sh: Preparation for uncached jumps through PMB.
Presently most of the 29-bit physical parts do P1/P2 segmentation
with a 1:1 cached/uncached mapping, jumping between the two to
control the caching behaviour. This provides the basic infrastructure
to maintain this behaviour on 32-bit physical parts that don't map
P1/P2 at all, using a shiny new linker section and corresponding
fixmap entry.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/include/asm-sh/fixmap.h b/include/asm-sh/fixmap.h
index 09463cd..721fcc4 100644
--- a/include/asm-sh/fixmap.h
+++ b/include/asm-sh/fixmap.h
@@ -49,6 +49,7 @@
#define FIX_N_COLOURS 16
FIX_CMAP_BEGIN,
FIX_CMAP_END = FIX_CMAP_BEGIN + FIX_N_COLOURS,
+ FIX_UNCACHED,
#ifdef CONFIG_HIGHMEM
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
diff --git a/include/asm-sh/sections.h b/include/asm-sh/sections.h
index bd9cbc9..8f8f4ad 100644
--- a/include/asm-sh/sections.h
+++ b/include/asm-sh/sections.h
@@ -4,6 +4,7 @@
#include <asm-generic/sections.h>
extern long __machvec_start, __machvec_end;
+extern char __uncached_start, __uncached_end;
extern char _ebss[];
#endif /* __ASM_SH_SECTIONS_H */
diff --git a/include/asm-sh/system.h b/include/asm-sh/system.h
index 969f3d4..9bda8d0 100644
--- a/include/asm-sh/system.h
+++ b/include/asm-sh/system.h
@@ -144,6 +144,8 @@
#define instruction_size(insn) (4)
#endif
+extern unsigned long cached_to_uncached;
+
/* XXX
* disable hlt during certain critical i/o operations
*/
diff --git a/include/asm-sh/system_32.h b/include/asm-sh/system_32.h
index ad37e8d..e918bac 100644
--- a/include/asm-sh/system_32.h
+++ b/include/asm-sh/system_32.h
@@ -58,29 +58,31 @@
last = __last; \
} while (0)
+#define __uses_jump_to_uncached __attribute__ ((__section__ (".uncached.text")))
+
/*
- * Jump to P2 area.
- * When handling TLB or caches, we need to do it from P2 area.
+ * Jump to uncached area.
+ * When handling TLB or caches, we need to do it from an uncached area.
*/
-#define jump_to_P2() \
-do { \
- unsigned long __dummy; \
- __asm__ __volatile__( \
- "mov.l 1f, %0\n\t" \
- "or %1, %0\n\t" \
- "jmp @%0\n\t" \
- " nop\n\t" \
- ".balign 4\n" \
- "1: .long 2f\n" \
- "2:" \
- : "=&r" (__dummy) \
- : "r" (0x20000000)); \
+#define jump_to_uncached() \
+do { \
+ unsigned long __dummy; \
+ \
+ __asm__ __volatile__( \
+ "mova 1f, %0\n\t" \
+ "add %1, %0\n\t" \
+ "jmp @%0\n\t" \
+ " nop\n\t" \
+ ".balign 4\n" \
+ "1:" \
+ : "=&z" (__dummy) \
+ : "r" (cached_to_uncached)); \
} while (0)
/*
- * Back to P1 area.
+ * Back to cached area.
*/
-#define back_to_P1() \
+#define back_to_cached() \
do { \
unsigned long __dummy; \
ctrl_barrier(); \
diff --git a/include/asm-sh/system_64.h b/include/asm-sh/system_64.h
index 0e466e9..943acf5 100644
--- a/include/asm-sh/system_64.h
+++ b/include/asm-sh/system_64.h
@@ -32,8 +32,9 @@
&next->thread); \
} while (0)
-/* No segmentation.. */
-#define jump_to_P2() do { } while (0)
-#define back_to_P1() do { } while (0)
+#define __uses_jump_to_uncached
+
+#define jump_to_uncached() do { } while (0)
+#define back_to_cached() do { } while (0)
#endif /* __ASM_SH_SYSTEM_64_H */