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linux-next/arch/frv/mb93090-mb00/pci-dma.c
Peter Zijlstra 3e4d3af501 mm: stack based kmap_atomic()
Keep the current interface but ignore the KM_type and use a stack based
approach.

The advantage is that we get rid of crappy code like:

	#define __KM_PTE			\
		(in_nmi() ? KM_NMI_PTE : 	\
		 in_irq() ? KM_IRQ_PTE :	\
		 KM_PTE0)

and in general can stop worrying about what context we're in and what kmap
slots might be appropriate for that.

The downside is that FRV kmap_atomic() gets more expensive.

For now we use a CPP trick suggested by Andrew:

  #define kmap_atomic(page, args...) __kmap_atomic(page)

to avoid having to touch all kmap_atomic() users in a single patch.

[ not compiled on:
  - mn10300: the arch doesn't actually build with highmem to begin with ]

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c]
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:08 -07:00

91 lines
2.1 KiB
C

/* pci-dma.c: Dynamic DMA mapping support for the FRV CPUs that have MMUs
*
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* 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.
*/
#include <linux/types.h>
#include <linux/dma-mapping.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/highmem.h>
#include <linux/scatterlist.h>
#include <asm/io.h>
void *dma_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t gfp)
{
void *ret;
ret = consistent_alloc(gfp, size, dma_handle);
if (ret)
memset(ret, 0, size);
return ret;
}
EXPORT_SYMBOL(dma_alloc_coherent);
void dma_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle)
{
consistent_free(vaddr);
}
EXPORT_SYMBOL(dma_free_coherent);
dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
enum dma_data_direction direction)
{
BUG_ON(direction == DMA_NONE);
frv_cache_wback_inv((unsigned long) ptr, (unsigned long) ptr + size);
return virt_to_bus(ptr);
}
EXPORT_SYMBOL(dma_map_single);
int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction direction)
{
unsigned long dampr2;
void *vaddr;
int i;
BUG_ON(direction == DMA_NONE);
dampr2 = __get_DAMPR(2);
for (i = 0; i < nents; i++) {
vaddr = kmap_atomic_primary(sg_page(&sg[i]), __KM_CACHE);
frv_dcache_writeback((unsigned long) vaddr,
(unsigned long) vaddr + PAGE_SIZE);
}
kunmap_atomic_primary(vaddr, __KM_CACHE);
if (dampr2) {
__set_DAMPR(2, dampr2);
__set_IAMPR(2, dampr2);
}
return nents;
}
EXPORT_SYMBOL(dma_map_sg);
dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset,
size_t size, enum dma_data_direction direction)
{
BUG_ON(direction == DMA_NONE);
flush_dcache_page(page);
return (dma_addr_t) page_to_phys(page) + offset;
}
EXPORT_SYMBOL(dma_map_page);