/* * linux/arch/arm/mm/arm925.S: MMU functions for ARM925 * * Copyright (C) 1999,2000 ARM Limited * Copyright (C) 2000 Deep Blue Solutions Ltd. * Copyright (C) 2002 RidgeRun, Inc. * Copyright (C) 2002-2003 MontaVista Software, Inc. * * Update for Linux-2.6 and cache flush improvements * Copyright (C) 2004 Nokia Corporation by Tony Lindgren <tony@atomide.com> * * hacked for non-paged-MM by Hyok S. Choi, 2004. * * 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 arm925. * * CONFIG_CPU_ARM925_CPU_IDLE -> nohlt * * Some additional notes based on deciphering the TI TRM on OMAP-5910: * * NOTE1: The TI925T Configuration Register bit "D-cache clean and flush * entry mode" must be 0 to flush the entries in both segments * at once. This is the default value. See TRM 2-20 and 2-24 for * more information. * * NOTE2: Default is the "D-cache clean and flush entry mode". It looks * like the "Transparent mode" must be on for partial cache flushes * to work in this mode. This mode only works with 16-bit external * memory. See TRM 2-24 for more information. * * NOTE3: Write-back cache flushing seems to be flakey with devices using * direct memory access, such as USB OHCI. The workaround is to use * write-through cache with CONFIG_CPU_DCACHE_WRITETHROUGH (this is * the default for OMAP-1510). */ #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 16 /* * The number of data cache segments. */ #define CACHE_DSEGMENTS 2 /* * The number of lines in a cache segment. */ #define CACHE_DENTRIES 256 /* * 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 8192 .text /* * cpu_arm925_proc_init() */ ENTRY(cpu_arm925_proc_init) mov pc, lr /* * cpu_arm925_proc_fin() */ ENTRY(cpu_arm925_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_arm925_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_arm925_reset) /* Send software reset to MPU and DSP */ mov ip, #0xff000000 orr ip, ip, #0x00fe0000 orr ip, ip, #0x0000ce00 mov r4, #1 strh r4, [ip, #0x10] 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_arm925_do_idle() * * Called with IRQs disabled */ .align 10 ENTRY(cpu_arm925_do_idle) mov r0, #0 mrc p15, 0, r1, c1, c0, 0 @ Read control register mcr p15, 0, r0, c7, c10, 4 @ Drain write buffer bic r2, r1, #1 << 12 mcr p15, 0, r2, c1, c0, 0 @ Disable I cache mcr p15, 0, r0, c7, c0, 4 @ Wait for interrupt mcr p15, 0, r1, c1, c0, 0 @ Restore ICache enable mov pc, lr /* * flush_user_cache_all() * * Clean and invalidate all cache entries in a particular * address space. */ ENTRY(arm925_flush_user_cache_all) /* FALLTHROUGH */ /* * flush_kern_cache_all() * * Clean and invalidate the entire cache. */ ENTRY(arm925_flush_kern_cache_all) mov r2, #VM_EXEC mov ip, #0 __flush_whole_cache: #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache #else /* Flush entries in both segments at once, see NOTE1 above */ mov r3, #(CACHE_DENTRIES - 1) << 4 @ 256 entries in segment 2: mcr p15, 0, r3, c7, c14, 2 @ clean+invalidate D index subs r3, r3, #1 << 4 bcs 2b @ entries 255 to 0 #endif 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) * * Clean and invalidate a range of cache entries in the * specified address range. * * - start - start address (inclusive) * - end - end address (exclusive) * - flags - vm_flags describing address space */ ENTRY(arm925_flush_user_cache_range) mov ip, #0 sub r3, r1, r0 @ calculate total size cmp r3, #CACHE_DLIMIT bgt __flush_whole_cache 1: tst r2, #VM_EXEC #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry add r0, r0, #CACHE_DLINESIZE mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry add r0, r0, #CACHE_DLINESIZE #else mcr p15, 0, r0, c7, c14, 1 @ clean and invalidate D entry mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry add r0, r0, #CACHE_DLINESIZE mcr p15, 0, r0, c7, c14, 1 @ clean and invalidate D entry mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry add r0, r0, #CACHE_DLINESIZE #endif 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(arm925_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(arm925_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(arm925_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) */ arm925_dma_inv_range: #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH tst 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 #endif bic r0, r0, #CACHE_DLINESIZE - 1 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) */ arm925_dma_clean_range: #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH 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 #endif 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(arm925_dma_flush_range) bic r0, r0, #CACHE_DLINESIZE - 1 1: #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry #else mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry #endif 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(arm925_dma_map_area) add r1, r1, r0 cmp r2, #DMA_TO_DEVICE beq arm925_dma_clean_range bcs arm925_dma_inv_range b arm925_dma_flush_range ENDPROC(arm925_dma_map_area) /* * dma_unmap_area(start, size, dir) * - start - kernel virtual start address * - size - size of region * - dir - DMA direction */ ENTRY(arm925_dma_unmap_area) mov pc, lr ENDPROC(arm925_dma_unmap_area) ENTRY(arm925_cache_fns) .long arm925_flush_kern_cache_all .long arm925_flush_user_cache_all .long arm925_flush_user_cache_range .long arm925_coherent_kern_range .long arm925_coherent_user_range .long arm925_flush_kern_dcache_area .long arm925_dma_map_area .long arm925_dma_unmap_area .long arm925_dma_flush_range ENTRY(cpu_arm925_dcache_clean_area) #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH 1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry add r0, r0, #CACHE_DLINESIZE subs r1, r1, #CACHE_DLINESIZE bhi 1b #endif mcr p15, 0, r0, c7, c10, 4 @ drain WB mov pc, lr /* =============================== PageTable ============================== */ /* * cpu_arm925_switch_mm(pgd) * * Set the translation base pointer to be as described by pgd. * * pgd: new page tables */ .align 5 ENTRY(cpu_arm925_switch_mm) #ifdef CONFIG_MMU mov ip, #0 #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache #else /* Flush entries in bothe segments at once, see NOTE1 above */ mov r3, #(CACHE_DENTRIES - 1) << 4 @ 256 entries in segment 2: mcr p15, 0, r3, c7, c14, 2 @ clean & invalidate D index subs r3, r3, #1 << 4 bcs 2b @ entries 255 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_arm925_set_pte_ext(ptep, pte, ext) * * Set a PTE and flush it out */ .align 5 ENTRY(cpu_arm925_set_pte_ext) #ifdef CONFIG_MMU armv3_set_pte_ext mov r0, r0 #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH mcr p15, 0, r0, c7, c10, 1 @ clean D entry #endif mcr p15, 0, r0, c7, c10, 4 @ drain WB #endif /* CONFIG_MMU */ mov pc, lr __CPUINIT .type __arm925_setup, #function __arm925_setup: mov r0, #0 #if defined(CONFIG_CPU_ICACHE_STREAMING_DISABLE) orr r0,r0,#1 << 7 #endif /* Transparent on, D-cache clean & flush mode. See NOTE2 above */ orr r0,r0,#1 << 1 @ transparent mode on mcr p15, 0, r0, c15, c1, 0 @ write TI config register 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 #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH mov r0, #4 @ disable write-back on caches explicitly mcr p15, 7, r0, c15, c0, 0 #endif adr r5, arm925_crval ldmia r5, {r5, r6} mrc p15, 0, r0, c1, c0 @ get control register v4 bic r0, r0, r5 orr r0, r0, r6 #ifdef CONFIG_CPU_CACHE_ROUND_ROBIN orr r0, r0, #0x4000 @ .1.. .... .... .... #endif mov pc, lr .size __arm925_setup, . - __arm925_setup /* * R * .RVI ZFRS BLDP WCAM * .011 0001 ..11 1101 * */ .type arm925_crval, #object arm925_crval: crval clear=0x00007f3f, mmuset=0x0000313d, ucset=0x00001130 __INITDATA /* * Purpose : Function pointers used to access above functions - all calls * come through these */ .type arm925_processor_functions, #object arm925_processor_functions: .word v4t_early_abort .word legacy_pabort .word cpu_arm925_proc_init .word cpu_arm925_proc_fin .word cpu_arm925_reset .word cpu_arm925_do_idle .word cpu_arm925_dcache_clean_area .word cpu_arm925_switch_mm .word cpu_arm925_set_pte_ext .size arm925_processor_functions, . - arm925_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_arm925_name, #object cpu_arm925_name: .asciz "ARM925T" .size cpu_arm925_name, . - cpu_arm925_name .align .section ".proc.info.init", #alloc, #execinstr .type __arm925_proc_info,#object __arm925_proc_info: .long 0x54029250 .long 0xfffffff0 .long PMD_TYPE_SECT | \ 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 __arm925_setup .long cpu_arch_name .long cpu_elf_name .long HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB .long cpu_arm925_name .long arm925_processor_functions .long v4wbi_tlb_fns .long v4wb_user_fns .long arm925_cache_fns .size __arm925_proc_info, . - __arm925_proc_info .type __arm915_proc_info,#object __arm915_proc_info: .long 0x54029150 .long 0xfffffff0 .long PMD_TYPE_SECT | \ 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 __arm925_setup .long cpu_arch_name .long cpu_elf_name .long HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB .long cpu_arm925_name .long arm925_processor_functions .long v4wbi_tlb_fns .long v4wb_user_fns .long arm925_cache_fns .size __arm925_proc_info, . - __arm925_proc_info