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// SPDX-License-Identifier: GPL-2.0-only
// SPDX-FileCopyrightText: 2021 Yann Sionneau <ysionneau@kalray.eu>, Kalray Inc.
#include <dma.h>
#include <asm/barrier.h>
#include <asm/io.h>
#include <asm/cache.h>
#include <asm/sfr.h>
#include <asm/sys_arch.h>
/*
* The implementation of arch should follow the following rules:
* map for_cpu for_device unmap
* TO_DEV writeback none writeback none
* FROM_DEV invalidate invalidate(*) invalidate invalidate(*)
* BIDIR writeback invalidate writeback invalidate
*
* (*) - only necessary if the CPU speculatively prefetches.
*
* (see https://lkml.org/lkml/2018/5/18/979)
*/
void dma_sync_single_for_device(dma_addr_t addr, size_t size,
enum dma_data_direction dir)
{
/* dcache is Write-Through: no need to flush to force writeback */
switch (dir) {
case DMA_FROM_DEVICE:
invalidate_dcache_range(addr, addr + size);
break;
case DMA_TO_DEVICE:
case DMA_BIDIRECTIONAL:
/* allow device to read buffer written by CPU */
wmb();
break;
default:
BUG();
}
}
void dma_sync_single_for_cpu(dma_addr_t addr, size_t size,
enum dma_data_direction dir)
{
/* CPU does not speculatively prefetches */
switch (dir) {
case DMA_FROM_DEVICE:
/* invalidate has been done during map/for_device */
case DMA_TO_DEVICE:
break;
case DMA_BIDIRECTIONAL:
invalidate_dcache_range(addr, addr + size);
break;
default:
BUG();
}
}
#define KVX_DDR_ALIAS_OFFSET \
(KVX_DDR_64BIT_RAM_WINDOW_BA - KVX_DDR_32BIT_RAM_WINDOW_BA)
#define KVX_DDR_ALIAS_WINDOW \
(KVX_DDR_64BIT_RAM_WINDOW_BA + KVX_DDR_ALIAS_OFFSET)
/* Local smem is aliased between 0 and 16MB */
#define KVX_SMEM_LOCAL_ALIAS 0x1000000ULL
dma_addr_t dma_map_single(struct device_d *dev, void *ptr, size_t size,
enum dma_data_direction dir)
{
uintptr_t addr = (uintptr_t) ptr;
dma_sync_single_for_device(addr, size, dir);
/* Local smem alias should never be used for dma */
if (addr < KVX_SMEM_LOCAL_ALIAS)
return addr + (1 + kvx_cluster_id()) * KVX_SMEM_LOCAL_ALIAS;
if (dev->dma_mask && addr <= dev->dma_mask)
return addr;
if (addr >= KVX_DDR_ALIAS_WINDOW)
return DMA_ERROR_CODE;
addr -= KVX_DDR_ALIAS_OFFSET;
if (dev->dma_mask && addr > dev->dma_mask)
return DMA_ERROR_CODE;
return addr;
}
void dma_unmap_single(struct device_d *dev, dma_addr_t addr, size_t size,
enum dma_data_direction dir)
{
dma_sync_single_for_cpu(addr, size, dir);
}
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