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authorSteven J. Hill <sjhill@mips.com>2012-07-06 21:56:01 +0200
committerRalf Baechle <ralf@linux-mips.org>2012-07-19 11:23:43 +0200
commitc022630633624a75b3b58f43dd3c6cc896a56cff (patch)
treeef2f21c01a55962e5e2157e7eaf6e0e49f5e5585 /arch/mips/mm
parent78d4803f75277f78ab4fc3be7ad462d78f726df9 (diff)
downloadop-kernel-dev-c022630633624a75b3b58f43dd3c6cc896a56cff.zip
op-kernel-dev-c022630633624a75b3b58f43dd3c6cc896a56cff.tar.gz
MIPS: Refactor 'clear_page' and 'copy_page' functions.
Remove usage of the '__attribute__((alias("...")))' hack that aliased to integer arrays containing micro-assembled instructions. This hack breaks when building a microMIPS kernel. It also makes the code much easier to understand. [ralf@linux-mips.org: Added back export of the clear_page and copy_page symbols so certain modules will work again. Also fixed build with CONFIG_SIBYTE_DMA_PAGEOPS enabled.] Signed-off-by: Steven J. Hill <sjhill@mips.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/3866/ Acked-by: David Daney <david.daney@cavium.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/mm')
-rw-r--r--arch/mips/mm/Makefile4
-rw-r--r--arch/mips/mm/page-funcs.S50
-rw-r--r--arch/mips/mm/page.c67
3 files changed, 70 insertions, 51 deletions
diff --git a/arch/mips/mm/Makefile b/arch/mips/mm/Makefile
index 4aa2028..fd6203f 100644
--- a/arch/mips/mm/Makefile
+++ b/arch/mips/mm/Makefile
@@ -3,8 +3,8 @@
#
obj-y += cache.o dma-default.o extable.o fault.o \
- gup.o init.o mmap.o page.o tlbex.o \
- tlbex-fault.o uasm.o
+ gup.o init.o mmap.o page.o page-funcs.o \
+ tlbex.o tlbex-fault.o uasm.o
obj-$(CONFIG_32BIT) += ioremap.o pgtable-32.o
obj-$(CONFIG_64BIT) += pgtable-64.o
diff --git a/arch/mips/mm/page-funcs.S b/arch/mips/mm/page-funcs.S
new file mode 100644
index 0000000..48a6b38
--- /dev/null
+++ b/arch/mips/mm/page-funcs.S
@@ -0,0 +1,50 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Micro-assembler generated clear_page/copy_page functions.
+ *
+ * Copyright (C) 2012 MIPS Technologies, Inc.
+ * Copyright (C) 2012 Ralf Baechle <ralf@linux-mips.org>
+ */
+#include <asm/asm.h>
+#include <asm/regdef.h>
+
+#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
+#define cpu_clear_page_function_name clear_page_cpu
+#define cpu_copy_page_function_name copy_page_cpu
+#else
+#define cpu_clear_page_function_name clear_page
+#define cpu_copy_page_function_name copy_page
+#endif
+
+/*
+ * Maximum sizes:
+ *
+ * R4000 128 bytes S-cache: 0x058 bytes
+ * R4600 v1.7: 0x05c bytes
+ * R4600 v2.0: 0x060 bytes
+ * With prefetching, 16 word strides 0x120 bytes
+ */
+EXPORT(__clear_page_start)
+LEAF(cpu_clear_page_function_name)
+1: j 1b /* Dummy, will be replaced. */
+ .space 288
+END(cpu_clear_page_function_name)
+EXPORT(__clear_page_end)
+
+/*
+ * Maximum sizes:
+ *
+ * R4000 128 bytes S-cache: 0x11c bytes
+ * R4600 v1.7: 0x080 bytes
+ * R4600 v2.0: 0x07c bytes
+ * With prefetching, 16 word strides 0x540 bytes
+ */
+EXPORT(__copy_page_start)
+LEAF(cpu_copy_page_function_name)
+1: j 1b /* Dummy, will be replaced. */
+ .space 1344
+END(cpu_copy_page_function_name)
+EXPORT(__copy_page_end)
diff --git a/arch/mips/mm/page.c b/arch/mips/mm/page.c
index cc0b6268..98f530e 100644
--- a/arch/mips/mm/page.c
+++ b/arch/mips/mm/page.c
@@ -6,6 +6,7 @@
* Copyright (C) 2003, 04, 05 Ralf Baechle (ralf@linux-mips.org)
* Copyright (C) 2007 Maciej W. Rozycki
* Copyright (C) 2008 Thiemo Seufer
+ * Copyright (C) 2012 MIPS Technologies, Inc.
*/
#include <linux/init.h>
#include <linux/kernel.h>
@@ -71,45 +72,6 @@ static struct uasm_reloc __cpuinitdata relocs[5];
#define cpu_is_r4600_v1_x() ((read_c0_prid() & 0xfffffff0) == 0x00002010)
#define cpu_is_r4600_v2_x() ((read_c0_prid() & 0xfffffff0) == 0x00002020)
-/*
- * Maximum sizes:
- *
- * R4000 128 bytes S-cache: 0x058 bytes
- * R4600 v1.7: 0x05c bytes
- * R4600 v2.0: 0x060 bytes
- * With prefetching, 16 word strides 0x120 bytes
- */
-
-static u32 clear_page_array[0x120 / 4];
-
-#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
-void clear_page_cpu(void *page) __attribute__((alias("clear_page_array")));
-#else
-void clear_page(void *page) __attribute__((alias("clear_page_array")));
-#endif
-
-EXPORT_SYMBOL(clear_page);
-
-/*
- * Maximum sizes:
- *
- * R4000 128 bytes S-cache: 0x11c bytes
- * R4600 v1.7: 0x080 bytes
- * R4600 v2.0: 0x07c bytes
- * With prefetching, 16 word strides 0x540 bytes
- */
-static u32 copy_page_array[0x540 / 4];
-
-#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
-void
-copy_page_cpu(void *to, void *from) __attribute__((alias("copy_page_array")));
-#else
-void copy_page(void *to, void *from) __attribute__((alias("copy_page_array")));
-#endif
-
-EXPORT_SYMBOL(copy_page);
-
-
static int pref_bias_clear_store __cpuinitdata;
static int pref_bias_copy_load __cpuinitdata;
static int pref_bias_copy_store __cpuinitdata;
@@ -282,10 +244,15 @@ static inline void __cpuinit build_clear_pref(u32 **buf, int off)
}
}
+extern u32 __clear_page_start;
+extern u32 __clear_page_end;
+extern u32 __copy_page_start;
+extern u32 __copy_page_end;
+
void __cpuinit build_clear_page(void)
{
int off;
- u32 *buf = (u32 *)&clear_page_array;
+ u32 *buf = &__clear_page_start;
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
int i;
@@ -356,17 +323,17 @@ void __cpuinit build_clear_page(void)
uasm_i_jr(&buf, RA);
uasm_i_nop(&buf);
- BUG_ON(buf > clear_page_array + ARRAY_SIZE(clear_page_array));
+ BUG_ON(buf > &__clear_page_end);
uasm_resolve_relocs(relocs, labels);
pr_debug("Synthesized clear page handler (%u instructions).\n",
- (u32)(buf - clear_page_array));
+ (u32)(buf - &__clear_page_start));
pr_debug("\t.set push\n");
pr_debug("\t.set noreorder\n");
- for (i = 0; i < (buf - clear_page_array); i++)
- pr_debug("\t.word 0x%08x\n", clear_page_array[i]);
+ for (i = 0; i < (buf - &__clear_page_start); i++)
+ pr_debug("\t.word 0x%08x\n", (&__clear_page_start)[i]);
pr_debug("\t.set pop\n");
}
@@ -427,7 +394,7 @@ static inline void build_copy_store_pref(u32 **buf, int off)
void __cpuinit build_copy_page(void)
{
int off;
- u32 *buf = (u32 *)&copy_page_array;
+ u32 *buf = &__copy_page_start;
struct uasm_label *l = labels;
struct uasm_reloc *r = relocs;
int i;
@@ -595,21 +562,23 @@ void __cpuinit build_copy_page(void)
uasm_i_jr(&buf, RA);
uasm_i_nop(&buf);
- BUG_ON(buf > copy_page_array + ARRAY_SIZE(copy_page_array));
+ BUG_ON(buf > &__copy_page_end);
uasm_resolve_relocs(relocs, labels);
pr_debug("Synthesized copy page handler (%u instructions).\n",
- (u32)(buf - copy_page_array));
+ (u32)(buf - &__copy_page_start));
pr_debug("\t.set push\n");
pr_debug("\t.set noreorder\n");
- for (i = 0; i < (buf - copy_page_array); i++)
- pr_debug("\t.word 0x%08x\n", copy_page_array[i]);
+ for (i = 0; i < (buf - &__copy_page_start); i++)
+ pr_debug("\t.word 0x%08x\n", (&__copy_page_start)[i]);
pr_debug("\t.set pop\n");
}
#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
+extern void clear_page_cpu(void *page);
+extern void copy_page_cpu(void *to, void *from);
/*
* Pad descriptors to cacheline, since each is exclusively owned by a
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