use the generic dma-noncoherent code for hexagon

use the generic dma-noncoherent code for hexagon

[Christoph Hellwig]

Hi Richard,

can you review these patches to switch hexagon to use the generic
dma-noncoherent code?  All the requirements are in mainline already
and we've switched various architectures over to it already.

[PATCH 1/3] hexagon: remove the sync_single_for_cpu DMA operation

[Christoph Hellwig]

hexagon does all the required cache maintainance at dma map time, and none
at unmap time.  It thus has to implement sync_single_for_device to match
the map cace for buffer reuse, but there is no point in doing another
invalidation in the sync_single_cpu_case, which in terms of cache
maintainance is equivalent to the unmap case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/hexagon/kernel/dma.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/arch/hexagon/kernel/dma.c b/arch/hexagon/kernel/dma.c
index 77459df34e2e..d2b717f352f4 100644
--- a/arch/hexagon/kernel/dma.c
+++ b/arch/hexagon/kernel/dma.c
@@ -181,13 +181,6 @@ static dma_addr_t hexagon_map_page(struct device *dev, struct page *page,
 	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)
@@ -205,7 +198,6 @@ const struct dma_map_ops hexagon_dma_ops = {
 	.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,
 };
-- 
2.18.0

[PATCH 2/3] hexagon: implement the sync_sg_for_device DMA operation

[Christoph Hellwig]

This methods needs to provide the equivalent of sync_single_for_device
for each S/G list element, but was missing.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/hexagon/kernel/dma.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/hexagon/kernel/dma.c b/arch/hexagon/kernel/dma.c
index d2b717f352f4..9e46556a227d 100644
--- a/arch/hexagon/kernel/dma.c
+++ b/arch/hexagon/kernel/dma.c
@@ -188,6 +188,18 @@ static void hexagon_sync_single_for_device(struct device *dev,
 	dma_sync(dma_addr_to_virt(dma_handle), size, dir);
 }
 
+static void hexagon_sync_sg_for_device(struct device *dev,
+		struct scatterlist *sgl, int nents, enum dma_data_direction dir)
+{
+	struct scatterlist *sg;
+	int i;
+
+	for_each_sg(sgl, sg, nents, i)
+		hexagon_sync_single_for_device(dev, sg_dma_address(sg),
+				sg->length, dir);
+}
+
+
 static int hexagon_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
 	return dma_addr == HEXAGON_MAPPING_ERROR;
@@ -199,6 +211,7 @@ const struct dma_map_ops hexagon_dma_ops = {
 	.map_sg		= hexagon_map_sg,
 	.map_page	= hexagon_map_page,
 	.sync_single_for_device = hexagon_sync_single_for_device,
+	.sync_sg_for_device = hexagon_sync_sg_for_device,
 	.mapping_error	= hexagon_mapping_error,
 };
 
-- 
2.18.0

[PATCH 3/3] hexagon: use generic dma_noncoherent_ops

[Christoph Hellwig]

Switch to the generic noncoherent direct mapping 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              | 148 ++-----------------------
 4 files changed, 11 insertions(+), 180 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 dd2fd9c0d292..47c4da3d64a4 100644
--- a/arch/hexagon/include/asm/Kbuild
+++ b/arch/hexagon/include/asm/Kbuild
@@ -6,6 +6,7 @@ generic-y += compat.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 9e46556a227d..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,
@@ -144,81 +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_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 void hexagon_sync_sg_for_device(struct device *dev,
-		struct scatterlist *sgl, int nents, enum dma_data_direction dir)
-{
-	struct scatterlist *sg;
-	int i;
-
-	for_each_sg(sgl, sg, nents, i)
-		hexagon_sync_single_for_device(dev, sg_dma_address(sg),
-				sg->length, 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_device = hexagon_sync_single_for_device,
-	.sync_sg_for_device = hexagon_sync_sg_for_device,
-	.mapping_error	= hexagon_mapping_error,
-};
-
-void __init hexagon_dma_init(void)
-{
-	if (dma_ops)
-		return;
-
-	dma_ops = &hexagon_dma_ops;
-}
-- 
2.18.0

Re: [PATCH 1/3] hexagon: remove the sync_single_for_cpu DMA operation

[Richard Kuo]

On Thu, Jul 19, 2018 at 05:56:33AM -0700, Christoph Hellwig wrote:
> hexagon does all the required cache maintainance at dma map time, and none
> at unmap time.  It thus has to implement sync_single_for_device to match
> the map cace for buffer reuse, but there is no point in doing another
> invalidation in the sync_single_cpu_case, which in terms of cache
> maintainance is equivalent to the unmap case.
> 
> Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
> ---
>  arch/hexagon/kernel/dma.c | 8 --------
>  1 file changed, 8 deletions(-)
> 

Patch series looks good.  Definitely appreciate the cleanup.

I can take it through my tree, or if not:

Acked-by: Richard Kuo <rkuo-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>

Thanks!

-- 
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, 
a Linux Foundation Collaborative Project

Re: [PATCH 1/3] hexagon: remove the sync_single_for_cpu DMA operation

[Christoph Hellwig]

On Tue, Jul 24, 2018 at 10:29:48PM -0500, Richard Kuo wrote:
> Patch series looks good.  Definitely appreciate the cleanup.
> 
> I can take it through my tree, or if not:
> 
> Acked-by: Richard Kuo <rkuo-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>

Please take it through your tree, thanks!

Re: [PATCH 1/3] hexagon: remove the sync_single_for_cpu DMA operation

[Christoph Hellwig]

On Wed, Jul 25, 2018 at 06:39:27AM +0200, Christoph Hellwig wrote:
> On Tue, Jul 24, 2018 at 10:29:48PM -0500, Richard Kuo wrote:
> > Patch series looks good.  Definitely appreciate the cleanup.
> > 
> > I can take it through my tree, or if not:
> > 
> > Acked-by: Richard Kuo <rkuo@codeaurora.org>
> 
> Please take it through your tree, thanks!

I haven't seen it in linux-next yet, do you still plan to take it?

Otherwise I'll merge it in the dma-mapping tree.

Re: [PATCH 1/3] hexagon: remove the sync_single_for_cpu DMA operation

[Christoph Hellwig]

On Tue, Jul 31, 2018 at 05:22:29PM +0200, Christoph Hellwig wrote:
> On Wed, Jul 25, 2018 at 06:39:27AM +0200, Christoph Hellwig wrote:
> > On Tue, Jul 24, 2018 at 10:29:48PM -0500, Richard Kuo wrote:
> > > Patch series looks good.  Definitely appreciate the cleanup.
> > > 
> > > I can take it through my tree, or if not:
> > > 
> > > Acked-by: Richard Kuo <rkuo-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
> > 
> > Please take it through your tree, thanks!
> 
> I haven't seen it in linux-next yet, do you still plan to take it?
> 
> Otherwise I'll merge it in the dma-mapping tree.

Given that I haven't seen this in linux-next nor haven't heard back
from you I assume you are on your well deserved summer vacation.

If I don't hear back until tomorrow night I'll merge it through the
dma-mapping tree, so that I have it in linux-next before heading out
to my summer vacation.

Re: [PATCH 1/3] hexagon: remove the sync_single_for_cpu DMA operation

[Richard Kuo]

On Tue, Aug 07, 2018 at 09:01:36AM +0200, Christoph Hellwig wrote:
> On Tue, Jul 31, 2018 at 05:22:29PM +0200, Christoph Hellwig wrote:
> > On Wed, Jul 25, 2018 at 06:39:27AM +0200, Christoph Hellwig wrote:
> > > On Tue, Jul 24, 2018 at 10:29:48PM -0500, Richard Kuo wrote:
> > > > Patch series looks good.  Definitely appreciate the cleanup.
> > > > 
> > > > I can take it through my tree, or if not:
> > > > 
> > > > Acked-by: Richard Kuo <rkuo-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
> > > 
> > > Please take it through your tree, thanks!
> > 
> > I haven't seen it in linux-next yet, do you still plan to take it?
> > 
> > Otherwise I'll merge it in the dma-mapping tree.
> 
> Given that I haven't seen this in linux-next nor haven't heard back
> from you I assume you are on your well deserved summer vacation.
> 
> If I don't hear back until tomorrow night I'll merge it through the
> dma-mapping tree, so that I have it in linux-next before heading out
> to my summer vacation.

I am here, and I have the patch queued up but it's waiting for approval
before I get to push it out through my tree.

That said, I am perfectly fine with this going through a different tree
if expedience is needed.


Thanks,
Richard Kuo


-- 
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, 
a Linux Foundation Collaborative Project

Re: [PATCH 1/3] hexagon: remove the sync_single_for_cpu DMA operation

[Christoph Hellwig]

On Tue, Aug 07, 2018 at 07:19:27PM -0500, Richard Kuo wrote:
> I am here, and I have the patch queued up but it's waiting for approval
> before I get to push it out through my tree.
> 
> That said, I am perfectly fine with this going through a different tree
> if expedience is needed.

I just want to make sure it makes it for 4.19.  In general going through
the arch maintainer tree is preferred, I just don't want to lose it.

Re: [PATCH 1/3] hexagon: remove the sync_single_for_cpu DMA operation

[Christoph Hellwig]

Given that it didn't make 4.19-rc1, I'll pull this into the dma-mapping
tree first thing for 4.20 as I have some other changes that will go on
top of it.