/* * arch/sh/mm/cache-sh4.c * * Copyright (C) 1999, 2000, 2002 Niibe Yutaka * Copyright (C) 2001 - 2007 Paul Mundt * Copyright (C) 2003 Richard Curnow * Copyright (c) 2007 STMicroelectronics (R&D) Ltd. * * 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. */ #include #include #include #include #include #include #include /* * The maximum number of pages we support up to when doing ranged dcache * flushing. Anything exceeding this will simply flush the dcache in its * entirety. */ #define MAX_DCACHE_PAGES 64 /* XXX: Tune for ways */ #define MAX_ICACHE_PAGES 32 static void __flush_dcache_segment_1way(unsigned long start, unsigned long extent); static void __flush_dcache_segment_2way(unsigned long start, unsigned long extent); static void __flush_dcache_segment_4way(unsigned long start, unsigned long extent); static void __flush_cache_4096(unsigned long addr, unsigned long phys, unsigned long exec_offset); /* * This is initialised here to ensure that it is not placed in the BSS. If * that were to happen, note that cache_init gets called before the BSS is * cleared, so this would get nulled out which would be hopeless. */ static void (*__flush_dcache_segment_fn)(unsigned long, unsigned long) = (void (*)(unsigned long, unsigned long))0xdeadbeef; /* * SH-4 has virtually indexed and physically tagged cache. */ void __init sh4_cache_init(void) { printk("PVR=%08x CVR=%08x PRR=%08x\n", ctrl_inl(CCN_PVR), ctrl_inl(CCN_CVR), ctrl_inl(CCN_PRR)); switch (boot_cpu_data.dcache.ways) { case 1: __flush_dcache_segment_fn = __flush_dcache_segment_1way; break; case 2: __flush_dcache_segment_fn = __flush_dcache_segment_2way; break; case 4: __flush_dcache_segment_fn = __flush_dcache_segment_4way; break; default: panic("unknown number of cache ways\n"); break; } } /* * Write back the range of D-cache, and purge the I-cache. * * Called from kernel/module.c:sys_init_module and routine for a.out format, * signal handler code and kprobes code */ void flush_icache_range(unsigned long start, unsigned long end) { int icacheaddr; unsigned long flags, v; int i; /* If there are too many pages then just blow the caches */ if (((end - start) >> PAGE_SHIFT) >= MAX_ICACHE_PAGES) { flush_cache_all(); } else { /* selectively flush d-cache then invalidate the i-cache */ /* this is inefficient, so only use for small ranges */ start &= ~(L1_CACHE_BYTES-1); end += L1_CACHE_BYTES-1; end &= ~(L1_CACHE_BYTES-1); local_irq_save(flags); jump_to_uncached(); for (v = start; v < end; v+=L1_CACHE_BYTES) { asm volatile("ocbwb %0" : /* no output */ : "m" (__m(v))); icacheaddr = CACHE_IC_ADDRESS_ARRAY | ( v & cpu_data->icache.entry_mask); for (i = 0; i < cpu_data->icache.ways; i++, icacheaddr += cpu_data->icache.way_incr) /* Clear i-cache line valid-bit */ ctrl_outl(0, icacheaddr); } back_to_cached(); local_irq_restore(flags); } } static inline void flush_cache_4096(unsigned long start, unsigned long phys) { unsigned long flags, exec_offset = 0; /* * All types of SH-4 require PC to be in P2 to operate on the I-cache. * Some types of SH-4 require PC to be in P2 to operate on the D-cache. */ if ((boot_cpu_data.flags & CPU_HAS_P2_FLUSH_BUG) || (start < CACHE_OC_ADDRESS_ARRAY)) exec_offset = 0x20000000; local_irq_save(flags); __flush_cache_4096(start | SH_CACHE_ASSOC, P1SEGADDR(phys), exec_offset); local_irq_restore(flags); } /* * Write back & invalidate the D-cache of the page. * (To avoid "alias" issues) */ void flush_dcache_page(struct page *page) { struct address_space *mapping = page_mapping(page); #ifndef CONFIG_SMP if (mapping && !mapping_mapped(mapping)) set_bit(PG_dcache_dirty, &page->flags); else #endif { unsigned long phys = PHYSADDR(page_address(page)); unsigned long addr = CACHE_OC_ADDRESS_ARRAY; int i, n; /* Loop all the D-cache */ n = boot_cpu_data.dcache.n_aliases; for (i = 0; i < n; i++, addr += 4096) flush_cache_4096(addr, phys); } wmb(); } /* TODO: Selective icache invalidation through IC address array.. */ static void __uses_jump_to_uncached flush_icache_all(void) { unsigned long flags, ccr; local_irq_save(flags); jump_to_uncached(); /* Flush I-cache */ ccr = ctrl_inl(CCR); ccr |= CCR_CACHE_ICI; ctrl_outl(ccr, CCR); /* * back_to_cached() will take care of the barrier for us, don't add * another one! */ back_to_cached(); local_irq_restore(flags); } static inline void flush_dcache_all(void) { (*__flush_dcache_segment_fn)(0UL, boot_cpu_data.dcache.way_size); wmb(); } void flush_cache_all(void) { flush_dcache_all(); flush_icache_all(); } static void __flush_cache_mm(struct mm_struct *mm, unsigned long start, unsigned long end) { unsigned long d = 0, p = start & PAGE_MASK; unsigned long alias_mask = boot_cpu_data.dcache.alias_mask; unsigned long n_aliases = boot_cpu_data.dcache.n_aliases; unsigned long select_bit; unsigned long all_aliases_mask; unsigned long addr_offset; pgd_t *dir; pmd_t *pmd; pud_t *pud; pte_t *pte; int i; dir = pgd_offset(mm, p); pud = pud_offset(dir, p); pmd = pmd_offset(pud, p); end = PAGE_ALIGN(end); all_aliases_mask = (1 << n_aliases) - 1; do { if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) { p &= PMD_MASK; p += PMD_SIZE; pmd++; continue; } pte = pte_offset_kernel(pmd, p); do { unsigned long phys; pte_t entry = *pte; if (!(pte_val(entry) & _PAGE_PRESENT)) { pte++; p += PAGE_SIZE; continue; } phys = pte_val(entry) & PTE_PHYS_MASK; if ((p ^ phys) & alias_mask) { d |= 1 << ((p & alias_mask) >> PAGE_SHIFT); d |= 1 << ((phys & alias_mask) >> PAGE_SHIFT); if (d == all_aliases_mask) goto loop_exit; } pte++; p += PAGE_SIZE; } while (p < end && ((unsigned long)pte & ~PAGE_MASK)); pmd++; } while (p < end); loop_exit: addr_offset = 0; select_bit = 1; for (i = 0; i < n_aliases; i++) { if (d & select_bit) { (*__flush_dcache_segment_fn)(addr_offset, PAGE_SIZE); wmb(); } select_bit <<= 1; addr_offset += PAGE_SIZE; } } /* * Note : (RPC) since the caches are physically tagged, the only point * of flush_cache_mm for SH-4 is to get rid of aliases from the * D-cache. The assumption elsewhere, e.g. flush_cache_range, is that * lines can stay resident so long as the virtual address they were * accessed with (hence cache set) is in accord with the physical * address (i.e. tag). It's no different here. So I reckon we don't * need to flush the I-cache, since aliases don't matter for that. We * should try that. * * Caller takes mm->mmap_sem. */ void flush_cache_mm(struct mm_struct *mm) { if (cpu_context(smp_processor_id(), mm) == NO_CONTEXT) return; /* * If cache is only 4k-per-way, there are never any 'aliases'. Since * the cache is physically tagged, the data can just be left in there. */ if (boot_cpu_data.dcache.n_aliases == 0) return; /* * Don't bother groveling around the dcache for the VMA ranges * if there are too many PTEs to make it worthwhile. */ if (mm->nr_ptes >= MAX_DCACHE_PAGES) flush_dcache_all(); else { struct vm_area_struct *vma; /* * In this case there are reasonably sized ranges to flush, * iterate through the VMA list and take care of any aliases. */ for (vma = mm->mmap; vma; vma = vma->vm_next) __flush_cache_mm(mm, vma->vm_start, vma->vm_end); } /* Only touch the icache if one of the VMAs has VM_EXEC set. */ if (mm->exec_vm) flush_icache_all(); } /* * Write back and invalidate I/D-caches for the page. * * ADDR: Virtual Address (U0 address) * PFN: Physical page number */ void flush_cache_page(struct vm_area_struct *vma, unsigned long address, unsigned long pfn) { unsigned long phys = pfn << PAGE_SHIFT; unsigned int alias_mask; if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT) return; alias_mask = boot_cpu_data.dcache.alias_mask; /* We only need to flush D-cache when we have alias */ if ((address^phys) & alias_mask) { /* Loop 4K of the D-cache */ flush_cache_4096( CACHE_OC_ADDRESS_ARRAY | (address & alias_mask), phys); /* Loop another 4K of the D-cache */ flush_cache_4096( CACHE_OC_ADDRESS_ARRAY | (phys & alias_mask), phys); } alias_mask = boot_cpu_data.icache.alias_mask; if (vma->vm_flags & VM_EXEC) { /* * Evict entries from the portion of the cache from which code * may have been executed at this address (virtual). There's * no need to evict from the portion corresponding to the * physical address as for the D-cache, because we know the * kernel has never executed the code through its identity * translation. */ flush_cache_4096( CACHE_IC_ADDRESS_ARRAY | (address & alias_mask), phys); } } /* * Write back and invalidate D-caches. * * START, END: Virtual Address (U0 address) * * NOTE: We need to flush the _physical_ page entry. * Flushing the cache lines for U0 only isn't enough. * We need to flush for P1 too, which may contain aliases. */ void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) { if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT) return; /* * If cache is only 4k-per-way, there are never any 'aliases'. Since * the cache is physically tagged, the data can just be left in there. */ if (boot_cpu_data.dcache.n_aliases == 0) return; /* * Don't bother with the lookup and alias check if we have a * wide range to cover, just blow away the dcache in its * entirety instead. -- PFM. */ if (((end - start) >> PAGE_SHIFT) >= MAX_DCACHE_PAGES) flush_dcache_all(); else __flush_cache_mm(vma->vm_mm, start, end); if (vma->vm_flags & VM_EXEC) { /* * TODO: Is this required??? Need to look at how I-cache * coherency is assured when new programs are loaded to see if * this matters. */ flush_icache_all(); } } /** * __flush_cache_4096 * * @addr: address in memory mapped cache array * @phys: P1 address to flush (has to match tags if addr has 'A' bit * set i.e. associative write) * @exec_offset: set to 0x20000000 if flush has to be executed from P2 * region else 0x0 * * The offset into the cache array implied by 'addr' selects the * 'colour' of the virtual address range that will be flushed. The * operation (purge/write-back) is selected by the lower 2 bits of * 'phys'. */ static void __flush_cache_4096(unsigned long addr, unsigned long phys, unsigned long exec_offset) { int way_count; unsigned long base_addr = addr; struct cache_info *dcache; unsigned long way_incr; unsigned long a, ea, p; unsigned long temp_pc; dcache = &boot_cpu_data.dcache; /* Write this way for better assembly. */ way_count = dcache->ways; way_incr = dcache->way_incr; /* * Apply exec_offset (i.e. branch to P2 if required.). * * FIXME: * * If I write "=r" for the (temp_pc), it puts this in r6 hence * trashing exec_offset before it's been added on - why? Hence * "=&r" as a 'workaround' */ asm volatile("mov.l 1f, %0\n\t" "add %1, %0\n\t" "jmp @%0\n\t" "nop\n\t" ".balign 4\n\t" "1: .long 2f\n\t" "2:\n" : "=&r" (temp_pc) : "r" (exec_offset)); /* * We know there will be >=1 iteration, so write as do-while to avoid * pointless nead-of-loop check for 0 iterations. */ do { ea = base_addr + PAGE_SIZE; a = base_addr; p = phys; do { *(volatile unsigned long *)a = p; /* * Next line: intentionally not p+32, saves an add, p * will do since only the cache tag bits need to * match. */ *(volatile unsigned long *)(a+32) = p; a += 64; p += 64; } while (a < ea); base_addr += way_incr; } while (--way_count != 0); } /* * Break the 1, 2 and 4 way variants of this out into separate functions to * avoid nearly all the overhead of having the conditional stuff in the function * bodies (+ the 1 and 2 way cases avoid saving any registers too). */ static void __flush_dcache_segment_1way(unsigned long start, unsigned long extent_per_way) { unsigned long orig_sr, sr_with_bl; unsigned long base_addr; unsigned long way_incr, linesz, way_size; struct cache_info *dcache; register unsigned long a0, a0e; asm volatile("stc sr, %0" : "=r" (orig_sr)); sr_with_bl = orig_sr | (1<<28); base_addr = ((unsigned long)&empty_zero_page[0]); /* * The previous code aligned base_addr to 16k, i.e. the way_size of all * existing SH-4 D-caches. Whilst I don't see a need to have this * aligned to any better than the cache line size (which it will be * anyway by construction), let's align it to at least the way_size of * any existing or conceivable SH-4 D-cache. -- RPC */ base_addr = ((base_addr >> 16) << 16); base_addr |= start; dcache = &boot_cpu_data.dcache; linesz = dcache->linesz; way_incr = dcache->way_incr; way_size = dcache->way_size; a0 = base_addr; a0e = base_addr + extent_per_way; do { asm volatile("ldc %0, sr" : : "r" (sr_with_bl)); asm volatile("movca.l r0, @%0\n\t" "ocbi @%0" : : "r" (a0)); a0 += linesz; asm volatile("movca.l r0, @%0\n\t" "ocbi @%0" : : "r" (a0)); a0 += linesz; asm volatile("movca.l r0, @%0\n\t" "ocbi @%0" : : "r" (a0)); a0 += linesz; asm volatile("movca.l r0, @%0\n\t" "ocbi @%0" : : "r" (a0)); asm volatile("ldc %0, sr" : : "r" (orig_sr)); a0 += linesz; } while (a0 < a0e); } static void __flush_dcache_segment_2way(unsigned long start, unsigned long extent_per_way) { unsigned long orig_sr, sr_with_bl; unsigned long base_addr; unsigned long way_incr, linesz, way_size; struct cache_info *dcache; register unsigned long a0, a1, a0e; asm volatile("stc sr, %0" : "=r" (orig_sr)); sr_with_bl = orig_sr | (1<<28); base_addr = ((unsigned long)&empty_zero_page[0]); /* See comment under 1-way above */ base_addr = ((base_addr >> 16) << 16); base_addr |= start; dcache = &boot_cpu_data.dcache; linesz = dcache->linesz; way_incr = dcache->way_incr; way_size = dcache->way_size; a0 = base_addr; a1 = a0 + way_incr; a0e = base_addr + extent_per_way; do { asm volatile("ldc %0, sr" : : "r" (sr_with_bl)); asm volatile("movca.l r0, @%0\n\t" "movca.l r0, @%1\n\t" "ocbi @%0\n\t" "ocbi @%1" : : "r" (a0), "r" (a1)); a0 += linesz; a1 += linesz; asm volatile("movca.l r0, @%0\n\t" "movca.l r0, @%1\n\t" "ocbi @%0\n\t" "ocbi @%1" : : "r" (a0), "r" (a1)); a0 += linesz; a1 += linesz; asm volatile("movca.l r0, @%0\n\t" "movca.l r0, @%1\n\t" "ocbi @%0\n\t" "ocbi @%1" : : "r" (a0), "r" (a1)); a0 += linesz; a1 += linesz; asm volatile("movca.l r0, @%0\n\t" "movca.l r0, @%1\n\t" "ocbi @%0\n\t" "ocbi @%1" : : "r" (a0), "r" (a1)); asm volatile("ldc %0, sr" : : "r" (orig_sr)); a0 += linesz; a1 += linesz; } while (a0 < a0e); } static void __flush_dcache_segment_4way(unsigned long start, unsigned long extent_per_way) { unsigned long orig_sr, sr_with_bl; unsigned long base_addr; unsigned long way_incr, linesz, way_size; struct cache_info *dcache; register unsigned long a0, a1, a2, a3, a0e; asm volatile("stc sr, %0" : "=r" (orig_sr)); sr_with_bl = orig_sr | (1<<28); base_addr = ((unsigned long)&empty_zero_page[0]); /* See comment under 1-way above */ base_addr = ((base_addr >> 16) << 16); base_addr |= start; dcache = &boot_cpu_data.dcache; linesz = dcache->linesz; way_incr = dcache->way_incr; way_size = dcache->way_size; a0 = base_addr; a1 = a0 + way_incr; a2 = a1 + way_incr; a3 = a2 + way_incr; a0e = base_addr + extent_per_way; do { asm volatile("ldc %0, sr" : : "r" (sr_with_bl)); asm volatile("movca.l r0, @%0\n\t" "movca.l r0, @%1\n\t" "movca.l r0, @%2\n\t" "movca.l r0, @%3\n\t" "ocbi @%0\n\t" "ocbi @%1\n\t" "ocbi @%2\n\t" "ocbi @%3\n\t" : : "r" (a0), "r" (a1), "r" (a2), "r" (a3)); a0 += linesz; a1 += linesz; a2 += linesz; a3 += linesz; asm volatile("movca.l r0, @%0\n\t" "movca.l r0, @%1\n\t" "movca.l r0, @%2\n\t" "movca.l r0, @%3\n\t" "ocbi @%0\n\t" "ocbi @%1\n\t" "ocbi @%2\n\t" "ocbi @%3\n\t" : : "r" (a0), "r" (a1), "r" (a2), "r" (a3)); a0 += linesz; a1 += linesz; a2 += linesz; a3 += linesz; asm volatile("movca.l r0, @%0\n\t" "movca.l r0, @%1\n\t" "movca.l r0, @%2\n\t" "movca.l r0, @%3\n\t" "ocbi @%0\n\t" "ocbi @%1\n\t" "ocbi @%2\n\t" "ocbi @%3\n\t" : : "r" (a0), "r" (a1), "r" (a2), "r" (a3)); a0 += linesz; a1 += linesz; a2 += linesz; a3 += linesz; asm volatile("movca.l r0, @%0\n\t" "movca.l r0, @%1\n\t" "movca.l r0, @%2\n\t" "movca.l r0, @%3\n\t" "ocbi @%0\n\t" "ocbi @%1\n\t" "ocbi @%2\n\t" "ocbi @%3\n\t" : : "r" (a0), "r" (a1), "r" (a2), "r" (a3)); asm volatile("ldc %0, sr" : : "r" (orig_sr)); a0 += linesz; a1 += linesz; a2 += linesz; a3 += linesz; } while (a0 < a0e); }