Commit 9d2ffe5c authored by Max Filippov's avatar Max Filippov
Browse files

xtensa: enable HAVE_DMA_CONTIGUOUS 



Enable HAVE_DMA_CONTIGUOUS, reserve contiguous memory at bootmem_init,
use dma_alloc_from_contiguous and dma_release_from_contiguous in
xtensa_dma_alloc/free.
This allows for big contiguous DMA buffer allocation from designated
area configured in the device tree.

Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
parent 3863c58c

arch/xtensa/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ config XTENSA 
	select GENERIC_SCHED_CLOCK

	select HAVE_DEBUG_KMEMLEAK

	select HAVE_DMA_API_DEBUG

	select HAVE_DMA_CONTIGUOUS

	select HAVE_EXIT_THREAD

	select HAVE_FUNCTION_TRACER

	select HAVE_FUTEX_CMPXCHG if !MMU

arch/xtensa/include/asm/Kbuild

+1 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ generic-y += bug.h 
generic-y += clkdev.h

generic-y += cputime.h

generic-y += div64.h

generic-y += dma-contiguous.h

generic-y += emergency-restart.h

generic-y += errno.h

generic-y += exec.h

arch/xtensa/kernel/pci-dma.c

+17 −4
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
 * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>

 */



#include <linux/dma-contiguous.h>

#include <linux/gfp.h>

#include <linux/highmem.h>

#include <linux/mm.h>
@@ -146,6 +147,8 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size, 
{

	unsigned long ret;

	unsigned long uncached = 0;

	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;

	struct page *page = NULL;



	/* ignore region speicifiers */
@@ -153,11 +156,18 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size, 


	if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))

		flag |= GFP_DMA;

	ret = (unsigned long)__get_free_pages(flag, get_order(size));



	if (ret == 0)

	if (gfpflags_allow_blocking(flag))

		page = dma_alloc_from_contiguous(dev, count, get_order(size));



	if (!page)

		page = alloc_pages(flag, get_order(size));



	if (!page)

		return NULL;



	ret = (unsigned long)page_address(page);



	/* We currently don't support coherent memory outside KSEG */



	BUG_ON(ret < XCHAL_KSEG_CACHED_VADDR ||
@@ -170,16 +180,19 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size, 
	return (void *)uncached;

}



static void xtensa_dma_free(struct device *hwdev, size_t size, void *vaddr,

static void xtensa_dma_free(struct device *dev, size_t size, void *vaddr,

			    dma_addr_t dma_handle, unsigned long attrs)

{

	unsigned long addr = (unsigned long)vaddr +

		XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;

	struct page *page = virt_to_page(addr);

	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;



	BUG_ON(addr < XCHAL_KSEG_CACHED_VADDR ||

	       addr > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1);



	free_pages(addr, get_order(size));

	if (!dma_release_from_contiguous(dev, page, count))

		__free_pages(page, get_order(size));

}



static dma_addr_t xtensa_map_page(struct device *dev, struct page *page,

arch/xtensa/mm/init.c

+2 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <linux/nodemask.h>

#include <linux/mm.h>

#include <linux/of_fdt.h>

#include <linux/dma-contiguous.h>



#include <asm/bootparam.h>

#include <asm/page.h>
@@ -60,6 +61,7 @@ void __init bootmem_init(void) 
	max_low_pfn = min(max_pfn, MAX_LOW_PFN);



	memblock_set_current_limit(PFN_PHYS(max_low_pfn));

	dma_contiguous_reserve(PFN_PHYS(max_low_pfn));



	memblock_dump_all();

}

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