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hexagon: use the generic global coherent pool

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

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Cain <bcain@codeaurora.org>
This commit is contained in:
Christoph Hellwig 2021-06-23 16:11:21 +02:00
parent 22f9feb499
commit c1dec343d7
2 changed files with 12 additions and 46 deletions
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1
arch/hexagon/Kconfig
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@ -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

57
arch/hexagon/kernel/dma.c
View File

@ -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);