aboutsummaryrefslogtreecommitdiff
path: root/arch/frv/mm/dma-alloc.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/frv/mm/dma-alloc.c
downloadlinux-stericsson-2.6.12-rc2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/frv/mm/dma-alloc.c')
-rw-r--r--arch/frv/mm/dma-alloc.c188
1 files changed, 188 insertions, 0 deletions
diff --git a/arch/frv/mm/dma-alloc.c b/arch/frv/mm/dma-alloc.c
new file mode 100644
index 000000000000..4b38d45435f6
--- /dev/null
+++ b/arch/frv/mm/dma-alloc.c
@@ -0,0 +1,188 @@
+/* dma-alloc.c: consistent DMA memory allocation
+ *
+ * Derived from arch/ppc/mm/cachemap.c
+ *
+ * PowerPC version derived from arch/arm/mm/consistent.c
+ * Copyright (C) 2001 Dan Malek (dmalek@jlc.net)
+ *
+ * linux/arch/arm/mm/consistent.c
+ *
+ * Copyright (C) 2000 Russell King
+ *
+ * Consistent memory allocators. Used for DMA devices that want to
+ * share uncached memory with the processor core. The function return
+ * is the virtual address and 'dma_handle' is the physical address.
+ * Mostly stolen from the ARM port, with some changes for PowerPC.
+ * -- Dan
+ * Modified for 36-bit support. -Matt
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/stddef.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+
+#include <asm/pgalloc.h>
+#include <asm/io.h>
+#include <asm/hardirq.h>
+#include <asm/mmu_context.h>
+#include <asm/pgtable.h>
+#include <asm/mmu.h>
+#include <asm/uaccess.h>
+#include <asm/smp.h>
+
+static int map_page(unsigned long va, unsigned long pa, pgprot_t prot)
+{
+ pgd_t *pge;
+ pud_t *pue;
+ pmd_t *pme;
+ pte_t *pte;
+ int err = -ENOMEM;
+
+ spin_lock(&init_mm.page_table_lock);
+
+ /* Use upper 10 bits of VA to index the first level map */
+ pge = pgd_offset_k(va);
+ pue = pud_offset(pge, va);
+ pme = pmd_offset(pue, va);
+
+ /* Use middle 10 bits of VA to index the second-level map */
+ pte = pte_alloc_kernel(&init_mm, pme, va);
+ if (pte != 0) {
+ err = 0;
+ set_pte(pte, mk_pte_phys(pa & PAGE_MASK, prot));
+ }
+
+ spin_unlock(&init_mm.page_table_lock);
+ return err;
+}
+
+/*
+ * This function will allocate the requested contiguous pages and
+ * map them into the kernel's vmalloc() space. This is done so we
+ * get unique mapping for these pages, outside of the kernel's 1:1
+ * virtual:physical mapping. This is necessary so we can cover large
+ * portions of the kernel with single large page TLB entries, and
+ * still get unique uncached pages for consistent DMA.
+ */
+void *consistent_alloc(int gfp, size_t size, dma_addr_t *dma_handle)
+{
+ struct vm_struct *area;
+ unsigned long page, va, pa;
+ void *ret;
+ int order, err, i;
+
+ if (in_interrupt())
+ BUG();
+
+ /* only allocate page size areas */
+ size = PAGE_ALIGN(size);
+ order = get_order(size);
+
+ page = __get_free_pages(gfp, order);
+ if (!page) {
+ BUG();
+ return NULL;
+ }
+
+ /* allocate some common virtual space to map the new pages */
+ area = get_vm_area(size, VM_ALLOC);
+ if (area == 0) {
+ free_pages(page, order);
+ return NULL;
+ }
+ va = VMALLOC_VMADDR(area->addr);
+ ret = (void *) va;
+
+ /* this gives us the real physical address of the first page */
+ *dma_handle = pa = virt_to_bus((void *) page);
+
+ /* set refcount=1 on all pages in an order>0 allocation so that vfree() will actually free
+ * all pages that were allocated.
+ */
+ if (order > 0) {
+ struct page *rpage = virt_to_page(page);
+
+ for (i = 1; i < (1 << order); i++)
+ set_page_count(rpage + i, 1);
+ }
+
+ err = 0;
+ for (i = 0; i < size && err == 0; i += PAGE_SIZE)
+ err = map_page(va + i, pa + i, PAGE_KERNEL_NOCACHE);
+
+ if (err) {
+ vfree((void *) va);
+ return NULL;
+ }
+
+ /* we need to ensure that there are no cachelines in use, or worse dirty in this area
+ * - can't do until after virtual address mappings are created
+ */
+ frv_cache_invalidate(va, va + size);
+
+ return ret;
+}
+
+/*
+ * free page(s) as defined by the above mapping.
+ */
+void consistent_free(void *vaddr)
+{
+ if (in_interrupt())
+ BUG();
+ vfree(vaddr);
+}
+
+/*
+ * make an area consistent.
+ */
+void consistent_sync(void *vaddr, size_t size, int direction)
+{
+ unsigned long start = (unsigned long) vaddr;
+ unsigned long end = start + size;
+
+ switch (direction) {
+ case PCI_DMA_NONE:
+ BUG();
+ case PCI_DMA_FROMDEVICE: /* invalidate only */
+ frv_cache_invalidate(start, end);
+ break;
+ case PCI_DMA_TODEVICE: /* writeback only */
+ frv_dcache_writeback(start, end);
+ break;
+ case PCI_DMA_BIDIRECTIONAL: /* writeback and invalidate */
+ frv_dcache_writeback(start, end);
+ break;
+ }
+}
+
+/*
+ * consistent_sync_page make a page are consistent. identical
+ * to consistent_sync, but takes a struct page instead of a virtual address
+ */
+
+void consistent_sync_page(struct page *page, unsigned long offset,
+ size_t size, int direction)
+{
+ void *start;
+
+ start = page_address(page) + offset;
+ consistent_sync(start, size, direction);
+}