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Diffstat (limited to 'arch/v850/kernel/v850e_cache.c')
| -rw-r--r-- | arch/v850/kernel/v850e_cache.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/arch/v850/kernel/v850e_cache.c b/arch/v850/kernel/v850e_cache.c new file mode 100644 index 0000000..ea3e51c --- /dev/null +++ b/arch/v850/kernel/v850e_cache.c @@ -0,0 +1,174 @@ +/* + * 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 (); +} |
