select CPU_CACHE_V4WB
229 select CPU_CACHE_VIVT 229 select CPU_CACHE_VIVT
230 select CPU_TLB_V4WB 230 select CPU_TLB_V4WB
231 select CPU_MINICACHE
232 231
233# XScale 232# XScale
234config CPU_XSCALE 233config CPU_XSCALE
@@ -239,7 +238,6 @@ config CPU_XSCALE
239 select CPU_ABRT_EV5T 238 select CPU_ABRT_EV5T
240 select CPU_CACHE_VIVT 239 select CPU_CACHE_VIVT
241 select CPU_TLB_V4WBI 240 select CPU_TLB_V4WBI
242 select CPU_MINICACHE
243 241
244# ARMv6 242# ARMv6
245config CPU_V6 243config CPU_V6
@@ -345,11 +343,6 @@ config CPU_TLB_V4WBI
345config CPU_TLB_V6 343config CPU_TLB_V6
346 bool 344 bool
347 345
348config CPU_MINICACHE
349 bool
350 help
351 Processor has a minicache.
352
353comment "Processor Features" 346comment "Processor Features"
354 347
355config ARM_THUMB 348config ARM_THUMB
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index ccf316c11e02..59f47d4c2dfe 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -31,8 +31,6 @@ obj-$(CONFIG_CPU_COPY_V6) += copypage-v6.o mmu.o
31obj-$(CONFIG_CPU_SA1100) += copypage-v4mc.o 31obj-$(CONFIG_CPU_SA1100) += copypage-v4mc.o
32obj-$(CONFIG_CPU_XSCALE) += copypage-xscale.o 32obj-$(CONFIG_CPU_XSCALE) += copypage-xscale.o
33 33
34obj-$(CONFIG_CPU_MINICACHE) += minicache.o
35
36obj-$(CONFIG_CPU_TLB_V3) += tlb-v3.o 34obj-$(CONFIG_CPU_TLB_V3) += tlb-v3.o
37obj-$(CONFIG_CPU_TLB_V4WT) += tlb-v4.o 35obj-$(CONFIG_CPU_TLB_V4WT) += tlb-v4.o
38obj-$(CONFIG_CPU_TLB_V4WB) += tlb-v4wb.o 36obj-$(CONFIG_CPU_TLB_V4WB) += tlb-v4wb.o
diff --git a/arch/arm/mm/copypage-xscale.S b/arch/arm/mm/copypage-xscale.S
deleted file mode 100644
index bb277316ef52..000000000000
--- a/arch/arm/mm/copypage-xscale.S
+++ /dev/null
@@ -1,113 +0,0 @@
1/*
2 * linux/arch/arm/lib/copypage-xscale.S
3 *
4 * Copyright (C) 2001 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/linkage.h>
11#include <linux/init.h>
12#include <asm/constants.h>
13
14/*
15 * General note:
16 * We don't really want write-allocate cache behaviour for these functions
17 * since that will just eat through 8K of the cache.
18 */
19
20 .text
21 .align 5
22/*
23 * XScale optimised copy_user_page
24 * r0 = destination
25 * r1 = source
26 * r2 = virtual user address of ultimate destination page
27 *
28 * The source page may have some clean entries in the cache already, but we
29 * can safely ignore them - break_cow() will flush them out of the cache
30 * if we eventually end up using our copied page.
31 *
32 * What we could do is use the mini-cache to buffer reads from the source
33 * page. We rely on the mini-cache being smaller than one page, so we'll
34 * cycle through the complete cache anyway.
35 */
36ENTRY(xscale_mc_copy_user_page)
37 stmfd sp!, {r4, r5, lr}
38 mov r5, r0
39 mov r0, r1
40 bl map_page_minicache
41 mov r1, r5
42 mov lr, #PAGE_SZ/64-1
43
44 /*
45 * Strangely enough, best performance is achieved
46 * when prefetching destination as well. (NP)
47 */
48 pld [r0, #0]
49 pld [r0, #32]
50 pld [r1, #0]
51 pld [r1, #32]
52
531: pld [r0, #64]
54 pld [r0, #96]
55 pld [r1, #64]
56 pld [r1, #96]
57
582: ldrd r2, [r0], #8
59 ldrd r4, [r0], #8
60 mov ip, r1
61 strd r2, [r1], #8
62 ldrd r2, [r0], #8
63 strd r4, [r1], #8
64 ldrd r4, [r0], #8
65 strd r2, [r1], #8
66 strd r4, [r1], #8
67 mcr p15, 0, ip, c7, c10, 1 @ clean D line
68 ldrd r2, [r0], #8
69 mcr p15, 0, ip, c7, c6, 1 @ invalidate D line
70 ldrd r4, [r0], #8
71 mov ip, r1
72 strd r2, [r1], #8
73 ldrd r2, [r0], #8
74 strd r4, [r1], #8
75 ldrd r4, [r0], #8
76 strd r2, [r1], #8
77 strd r4, [r1], #8
78 mcr p15, 0, ip, c7, c10, 1 @ clean D line
79 subs lr, lr, #1
80 mcr p15, 0, ip, c7, c6, 1 @ invalidate D line
81 bgt 1b
82 beq 2b
83
84 ldmfd sp!, {r4, r5, pc}
85
86 .align 5
87/*
88 * XScale optimised clear_user_page
89 * r0 = destination
90 * r1 = virtual user address of ultimate destination page
91 */
92ENTRY(xscale_mc_clear_user_page)
93 mov r1, #PAGE_SZ/32
94 mov r2, #0
95 mov r3, #0
961: mov ip, r0
97 strd r2, [r0], #8
98 strd r2, [r0], #8
99 strd r2, [r0], #8
100 strd r2, [r0], #8
101 mcr p15, 0, ip, c7, c10, 1 @ clean D line
102 subs r1, r1, #1
103 mcr p15, 0, ip, c7, c6, 1 @ invalidate D line
104 bne 1b
105 mov pc, lr
106
107 __INITDATA
108
109 .type xscale_mc_user_fns, #object
110ENTRY(xscale_mc_user_fns)
111 .long xscale_mc_clear_user_page
112 .long xscale_mc_copy_user_page
113 .size xscale_mc_user_fns, . - xscale_mc_user_fns
diff --git a/arch/arm/mm/copypage-xscale.c b/arch/arm/mm/copypage-xscale.c
new file mode 100644
index 000000000000..42a6ee255ce0
--- /dev/null
+++ b/arch/arm/mm/copypage-xscale.c
@@ -0,0 +1,131 @@
1/*
2 * linux/arch/arm/lib/copypage-xscale.S
3 *
4 * Copyright (C) 1995-2005 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This handles the mini data cache, as found on SA11x0 and XScale
11 * processors. When we copy a user page page, we map it in such a way
12 * that accesses to this page will not touch the main data cache, but
13 * will be cached in the mini data cache. This prevents us thrashing
14 * the main data cache on page faults.
15 */
16#include <linux/init.h>
17#include <linux/mm.h>
18
19#include <asm/page.h>
20#include <asm/pgtable.h>
21#include <asm/tlbflush.h>
22
23/*
24 * 0xffff8000 to 0xffffffff is reserved for any ARM architecture
25 * specific hacks for copying pages efficiently.
26 */
27#define COPYPAGE_MINICACHE 0xffff8000
28
29#define minicache_pgprot __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | \
30 L_PTE_CACHEABLE)
31
32#define TOP_PTE(x) pte_offset_kernel(top_pmd, x)
33
34static DEFINE_SPINLOCK(minicache_lock);
35
36/*
37 * XScale mini-dcache optimised copy_user_page
38 *
39 * We flush the destination cache lines just before we write the data into the
40 * corresponding address. Since the Dcache is read-allocate, this removes the
41 * Dcache aliasing issue. The writes will be forwarded to the write buffer,
42 * and merged as appropriate.
43 */
44static void __attribute__((naked))
45mc_copy_user_page(void *from, void *to)
46{
47 /*
48 * Strangely enough, best performance is achieved
49 * when prefetching destination as well. (NP)
50 */
51 asm volatile(
52 "stmfd sp!, {r4, r5, lr} \n\
53 mov lr, %2 \n\
54 pld [r0, #0] \n\
55 pld [r0, #32] \n\
56 pld [r1, #0] \n\
57 pld [r1, #32] \n\
581: pld [r0, #64] \n\
59 pld [r0, #96] \n\
60 pld [r1, #64] \n\
61 pld [r1, #96] \n\
622: ldrd r2, [r0], #8 \n\
63 ldrd r4, [r0], #8 \n\
64 mov ip, r1 \n\
65 strd r2, [r1], #8 \n\
66 ldrd r2, [r0], #8 \n\
67 strd r4, [r1], #8 \n\
68 ldrd r4, [r0], #8 \n\
69 strd r2, [r1], #8 \n\
70 strd r4, [r1], #8 \n\
71 mcr p15, 0, ip, c7, c10, 1 @ clean D line\n\
72 ldrd r2, [r0], #8 \n\
73 mcr p15, 0, ip, c7, c6, 1 @ invalidate D line\n\
74 ldrd r4, [r0], #8 \n\
75 mov ip, r1 \n\
76 strd r2, [r1], #8 \n\
77 ldrd r2, [r0], #8 \n\
78 strd r4, [r1], #8 \n\
79 ldrd r4, [r0], #8 \n\
80 strd r2, [r1], #8 \n\
81 strd r4, [r1], #8 \n\
82 mcr p15, 0, ip, c7, c10, 1 @ clean D line\n\
83 subs lr, lr, #1 \n\
84 mcr p15, 0, ip, c7, c6, 1 @ invalidate D line\n\
85 bgt 1b \n\
86 beq 2b \n\
87 ldmfd sp!, {r4, r5, pc} "
88 :
89 : "r" (from), "r" (to), "I" (PAGE_SIZE / 64 - 1));
90}
91
92void xscale_mc_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr)
93{
94 spin_lock(&minicache_lock);
95
96 set_pte(TOP_PTE(COPYPAGE_MINICACHE), pfn_pte(__pa(kfrom) >> PAGE_SHIFT, minicache_pgprot));
97 flush_tlb_kernel_page(COPYPAGE_MINICACHE);
98
99 mc_copy_user_page((void *)COPYPAGE_MINICACHE, kto);
100
101 spin_unlock(&minicache_lock);
102}
103
104/*
105 * XScale optimised clear_user_page
106 */
107void __attribute__((naked))
108xscale_mc_clear_user_page(void *kaddr, unsigned long vaddr)
109{
110 asm volatile(
111 "mov r1, %0 \n\
112 mov r2, #0 \n\
113 mov r3, #0 \n\
1141: mov ip, r0 \n\
115 strd r2, [r0], #8 \n\
116 strd r2, [r0], #8 \n\
117 strd r2, [r0], #8 \n\
118 strd r2, [r0], #8 \n\
119 mcr p15, 0, ip, c7, c10, 1 @ clean D line\n\
120 subs r1, r1, #1 \n\
121 mcr p15, 0, ip, c7, c6, 1 @ invalidate D line\n\
122 bne 1b \n\
123 mov pc, lr"
124 :
125 : "I" (PAGE_SIZE / 32));
126}
127
128struct cpu_user_fns xscale_mc_user_fns __initdata = {
129 .cpu_clear_user_page = xscale_mc_clear_user_page,
130 .cpu_copy_user_page = xscale_mc_copy_user_page,
131};
diff --git a/arch/arm/mm/minicache.c b/arch/arm/mm/minicache.c
index dedf2ab01b2a..e69de29bb2d1 100644
--- a/arch/arm/mm/minicache.c
+++ b/arch/arm/mm/minicache.c
@@ -1,73 +0,0 @@
1/*
2 * linux/arch/arm/mm/minicache.c
3 *
4 * Copyright (C) 2001 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This handles the mini data cache, as found on SA11x0 and XScale
11 * processors. When we copy a user page page, we map it in such a way
12 * that accesses to this page will not touch the main data cache, but
13 * will be cached in the mini data cache. This prevents us thrashing
14 * the main data cache on page faults.
15 */
16#include <linux/init.h>
17#include <linux/mm.h>
18
19#include <asm/page.h>
20#include <asm/pgtable.h>
21#include <asm/tlbflush.h>
22
23/*
24 * 0xffff8000 to 0xffffffff is reserved for any ARM architecture
25 * specific hacks for copying pages efficiently.
26 */
27#define minicache_address (0xffff8000)
28#define minicache_pgprot __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | \
29 L_PTE_CACHEABLE)
30
31static pte_t *minicache_pte;
32
33/*
34 * Note that this is intended to be called only from the copy_user_page
35 * asm code; anything else will require special locking to prevent the
36 * mini-cache space being re-used. (Note: probably preempt unsafe).
37 *
38 * We rely on the fact that the minicache is 2K, and we'll be pushing
39 * 4K of data through it, so we don't actually have to specifically
40 * flush the minicache when we change the mapping.
41 *
42 * Note also: assert(PAGE_OFFSET <= virt < high_memory).
43 * Unsafe: preempt, kmap.
44 */
45unsigned long map_page_minicache(unsigned long virt)
46{
47 set_pte(minicache_pte, pfn_pte(__pa(virt) >> PAGE_SHIFT, minicache_pgprot));
48 flush_tlb_kernel_page(minicache_address);
49
50 return minicache_address;
51}
52
53static int __init minicache_init(void)
54{
55 pgd_t *pgd;
56 pmd_t *pmd;
57
58 spin_lock(&init_mm.page_table_lock);
59
60 pgd = pgd_offset_k(minicache_address);
61 pmd = pmd_alloc(&init_mm, pgd, minicache_address);
62 if (!pmd)
63 BUG();
64 minicache_pte = pte_alloc_kernel(&init_mm, pmd, minicache_address);
65 if (!minicache_pte)
66 BUG();
67
68 spin_unlock(&init_mm.page_table_lock);
69
70 return 0;
71}
72
73core_initcall(minicache_init);
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-12 18:27:45 -0500