[PATCH 09/22] hexagon: use generic dma_noncoherent_ops

Christoph Hellwig
2018-04-20T08:04:29Z

Switch to the generic noncoherent direct mapping implementation.

This removes the previous sync_single_for_cpu implementation, which looks
bogus given that no syncing is happening in the similar but more
important unmap_single case.

This adds the previously missing sync_sg_for_device implementation that
matches the pre-existing sync_single_for_device implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/hexagon/Kconfig | 2 +
arch/hexagon/include/asm/Kbuild | 1 +
arch/hexagon/include/asm/dma-mapping.h | 40 -------
arch/hexagon/kernel/dma.c | 143 ++-----------------------
4 files changed, 11 insertions(+), 175 deletions(-)
delete mode 100644 arch/hexagon/include/asm/dma-mapping.h

diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
index 37adb2003033..bcbdcb32935c 100644
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -4,6 +4,7 @@ comment "Linux Kernel Configuration for Hexagon"

config HEXAGON
def_bool y
+ select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select HAVE_OPROFILE
# Other pending projects/to-do items.
# select HAVE_REGS_AND_STACK_ACCESS_API
@@ -28,6 +29,7 @@ config HEXAGON
select GENERIC_CLOCKEVENTS_BROADCAST
select MODULES_USE_ELF_RELA
select GENERIC_CPU_DEVICES
+ select DMA_NONCOHERENT_OPS
---help---
Qualcomm Hexagon is a processor architecture designed for high
performance and low power across a wide variety of applications.
diff --git a/arch/hexagon/include/asm/Kbuild b/arch/hexagon/include/asm/Kbuild
index e9743f689fb8..843a8086e980 100644
--- a/arch/hexagon/include/asm/Kbuild
+++ b/arch/hexagon/include/asm/Kbuild
@@ -5,6 +5,7 @@ generic-y += bugs.h
generic-y += current.h
generic-y += device.h
generic-y += div64.h
+generic-y += dma-mapping.h
generic-y += emergency-restart.h
generic-y += extable.h
generic-y += fb.h
diff --git a/arch/hexagon/include/asm/dma-mapping.h b/arch/hexagon/include/asm/dma-mapping.h
deleted file mode 100644
index 263f6acbfb0f..000000000000
--- a/arch/hexagon/include/asm/dma-mapping.h
+++ /dev/null
@@ -1,40 +0,0 @@
-/*
- * DMA operations for the Hexagon architecture
- *
- * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 and
- * only version 2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA.
- */
-
-#ifndef _ASM_DMA_MAPPING_H
-#define _ASM_DMA_MAPPING_H
-
-#include <linux/types.h>
-#include <linux/cache.h>
-#include <linux/mm.h>
-#include <linux/scatterlist.h>
-#include <linux/dma-debug.h>
-#include <asm/io.h>
-
-struct device;
-
-extern const struct dma_map_ops *dma_ops;
-
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
-{
- return dma_ops;
-}
-
-#endif
diff --git a/arch/hexagon/kernel/dma.c b/arch/hexagon/kernel/dma.c
index 77459df34e2e..ffc4ae8e126f 100644
--- a/arch/hexagon/kernel/dma.c
+++ b/arch/hexagon/kernel/dma.c
@@ -18,32 +18,19 @@
* 02110-1301, USA.
*/

-#include <linux/dma-mapping.h>
-#include <linux/dma-direct.h>
+#include <linux/dma-noncoherent.h>
#include <linux/bootmem.h>
#include <linux/genalloc.h>
-#include <asm/dma-mapping.h>
#include <linux/module.h>
#include <asm/page.h>

-#define HEXAGON_MAPPING_ERROR 0
-
-const struct dma_map_ops *dma_ops;
-EXPORT_SYMBOL(dma_ops);
-
-static inline void *dma_addr_to_virt(dma_addr_t dma_addr)
-{
- return phys_to_virt((unsigned long) dma_addr);
-}
-
static struct gen_pool *coherent_pool;

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

-static void *hexagon_dma_alloc_coherent(struct device *dev, size_t size,
- dma_addr_t *dma_addr, gfp_t flag,
- unsigned long attrs)
+void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_addr,
+ gfp_t flag, unsigned long attrs)
{
void *ret;

@@ -75,58 +62,17 @@ static void *hexagon_dma_alloc_coherent(struct device *dev, size_t size,
return ret;
}

-static void hexagon_free_coherent(struct device *dev, size_t size, void *vaddr,
- dma_addr_t dma_addr, unsigned long attrs)
+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);
}

-static int check_addr(const char *name, struct device *hwdev,
- dma_addr_t bus, size_t size)
-{
- if (hwdev && hwdev->dma_mask && !dma_capable(hwdev, bus, size)) {
- if (*hwdev->dma_mask >= DMA_BIT_MASK(32))
- printk(KERN_ERR
- "%s: overflow %Lx+%zu of device mask %Lx\n",
- name, (long long)bus, size,
- (long long)*hwdev->dma_mask);
- return 0;
- }
- return 1;
-}
-
-static int hexagon_map_sg(struct device *hwdev, struct scatterlist *sg,
- int nents, enum dma_data_direction dir,
- unsigned long attrs)
+void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
+ size_t size, enum dma_data_direction dir)
{
- struct scatterlist *s;
- int i;
-
- WARN_ON(nents == 0 || sg[0].length == 0);
-
- for_each_sg(sg, s, nents, i) {
- s->dma_address = sg_phys(s);
- if (!check_addr("map_sg", hwdev, s->dma_address, s->length))
- return 0;
-
- s->dma_length = s->length;
+ void *addr = phys_to_virt(paddr);

- if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
- continue;
-
- flush_dcache_range(dma_addr_to_virt(s->dma_address),
- dma_addr_to_virt(s->dma_address + s->length));
- }
-
- return nents;
-}
-
-/*
- * address is virtual
- */
-static inline void dma_sync(void *addr, size_t size,
- enum dma_data_direction dir)
-{
switch (dir) {
case DMA_TO_DEVICE:
hexagon_clean_dcache_range((unsigned long) addr,
@@ -144,76 +90,3 @@ static inline void dma_sync(void *addr, size_t size,
BUG();
}
}
-
-/**
- * hexagon_map_page() - maps an address for device DMA
- * @dev: pointer to DMA device
- * @page: pointer to page struct of DMA memory
- * @offset: offset within page
- * @size: size of memory to map
- * @dir: transfer direction
- * @attrs: pointer to DMA attrs (not used)
- *
- * Called to map a memory address to a DMA address prior
- * to accesses to/from device.
- *
- * We don't particularly have many hoops to jump through
- * so far. Straight translation between phys and virtual.
- *
- * DMA is not cache coherent so sync is necessary; this
- * seems to be a convenient place to do it.
- *
- */
-static dma_addr_t hexagon_map_page(struct device *dev, struct page *page,
- unsigned long offset, size_t size,
- enum dma_data_direction dir,
- unsigned long attrs)
-{
- dma_addr_t bus = page_to_phys(page) + offset;
- WARN_ON(size == 0);
-
- if (!check_addr("map_single", dev, bus, size))
- return HEXAGON_MAPPING_ERROR;
-
- if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
- dma_sync(dma_addr_to_virt(bus), size, dir);
-
- return bus;
-}
-
-static void hexagon_sync_single_for_cpu(struct device *dev,
- dma_addr_t dma_handle, size_t size,
- enum dma_data_direction dir)
-{
- dma_sync(dma_addr_to_virt(dma_handle), size, dir);
-}
-
-static void hexagon_sync_single_for_device(struct device *dev,
- dma_addr_t dma_handle, size_t size,
- enum dma_data_direction dir)
-{
- dma_sync(dma_addr_to_virt(dma_handle), size, dir);
-}
-
-static int hexagon_mapping_error(struct device *dev, dma_addr_t dma_addr)
-{
- return dma_addr == HEXAGON_MAPPING_ERROR;
-}
-
-const struct dma_map_ops hexagon_dma_ops = {
- .alloc = hexagon_dma_alloc_coherent,
- .free = hexagon_free_coherent,
- .map_sg = hexagon_map_sg,
- .map_page = hexagon_map_page,
- .sync_single_for_cpu = hexagon_sync_single_for_cpu,
- .sync_single_for_device = hexagon_sync_single_for_device,
- .mapping_error = hexagon_mapping_error,
-};
-
-void __init hexagon_dma_init(void)
-{
- if (dma_ops)
- return;
-
- dma_ops = &hexagon_dma_ops;
-}
--
2.17.0