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Commit a1e2833d authored by Paul Mundt's avatar Paul Mundt
Browse files

sh: Kill off broken dma page ops. 



There's no point in keeping these around, they've been broken
for some time, and the dmaenging/async_tx framework provides a
far more reasonable interface.

Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent dd950587

arch/sh/drivers/dma/Kconfig

+0 −17
Original line number Diff line number Diff line
@@ -36,23 +36,6 @@ config NR_DMA_CHANNELS 
	  support. Setting this to a higher value allows for cascading DMACs

	  with additional channels.



config DMA_PAGE_OPS

	bool "Use DMAC for page copy/clear"

	depends on SH_DMA && BROKEN

	help

	  Selecting this option will use a dual-address mode configured channel

	  in the SH DMAC for copy_page()/clear_page(). Primarily a performance

	  hack.



config DMA_PAGE_OPS_CHANNEL

	depends on DMA_PAGE_OPS

	int "DMA channel for sh memory-manager page copy/clear"

	default "3"

	help

	  This allows the specification of the dual address dma channel,

	  in case channel 3 is unavailable. On the SH4, channels 1,2, and 3

	  are dual-address capable.



config SH_DMABRG

	bool "SH7760 DMABRG support"

	depends on CPU_SUBTYPE_SH7760

arch/sh/mm/Makefile

+1 −3
Original line number Diff line number Diff line
@@ -8,9 +8,6 @@ obj-$(CONFIG_CPU_SH2) += cache-sh2.o 
obj-$(CONFIG_CPU_SH3)	+= cache-sh3.o

obj-$(CONFIG_CPU_SH4)	+= cache-sh4.o



obj-$(CONFIG_DMA_PAGE_OPS)	+= pg-dma.o

obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o



mmu-y			:= fault-nommu.o tlb-nommu.o pg-nommu.o

mmu-$(CONFIG_MMU)	:= fault.o clear_page.o copy_page.o tlb-flush.o	\

			   ioremap.o
@@ -27,6 +24,7 @@ obj-$(CONFIG_CPU_SH4) += tlb-sh4.o pg-sh4.o 
obj-$(CONFIG_SH7705_CACHE_32KB) += pg-sh7705.o

endif



obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o

obj-$(CONFIG_SH7705_CACHE_32KB)	+= cache-sh7705.o

obj-$(CONFIG_32BIT)		+= pmb.o

obj-$(CONFIG_NUMA)		+= numa.o

arch/sh/mm/pg-dma.c

deleted100644 → 0
+0 −95
Original line number Diff line number Diff line 
/*

 * arch/sh/mm/pg-dma.c

 *

 * Fast clear_page()/copy_page() implementation using the SH DMAC

 *

 * Copyright (C) 2003  Paul Mundt

 *

 * 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/kernel.h>

#include <linux/module.h>

#include <asm/semaphore.h>

#include <asm/mmu_context.h>

#include <asm/addrspace.h>

#include <asm/atomic.h>

#include <asm/page.h>

#include <asm/dma.h>

#include <asm/io.h>



/* Channel to use for page ops, must be dual-address mode capable. */

static int dma_channel = CONFIG_DMA_PAGE_OPS_CHANNEL;



static void copy_page_dma(void *to, void *from)

{

	/* 

	 * This doesn't seem to get triggered until further along in the

	 * boot process, at which point the DMAC is already initialized.

	 * Fix this in the same fashion as clear_page_dma() in the event

	 * that this crashes due to the DMAC not being initialized.

	 */



	flush_icache_range((unsigned long)from, PAGE_SIZE);

	dma_write_page(dma_channel, (unsigned long)from, (unsigned long)to);

	dma_wait_for_completion(dma_channel);

}



static void clear_page_dma(void *to)

{

	/*

	 * We get invoked quite early on, if the DMAC hasn't been initialized

	 * yet, fall back on the slow manual implementation.

	 */

	if (dma_info[dma_channel].chan != dma_channel) {

		clear_page_slow(to);

		return;

	}



	dma_write_page(dma_channel, (unsigned long)empty_zero_page,

				    (unsigned long)to);



	/*

	 * FIXME: Something is a bit racy here, if we poll the counter right

	 * away, we seem to lock. flushing the page from the dcache doesn't

	 * seem to make a difference one way or the other, though either a full

	 * icache or dcache flush does.

	 *

	 * The location of this is important as well, and must happen prior to

	 * the completion loop but after the transfer was initiated.

	 *

	 * Oddly enough, this doesn't appear to be an issue for copy_page()..

	 */

	flush_icache_range((unsigned long)to, PAGE_SIZE);



	dma_wait_for_completion(dma_channel);

}



static int __init pg_dma_init(void)

{

	int ret;

	

	ret = request_dma(dma_channel, "page ops");

	if (ret != 0)

		return ret;



	copy_page = copy_page_dma;

	clear_page = clear_page_dma;



	return ret;

}



static void __exit pg_dma_exit(void)

{

	free_dma(dma_channel);

}



module_init(pg_dma_init);

module_exit(pg_dma_exit);



MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");

MODULE_DESCRIPTION("Optimized page copy/clear routines using a dual-address mode capable DMAC channel");

MODULE_LICENSE("GPL");