Commit c1dec343 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

hexagon: use the generic global coherent pool 



Switch hexagon to use the generic code for dma_alloc_coherent from
a global pre-filled pool.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarBrian Cain <bcain@codeaurora.org>
parent 22f9feb4

arch/hexagon/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ config HEXAGON 
	select ARCH_32BIT_OFF_T

	select ARCH_HAS_SYNC_DMA_FOR_DEVICE

	select ARCH_NO_PREEMPT

	select DMA_GLOBAL_POOL

	# Other pending projects/to-do items.

	# select HAVE_REGS_AND_STACK_ACCESS_API

	# select HAVE_HW_BREAKPOINT if PERF_EVENTS

arch/hexagon/kernel/dma.c

+11 −46
Original line number Diff line number Diff line
@@ -7,54 +7,8 @@ 


#include <linux/dma-map-ops.h>

#include <linux/memblock.h>

#include <linux/genalloc.h>

#include <linux/module.h>

#include <asm/page.h>



static struct gen_pool *coherent_pool;





/* Allocates from a pool of uncached memory that was reserved at boot time */



void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_addr,

		gfp_t flag, unsigned long attrs)

{

	void *ret;



	/*

	 * Our max_low_pfn should have been backed off by 16MB in

	 * mm/init.c to create DMA coherent space.  Use that as the VA

	 * for the pool.

	 */



	if (coherent_pool == NULL) {

		coherent_pool = gen_pool_create(PAGE_SHIFT, -1);



		if (coherent_pool == NULL)

			panic("Can't create %s() memory pool!", __func__);

		else

			gen_pool_add(coherent_pool,

				(unsigned long)pfn_to_virt(max_low_pfn),

				hexagon_coherent_pool_size, -1);

	}



	ret = (void *) gen_pool_alloc(coherent_pool, size);



	if (ret) {

		memset(ret, 0, size);

		*dma_addr = (dma_addr_t) virt_to_phys(ret);

	} else

		*dma_addr = ~0;



	return ret;

}



void arch_dma_free(struct device *dev, size_t size, void *vaddr,

		dma_addr_t dma_addr, unsigned long attrs)

{

	gen_pool_free(coherent_pool, (unsigned long) vaddr, size);

}



void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,

		enum dma_data_direction dir)

{
@@ -77,3 +31,14 @@ void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, 
		BUG();

	}

}



/*

 * Our max_low_pfn should have been backed off by 16MB in mm/init.c to create

 * DMA coherent space.  Use that for the pool.

 */

static int __init hexagon_dma_init(void)

{

	return dma_init_global_coherent(PFN_PHYS(max_low_pfn),

					hexagon_coherent_pool_size);

}

core_initcall(hexagon_dma_init);