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-rw-r--r--arch/v850/kernel/v850e_cache.c174
1 files changed, 174 insertions, 0 deletions
diff --git a/arch/v850/kernel/v850e_cache.c b/arch/v850/kernel/v850e_cache.c
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index 0000000..ea3e51c
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+++ b/arch/v850/kernel/v850e_cache.c
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+/*
+ * arch/v850/kernel/v850e_cache.c -- Cache control for V850E cache memories
+ *
+ * Copyright (C) 2003 NEC Electronics Corporation
+ * Copyright (C) 2003 Miles Bader <miles@gnu.org>
+ *
+ * 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.
+ *
+ * Written by Miles Bader <miles@gnu.org>
+ */
+
+/* This file implements cache control for the rather simple cache used on
+ some V850E CPUs, specifically the NB85E/TEG CPU-core and the V850E/ME2
+ CPU. V850E2 processors have their own (better) cache
+ implementation. */
+
+#include <asm/entry.h>
+#include <asm/cacheflush.h>
+#include <asm/v850e_cache.h>
+
+#define WAIT_UNTIL_CLEAR(value) while (value) {}
+
+/* Set caching params via the BHC and DCC registers. */
+void v850e_cache_enable (u16 bhc, u16 icc, u16 dcc)
+{
+ unsigned long *r0_ram = (unsigned long *)R0_RAM_ADDR;
+ register u16 bhc_val asm ("r6") = bhc;
+
+ /* Read the instruction cache control register (ICC) and confirm
+ that bits 0 and 1 (TCLR0, TCLR1) are all cleared. */
+ WAIT_UNTIL_CLEAR (V850E_CACHE_ICC & 0x3);
+ V850E_CACHE_ICC = icc;
+
+#ifdef V850E_CACHE_DCC
+ /* Configure data-cache. */
+ V850E_CACHE_DCC = dcc;
+#endif /* V850E_CACHE_DCC */
+
+ /* Configure caching for various memory regions by writing the BHC
+ register. The documentation says that an instruction _cannot_
+ enable/disable caching for the memory region in which the
+ instruction itself exists; to work around this, we store
+ appropriate instructions into the on-chip RAM area (which is never
+ cached), and briefly jump there to do the work. */
+#ifdef V850E_CACHE_WRITE_IBS
+ *r0_ram++ = 0xf0720760; /* st.h r0, 0xfffff072[r0] */
+#endif
+ *r0_ram++ = 0xf06a3760; /* st.h r6, 0xfffff06a[r0] */
+ *r0_ram = 0x5640006b; /* jmp [r11] */
+
+ asm ("mov hilo(1f), r11; jmp [%1]; 1:;"
+ :: "r" (bhc_val), "r" (R0_RAM_ADDR) : "r11");
+}
+
+static void clear_icache (void)
+{
+ /* 1. Read the instruction cache control register (ICC) and confirm
+ that bits 0 and 1 (TCLR0, TCLR1) are all cleared. */
+ WAIT_UNTIL_CLEAR (V850E_CACHE_ICC & 0x3);
+
+ /* 2. Read the ICC register and confirm that bit 12 (LOCK0) is
+ cleared. Bit 13 of the ICC register is always cleared. */
+ WAIT_UNTIL_CLEAR (V850E_CACHE_ICC & 0x1000);
+
+ /* 3. Set the TCLR0 and TCLR1 bits of the ICC register as follows,
+ when clearing way 0 and way 1 at the same time:
+ (a) Set the TCLR0 and TCLR1 bits.
+ (b) Read the TCLR0 and TCLR1 bits to confirm that these bits
+ are cleared.
+ (c) Perform (a) and (b) above again. */
+ V850E_CACHE_ICC |= 0x3;
+ WAIT_UNTIL_CLEAR (V850E_CACHE_ICC & 0x3);
+
+#ifdef V850E_CACHE_REPEAT_ICC_WRITE
+ /* Do it again. */
+ V850E_CACHE_ICC |= 0x3;
+ WAIT_UNTIL_CLEAR (V850E_CACHE_ICC & 0x3);
+#endif
+}
+
+#ifdef V850E_CACHE_DCC
+/* Flush or clear (or both) the data cache, depending on the value of FLAGS;
+ the procedure is the same for both, just the control bits used differ (and
+ both may be performed simultaneously). */
+static void dcache_op (unsigned short flags)
+{
+ /* 1. Read the data cache control register (DCC) and confirm that bits
+ 0, 1, 4, and 5 (DC00, DC01, DC04, DC05) are all cleared. */
+ WAIT_UNTIL_CLEAR (V850E_CACHE_DCC & 0x33);
+
+ /* 2. Clear DCC register bit 12 (DC12), bit 13 (DC13), or both
+ depending on the way for which tags are to be cleared. */
+ V850E_CACHE_DCC &= ~0xC000;
+
+ /* 3. Set DCC register bit 0 (DC00), bit 1 (DC01) or both depending on
+ the way for which tags are to be cleared.
+ ...
+ Set DCC register bit 4 (DC04), bit 5 (DC05), or both depending
+ on the way to be data flushed. */
+ V850E_CACHE_DCC |= flags;
+
+ /* 4. Read DCC register bit DC00, DC01 [DC04, DC05], or both depending
+ on the way for which tags were cleared [flushed] and confirm
+ that that bit is cleared. */
+ WAIT_UNTIL_CLEAR (V850E_CACHE_DCC & flags);
+}
+#endif /* V850E_CACHE_DCC */
+
+/* Flushes the contents of the dcache to memory. */
+static inline void flush_dcache (void)
+{
+#ifdef V850E_CACHE_DCC
+ /* We only need to do something if in write-back mode. */
+ if (V850E_CACHE_DCC & 0x0400)
+ dcache_op (0x30);
+#endif /* V850E_CACHE_DCC */
+}
+
+/* Flushes the contents of the dcache to memory, and then clears it. */
+static inline void clear_dcache (void)
+{
+#ifdef V850E_CACHE_DCC
+ /* We only need to do something if the dcache is enabled. */
+ if (V850E_CACHE_DCC & 0x0C00)
+ dcache_op (0x33);
+#endif /* V850E_CACHE_DCC */
+}
+
+/* Clears the dcache without flushing to memory first. */
+static inline void clear_dcache_no_flush (void)
+{
+#ifdef V850E_CACHE_DCC
+ /* We only need to do something if the dcache is enabled. */
+ if (V850E_CACHE_DCC & 0x0C00)
+ dcache_op (0x3);
+#endif /* V850E_CACHE_DCC */
+}
+
+static inline void cache_exec_after_store (void)
+{
+ flush_dcache ();
+ clear_icache ();
+}
+
+
+/* Exported functions. */
+
+void flush_icache (void)
+{
+ cache_exec_after_store ();
+}
+
+void flush_icache_range (unsigned long start, unsigned long end)
+{
+ cache_exec_after_store ();
+}
+
+void flush_icache_page (struct vm_area_struct *vma, struct page *page)
+{
+ cache_exec_after_store ();
+}
+
+void flush_icache_user_range (struct vm_area_struct *vma, struct page *page,
+ unsigned long adr, int len)
+{
+ cache_exec_after_store ();
+}
+
+void flush_cache_sigtramp (unsigned long addr)
+{
+ cache_exec_after_store ();
+}
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