/* * linux/arch/arm/mm/proc-arm920.S: MMU functions for ARM920 * * Copyright (C) 1999,2000 ARM Limited * Copyright (C) 2000 Deep Blue Solutions Ltd. * hacked for non-paged-MM by Hyok S. Choi, 2003. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * * These are the low level assembler for performing cache and TLB * functions on the arm920. * * CONFIG_CPU_ARM920_CPU_IDLE -> nohlt */ #include <linux/linkage.h> #include <linux/init.h> #include <asm/assembler.h> #include <asm/hwcap.h> #include <asm/pgtable-hwdef.h> #include <asm/pgtable.h> #include <asm/page.h> #include <asm/ptrace.h> #include "proc-macros.S" /* * The size of one data cache line. */ #define CACHE_DLINESIZE 32 /* * The number of data cache segments. */ #define CACHE_DSEGMENTS 8 /* * The number of lines in a cache segment. */ #define CACHE_DENTRIES 64 /* * This is the size at which it becomes more efficient to * clean the whole cache, rather than using the individual * cache line maintainence instructions. */ #define CACHE_DLIMIT 65536 .text /* * cpu_arm920_proc_init() */ ENTRY(cpu_arm920_proc_init) mov pc, lr /* * cpu_arm920_proc_fin() */ ENTRY(cpu_arm920_proc_fin) mrc p15, 0, r0, c1, c0, 0 @ ctrl register bic r0, r0, #0x1000 @ ...i............ bic r0, r0, #0x000e @ ............wca. mcr p15, 0, r0, c1, c0, 0 @ disable caches mov pc, lr /* * cpu_arm920_reset(loc) * * Perform a soft reset of the system. Put the CPU into the * same state as it would be if it had been reset, and branch * to what would be the reset vector. * * loc: location to jump to for soft reset */ .align 5 ENTRY(cpu_arm920_reset) mov ip, #0 mcr p15, 0, ip, c7, c7, 0 @ invalidate I,D caches mcr p15, 0, ip, c7, c10, 4 @ drain WB #ifdef CONFIG_MMU mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs #endif mrc p15, 0, ip, c1, c0, 0 @ ctrl register bic ip, ip, #0x000f @ ............wcam bic ip, ip, #0x1100 @ ...i...s........ mcr p15, 0, ip, c1, c0, 0 @ ctrl register mov pc, r0 /* * cpu_arm920_do_idle() */ .align 5 ENTRY(cpu_arm920_do_idle) mcr p15, 0, r0, c7, c0, 4 @ Wait for interrupt mov pc, lr #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH /* * flush_user_cache_all() * * Invalidate all cache entries in a particular address * space. */ ENTRY(arm920_flush_user_cache_all) /* FALLTHROUGH */ /* * flush_kern_cache_all() * * Clean and invalidate the entire cache. */ ENTRY(arm920_flush_kern_cache_all) mov r2, #VM_EXEC mov ip, #0 __flush_whole_cache: mov r1, #(CACHE_DSEGMENTS - 1) << 5 @ 8 segments 1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries 2: mcr p15, 0, r3, c7, c14, 2 @ clean+invalidate D index subs r3, r3, #1 << 26 bcs 2b @ entries 63 to 0 subs r1, r1, #1 << 5 bcs 1b @ segments 7 to 0 tst r2, #VM_EXEC mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache mcrne p15, 0, ip, c7, c10, 4 @ drain WB mov pc, lr /* * flush_user_cache_range(start, end, flags) * * Invalidate a range of cache entries in the specified * address space. * * - start - start address (inclusive) * - end - end address (exclusive) * - flags - vm_flags for address space */ ENTRY(arm920_flush_user_cache_range) mov ip, #0 sub r3, r1, r0 @ calculate total size cmp r3, #CACHE_DLIMIT bhs __flush_whole_cache 1: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry tst r2, #VM_EXEC mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry add r0, r0, #CACHE_DLINESIZE cmp r0, r1 blo 1b tst r2, #VM_EXEC mcrne p15, 0, ip, c7, c10, 4 @ drain WB mov pc, lr /* * coherent_kern_range(start, end) * * Ensure coherency between the Icache and the Dcache in the * region described by start, end. If you have non-snooping * Harvard caches, you need to implement this function. * * - start - virtual start address * - end - virtual end address */ ENTRY(arm920_coherent_kern_range) /* FALLTHROUGH */ /* * coherent_user_range(start, end) * * Ensure coherency between the Icache and the Dcache in the * region described by start, end. If you have non-snooping * Harvard caches, you need to implement this function. * * - start - virtual start address * - end - virtual end address */ ENTRY(arm920_coherent_user_range) bic r0, r0, #CACHE_DLINESIZE - 1 1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry mcr p15, 0, r0, c7, c5, 1 @ invalidate I entry add r0, r0, #CACHE_DLINESIZE cmp r0, r1 blo 1b mcr p15, 0, r0, c7, c10, 4 @ drain WB mov pc, lr /* * flush_kern_dcache_area(void *addr, size_t size) * * Ensure no D cache aliasing occurs, either with itself or * the I cache * * - addr - kernel address * - size - region size */ ENTRY(arm920_flush_kern_dcache_area) add r1, r0, r1 1: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry add r0, r0, #CACHE_DLINESIZE cmp r0, r1 blo 1b mov r0, #0 mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache mcr p15, 0, r0, c7, c10, 4 @ drain WB mov pc, lr /* * dma_inv_range(start, end) * * Invalidate (discard) the specified virtual address range. * May not write back any entries. If 'start' or 'end' * are not cache line aligned, those lines must be written * back. * * - start - virtual start address * - end - virtual end address * * (same as v4wb) */ arm920_dma_inv_range: tst r0, #CACHE_DLINESIZE - 1 bic r0, r0, #CACHE_DLINESIZE - 1 mcrne p15, 0, r0, c7, c10, 1 @ clean D entry tst r1, #CACHE_DLINESIZE - 1 mcrne p15, 0, r1, c7, c10, 1 @ clean D entry 1: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry add r0, r0, #CACHE_DLINESIZE cmp r0, r1 blo 1b mcr p15, 0, r0, c7, c10, 4 @ drain WB mov pc, lr /* * dma_clean_range(start, end) * * Clean the specified virtual address range. * * - start - virtual start address * - end - virtual end address * * (same as v4wb) */ arm920_dma_clean_range: bic r0, r0, #CACHE_DLINESIZE - 1 1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry add r0, r0, #CACHE_DLINESIZE cmp r0, r1 blo 1b mcr p15, 0, r0, c7, c10, 4 @ drain WB mov pc, lr /* * dma_flush_range(start, end) * * Clean and invalidate the specified virtual address range. * * - start - virtual start address * - end - virtual end address */ ENTRY(arm920_dma_flush_range) bic r0, r0, #CACHE_DLINESIZE - 1 1: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry add r0, r0, #CACHE_DLINESIZE cmp r0, r1 blo 1b mcr p15, 0, r0, c7, c10, 4 @ drain WB mov pc, lr /* * dma_map_area(start, size, dir) * - start - kernel virtual start address * - size - size of region * - dir - DMA direction */ ENTRY(arm920_dma_map_area) add r1, r1, r0 cmp r2, #DMA_TO_DEVICE beq arm920_dma_clean_range bcs arm920_dma_inv_range b arm920_dma_flush_range ENDPROC(arm920_dma_map_area) /* * dma_unmap_area(start, size, dir) * - start - kernel virtual start address * - size - size of region * - dir - DMA direction */ ENTRY(arm920_dma_unmap_area) mov pc, lr ENDPROC(arm920_dma_unmap_area) ENTRY(arm920_cache_fns) .long arm920_flush_kern_cache_all .long arm920_flush_user_cache_all .long arm920_flush_user_cache_range .long arm920_coherent_kern_range .long arm920_coherent_user_range .long arm920_flush_kern_dcache_area .long arm920_dma_map_area .long arm920_dma_unmap_area .long arm920_dma_flush_range #endif ENTRY(cpu_arm920_dcache_clean_area) 1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry add r0, r0, #CACHE_DLINESIZE subs r1, r1, #CACHE_DLINESIZE bhi 1b mov pc, lr /* =============================== PageTable ============================== */ /* * cpu_arm920_switch_mm(pgd) * * Set the translation base pointer to be as described by pgd. * * pgd: new page tables */ .align 5 ENTRY(cpu_arm920_switch_mm) #ifdef CONFIG_MMU mov ip, #0 #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache #else @ && 'Clean & Invalidate whole DCache' @ && Re-written to use Index Ops. @ && Uses registers r1, r3 and ip mov r1, #(CACHE_DSEGMENTS - 1) << 5 @ 8 segments 1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries 2: mcr p15, 0, r3, c7, c14, 2 @ clean & invalidate D index subs r3, r3, #1 << 26 bcs 2b @ entries 63 to 0 subs r1, r1, #1 << 5 bcs 1b @ segments 7 to 0 #endif mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache mcr p15, 0, ip, c7, c10, 4 @ drain WB mcr p15, 0, r0, c2, c0, 0 @ load page table pointer mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs #endif mov pc, lr /* * cpu_arm920_set_pte(ptep, pte, ext) * * Set a PTE and flush it out */ .align 5 ENTRY(cpu_arm920_set_pte_ext) #ifdef CONFIG_MMU armv3_set_pte_ext mov r0, r0 mcr p15, 0, r0, c7, c10, 1 @ clean D entry mcr p15, 0, r0, c7, c10, 4 @ drain WB #endif mov pc, lr __CPUINIT .type __arm920_setup, #function __arm920_setup: mov r0, #0 mcr p15, 0, r0, c7, c7 @ invalidate I,D caches on v4 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer on v4 #ifdef CONFIG_MMU mcr p15, 0, r0, c8, c7 @ invalidate I,D TLBs on v4 #endif adr r5, arm920_crval ldmia r5, {r5, r6} mrc p15, 0, r0, c1, c0 @ get control register v4 bic r0, r0, r5 orr r0, r0, r6 mov pc, lr .size __arm920_setup, . - __arm920_setup /* * R * .RVI ZFRS BLDP WCAM * ..11 0001 ..11 0101 * */ .type arm920_crval, #object arm920_crval: crval clear=0x00003f3f, mmuset=0x00003135, ucset=0x00001130 __INITDATA /* * Purpose : Function pointers used to access above functions - all calls * come through these */ .type arm920_processor_functions, #object arm920_processor_functions: .word v4t_early_abort .word legacy_pabort .word cpu_arm920_proc_init .word cpu_arm920_proc_fin .word cpu_arm920_reset .word cpu_arm920_do_idle .word cpu_arm920_dcache_clean_area .word cpu_arm920_switch_mm .word cpu_arm920_set_pte_ext .size arm920_processor_functions, . - arm920_processor_functions .section ".rodata" .type cpu_arch_name, #object cpu_arch_name: .asciz "armv4t" .size cpu_arch_name, . - cpu_arch_name .type cpu_elf_name, #object cpu_elf_name: .asciz "v4" .size cpu_elf_name, . - cpu_elf_name .type cpu_arm920_name, #object cpu_arm920_name: .asciz "ARM920T" .size cpu_arm920_name, . - cpu_arm920_name .align .section ".proc.info.init", #alloc, #execinstr .type __arm920_proc_info,#object __arm920_proc_info: .long 0x41009200 .long 0xff00fff0 .long PMD_TYPE_SECT | \ PMD_SECT_BUFFERABLE | \ PMD_SECT_CACHEABLE | \ PMD_BIT4 | \ PMD_SECT_AP_WRITE | \ PMD_SECT_AP_READ .long PMD_TYPE_SECT | \ PMD_BIT4 | \ PMD_SECT_AP_WRITE | \ PMD_SECT_AP_READ b __arm920_setup .long cpu_arch_name .long cpu_elf_name .long HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB .long cpu_arm920_name .long arm920_processor_functions .long v4wbi_tlb_fns .long v4wb_user_fns #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH .long arm920_cache_fns #else .long v4wt_cache_fns #endif .size __arm920_proc_info, . - __arm920_proc_info