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/arch/sh/kernel/cpu/init.c b/arch/sh/kernel/cpu/init.c
index fd1688e6..0f0c76a 100644
--- a/arch/sh/kernel/cpu/init.c
+++ b/arch/sh/kernel/cpu/init.c
@@ -64,11 +64,11 @@
* Generic first-level cache init
*/
#ifdef CONFIG_SUPERH32
-static void __init cache_init(void)
+static void __uses_jump_to_uncached cache_init(void)
{
unsigned long ccr, flags;
- jump_to_P2();
+ jump_to_uncached();
ccr = ctrl_inl(CCR);
/*
@@ -145,7 +145,7 @@
#endif
ctrl_outl(flags, CCR);
- back_to_P1();
+ back_to_cached();
}
#else
#define cache_init() do { } while (0)
diff --git a/arch/sh/kernel/cpu/sh3/probe.c b/arch/sh/kernel/cpu/sh3/probe.c
index bf579e0..22070e4 100644
--- a/arch/sh/kernel/cpu/sh3/probe.c
+++ b/arch/sh/kernel/cpu/sh3/probe.c
@@ -16,11 +16,11 @@
#include <asm/cache.h>
#include <asm/io.h>
-int __init detect_cpu_and_cache_system(void)
+int __uses_jump_to_uncached detect_cpu_and_cache_system(void)
{
unsigned long addr0, addr1, data0, data1, data2, data3;
- jump_to_P2();
+ jump_to_uncached();
/*
* Check if the entry shadows or not.
* When shadowed, it's 128-entry system.
@@ -48,7 +48,7 @@
ctrl_outl(data0&~SH_CACHE_VALID, addr0);
ctrl_outl(data2&~SH_CACHE_VALID, addr1);
- back_to_P1();
+ back_to_cached();
boot_cpu_data.dcache.ways = 4;
boot_cpu_data.dcache.entry_shift = 4;
diff --git a/arch/sh/kernel/vmlinux_32.lds.S b/arch/sh/kernel/vmlinux_32.lds.S
index 0956fb3..50c69c1 100644
--- a/arch/sh/kernel/vmlinux_32.lds.S
+++ b/arch/sh/kernel/vmlinux_32.lds.S
@@ -43,6 +43,15 @@
NOTES
RO_DATA(PAGE_SIZE)
+ /*
+ * Code which must be executed uncached and the associated data
+ */
+ . = ALIGN(PAGE_SIZE);
+ __uncached_start = .;
+ .uncached.text : { *(.uncached.text) }
+ .uncached.data : { *(.uncached.data) }
+ __uncached_end = .;
+
. = ALIGN(THREAD_SIZE);
.data : { /* Data */
*(.data.init_task)
diff --git a/arch/sh/mm/cache-debugfs.c b/arch/sh/mm/cache-debugfs.c
index de6d2c9..db6d950 100644
--- a/arch/sh/mm/cache-debugfs.c
+++ b/arch/sh/mm/cache-debugfs.c
@@ -22,7 +22,8 @@
CACHE_TYPE_UNIFIED,
};
-static int cache_seq_show(struct seq_file *file, void *iter)
+static int __uses_jump_to_uncached cache_seq_show(struct seq_file *file,
+ void *iter)
{
unsigned int cache_type = (unsigned int)file->private;
struct cache_info *cache;
@@ -34,11 +35,11 @@
* Go uncached immediately so we don't skew the results any
* more than we already are..
*/
- jump_to_P2();
+ jump_to_uncached();
ccr = ctrl_inl(CCR);
if ((ccr & CCR_CACHE_ENABLE) == 0) {
- back_to_P1();
+ back_to_cached();
seq_printf(file, "disabled\n");
return 0;
@@ -104,7 +105,7 @@
addrstart += cache->way_incr;
}
- back_to_P1();
+ back_to_cached();
return 0;
}
diff --git a/arch/sh/mm/cache-sh4.c b/arch/sh/mm/cache-sh4.c
index 226b190..43d7ff6b 100644
--- a/arch/sh/mm/cache-sh4.c
+++ b/arch/sh/mm/cache-sh4.c
@@ -190,7 +190,7 @@
* .. which happens to be the same behavior as flush_icache_range().
* So, we simply flush out a line.
*/
-void flush_cache_sigtramp(unsigned long addr)
+void __uses_jump_to_uncached flush_cache_sigtramp(unsigned long addr)
{
unsigned long v, index;
unsigned long flags;
@@ -205,13 +205,13 @@
(v & boot_cpu_data.icache.entry_mask);
local_irq_save(flags);
- jump_to_P2();
+ jump_to_uncached();
for (i = 0; i < boot_cpu_data.icache.ways;
i++, index += boot_cpu_data.icache.way_incr)
ctrl_outl(0, index); /* Clear out Valid-bit */
- back_to_P1();
+ back_to_cached();
wmb();
local_irq_restore(flags);
}
@@ -256,12 +256,12 @@
}
/* TODO: Selective icache invalidation through IC address array.. */
-static inline void flush_icache_all(void)
+static inline void __uses_jump_to_uncached flush_icache_all(void)
{
unsigned long flags, ccr;
local_irq_save(flags);
- jump_to_P2();
+ jump_to_uncached();
/* Flush I-cache */
ccr = ctrl_inl(CCR);
@@ -269,11 +269,11 @@
ctrl_outl(ccr, CCR);
/*
- * back_to_P1() will take care of the barrier for us, don't add
+ * back_to_cached() will take care of the barrier for us, don't add
* another one!
*/
- back_to_P1();
+ back_to_cached();
local_irq_restore(flags);
}
diff --git a/arch/sh/mm/cache-sh7705.c b/arch/sh/mm/cache-sh7705.c
index 4896d73..22dacc7 100644
--- a/arch/sh/mm/cache-sh7705.c
+++ b/arch/sh/mm/cache-sh7705.c
@@ -71,7 +71,7 @@
/*
* Writeback&Invalidate the D-cache of the page
*/
-static void __flush_dcache_page(unsigned long phys)
+static void __uses_jump_to_uncached __flush_dcache_page(unsigned long phys)
{
unsigned long ways, waysize, addrstart;
unsigned long flags;
@@ -92,7 +92,7 @@
* possible.
*/
local_irq_save(flags);
- jump_to_P2();
+ jump_to_uncached();
ways = current_cpu_data.dcache.ways;
waysize = current_cpu_data.dcache.sets;
@@ -118,7 +118,7 @@
addrstart += current_cpu_data.dcache.way_incr;
} while (--ways);
- back_to_P1();
+ back_to_cached();
local_irq_restore(flags);
}
@@ -132,15 +132,15 @@
__flush_dcache_page(PHYSADDR(page_address(page)));
}
-void flush_cache_all(void)
+void __uses_jump_to_uncached flush_cache_all(void)
{
unsigned long flags;
local_irq_save(flags);
- jump_to_P2();
+ jump_to_uncached();
cache_wback_all();
- back_to_P1();
+ back_to_cached();
local_irq_restore(flags);
}
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 79c3097..094225e 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -23,6 +23,7 @@
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
pgd_t swapper_pg_dir[PTRS_PER_PGD];
+unsigned long cached_to_uncached = 0;
void show_mem(void)
{
@@ -99,7 +100,8 @@
set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
- flush_tlb_one(get_asid(), addr);
+ if (cached_to_uncached)
+ flush_tlb_one(get_asid(), addr);
}
/*
@@ -164,6 +166,18 @@
}
free_area_init_nodes(max_zone_pfns);
+
+ /* Set up the uncached fixmap */
+ set_fixmap_nocache(FIX_UNCACHED, __pa(&__uncached_start));
+
+#ifdef CONFIG_29BIT
+ /*
+ * Handle trivial transitions between cached and uncached
+ * segments, making use of the 1:1 mapping relationship in
+ * 512MB lowmem.
+ */
+ cached_to_uncached = P2SEG - P1SEG;
+#endif
}
static struct kcore_list kcore_mem, kcore_vmalloc;
diff --git a/arch/sh/mm/pmb.c b/arch/sh/mm/pmb.c
index ef6ab39..ab81c60 100644
--- a/arch/sh/mm/pmb.c
+++ b/arch/sh/mm/pmb.c
@@ -163,18 +163,18 @@
return 0;
}
-int set_pmb_entry(struct pmb_entry *pmbe)
+int __uses_jump_to_uncached set_pmb_entry(struct pmb_entry *pmbe)
{
int ret;
- jump_to_P2();
+ jump_to_uncached();
ret = __set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &pmbe->entry);
- back_to_P1();
+ back_to_cached();
return ret;
}
-void clear_pmb_entry(struct pmb_entry *pmbe)
+void __uses_jump_to_uncached clear_pmb_entry(struct pmb_entry *pmbe)
{
unsigned int entry = pmbe->entry;
unsigned long addr;
@@ -188,7 +188,7 @@
entry >= NR_PMB_ENTRIES))
return;
- jump_to_P2();
+ jump_to_uncached();
/* Clear V-bit */
addr = mk_pmb_addr(entry);
@@ -197,7 +197,7 @@
addr = mk_pmb_data(entry);
ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr);
- back_to_P1();
+ back_to_cached();
clear_bit(entry, &pmb_map);
}
@@ -302,7 +302,7 @@
pmbe->entry = PMB_NO_ENTRY;
}
-static int __init pmb_init(void)
+static int __uses_jump_to_uncached pmb_init(void)
{
unsigned int nr_entries = ARRAY_SIZE(pmb_init_map);
unsigned int entry, i;
@@ -312,7 +312,7 @@
pmb_cache = kmem_cache_create("pmb", sizeof(struct pmb_entry), 0,
SLAB_PANIC, pmb_cache_ctor);
- jump_to_P2();
+ jump_to_uncached();
/*
* Ordering is important, P2 must be mapped in the PMB before we
@@ -335,7 +335,7 @@
i |= MMUCR_TI;
ctrl_outl(i, MMUCR);
- back_to_P1();
+ back_to_cached();
return 0;
}
diff --git a/arch/sh/mm/tlb-sh4.c b/arch/sh/mm/tlb-sh4.c
index 2d1dd60..f0c7b73 100644
--- a/arch/sh/mm/tlb-sh4.c
+++ b/arch/sh/mm/tlb-sh4.c
@@ -79,7 +79,8 @@
local_irq_restore(flags);
}
-void local_flush_tlb_one(unsigned long asid, unsigned long page)
+void __uses_jump_to_uncached local_flush_tlb_one(unsigned long asid,
+ unsigned long page)
{
unsigned long addr, data;
@@ -91,7 +92,7 @@
*/
addr = MMU_UTLB_ADDRESS_ARRAY | MMU_PAGE_ASSOC_BIT;
data = page | asid; /* VALID bit is off */
- jump_to_P2();
+ jump_to_uncached();
ctrl_outl(data, addr);
- back_to_P1();
+ back_to_cached();
}
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 */
