1 files changed, 389 insertions, 0 deletions
diff --git a/arch/sh/mm/cache-sh4.c b/arch/sh/mm/cache-sh4.c
new file mode 100644
index 000000000..ddfa9685f
--- /dev/null
+++ b/arch/sh/mm/cache-sh4.c
@@ -0,0 +1,389 @@
+/*
+ * arch/sh/mm/cache-sh4.c
+ *
+ * Copyright (C) 1999, 2000, 2002  Niibe Yutaka
+ * Copyright (C) 2001 - 2009  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 <linux/init.h>
+#include <linux/mm.h>
+#include <linux/io.h>
+#include <linux/mutex.h>
+#include <linux/fs.h>
+#include <linux/highmem.h>
+#include <asm/mmu_context.h>
+#include <asm/cache_insns.h>
+#include <asm/cacheflush.h>
+
+/*
+ * 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_ICACHE_PAGES	32
+
+static void __flush_cache_one(unsigned long addr, unsigned long phys,
+			       unsigned long exec_offset);
+
+/*
+ * 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
+ */
+static void sh4_flush_icache_range(void *args)
+{
+	struct flusher_data *data = args;
+	unsigned long start, end;
+	unsigned long flags, v;
+	int i;
+
+	start = data->addr1;
+	end = data->addr2;
+
+	/* If there are too many pages then just blow away the caches */
+	if (((end - start) >> PAGE_SHIFT) >= MAX_ICACHE_PAGES) {
+		local_flush_cache_all(NULL);
+		return;
+	}
+
+	/*
+	 * Selectively flush d-cache then invalidate the i-cache.
+	 * This is inefficient, so only use this 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) {
+		unsigned long icacheaddr;
+		int j, n;
+
+		__ocbwb(v);
+
+		icacheaddr = CACHE_IC_ADDRESS_ARRAY | (v &
+				cpu_data->icache.entry_mask);
+
+		/* Clear i-cache line valid-bit */
+		n = boot_cpu_data.icache.n_aliases;
+		for (i = 0; i < cpu_data->icache.ways; i++) {
+			for (j = 0; j < n; j++)
+				__raw_writel(0, icacheaddr + (j * PAGE_SIZE));
+			icacheaddr += cpu_data->icache.way_incr;
+		}
+	}
+
+	back_to_cached();
+	local_irq_restore(flags);
+}
+
+static inline void flush_cache_one(unsigned long start, unsigned long phys)
+{
+	unsigned long flags, exec_offset = 0;
+
+	/*
+	 * All types of SH-4 require PC to be uncached to operate on the I-cache.
+	 * Some types of SH-4 require PC to be uncached to operate on the D-cache.
+	 */
+	if ((boot_cpu_data.flags & CPU_HAS_P2_FLUSH_BUG) ||
+	    (start < CACHE_OC_ADDRESS_ARRAY))
+		exec_offset = cached_to_uncached;
+
+	local_irq_save(flags);
+	__flush_cache_one(start, phys, exec_offset);
+	local_irq_restore(flags);
+}
+
+/*
+ * Write back & invalidate the D-cache of the page.
+ * (To avoid "alias" issues)
+ */
+static void sh4_flush_dcache_page(void *arg)
+{
+	struct page *page = arg;
+	unsigned long addr = (unsigned long)page_address(page);
+#ifndef CONFIG_SMP
+	struct address_space *mapping = page_mapping_file(page);
+
+	if (mapping && !mapping_mapped(mapping))
+		clear_bit(PG_dcache_clean, &page->flags);
+	else
+#endif
+		flush_cache_one(CACHE_OC_ADDRESS_ARRAY |
+				(addr & shm_align_mask), page_to_phys(page));
+
+	wmb();
+}
+
+/* TODO: Selective icache invalidation through IC address array.. */
+static void flush_icache_all(void)
+{
+	unsigned long flags, ccr;
+
+	local_irq_save(flags);
+	jump_to_uncached();
+
+	/* Flush I-cache */
+	ccr = __raw_readl(SH_CCR);
+	ccr |= CCR_CACHE_ICI;
+	__raw_writel(ccr, SH_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 void flush_dcache_all(void)
+{
+	unsigned long addr, end_addr, entry_offset;
+
+	end_addr = CACHE_OC_ADDRESS_ARRAY +
+		(current_cpu_data.dcache.sets <<
+		 current_cpu_data.dcache.entry_shift) *
+			current_cpu_data.dcache.ways;
+
+	entry_offset = 1 << current_cpu_data.dcache.entry_shift;
+
+	for (addr = CACHE_OC_ADDRESS_ARRAY; addr < end_addr; ) {
+		__raw_writel(0, addr); addr += entry_offset;
+		__raw_writel(0, addr); addr += entry_offset;
+		__raw_writel(0, addr); addr += entry_offset;
+		__raw_writel(0, addr); addr += entry_offset;
+		__raw_writel(0, addr); addr += entry_offset;
+		__raw_writel(0, addr); addr += entry_offset;
+		__raw_writel(0, addr); addr += entry_offset;
+		__raw_writel(0, addr); addr += entry_offset;
+	}
+}
+
+static void sh4_flush_cache_all(void *unused)
+{
+	flush_dcache_all();
+	flush_icache_all();
+}
+
+/*
+ * 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.
+ *
+ * Caller takes mm->mmap_lock.
+ */
+static void sh4_flush_cache_mm(void *arg)
+{
+	struct mm_struct *mm = arg;
+
+	if (cpu_context(smp_processor_id(), mm) == NO_CONTEXT)
+		return;
+
+	flush_dcache_all();
+}
+
+/*
+ * Write back and invalidate I/D-caches for the page.
+ *
+ * ADDR: Virtual Address (U0 address)
+ * PFN: Physical page number
+ */
+static void sh4_flush_cache_page(void *args)
+{
+	struct flusher_data *data = args;
+	struct vm_area_struct *vma;
+	struct page *page;
+	unsigned long address, pfn, phys;
+	int map_coherent = 0;
+	pmd_t *pmd;
+	pte_t *pte;
+	void *vaddr;
+
+	vma = data->vma;
+	address = data->addr1 & PAGE_MASK;
+	pfn = data->addr2;
+	phys = pfn << PAGE_SHIFT;
+	page = pfn_to_page(pfn);
+
+	if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT)
+		return;
+
+	pmd = pmd_off(vma->vm_mm, address);
+	pte = pte_offset_kernel(pmd, address);
+
+	/* If the page isn't present, there is nothing to do here. */
+	if (!(pte_val(*pte) & _PAGE_PRESENT))
+		return;
+
+	if ((vma->vm_mm == current->active_mm))
+		vaddr = NULL;
+	else {
+		/*
+		 * Use kmap_coherent or kmap_atomic to do flushes for
+		 * another ASID than the current one.
+		 */
+		map_coherent = (current_cpu_data.dcache.n_aliases &&
+			test_bit(PG_dcache_clean, &page->flags) &&
+			page_mapcount(page));
+		if (map_coherent)
+			vaddr = kmap_coherent(page, address);
+		else
+			vaddr = kmap_atomic(page);
+
+		address = (unsigned long)vaddr;
+	}
+
+	flush_cache_one(CACHE_OC_ADDRESS_ARRAY |
+			(address & shm_align_mask), phys);
+
+	if (vma->vm_flags & VM_EXEC)
+		flush_icache_all();
+
+	if (vaddr) {
+		if (map_coherent)
+			kunmap_coherent(vaddr);
+		else
+			kunmap_atomic(vaddr);
+	}
+}
+
+/*
+ * 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.
+ */
+static void sh4_flush_cache_range(void *args)
+{
+	struct flusher_data *data = args;
+	struct vm_area_struct *vma;
+	unsigned long start, end;
+
+	vma = data->vma;
+	start = data->addr1;
+	end = data->addr2;
+
+	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;
+
+	flush_dcache_all();
+
+	if (vma->vm_flags & VM_EXEC)
+		flush_icache_all();
+}
+
+/**
+ * __flush_cache_one
+ *
+ * @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_one(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);
+}
+
+extern void __weak sh4__flush_region_init(void);
+
+/*
+ * SH-4 has virtually indexed and physically tagged cache.
+ */
+void __init sh4_cache_init(void)
+{
+	printk("PVR=%08x CVR=%08x PRR=%08x\n",
+		__raw_readl(CCN_PVR),
+		__raw_readl(CCN_CVR),
+		__raw_readl(CCN_PRR));
+
+	local_flush_icache_range	= sh4_flush_icache_range;
+	local_flush_dcache_page		= sh4_flush_dcache_page;
+	local_flush_cache_all		= sh4_flush_cache_all;
+	local_flush_cache_mm		= sh4_flush_cache_mm;
+	local_flush_cache_dup_mm	= sh4_flush_cache_mm;
+	local_flush_cache_page		= sh4_flush_cache_page;
+	local_flush_cache_range		= sh4_flush_cache_range;
+
+	sh4__flush_region_init();
+}