fully convert arm to use dma-direct

fully convert arm to use dma-direct

[Christoph Hellwig]

Hi all,

arm is the last platform not using the dma-direct code for directly
mapped DMA.  With the dmaboune removal from Arnd we can easily switch
arm to always use dma-direct now (it already does for LPAE configs
and nommu).  I'd love to merge this series through the dma-mapping tree
as it gives us the opportunity for additional core dma-mapping
improvements.

Diffstat:
 arch/arm/common/dmabounce.c                          |  582 -------------------
 arch/arm/include/asm/dma-mapping.h                   |  128 ----
 b/arch/arm/Kconfig                                   |    5 
 b/arch/arm/common/Kconfig                            |    6 
 b/arch/arm/common/Makefile                           |    1 
 b/arch/arm/common/sa1111.c                           |   64 --
 b/arch/arm/include/asm/device.h                      |    3 
 b/arch/arm/include/asm/dma-direct.h                  |   49 -
 b/arch/arm/include/asm/memory.h                      |    2 
 b/arch/arm/mach-footbridge/Kconfig                   |    1 
 b/arch/arm/mach-footbridge/common.c                  |   19 
 b/arch/arm/mach-footbridge/include/mach/dma-direct.h |    8 
 b/arch/arm/mach-footbridge/include/mach/memory.h     |    4 
 b/arch/arm/mach-highbank/highbank.c                  |    2 
 b/arch/arm/mach-mvebu/coherency.c                    |    2 
 b/arch/arm/mm/dma-mapping.c                          |  381 ------------
 b/drivers/usb/core/hcd.c                             |   17 
 b/drivers/usb/host/ohci-sa1111.c                     |   25 
 18 files changed, 84 insertions(+), 1215 deletions(-)

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 1/7] ARM: sa1100/assabet: move dmabounce hack to ohci driver

[Christoph Hellwig]

From: Arnd Bergmann <arnd@arndb.de>

The sa1111 platform is one of the two remaining users of the old Arm
specific "dmabounce" code, which is an earlier implementation of the
generic swiotlb.

Linus Walleij submitted a patch that removes dmabounce support from
the ixp4xx, and I had a look at the other user, which is the sa1111
companion chip.

Looking at how dmabounce is used, I could narrow it down to one driver
one three machines:

 - dmabounce is only initialized on assabet/neponset, jornada720 and
   badge4, which are the platforms that have an sa1111 and support
   DMA on it.

 - All three of these suffer from "erratum #7" that requires only
   doing DMA to half the memory sections based on one of the address
   lines, in addition, the neponset also can't DMA to the RAM that
   is connected to sa1111 itself.

 - the pxa lubbock machine also has sa1111, but does not support DMA
   on it and does not set dmabounce.

 - only the OHCI and audio devices on sa1111 support DMA, but as
   there is no audio driver for this hardware, only OHCI remains.

In the OHCI code, I noticed that two other platforms already have
a local bounce buffer support in the form of the "local_mem"
allocator. Specifically, TMIO and SM501 use this on a few other ARM
boards with 16KB or 128KB of local SRAM that can be accessed from the
OHCI and from the CPU.

While this is not the same problem as on sa1111, I could not find a
reason why we can't re-use the existing implementation but replace the
physical SRAM address mapping with a locally allocated DMA buffer.

There are two main downsides:

 - rather than using a dynamically sized pool, this buffer needs
   to be allocated at probe time using a fixed size. Without
   having any idea of what it should be, I picked a size of
   64KB, which is between what the other two OHCI front-ends use
   in their SRAM. If anyone has a better idea what that size
   is reasonable, this can be trivially changed.

 - Previously, only USB transfers to unaddressable memory needed
   to go through the bounce buffer, now all of them do, which may
   impact runtime performance for USB endpoints that do a lot of
   transfers.

On the upside, the local_mem support uses write-combining buffers,
which should be a bit faster for transfers to the device compared to
normal uncached coherent memory as used in dmabounce.

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/arm/common/Kconfig        |  2 +-
 arch/arm/common/sa1111.c       | 64 ----------------------------------
 drivers/usb/core/hcd.c         | 17 +++++++--
 drivers/usb/host/ohci-sa1111.c | 25 +++++++++++++
 4 files changed, 40 insertions(+), 68 deletions(-)

diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig
index c8e198631d418..bc158fd227e12 100644
--- a/arch/arm/common/Kconfig
+++ b/arch/arm/common/Kconfig
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 config SA1111
 	bool
-	select DMABOUNCE if !ARCH_PXA
+	select ZONE_DMA if ARCH_SA1100
 
 config DMABOUNCE
 	bool
diff --git a/arch/arm/common/sa1111.c b/arch/arm/common/sa1111.c
index 5367f03beb468..eaf2b527b0673 100644
--- a/arch/arm/common/sa1111.c
+++ b/arch/arm/common/sa1111.c
@@ -1386,70 +1386,9 @@ void sa1111_driver_unregister(struct sa1111_driver *driver)
 }
 EXPORT_SYMBOL(sa1111_driver_unregister);
 
-#ifdef CONFIG_DMABOUNCE
-/*
- * According to the "Intel StrongARM SA-1111 Microprocessor Companion
- * Chip Specification Update" (June 2000), erratum #7, there is a
- * significant bug in the SA1111 SDRAM shared memory controller.  If
- * an access to a region of memory above 1MB relative to the bank base,
- * it is important that address bit 10 _NOT_ be asserted. Depending
- * on the configuration of the RAM, bit 10 may correspond to one
- * of several different (processor-relative) address bits.
- *
- * This routine only identifies whether or not a given DMA address
- * is susceptible to the bug.
- *
- * This should only get called for sa1111_device types due to the
- * way we configure our device dma_masks.
- */
-static int sa1111_needs_bounce(struct device *dev, dma_addr_t addr, size_t size)
-{
-	/*
-	 * Section 4.6 of the "Intel StrongARM SA-1111 Development Module
-	 * User's Guide" mentions that jumpers R51 and R52 control the
-	 * target of SA-1111 DMA (either SDRAM bank 0 on Assabet, or
-	 * SDRAM bank 1 on Neponset). The default configuration selects
-	 * Assabet, so any address in bank 1 is necessarily invalid.
-	 */
-	return (machine_is_assabet() || machine_is_pfs168()) &&
-		(addr >= 0xc8000000 || (addr + size) >= 0xc8000000);
-}
-
-static int sa1111_notifier_call(struct notifier_block *n, unsigned long action,
-	void *data)
-{
-	struct sa1111_dev *dev = to_sa1111_device(data);
-
-	switch (action) {
-	case BUS_NOTIFY_ADD_DEVICE:
-		if (dev->dev.dma_mask && dev->dma_mask < 0xffffffffUL) {
-			int ret = dmabounce_register_dev(&dev->dev, 1024, 4096,
-					sa1111_needs_bounce);
-			if (ret)
-				dev_err(&dev->dev, "failed to register with dmabounce: %d\n", ret);
-		}
-		break;
-
-	case BUS_NOTIFY_DEL_DEVICE:
-		if (dev->dev.dma_mask && dev->dma_mask < 0xffffffffUL)
-			dmabounce_unregister_dev(&dev->dev);
-		break;
-	}
-	return NOTIFY_OK;
-}
-
-static struct notifier_block sa1111_bus_notifier = {
-	.notifier_call = sa1111_notifier_call,
-};
-#endif
-
 static int __init sa1111_init(void)
 {
 	int ret = bus_register(&sa1111_bus_type);
-#ifdef CONFIG_DMABOUNCE
-	if (ret == 0)
-		bus_register_notifier(&sa1111_bus_type, &sa1111_bus_notifier);
-#endif
 	if (ret == 0)
 		platform_driver_register(&sa1111_device_driver);
 	return ret;
@@ -1458,9 +1397,6 @@ static int __init sa1111_init(void)
 static void __exit sa1111_exit(void)
 {
 	platform_driver_unregister(&sa1111_device_driver);
-#ifdef CONFIG_DMABOUNCE
-	bus_unregister_notifier(&sa1111_bus_type, &sa1111_bus_notifier);
-#endif
 	bus_unregister(&sa1111_bus_type);
 }
 
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index d9712c2602afe..3893be6303522 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1251,7 +1251,8 @@ void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
 EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
 
 /*
- * Some usb host controllers can only perform dma using a small SRAM area.
+ * Some usb host controllers can only perform dma using a small SRAM area,
+ * or have restrictions on addressable DRAM.
  * The usb core itself is however optimized for host controllers that can dma
  * using regular system memory - like pci devices doing bus mastering.
  *
@@ -3100,8 +3101,18 @@ int usb_hcd_setup_local_mem(struct usb_hcd *hcd, phys_addr_t phys_addr,
 	if (IS_ERR(hcd->localmem_pool))
 		return PTR_ERR(hcd->localmem_pool);
 
-	local_mem = devm_memremap(hcd->self.sysdev, phys_addr,
-				  size, MEMREMAP_WC);
+	/*
+	 * if a physical SRAM address was passed, map it, otherwise
+	 * allocate system memory as a buffer.
+	 */
+	if (phys_addr)
+		local_mem = devm_memremap(hcd->self.sysdev, phys_addr,
+					  size, MEMREMAP_WC);
+	else
+		local_mem = dmam_alloc_attrs(hcd->self.sysdev, size, &dma,
+					     GFP_KERNEL,
+					     DMA_ATTR_WRITE_COMBINE);
+
 	if (IS_ERR(local_mem))
 		return PTR_ERR(local_mem);
 
diff --git a/drivers/usb/host/ohci-sa1111.c b/drivers/usb/host/ohci-sa1111.c
index feca826d3f6a8..75c2b28b33794 100644
--- a/drivers/usb/host/ohci-sa1111.c
+++ b/drivers/usb/host/ohci-sa1111.c
@@ -203,6 +203,31 @@ static int ohci_hcd_sa1111_probe(struct sa1111_dev *dev)
 		goto err1;
 	}
 
+	/*
+	 * According to the "Intel StrongARM SA-1111 Microprocessor Companion
+	 * Chip Specification Update" (June 2000), erratum #7, there is a
+	 * significant bug in the SA1111 SDRAM shared memory controller.  If
+	 * an access to a region of memory above 1MB relative to the bank base,
+	 * it is important that address bit 10 _NOT_ be asserted. Depending
+	 * on the configuration of the RAM, bit 10 may correspond to one
+	 * of several different (processor-relative) address bits.
+	 *
+	 * Section 4.6 of the "Intel StrongARM SA-1111 Development Module
+	 * User's Guide" mentions that jumpers R51 and R52 control the
+	 * target of SA-1111 DMA (either SDRAM bank 0 on Assabet, or
+	 * SDRAM bank 1 on Neponset). The default configuration selects
+	 * Assabet, so any address in bank 1 is necessarily invalid.
+	 *
+	 * As a workaround, use a bounce buffer in addressable memory
+	 * as local_mem, relying on ZONE_DMA to provide an area that
+	 * fits within the above constraints.
+	 *
+	 * SZ_64K is an estimate for what size this might need.
+	 */
+	ret = usb_hcd_setup_local_mem(hcd, 0, 0, SZ_64K);
+	if (ret)
+		goto err1;
+
 	if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
 		dev_dbg(&dev->dev, "request_mem_region failed\n");
 		ret = -EBUSY;
-- 
2.30.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 2/7] ARM: remove dmabounce

[Christoph Hellwig]

Remove the now unused dmabounce code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/arm/common/Kconfig            |   4 -
 arch/arm/common/Makefile           |   1 -
 arch/arm/common/dmabounce.c        | 582 -----------------------------
 arch/arm/include/asm/device.h      |   3 -
 arch/arm/include/asm/dma-mapping.h |  29 --
 5 files changed, 619 deletions(-)
 delete mode 100644 arch/arm/common/dmabounce.c

diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig
index bc158fd227e12..d2fdb1796f488 100644
--- a/arch/arm/common/Kconfig
+++ b/arch/arm/common/Kconfig
@@ -3,10 +3,6 @@ config SA1111
 	bool
 	select ZONE_DMA if ARCH_SA1100
 
-config DMABOUNCE
-	bool
-	select ZONE_DMA
-
 config KRAIT_L2_ACCESSORS
 	bool
 
diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
index 8cd574be94cfe..7bae8cbaafe78 100644
--- a/arch/arm/common/Makefile
+++ b/arch/arm/common/Makefile
@@ -6,7 +6,6 @@
 obj-y				+= firmware.o
 
 obj-$(CONFIG_SA1111)		+= sa1111.o
-obj-$(CONFIG_DMABOUNCE)		+= dmabounce.o
 obj-$(CONFIG_KRAIT_L2_ACCESSORS) += krait-l2-accessors.o
 obj-$(CONFIG_SHARP_LOCOMO)	+= locomo.o
 obj-$(CONFIG_SHARP_PARAM)	+= sharpsl_param.o
diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c
deleted file mode 100644
index 7996c04393d50..0000000000000
--- a/arch/arm/common/dmabounce.c
+++ /dev/null
@@ -1,582 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- *  arch/arm/common/dmabounce.c
- *
- *  Special dma_{map/unmap/dma_sync}_* routines for systems that have
- *  limited DMA windows. These functions utilize bounce buffers to
- *  copy data to/from buffers located outside the DMA region. This
- *  only works for systems in which DMA memory is at the bottom of
- *  RAM, the remainder of memory is at the top and the DMA memory
- *  can be marked as ZONE_DMA. Anything beyond that such as discontiguous
- *  DMA windows will require custom implementations that reserve memory
- *  areas at early bootup.
- *
- *  Original version by Brad Parker (brad@heeltoe.com)
- *  Re-written by Christopher Hoover <ch@murgatroid.com>
- *  Made generic by Deepak Saxena <dsaxena@plexity.net>
- *
- *  Copyright (C) 2002 Hewlett Packard Company.
- *  Copyright (C) 2004 MontaVista Software, Inc.
- */
-
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/slab.h>
-#include <linux/page-flags.h>
-#include <linux/device.h>
-#include <linux/dma-direct.h>
-#include <linux/dma-map-ops.h>
-#include <linux/dmapool.h>
-#include <linux/list.h>
-#include <linux/scatterlist.h>
-
-#include <asm/cacheflush.h>
-#include <asm/dma-iommu.h>
-
-#undef STATS
-
-#ifdef STATS
-#define DO_STATS(X) do { X ; } while (0)
-#else
-#define DO_STATS(X) do { } while (0)
-#endif
-
-/* ************************************************** */
-
-struct safe_buffer {
-	struct list_head node;
-
-	/* original request */
-	void		*ptr;
-	size_t		size;
-	int		direction;
-
-	/* safe buffer info */
-	struct dmabounce_pool *pool;
-	void		*safe;
-	dma_addr_t	safe_dma_addr;
-};
-
-struct dmabounce_pool {
-	unsigned long	size;
-	struct dma_pool	*pool;
-#ifdef STATS
-	unsigned long	allocs;
-#endif
-};
-
-struct dmabounce_device_info {
-	struct device *dev;
-	struct list_head safe_buffers;
-#ifdef STATS
-	unsigned long total_allocs;
-	unsigned long map_op_count;
-	unsigned long bounce_count;
-	int attr_res;
-#endif
-	struct dmabounce_pool	small;
-	struct dmabounce_pool	large;
-
-	rwlock_t lock;
-
-	int (*needs_bounce)(struct device *, dma_addr_t, size_t);
-};
-
-#ifdef STATS
-static ssize_t dmabounce_show(struct device *dev, struct device_attribute *attr,
-			      char *buf)
-{
-	struct dmabounce_device_info *device_info = dev->archdata.dmabounce;
-	return sprintf(buf, "%lu %lu %lu %lu %lu %lu\n",
-		device_info->small.allocs,
-		device_info->large.allocs,
-		device_info->total_allocs - device_info->small.allocs -
-			device_info->large.allocs,
-		device_info->total_allocs,
-		device_info->map_op_count,
-		device_info->bounce_count);
-}
-
-static DEVICE_ATTR(dmabounce_stats, 0400, dmabounce_show, NULL);
-#endif
-
-
-/* allocate a 'safe' buffer and keep track of it */
-static inline struct safe_buffer *
-alloc_safe_buffer(struct dmabounce_device_info *device_info, void *ptr,
-		  size_t size, enum dma_data_direction dir)
-{
-	struct safe_buffer *buf;
-	struct dmabounce_pool *pool;
-	struct device *dev = device_info->dev;
-	unsigned long flags;
-
-	dev_dbg(dev, "%s(ptr=%p, size=%d, dir=%d)\n",
-		__func__, ptr, size, dir);
-
-	if (size <= device_info->small.size) {
-		pool = &device_info->small;
-	} else if (size <= device_info->large.size) {
-		pool = &device_info->large;
-	} else {
-		pool = NULL;
-	}
-
-	buf = kmalloc(sizeof(struct safe_buffer), GFP_ATOMIC);
-	if (buf == NULL) {
-		dev_warn(dev, "%s: kmalloc failed\n", __func__);
-		return NULL;
-	}
-
-	buf->ptr = ptr;
-	buf->size = size;
-	buf->direction = dir;
-	buf->pool = pool;
-
-	if (pool) {
-		buf->safe = dma_pool_alloc(pool->pool, GFP_ATOMIC,
-					   &buf->safe_dma_addr);
-	} else {
-		buf->safe = dma_alloc_coherent(dev, size, &buf->safe_dma_addr,
-					       GFP_ATOMIC);
-	}
-
-	if (buf->safe == NULL) {
-		dev_warn(dev,
-			 "%s: could not alloc dma memory (size=%d)\n",
-			 __func__, size);
-		kfree(buf);
-		return NULL;
-	}
-
-#ifdef STATS
-	if (pool)
-		pool->allocs++;
-	device_info->total_allocs++;
-#endif
-
-	write_lock_irqsave(&device_info->lock, flags);
-	list_add(&buf->node, &device_info->safe_buffers);
-	write_unlock_irqrestore(&device_info->lock, flags);
-
-	return buf;
-}
-
-/* determine if a buffer is from our "safe" pool */
-static inline struct safe_buffer *
-find_safe_buffer(struct dmabounce_device_info *device_info, dma_addr_t safe_dma_addr)
-{
-	struct safe_buffer *b, *rb = NULL;
-	unsigned long flags;
-
-	read_lock_irqsave(&device_info->lock, flags);
-
-	list_for_each_entry(b, &device_info->safe_buffers, node)
-		if (b->safe_dma_addr <= safe_dma_addr &&
-		    b->safe_dma_addr + b->size > safe_dma_addr) {
-			rb = b;
-			break;
-		}
-
-	read_unlock_irqrestore(&device_info->lock, flags);
-	return rb;
-}
-
-static inline void
-free_safe_buffer(struct dmabounce_device_info *device_info, struct safe_buffer *buf)
-{
-	unsigned long flags;
-
-	dev_dbg(device_info->dev, "%s(buf=%p)\n", __func__, buf);
-
-	write_lock_irqsave(&device_info->lock, flags);
-
-	list_del(&buf->node);
-
-	write_unlock_irqrestore(&device_info->lock, flags);
-
-	if (buf->pool)
-		dma_pool_free(buf->pool->pool, buf->safe, buf->safe_dma_addr);
-	else
-		dma_free_coherent(device_info->dev, buf->size, buf->safe,
-				    buf->safe_dma_addr);
-
-	kfree(buf);
-}
-
-/* ************************************************** */
-
-static struct safe_buffer *find_safe_buffer_dev(struct device *dev,
-		dma_addr_t dma_addr, const char *where)
-{
-	if (!dev || !dev->archdata.dmabounce)
-		return NULL;
-	if (dma_mapping_error(dev, dma_addr)) {
-		dev_err(dev, "Trying to %s invalid mapping\n", where);
-		return NULL;
-	}
-	return find_safe_buffer(dev->archdata.dmabounce, dma_addr);
-}
-
-static int needs_bounce(struct device *dev, dma_addr_t dma_addr, size_t size)
-{
-	if (!dev || !dev->archdata.dmabounce)
-		return 0;
-
-	if (dev->dma_mask) {
-		unsigned long limit, mask = *dev->dma_mask;
-
-		limit = (mask + 1) & ~mask;
-		if (limit && size > limit) {
-			dev_err(dev, "DMA mapping too big (requested %#x "
-				"mask %#Lx)\n", size, *dev->dma_mask);
-			return -E2BIG;
-		}
-
-		/* Figure out if we need to bounce from the DMA mask. */
-		if ((dma_addr | (dma_addr + size - 1)) & ~mask)
-			return 1;
-	}
-
-	return !!dev->archdata.dmabounce->needs_bounce(dev, dma_addr, size);
-}
-
-static inline dma_addr_t map_single(struct device *dev, void *ptr, size_t size,
-				    enum dma_data_direction dir,
-				    unsigned long attrs)
-{
-	struct dmabounce_device_info *device_info = dev->archdata.dmabounce;
-	struct safe_buffer *buf;
-
-	if (device_info)
-		DO_STATS ( device_info->map_op_count++ );
-
-	buf = alloc_safe_buffer(device_info, ptr, size, dir);
-	if (buf == NULL) {
-		dev_err(dev, "%s: unable to map unsafe buffer %p!\n",
-		       __func__, ptr);
-		return DMA_MAPPING_ERROR;
-	}
-
-	dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x) mapped to %p (dma=%#x)\n",
-		__func__, buf->ptr, virt_to_dma(dev, buf->ptr),
-		buf->safe, buf->safe_dma_addr);
-
-	if ((dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) &&
-	    !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
-		dev_dbg(dev, "%s: copy unsafe %p to safe %p, size %d\n",
-			__func__, ptr, buf->safe, size);
-		memcpy(buf->safe, ptr, size);
-	}
-
-	return buf->safe_dma_addr;
-}
-
-static inline void unmap_single(struct device *dev, struct safe_buffer *buf,
-				size_t size, enum dma_data_direction dir,
-				unsigned long attrs)
-{
-	BUG_ON(buf->size != size);
-	BUG_ON(buf->direction != dir);
-
-	dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x) mapped to %p (dma=%#x)\n",
-		__func__, buf->ptr, virt_to_dma(dev, buf->ptr),
-		buf->safe, buf->safe_dma_addr);
-
-	DO_STATS(dev->archdata.dmabounce->bounce_count++);
-
-	if ((dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) &&
-	    !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
-		void *ptr = buf->ptr;
-
-		dev_dbg(dev, "%s: copy back safe %p to unsafe %p size %d\n",
-			__func__, buf->safe, ptr, size);
-		memcpy(ptr, buf->safe, size);
-
-		/*
-		 * Since we may have written to a page cache page,
-		 * we need to ensure that the data will be coherent
-		 * with user mappings.
-		 */
-		__cpuc_flush_dcache_area(ptr, size);
-	}
-	free_safe_buffer(dev->archdata.dmabounce, buf);
-}
-
-/* ************************************************** */
-
-/*
- * see if a buffer address is in an 'unsafe' range.  if it is
- * allocate a 'safe' buffer and copy the unsafe buffer into it.
- * substitute the safe buffer for the unsafe one.
- * (basically move the buffer from an unsafe area to a safe one)
- */
-static dma_addr_t dmabounce_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 dma_addr;
-	int ret;
-
-	dev_dbg(dev, "%s(page=%p,off=%#lx,size=%zx,dir=%x)\n",
-		__func__, page, offset, size, dir);
-
-	dma_addr = pfn_to_dma(dev, page_to_pfn(page)) + offset;
-
-	ret = needs_bounce(dev, dma_addr, size);
-	if (ret < 0)
-		return DMA_MAPPING_ERROR;
-
-	if (ret == 0) {
-		arm_dma_ops.sync_single_for_device(dev, dma_addr, size, dir);
-		return dma_addr;
-	}
-
-	if (PageHighMem(page)) {
-		dev_err(dev, "DMA buffer bouncing of HIGHMEM pages is not supported\n");
-		return DMA_MAPPING_ERROR;
-	}
-
-	return map_single(dev, page_address(page) + offset, size, dir, attrs);
-}
-
-/*
- * see if a mapped address was really a "safe" buffer and if so, copy
- * the data from the safe buffer back to the unsafe buffer and free up
- * the safe buffer.  (basically return things back to the way they
- * should be)
- */
-static void dmabounce_unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size,
-		enum dma_data_direction dir, unsigned long attrs)
-{
-	struct safe_buffer *buf;
-
-	dev_dbg(dev, "%s(dma=%#x,size=%d,dir=%x)\n",
-		__func__, dma_addr, size, dir);
-
-	buf = find_safe_buffer_dev(dev, dma_addr, __func__);
-	if (!buf) {
-		arm_dma_ops.sync_single_for_cpu(dev, dma_addr, size, dir);
-		return;
-	}
-
-	unmap_single(dev, buf, size, dir, attrs);
-}
-
-static int __dmabounce_sync_for_cpu(struct device *dev, dma_addr_t addr,
-		size_t sz, enum dma_data_direction dir)
-{
-	struct safe_buffer *buf;
-	unsigned long off;
-
-	dev_dbg(dev, "%s(dma=%#x,sz=%zx,dir=%x)\n",
-		__func__, addr, sz, dir);
-
-	buf = find_safe_buffer_dev(dev, addr, __func__);
-	if (!buf)
-		return 1;
-
-	off = addr - buf->safe_dma_addr;
-
-	BUG_ON(buf->direction != dir);
-
-	dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x off=%#lx) mapped to %p (dma=%#x)\n",
-		__func__, buf->ptr, virt_to_dma(dev, buf->ptr), off,
-		buf->safe, buf->safe_dma_addr);
-
-	DO_STATS(dev->archdata.dmabounce->bounce_count++);
-
-	if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) {
-		dev_dbg(dev, "%s: copy back safe %p to unsafe %p size %d\n",
-			__func__, buf->safe + off, buf->ptr + off, sz);
-		memcpy(buf->ptr + off, buf->safe + off, sz);
-	}
-	return 0;
-}
-
-static void dmabounce_sync_for_cpu(struct device *dev,
-		dma_addr_t handle, size_t size, enum dma_data_direction dir)
-{
-	if (!__dmabounce_sync_for_cpu(dev, handle, size, dir))
-		return;
-
-	arm_dma_ops.sync_single_for_cpu(dev, handle, size, dir);
-}
-
-static int __dmabounce_sync_for_device(struct device *dev, dma_addr_t addr,
-		size_t sz, enum dma_data_direction dir)
-{
-	struct safe_buffer *buf;
-	unsigned long off;
-
-	dev_dbg(dev, "%s(dma=%#x,sz=%zx,dir=%x)\n",
-		__func__, addr, sz, dir);
-
-	buf = find_safe_buffer_dev(dev, addr, __func__);
-	if (!buf)
-		return 1;
-
-	off = addr - buf->safe_dma_addr;
-
-	BUG_ON(buf->direction != dir);
-
-	dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x off=%#lx) mapped to %p (dma=%#x)\n",
-		__func__, buf->ptr, virt_to_dma(dev, buf->ptr), off,
-		buf->safe, buf->safe_dma_addr);
-
-	DO_STATS(dev->archdata.dmabounce->bounce_count++);
-
-	if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) {
-		dev_dbg(dev, "%s: copy out unsafe %p to safe %p, size %d\n",
-			__func__,buf->ptr + off, buf->safe + off, sz);
-		memcpy(buf->safe + off, buf->ptr + off, sz);
-	}
-	return 0;
-}
-
-static void dmabounce_sync_for_device(struct device *dev,
-		dma_addr_t handle, size_t size, enum dma_data_direction dir)
-{
-	if (!__dmabounce_sync_for_device(dev, handle, size, dir))
-		return;
-
-	arm_dma_ops.sync_single_for_device(dev, handle, size, dir);
-}
-
-static int dmabounce_dma_supported(struct device *dev, u64 dma_mask)
-{
-	if (dev->archdata.dmabounce)
-		return 0;
-
-	return arm_dma_ops.dma_supported(dev, dma_mask);
-}
-
-static const struct dma_map_ops dmabounce_ops = {
-	.alloc			= arm_dma_alloc,
-	.free			= arm_dma_free,
-	.mmap			= arm_dma_mmap,
-	.get_sgtable		= arm_dma_get_sgtable,
-	.map_page		= dmabounce_map_page,
-	.unmap_page		= dmabounce_unmap_page,
-	.sync_single_for_cpu	= dmabounce_sync_for_cpu,
-	.sync_single_for_device	= dmabounce_sync_for_device,
-	.map_sg			= arm_dma_map_sg,
-	.unmap_sg		= arm_dma_unmap_sg,
-	.sync_sg_for_cpu	= arm_dma_sync_sg_for_cpu,
-	.sync_sg_for_device	= arm_dma_sync_sg_for_device,
-	.dma_supported		= dmabounce_dma_supported,
-};
-
-static int dmabounce_init_pool(struct dmabounce_pool *pool, struct device *dev,
-		const char *name, unsigned long size)
-{
-	pool->size = size;
-	DO_STATS(pool->allocs = 0);
-	pool->pool = dma_pool_create(name, dev, size,
-				     0 /* byte alignment */,
-				     0 /* no page-crossing issues */);
-
-	return pool->pool ? 0 : -ENOMEM;
-}
-
-int dmabounce_register_dev(struct device *dev, unsigned long small_buffer_size,
-		unsigned long large_buffer_size,
-		int (*needs_bounce_fn)(struct device *, dma_addr_t, size_t))
-{
-	struct dmabounce_device_info *device_info;
-	int ret;
-
-	device_info = kmalloc(sizeof(struct dmabounce_device_info), GFP_ATOMIC);
-	if (!device_info) {
-		dev_err(dev,
-			"Could not allocated dmabounce_device_info\n");
-		return -ENOMEM;
-	}
-
-	ret = dmabounce_init_pool(&device_info->small, dev,
-				  "small_dmabounce_pool", small_buffer_size);
-	if (ret) {
-		dev_err(dev,
-			"dmabounce: could not allocate DMA pool for %ld byte objects\n",
-			small_buffer_size);
-		goto err_free;
-	}
-
-	if (large_buffer_size) {
-		ret = dmabounce_init_pool(&device_info->large, dev,
-					  "large_dmabounce_pool",
-					  large_buffer_size);
-		if (ret) {
-			dev_err(dev,
-				"dmabounce: could not allocate DMA pool for %ld byte objects\n",
-				large_buffer_size);
-			goto err_destroy;
-		}
-	}
-
-	device_info->dev = dev;
-	INIT_LIST_HEAD(&device_info->safe_buffers);
-	rwlock_init(&device_info->lock);
-	device_info->needs_bounce = needs_bounce_fn;
-
-#ifdef STATS
-	device_info->total_allocs = 0;
-	device_info->map_op_count = 0;
-	device_info->bounce_count = 0;
-	device_info->attr_res = device_create_file(dev, &dev_attr_dmabounce_stats);
-#endif
-
-	dev->archdata.dmabounce = device_info;
-	set_dma_ops(dev, &dmabounce_ops);
-
-	dev_info(dev, "dmabounce: registered device\n");
-
-	return 0;
-
- err_destroy:
-	dma_pool_destroy(device_info->small.pool);
- err_free:
-	kfree(device_info);
-	return ret;
-}
-EXPORT_SYMBOL(dmabounce_register_dev);
-
-void dmabounce_unregister_dev(struct device *dev)
-{
-	struct dmabounce_device_info *device_info = dev->archdata.dmabounce;
-
-	dev->archdata.dmabounce = NULL;
-	set_dma_ops(dev, NULL);
-
-	if (!device_info) {
-		dev_warn(dev,
-			 "Never registered with dmabounce but attempting"
-			 "to unregister!\n");
-		return;
-	}
-
-	if (!list_empty(&device_info->safe_buffers)) {
-		dev_err(dev,
-			"Removing from dmabounce with pending buffers!\n");
-		BUG();
-	}
-
-	if (device_info->small.pool)
-		dma_pool_destroy(device_info->small.pool);
-	if (device_info->large.pool)
-		dma_pool_destroy(device_info->large.pool);
-
-#ifdef STATS
-	if (device_info->attr_res == 0)
-		device_remove_file(dev, &dev_attr_dmabounce_stats);
-#endif
-
-	kfree(device_info);
-
-	dev_info(dev, "dmabounce: device unregistered\n");
-}
-EXPORT_SYMBOL(dmabounce_unregister_dev);
-
-MODULE_AUTHOR("Christopher Hoover <ch@hpl.hp.com>, Deepak Saxena <dsaxena@plexity.net>");
-MODULE_DESCRIPTION("Special dma_{map/unmap/dma_sync}_* routines for systems with limited DMA windows");
-MODULE_LICENSE("GPL");
diff --git a/arch/arm/include/asm/device.h b/arch/arm/include/asm/device.h
index be666f58bf7ae..8754c0f5fc904 100644
--- a/arch/arm/include/asm/device.h
+++ b/arch/arm/include/asm/device.h
@@ -6,9 +6,6 @@
 #define ASMARM_DEVICE_H
 
 struct dev_archdata {
-#ifdef CONFIG_DMABOUNCE
-	struct dmabounce_device_info *dmabounce;
-#endif
 #ifdef CONFIG_ARM_DMA_USE_IOMMU
 	struct dma_iommu_mapping	*mapping;
 #endif
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 77082246a5e12..1e015a7ad86aa 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -80,35 +80,6 @@ extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
  *
  */
 
-/**
- * dmabounce_register_dev
- *
- * @dev: valid struct device pointer
- * @small_buf_size: size of buffers to use with small buffer pool
- * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
- * @needs_bounce_fn: called to determine whether buffer needs bouncing
- *
- * This function should be called by low-level platform code to register
- * a device as requireing DMA buffer bouncing. The function will allocate
- * appropriate DMA pools for the device.
- */
-extern int dmabounce_register_dev(struct device *, unsigned long,
-		unsigned long, int (*)(struct device *, dma_addr_t, size_t));
-
-/**
- * dmabounce_unregister_dev
- *
- * @dev: valid struct device pointer
- *
- * This function should be called by low-level platform code when device
- * that was previously registered with dmabounce_register_dev is removed
- * from the system.
- *
- */
-extern void dmabounce_unregister_dev(struct device *);
-
-
-
 /*
  * The scatter list versions of the above methods.
  */
-- 
2.30.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 2/7] ARM: remove dmabounce

[Arnd Bergmann]

On Thu, Apr 21, 2022 at 9:41 AM Christoph Hellwig <hch@lst.de> wrote:
>
> Remove the now unused dmabounce code.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 3/7] ARM: mark various dma-mapping routines static in dma-mapping.c

[Christoph Hellwig]

With the dmabounce removal these aren't used outside of dma-mapping.c,
so mark them static.  Move the dma_map_ops declarations down a bit
to avoid lots of forward declarations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/arm/include/asm/dma-mapping.h |  75 ----------------------
 arch/arm/mm/dma-mapping.c          | 100 +++++++++++++----------------
 2 files changed, 46 insertions(+), 129 deletions(-)

diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 1e015a7ad86aa..6427b934bd11c 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -20,80 +20,5 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 	return NULL;
 }
 
-/**
- * arm_dma_alloc - allocate consistent memory for DMA
- * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
- * @size: required memory size
- * @handle: bus-specific DMA address
- * @attrs: optinal attributes that specific mapping properties
- *
- * Allocate some memory for a device for performing DMA.  This function
- * allocates pages, and will return the CPU-viewed address, and sets @handle
- * to be the device-viewed address.
- */
-extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
-			   gfp_t gfp, unsigned long attrs);
-
-/**
- * arm_dma_free - free memory allocated by arm_dma_alloc
- * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
- * @size: size of memory originally requested in dma_alloc_coherent
- * @cpu_addr: CPU-view address returned from dma_alloc_coherent
- * @handle: device-view address returned from dma_alloc_coherent
- * @attrs: optinal attributes that specific mapping properties
- *
- * Free (and unmap) a DMA buffer previously allocated by
- * arm_dma_alloc().
- *
- * References to memory and mappings associated with cpu_addr/handle
- * during and after this call executing are illegal.
- */
-extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
-			 dma_addr_t handle, unsigned long attrs);
-
-/**
- * arm_dma_mmap - map a coherent DMA allocation into user space
- * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
- * @vma: vm_area_struct describing requested user mapping
- * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
- * @handle: device-view address returned from dma_alloc_coherent
- * @size: size of memory originally requested in dma_alloc_coherent
- * @attrs: optinal attributes that specific mapping properties
- *
- * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
- * into user space.  The coherent DMA buffer must not be freed by the
- * driver until the user space mapping has been released.
- */
-extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
-			void *cpu_addr, dma_addr_t dma_addr, size_t size,
-			unsigned long attrs);
-
-/*
- * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
- * and utilize bounce buffers as needed to work around limited DMA windows.
- *
- * On the SA-1111, a bug limits DMA to only certain regions of RAM.
- * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
- * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
- *
- * The following are helper functions used by the dmabounce subystem
- *
- */
-
-/*
- * The scatter list versions of the above methods.
- */
-extern int arm_dma_map_sg(struct device *, struct scatterlist *, int,
-		enum dma_data_direction, unsigned long attrs);
-extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int,
-		enum dma_data_direction, unsigned long attrs);
-extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
-		enum dma_data_direction);
-extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
-		enum dma_data_direction);
-extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
-		void *cpu_addr, dma_addr_t dma_addr, size_t size,
-		unsigned long attrs);
-
 #endif /* __KERNEL__ */
 #endif
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 82ffac621854f..0ee5adbdd3f1d 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -193,50 +193,6 @@ static int arm_dma_supported(struct device *dev, u64 mask)
 	return dma_to_pfn(dev, mask) >= max_dma_pfn;
 }
 
-const struct dma_map_ops arm_dma_ops = {
-	.alloc			= arm_dma_alloc,
-	.free			= arm_dma_free,
-	.alloc_pages		= dma_direct_alloc_pages,
-	.free_pages		= dma_direct_free_pages,
-	.mmap			= arm_dma_mmap,
-	.get_sgtable		= arm_dma_get_sgtable,
-	.map_page		= arm_dma_map_page,
-	.unmap_page		= arm_dma_unmap_page,
-	.map_sg			= arm_dma_map_sg,
-	.unmap_sg		= arm_dma_unmap_sg,
-	.map_resource		= dma_direct_map_resource,
-	.sync_single_for_cpu	= arm_dma_sync_single_for_cpu,
-	.sync_single_for_device	= arm_dma_sync_single_for_device,
-	.sync_sg_for_cpu	= arm_dma_sync_sg_for_cpu,
-	.sync_sg_for_device	= arm_dma_sync_sg_for_device,
-	.dma_supported		= arm_dma_supported,
-	.get_required_mask	= dma_direct_get_required_mask,
-};
-EXPORT_SYMBOL(arm_dma_ops);
-
-static void *arm_coherent_dma_alloc(struct device *dev, size_t size,
-	dma_addr_t *handle, gfp_t gfp, unsigned long attrs);
-static void arm_coherent_dma_free(struct device *dev, size_t size, void *cpu_addr,
-				  dma_addr_t handle, unsigned long attrs);
-static int arm_coherent_dma_mmap(struct device *dev, struct vm_area_struct *vma,
-		 void *cpu_addr, dma_addr_t dma_addr, size_t size,
-		 unsigned long attrs);
-
-const struct dma_map_ops arm_coherent_dma_ops = {
-	.alloc			= arm_coherent_dma_alloc,
-	.free			= arm_coherent_dma_free,
-	.alloc_pages		= dma_direct_alloc_pages,
-	.free_pages		= dma_direct_free_pages,
-	.mmap			= arm_coherent_dma_mmap,
-	.get_sgtable		= arm_dma_get_sgtable,
-	.map_page		= arm_coherent_dma_map_page,
-	.map_sg			= arm_dma_map_sg,
-	.map_resource		= dma_direct_map_resource,
-	.dma_supported		= arm_dma_supported,
-	.get_required_mask	= dma_direct_get_required_mask,
-};
-EXPORT_SYMBOL(arm_coherent_dma_ops);
-
 static void __dma_clear_buffer(struct page *page, size_t size, int coherent_flag)
 {
 	/*
@@ -742,7 +698,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
  * Allocate DMA-coherent memory space and return both the kernel remapped
  * virtual and bus address for that space.
  */
-void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
+static void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
 		    gfp_t gfp, unsigned long attrs)
 {
 	pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL);
@@ -791,7 +747,7 @@ static int arm_coherent_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 	return __arm_dma_mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
 }
 
-int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
+static int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 		 void *cpu_addr, dma_addr_t dma_addr, size_t size,
 		 unsigned long attrs)
 {
@@ -824,7 +780,7 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
 	kfree(buf);
 }
 
-void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
+static void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
 		  dma_addr_t handle, unsigned long attrs)
 {
 	__arm_dma_free(dev, size, cpu_addr, handle, attrs, false);
@@ -836,7 +792,7 @@ static void arm_coherent_dma_free(struct device *dev, size_t size, void *cpu_add
 	__arm_dma_free(dev, size, cpu_addr, handle, attrs, true);
 }
 
-int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
+static int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
 		 void *cpu_addr, dma_addr_t handle, size_t size,
 		 unsigned long attrs)
 {
@@ -977,7 +933,7 @@ static void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
  * Device ownership issues as mentioned for dma_map_single are the same
  * here.
  */
-int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+static int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 		enum dma_data_direction dir, unsigned long attrs)
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
@@ -1013,8 +969,8 @@ int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
  * Unmap a set of streaming mode DMA translations.  Again, CPU access
  * rules concerning calls here are the same as for dma_unmap_single().
  */
-void arm_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
-		enum dma_data_direction dir, unsigned long attrs)
+static void arm_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
+		int nents, enum dma_data_direction dir, unsigned long attrs)
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 	struct scatterlist *s;
@@ -1032,7 +988,7 @@ void arm_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
  * @nents: number of buffers to map (returned from dma_map_sg)
  * @dir: DMA transfer direction (same as was passed to dma_map_sg)
  */
-void arm_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
+static void arm_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
 			int nents, enum dma_data_direction dir)
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
@@ -1051,8 +1007,8 @@ void arm_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
  * @nents: number of buffers to map (returned from dma_map_sg)
  * @dir: DMA transfer direction (same as was passed to dma_map_sg)
  */
-void arm_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
-			int nents, enum dma_data_direction dir)
+static void arm_dma_sync_sg_for_device(struct device *dev,
+		struct scatterlist *sg, int nents, enum dma_data_direction dir)
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 	struct scatterlist *s;
@@ -1063,6 +1019,42 @@ void arm_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 					    dir);
 }
 
+const struct dma_map_ops arm_dma_ops = {
+	.alloc			= arm_dma_alloc,
+	.free			= arm_dma_free,
+	.alloc_pages		= dma_direct_alloc_pages,
+	.free_pages		= dma_direct_free_pages,
+	.mmap			= arm_dma_mmap,
+	.get_sgtable		= arm_dma_get_sgtable,
+	.map_page		= arm_dma_map_page,
+	.unmap_page		= arm_dma_unmap_page,
+	.map_sg			= arm_dma_map_sg,
+	.unmap_sg		= arm_dma_unmap_sg,
+	.map_resource		= dma_direct_map_resource,
+	.sync_single_for_cpu	= arm_dma_sync_single_for_cpu,
+	.sync_single_for_device	= arm_dma_sync_single_for_device,
+	.sync_sg_for_cpu	= arm_dma_sync_sg_for_cpu,
+	.sync_sg_for_device	= arm_dma_sync_sg_for_device,
+	.dma_supported		= arm_dma_supported,
+	.get_required_mask	= dma_direct_get_required_mask,
+};
+EXPORT_SYMBOL(arm_dma_ops);
+
+const struct dma_map_ops arm_coherent_dma_ops = {
+	.alloc			= arm_coherent_dma_alloc,
+	.free			= arm_coherent_dma_free,
+	.alloc_pages		= dma_direct_alloc_pages,
+	.free_pages		= dma_direct_free_pages,
+	.mmap			= arm_coherent_dma_mmap,
+	.get_sgtable		= arm_dma_get_sgtable,
+	.map_page		= arm_coherent_dma_map_page,
+	.map_sg			= arm_dma_map_sg,
+	.map_resource		= dma_direct_map_resource,
+	.dma_supported		= arm_dma_supported,
+	.get_required_mask	= dma_direct_get_required_mask,
+};
+EXPORT_SYMBOL(arm_coherent_dma_ops);
+
 static const struct dma_map_ops *arm_get_dma_map_ops(bool coherent)
 {
 	/*
-- 
2.30.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 3/7] ARM: mark various dma-mapping routines static in dma-mapping.c

[Arnd Bergmann]

On Thu, Apr 21, 2022 at 9:42 AM Christoph Hellwig <hch@lst.de> wrote:
>
> With the dmabounce removal these aren't used outside of dma-mapping.c,
> so mark them static.  Move the dma_map_ops declarations down a bit
> to avoid lots of forward declarations.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 4/7] ARM: remove the unused virt_to_dma helper

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/arm/include/asm/dma-direct.h | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/arch/arm/include/asm/dma-direct.h b/arch/arm/include/asm/dma-direct.h
index 77fcb7ee5ec90..6fd52713b5d12 100644
--- a/arch/arm/include/asm/dma-direct.h
+++ b/arch/arm/include/asm/dma-direct.h
@@ -5,7 +5,7 @@
 #include <asm/memory.h>
 
 /*
- * dma_to_pfn/pfn_to_dma/virt_to_dma are architecture private
+ * dma_to_pfn/pfn_to_dma are architecture private
  * functions used internally by the DMA-mapping API to provide DMA
  * addresses. They must not be used by drivers.
  */
@@ -25,14 +25,6 @@ static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
 	return pfn;
 }
 
-static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
-{
-	if (dev)
-		return pfn_to_dma(dev, virt_to_pfn(addr));
-
-	return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
-}
-
 static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
 {
 	unsigned int offset = paddr & ~PAGE_MASK;
-- 
2.30.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 4/7] ARM: remove the unused virt_to_dma helper

[Arnd Bergmann]

On Thu, Apr 21, 2022 at 9:42 AM Christoph Hellwig <hch@lst.de> wrote:
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

I generally prefer to have at least something useful in the description, e.g.
why it's now unused and what it was used for before.

> -static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
> -{
> -       if (dev)
> -               return pfn_to_dma(dev, virt_to_pfn(addr));
> -
> -       return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
> -}

I think __virt_to_bus() is now unused as well and could be removed
in the same step.

It looks like __bus_to_virt() is still used in the ISA DMA API, but
as that is only used on footbridge and rpc, the generic version of
that could be moved into rpc (footbridge already has a custom
version).

    Arnd

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 4/7] ARM: remove the unused virt_to_dma helper

[Christoph Hellwig]

On Thu, Apr 21, 2022 at 10:00:55AM +0200, Arnd Bergmann wrote:
> I think __virt_to_bus() is now unused as well and could be removed
> in the same step.

Yes.

> It looks like __bus_to_virt() is still used in the ISA DMA API, but
> as that is only used on footbridge and rpc, the generic version of
> that could be moved into rpc (footbridge already has a custom
> version).

That sounds like a useful cleanup, but isn't really in scope for
this series.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 5/7] ARM: use dma_to_phys/phys_to_dma in the dma-mapping code

[Christoph Hellwig]

Use the helpers as expected by the dma-direct code in the old arm
dma-mapping code to ease a gradual switch to the common DMA code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/arm/mm/dma-mapping.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 0ee5adbdd3f1d..e09d79a328fa1 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -128,14 +128,14 @@ static dma_addr_t arm_dma_map_page(struct device *dev, struct page *page,
 {
 	if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
 		__dma_page_cpu_to_dev(page, offset, size, dir);
-	return pfn_to_dma(dev, page_to_pfn(page)) + offset;
+	return phys_to_dma(dev, page_to_phys(page) + offset);
 }
 
 static dma_addr_t arm_coherent_dma_map_page(struct device *dev, struct page *page,
 	     unsigned long offset, size_t size, enum dma_data_direction dir,
 	     unsigned long attrs)
 {
-	return pfn_to_dma(dev, page_to_pfn(page)) + offset;
+	return phys_to_dma(dev, page_to_phys(page) + offset);
 }
 
 /**
@@ -156,7 +156,7 @@ static void arm_dma_unmap_page(struct device *dev, dma_addr_t handle,
 		size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
 	if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
-		__dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
+		__dma_page_dev_to_cpu(phys_to_page(dma_to_phys(dev, handle)),
 				      handle & ~PAGE_MASK, size, dir);
 }
 
@@ -164,7 +164,7 @@ static void arm_dma_sync_single_for_cpu(struct device *dev,
 		dma_addr_t handle, size_t size, enum dma_data_direction dir)
 {
 	unsigned int offset = handle & (PAGE_SIZE - 1);
-	struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset));
+	struct page *page = phys_to_page(dma_to_phys(dev, handle-offset));
 	__dma_page_dev_to_cpu(page, offset, size, dir);
 }
 
@@ -172,7 +172,7 @@ static void arm_dma_sync_single_for_device(struct device *dev,
 		dma_addr_t handle, size_t size, enum dma_data_direction dir)
 {
 	unsigned int offset = handle & (PAGE_SIZE - 1);
-	struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset));
+	struct page *page = phys_to_page(dma_to_phys(dev, handle-offset));
 	__dma_page_cpu_to_dev(page, offset, size, dir);
 }
 
@@ -190,7 +190,7 @@ static int arm_dma_supported(struct device *dev, u64 mask)
 	 * Translate the device's DMA mask to a PFN limit.  This
 	 * PFN number includes the page which we can DMA to.
 	 */
-	return dma_to_pfn(dev, mask) >= max_dma_pfn;
+	return PHYS_PFN(dma_to_phys(dev, mask)) >= max_dma_pfn;
 }
 
 static void __dma_clear_buffer(struct page *page, size_t size, int coherent_flag)
@@ -681,7 +681,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
 	if (page) {
 		unsigned long flags;
 
-		*handle = pfn_to_dma(dev, page_to_pfn(page));
+		*handle = phys_to_dma(dev, page_to_phys(page));
 		buf->virt = args.want_vaddr ? addr : page;
 
 		spin_lock_irqsave(&arm_dma_bufs_lock, flags);
@@ -721,7 +721,7 @@ static int __arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 	int ret = -ENXIO;
 	unsigned long nr_vma_pages = vma_pages(vma);
 	unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
-	unsigned long pfn = dma_to_pfn(dev, dma_addr);
+	unsigned long pfn = PHYS_PFN(dma_to_phys(dev, dma_addr));
 	unsigned long off = vma->vm_pgoff;
 
 	if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
@@ -762,7 +762,7 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
 			   dma_addr_t handle, unsigned long attrs,
 			   bool is_coherent)
 {
-	struct page *page = pfn_to_page(dma_to_pfn(dev, handle));
+	struct page *page = phys_to_page(dma_to_phys(dev, handle));
 	struct arm_dma_buffer *buf;
 	struct arm_dma_free_args args = {
 		.dev = dev,
@@ -796,15 +796,15 @@ static int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
 		 void *cpu_addr, dma_addr_t handle, size_t size,
 		 unsigned long attrs)
 {
-	unsigned long pfn = dma_to_pfn(dev, handle);
+	phys_addr_t paddr = dma_to_phys(dev, handle);
 	struct page *page;
 	int ret;
 
 	/* If the PFN is not valid, we do not have a struct page */
-	if (!pfn_valid(pfn))
+	if (!pfn_valid(PHYS_PFN(paddr)))
 		return -ENXIO;
 
-	page = pfn_to_page(pfn);
+	page = phys_to_page(paddr);
 
 	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
 	if (unlikely(ret))
-- 
2.30.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 5/7] ARM: use dma_to_phys/phys_to_dma in the dma-mapping code

[Arnd Bergmann]

On Thu, Apr 21, 2022 at 9:42 AM Christoph Hellwig <hch@lst.de> wrote:
>
> Use the helpers as expected by the dma-direct code in the old arm
> dma-mapping code to ease a gradual switch to the common DMA code.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 6/7] ARM: use the common dma_to_phys/phys_to_dma implementation where possible

[Christoph Hellwig]

Only the footbridge platforms provide their own DMA address translation
helpers, so switch to the generic version for all other platforms, and
consolidate the footbridge implementation to remove two levels of
indirection.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/arm/Kconfig                              |  1 -
 arch/arm/include/asm/dma-direct.h             | 41 +------------------
 arch/arm/include/asm/memory.h                 |  2 -
 arch/arm/mach-footbridge/Kconfig              |  1 +
 arch/arm/mach-footbridge/common.c             | 19 +++++----
 .../mach-footbridge/include/mach/dma-direct.h |  8 ++++
 .../arm/mach-footbridge/include/mach/memory.h |  4 --
 7 files changed, 21 insertions(+), 55 deletions(-)
 create mode 100644 arch/arm/mach-footbridge/include/mach/dma-direct.h

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 2e8091e2d8a86..ac2e3e4957d66 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -15,7 +15,6 @@ config ARM
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
-	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_SETUP_DMA_OPS
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
diff --git a/arch/arm/include/asm/dma-direct.h b/arch/arm/include/asm/dma-direct.h
index 6fd52713b5d12..4f7bcde03abb5 100644
--- a/arch/arm/include/asm/dma-direct.h
+++ b/arch/arm/include/asm/dma-direct.h
@@ -1,40 +1 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef ASM_ARM_DMA_DIRECT_H
-#define ASM_ARM_DMA_DIRECT_H 1
-
-#include <asm/memory.h>
-
-/*
- * dma_to_pfn/pfn_to_dma are architecture private
- * functions used internally by the DMA-mapping API to provide DMA
- * addresses. They must not be used by drivers.
- */
-static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
-{
-	if (dev && dev->dma_range_map)
-		pfn = PFN_DOWN(translate_phys_to_dma(dev, PFN_PHYS(pfn)));
-	return (dma_addr_t)__pfn_to_bus(pfn);
-}
-
-static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
-{
-	unsigned long pfn = __bus_to_pfn(addr);
-
-	if (dev && dev->dma_range_map)
-		pfn = PFN_DOWN(translate_dma_to_phys(dev, PFN_PHYS(pfn)));
-	return pfn;
-}
-
-static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
-{
-	unsigned int offset = paddr & ~PAGE_MASK;
-	return pfn_to_dma(dev, __phys_to_pfn(paddr)) + offset;
-}
-
-static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
-{
-	unsigned int offset = dev_addr & ~PAGE_MASK;
-	return __pfn_to_phys(dma_to_pfn(dev, dev_addr)) + offset;
-}
-
-#endif /* ASM_ARM_DMA_DIRECT_H */
+#include <mach/dma-direct.h>
diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
index f673e13e0f942..a55a9038abc89 100644
--- a/arch/arm/include/asm/memory.h
+++ b/arch/arm/include/asm/memory.h
@@ -378,8 +378,6 @@ static inline unsigned long __virt_to_idmap(unsigned long x)
 #ifndef __virt_to_bus
 #define __virt_to_bus	__virt_to_phys
 #define __bus_to_virt	__phys_to_virt
-#define __pfn_to_bus(x)	__pfn_to_phys(x)
-#define __bus_to_pfn(x)	__phys_to_pfn(x)
 #endif
 
 /*
diff --git a/arch/arm/mach-footbridge/Kconfig b/arch/arm/mach-footbridge/Kconfig
index 728aff93fba9d..b5bbdcf2e4896 100644
--- a/arch/arm/mach-footbridge/Kconfig
+++ b/arch/arm/mach-footbridge/Kconfig
@@ -60,6 +60,7 @@ endmenu
 
 # Footbridge support
 config FOOTBRIDGE
+	select ARCH_HAS_PHYS_TO_DMA
 	bool
 
 # Footbridge in host mode
diff --git a/arch/arm/mach-footbridge/common.c b/arch/arm/mach-footbridge/common.c
index 322495df271d5..5020eb96b025d 100644
--- a/arch/arm/mach-footbridge/common.c
+++ b/arch/arm/mach-footbridge/common.c
@@ -12,6 +12,7 @@
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/spinlock.h>
+#include <linux/dma-direct.h>
 #include <video/vga.h>
 
 #include <asm/page.h>
@@ -335,17 +336,19 @@ unsigned long __bus_to_virt(unsigned long res)
 	return res;
 }
 EXPORT_SYMBOL(__bus_to_virt);
-
-unsigned long __pfn_to_bus(unsigned long pfn)
+#else
+static inline unsigned long fb_bus_sdram_offset(void)
 {
-	return __pfn_to_phys(pfn) + (fb_bus_sdram_offset() - PHYS_OFFSET);
+	return BUS_OFFSET;
 }
-EXPORT_SYMBOL(__pfn_to_bus);
+#endif /* CONFIG_FOOTBRIDGE_ADDIN */
 
-unsigned long __bus_to_pfn(unsigned long bus)
+dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
 {
-	return __phys_to_pfn(bus - (fb_bus_sdram_offset() - PHYS_OFFSET));
+	return paddr + (fb_bus_sdram_offset() - PHYS_OFFSET);
 }
-EXPORT_SYMBOL(__bus_to_pfn);
 
-#endif
+phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
+{
+	return dev_addr - (fb_bus_sdram_offset() - PHYS_OFFSET);
+}
diff --git a/arch/arm/mach-footbridge/include/mach/dma-direct.h b/arch/arm/mach-footbridge/include/mach/dma-direct.h
new file mode 100644
index 0000000000000..01f9e8367c009
--- /dev/null
+++ b/arch/arm/mach-footbridge/include/mach/dma-direct.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef MACH_FOOTBRIDGE_DMA_DIRECT_H
+#define MACH_FOOTBRIDGE_DMA_DIRECT_H 1
+
+dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
+phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr);
+
+#endif /* MACH_FOOTBRIDGE_DMA_DIRECT_H */
diff --git a/arch/arm/mach-footbridge/include/mach/memory.h b/arch/arm/mach-footbridge/include/mach/memory.h
index 46fd4a8872b9a..3a5d2638c18f8 100644
--- a/arch/arm/mach-footbridge/include/mach/memory.h
+++ b/arch/arm/mach-footbridge/include/mach/memory.h
@@ -26,8 +26,6 @@
 #ifndef __ASSEMBLY__
 extern unsigned long __virt_to_bus(unsigned long);
 extern unsigned long __bus_to_virt(unsigned long);
-extern unsigned long __pfn_to_bus(unsigned long);
-extern unsigned long __bus_to_pfn(unsigned long);
 #endif
 #define __virt_to_bus	__virt_to_bus
 #define __bus_to_virt	__bus_to_virt
@@ -42,8 +40,6 @@ extern unsigned long __bus_to_pfn(unsigned long);
 #define BUS_OFFSET		0xe0000000
 #define __virt_to_bus(x)	((x) + (BUS_OFFSET - PAGE_OFFSET))
 #define __bus_to_virt(x)	((x) - (BUS_OFFSET - PAGE_OFFSET))
-#define __pfn_to_bus(x)		(__pfn_to_phys(x) + (BUS_OFFSET - PHYS_OFFSET))
-#define __bus_to_pfn(x)		__phys_to_pfn((x) - (BUS_OFFSET - PHYS_OFFSET))
 
 #else
 
-- 
2.30.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 6/7] ARM: use the common dma_to_phys/phys_to_dma implementation where possible

[Arnd Bergmann]

On Thu, Apr 21, 2022 at 9:42 AM Christoph Hellwig <hch@lst.de> wrote:
>
> Only the footbridge platforms provide their own DMA address translation
> helpers, so switch to the generic version for all other platforms, and
> consolidate the footbridge implementation to remove two levels of
> indirection.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

> ---
> @@ -335,17 +336,19 @@ unsigned long __bus_to_virt(unsigned long res)
>         return res;
>  }
>  EXPORT_SYMBOL(__bus_to_virt);
> -
> -unsigned long __pfn_to_bus(unsigned long pfn)
> +#else
> +static inline unsigned long fb_bus_sdram_offset(void)
>  {
> -       return __pfn_to_phys(pfn) + (fb_bus_sdram_offset() - PHYS_OFFSET);
> +       return BUS_OFFSET;
>  }
> -EXPORT_SYMBOL(__pfn_to_bus);
> +#endif /* CONFIG_FOOTBRIDGE_ADDIN */

I have an older patch to remove CONFIG_FOOTBRIDGE_ADDIN
completely, as it does a couple of other nasty things and there are
apparently no users. Would that help here?

       Arnd

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 6/7] ARM: use the common dma_to_phys/phys_to_dma implementation where possible

[Christoph Hellwig]

On Thu, Apr 21, 2022 at 10:05:11AM +0200, Arnd Bergmann wrote:
> > -unsigned long __pfn_to_bus(unsigned long pfn)
> > +#else
> > +static inline unsigned long fb_bus_sdram_offset(void)
> >  {
> > -       return __pfn_to_phys(pfn) + (fb_bus_sdram_offset() - PHYS_OFFSET);
> > +       return BUS_OFFSET;
> >  }
> > -EXPORT_SYMBOL(__pfn_to_bus);
> > +#endif /* CONFIG_FOOTBRIDGE_ADDIN */
> 
> I have an older patch to remove CONFIG_FOOTBRIDGE_ADDIN
> completely, as it does a couple of other nasty things and there are
> apparently no users. Would that help here?

For this series it doesn't really make much of a difference.  The addin
case actually is simpler than the host mode for DMA,  But overall
CONFIG_FOOTBRIDGE_ADDIN seems to be a collection of special cases, so
if it is unused and can be remove that would probably be a good thing.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 7/7] ARM: use dma-direct unconditionally

[Christoph Hellwig]

Use dma-direct unconditionally on arm.  It has already been used for
some time for LPAE and nommu configurations.

This mostly changes the streaming mapping implementation and the (simple)
coherent allocator for device that are DMA coherent.  The existing
complex allocator for uncached mappings for non-coherent devices is still
used as is using the arch_dma_alloc/arch_dma_free hooks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/arm/Kconfig                   |   4 +-
 arch/arm/include/asm/dma-mapping.h |  24 --
 arch/arm/mach-highbank/highbank.c  |   2 +-
 arch/arm/mach-mvebu/coherency.c    |   2 +-
 arch/arm/mm/dma-mapping.c          | 365 ++---------------------------
 5 files changed, 19 insertions(+), 378 deletions(-)
 delete mode 100644 arch/arm/include/asm/dma-mapping.h

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index ac2e3e4957d66..3258630beee6c 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -19,8 +19,8 @@ config ARM
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
 	select ARCH_HAS_STRICT_MODULE_RWX if MMU
-	select ARCH_HAS_SYNC_DMA_FOR_DEVICE if SWIOTLB || !MMU
-	select ARCH_HAS_SYNC_DMA_FOR_CPU if SWIOTLB || !MMU
+	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
+	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_TEARDOWN_DMA_OPS if MMU
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAVE_CUSTOM_GPIO_H
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
deleted file mode 100644
index 6427b934bd11c..0000000000000
--- a/arch/arm/include/asm/dma-mapping.h
+++ /dev/null
@@ -1,24 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef ASMARM_DMA_MAPPING_H
-#define ASMARM_DMA_MAPPING_H
-
-#ifdef __KERNEL__
-
-#include <linux/mm_types.h>
-#include <linux/scatterlist.h>
-
-#include <xen/xen.h>
-#include <asm/xen/hypervisor.h>
-
-extern const struct dma_map_ops arm_dma_ops;
-extern const struct dma_map_ops arm_coherent_dma_ops;
-
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
-{
-	if (IS_ENABLED(CONFIG_MMU) && !IS_ENABLED(CONFIG_ARM_LPAE))
-		return &arm_dma_ops;
-	return NULL;
-}
-
-#endif /* __KERNEL__ */
-#endif
diff --git a/arch/arm/mach-highbank/highbank.c b/arch/arm/mach-highbank/highbank.c
index db607955a7e45..5d4f977ac7d2a 100644
--- a/arch/arm/mach-highbank/highbank.c
+++ b/arch/arm/mach-highbank/highbank.c
@@ -98,7 +98,7 @@ static int highbank_platform_notifier(struct notifier_block *nb,
 	if (of_property_read_bool(dev->of_node, "dma-coherent")) {
 		val = readl(sregs_base + reg);
 		writel(val | 0xff01, sregs_base + reg);
-		set_dma_ops(dev, &arm_coherent_dma_ops);
+		dev->dma_coherent = true;
 	}
 
 	return NOTIFY_OK;
diff --git a/arch/arm/mach-mvebu/coherency.c b/arch/arm/mach-mvebu/coherency.c
index 49e3c8d20c2fa..865ac4bc060df 100644
--- a/arch/arm/mach-mvebu/coherency.c
+++ b/arch/arm/mach-mvebu/coherency.c
@@ -98,7 +98,7 @@ static int mvebu_hwcc_notifier(struct notifier_block *nb,
 
 	if (event != BUS_NOTIFY_ADD_DEVICE)
 		return NOTIFY_DONE;
-	set_dma_ops(dev, &arm_coherent_dma_ops);
+	dev->dma_coherent = true;
 
 	return NOTIFY_OK;
 }
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index e09d79a328fa1..0f76222cbcbb9 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -103,79 +103,8 @@ static struct arm_dma_buffer *arm_dma_buffer_find(void *virt)
  * before transfers and delay cache invalidation until transfer completion.
  *
  */
-static void __dma_page_cpu_to_dev(struct page *, unsigned long,
-		size_t, enum dma_data_direction);
-static void __dma_page_dev_to_cpu(struct page *, unsigned long,
-		size_t, enum dma_data_direction);
-
-/**
- * arm_dma_map_page - map a portion of a page for streaming DMA
- * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
- * @page: page that buffer resides in
- * @offset: offset into page for start of buffer
- * @size: size of buffer to map
- * @dir: DMA transfer direction
- *
- * Ensure that any data held in the cache is appropriately discarded
- * or written back.
- *
- * The device owns this memory once this call has completed.  The CPU
- * can regain ownership by calling dma_unmap_page().
- */
-static dma_addr_t arm_dma_map_page(struct device *dev, struct page *page,
-	     unsigned long offset, size_t size, enum dma_data_direction dir,
-	     unsigned long attrs)
-{
-	if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
-		__dma_page_cpu_to_dev(page, offset, size, dir);
-	return phys_to_dma(dev, page_to_phys(page) + offset);
-}
-
-static dma_addr_t arm_coherent_dma_map_page(struct device *dev, struct page *page,
-	     unsigned long offset, size_t size, enum dma_data_direction dir,
-	     unsigned long attrs)
-{
-	return phys_to_dma(dev, page_to_phys(page) + offset);
-}
-
-/**
- * arm_dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
- * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
- * @handle: DMA address of buffer
- * @size: size of buffer (same as passed to dma_map_page)
- * @dir: DMA transfer direction (same as passed to dma_map_page)
- *
- * Unmap a page streaming mode DMA translation.  The handle and size
- * must match what was provided in the previous dma_map_page() call.
- * All other usages are undefined.
- *
- * After this call, reads by the CPU to the buffer are guaranteed to see
- * whatever the device wrote there.
- */
-static void arm_dma_unmap_page(struct device *dev, dma_addr_t handle,
-		size_t size, enum dma_data_direction dir, unsigned long attrs)
-{
-	if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
-		__dma_page_dev_to_cpu(phys_to_page(dma_to_phys(dev, handle)),
-				      handle & ~PAGE_MASK, size, dir);
-}
-
-static void arm_dma_sync_single_for_cpu(struct device *dev,
-		dma_addr_t handle, size_t size, enum dma_data_direction dir)
-{
-	unsigned int offset = handle & (PAGE_SIZE - 1);
-	struct page *page = phys_to_page(dma_to_phys(dev, handle-offset));
-	__dma_page_dev_to_cpu(page, offset, size, dir);
-}
-
-static void arm_dma_sync_single_for_device(struct device *dev,
-		dma_addr_t handle, size_t size, enum dma_data_direction dir)
-{
-	unsigned int offset = handle & (PAGE_SIZE - 1);
-	struct page *page = phys_to_page(dma_to_phys(dev, handle-offset));
-	__dma_page_cpu_to_dev(page, offset, size, dir);
-}
 
+#ifdef CONFIG_ARM_DMA_USE_IOMMU
 /*
  * Return whether the given device DMA address mask can be supported
  * properly.  For example, if your device can only drive the low 24-bits
@@ -192,6 +121,7 @@ static int arm_dma_supported(struct device *dev, u64 mask)
 	 */
 	return PHYS_PFN(dma_to_phys(dev, mask)) >= max_dma_pfn;
 }
+#endif
 
 static void __dma_clear_buffer(struct page *page, size_t size, int coherent_flag)
 {
@@ -694,67 +624,6 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
 	return args.want_vaddr ? addr : page;
 }
 
-/*
- * Allocate DMA-coherent memory space and return both the kernel remapped
- * virtual and bus address for that space.
- */
-static void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
-		    gfp_t gfp, unsigned long attrs)
-{
-	pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL);
-
-	return __dma_alloc(dev, size, handle, gfp, prot, false,
-			   attrs, __builtin_return_address(0));
-}
-
-static void *arm_coherent_dma_alloc(struct device *dev, size_t size,
-	dma_addr_t *handle, gfp_t gfp, unsigned long attrs)
-{
-	return __dma_alloc(dev, size, handle, gfp, PAGE_KERNEL, true,
-			   attrs, __builtin_return_address(0));
-}
-
-static int __arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
-		 void *cpu_addr, dma_addr_t dma_addr, size_t size,
-		 unsigned long attrs)
-{
-	int ret = -ENXIO;
-	unsigned long nr_vma_pages = vma_pages(vma);
-	unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
-	unsigned long pfn = PHYS_PFN(dma_to_phys(dev, dma_addr));
-	unsigned long off = vma->vm_pgoff;
-
-	if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
-		return ret;
-
-	if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
-		ret = remap_pfn_range(vma, vma->vm_start,
-				      pfn + off,
-				      vma->vm_end - vma->vm_start,
-				      vma->vm_page_prot);
-	}
-
-	return ret;
-}
-
-/*
- * Create userspace mapping for the DMA-coherent memory.
- */
-static int arm_coherent_dma_mmap(struct device *dev, struct vm_area_struct *vma,
-		 void *cpu_addr, dma_addr_t dma_addr, size_t size,
-		 unsigned long attrs)
-{
-	return __arm_dma_mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
-}
-
-static int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
-		 void *cpu_addr, dma_addr_t dma_addr, size_t size,
-		 unsigned long attrs)
-{
-	vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
-	return __arm_dma_mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
-}
-
 /*
  * Free a buffer as defined by the above mapping.
  */
@@ -780,40 +649,6 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
 	kfree(buf);
 }
 
-static void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
-		  dma_addr_t handle, unsigned long attrs)
-{
-	__arm_dma_free(dev, size, cpu_addr, handle, attrs, false);
-}
-
-static void arm_coherent_dma_free(struct device *dev, size_t size, void *cpu_addr,
-				  dma_addr_t handle, unsigned long attrs)
-{
-	__arm_dma_free(dev, size, cpu_addr, handle, attrs, true);
-}
-
-static int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
-		 void *cpu_addr, dma_addr_t handle, size_t size,
-		 unsigned long attrs)
-{
-	phys_addr_t paddr = dma_to_phys(dev, handle);
-	struct page *page;
-	int ret;
-
-	/* If the PFN is not valid, we do not have a struct page */
-	if (!pfn_valid(PHYS_PFN(paddr)))
-		return -ENXIO;
-
-	page = phys_to_page(paddr);
-
-	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
-	if (unlikely(ret))
-		return ret;
-
-	sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
-	return 0;
-}
-
 static void dma_cache_maint_page(struct page *page, unsigned long offset,
 	size_t size, enum dma_data_direction dir,
 	void (*op)(const void *, size_t, int))
@@ -917,158 +752,6 @@ static void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
 	}
 }
 
-/**
- * arm_dma_map_sg - map a set of SG buffers for streaming mode DMA
- * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
- * @sg: list of buffers
- * @nents: number of buffers to map
- * @dir: DMA transfer direction
- *
- * Map a set of buffers described by scatterlist in streaming mode for DMA.
- * This is the scatter-gather version of the dma_map_single interface.
- * Here the scatter gather list elements are each tagged with the
- * appropriate dma address and length.  They are obtained via
- * sg_dma_{address,length}.
- *
- * Device ownership issues as mentioned for dma_map_single are the same
- * here.
- */
-static int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
-		enum dma_data_direction dir, unsigned long attrs)
-{
-	const struct dma_map_ops *ops = get_dma_ops(dev);
-	struct scatterlist *s;
-	int i, j, ret;
-
-	for_each_sg(sg, s, nents, i) {
-#ifdef CONFIG_NEED_SG_DMA_LENGTH
-		s->dma_length = s->length;
-#endif
-		s->dma_address = ops->map_page(dev, sg_page(s), s->offset,
-						s->length, dir, attrs);
-		if (dma_mapping_error(dev, s->dma_address)) {
-			ret = -EIO;
-			goto bad_mapping;
-		}
-	}
-	return nents;
-
- bad_mapping:
-	for_each_sg(sg, s, i, j)
-		ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs);
-	return ret;
-}
-
-/**
- * arm_dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
- * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
- * @sg: list of buffers
- * @nents: number of buffers to unmap (same as was passed to dma_map_sg)
- * @dir: DMA transfer direction (same as was passed to dma_map_sg)
- *
- * Unmap a set of streaming mode DMA translations.  Again, CPU access
- * rules concerning calls here are the same as for dma_unmap_single().
- */
-static void arm_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
-		int nents, enum dma_data_direction dir, unsigned long attrs)
-{
-	const struct dma_map_ops *ops = get_dma_ops(dev);
-	struct scatterlist *s;
-
-	int i;
-
-	for_each_sg(sg, s, nents, i)
-		ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs);
-}
-
-/**
- * arm_dma_sync_sg_for_cpu
- * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
- * @sg: list of buffers
- * @nents: number of buffers to map (returned from dma_map_sg)
- * @dir: DMA transfer direction (same as was passed to dma_map_sg)
- */
-static void arm_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
-			int nents, enum dma_data_direction dir)
-{
-	const struct dma_map_ops *ops = get_dma_ops(dev);
-	struct scatterlist *s;
-	int i;
-
-	for_each_sg(sg, s, nents, i)
-		ops->sync_single_for_cpu(dev, sg_dma_address(s), s->length,
-					 dir);
-}
-
-/**
- * arm_dma_sync_sg_for_device
- * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
- * @sg: list of buffers
- * @nents: number of buffers to map (returned from dma_map_sg)
- * @dir: DMA transfer direction (same as was passed to dma_map_sg)
- */
-static void arm_dma_sync_sg_for_device(struct device *dev,
-		struct scatterlist *sg, int nents, enum dma_data_direction dir)
-{
-	const struct dma_map_ops *ops = get_dma_ops(dev);
-	struct scatterlist *s;
-	int i;
-
-	for_each_sg(sg, s, nents, i)
-		ops->sync_single_for_device(dev, sg_dma_address(s), s->length,
-					    dir);
-}
-
-const struct dma_map_ops arm_dma_ops = {
-	.alloc			= arm_dma_alloc,
-	.free			= arm_dma_free,
-	.alloc_pages		= dma_direct_alloc_pages,
-	.free_pages		= dma_direct_free_pages,
-	.mmap			= arm_dma_mmap,
-	.get_sgtable		= arm_dma_get_sgtable,
-	.map_page		= arm_dma_map_page,
-	.unmap_page		= arm_dma_unmap_page,
-	.map_sg			= arm_dma_map_sg,
-	.unmap_sg		= arm_dma_unmap_sg,
-	.map_resource		= dma_direct_map_resource,
-	.sync_single_for_cpu	= arm_dma_sync_single_for_cpu,
-	.sync_single_for_device	= arm_dma_sync_single_for_device,
-	.sync_sg_for_cpu	= arm_dma_sync_sg_for_cpu,
-	.sync_sg_for_device	= arm_dma_sync_sg_for_device,
-	.dma_supported		= arm_dma_supported,
-	.get_required_mask	= dma_direct_get_required_mask,
-};
-EXPORT_SYMBOL(arm_dma_ops);
-
-const struct dma_map_ops arm_coherent_dma_ops = {
-	.alloc			= arm_coherent_dma_alloc,
-	.free			= arm_coherent_dma_free,
-	.alloc_pages		= dma_direct_alloc_pages,
-	.free_pages		= dma_direct_free_pages,
-	.mmap			= arm_coherent_dma_mmap,
-	.get_sgtable		= arm_dma_get_sgtable,
-	.map_page		= arm_coherent_dma_map_page,
-	.map_sg			= arm_dma_map_sg,
-	.map_resource		= dma_direct_map_resource,
-	.dma_supported		= arm_dma_supported,
-	.get_required_mask	= dma_direct_get_required_mask,
-};
-EXPORT_SYMBOL(arm_coherent_dma_ops);
-
-static const struct dma_map_ops *arm_get_dma_map_ops(bool coherent)
-{
-	/*
-	 * When CONFIG_ARM_LPAE is set, physical address can extend above
-	 * 32-bits, which then can't be addressed by devices that only support
-	 * 32-bit DMA.
-	 * Use the generic dma-direct / swiotlb ops code in that case, as that
-	 * handles bounce buffering for us.
-	 */
-	if (IS_ENABLED(CONFIG_ARM_LPAE))
-		return NULL;
-	return coherent ? &arm_coherent_dma_ops : &arm_dma_ops;
-}
-
 #ifdef CONFIG_ARM_DMA_USE_IOMMU
 
 static int __dma_info_to_prot(enum dma_data_direction dir, unsigned long attrs)
@@ -2193,40 +1876,35 @@ void arm_iommu_detach_device(struct device *dev)
 	iommu_detach_device(mapping->domain, dev);
 	kref_put(&mapping->kref, release_iommu_mapping);
 	to_dma_iommu_mapping(dev) = NULL;
-	set_dma_ops(dev, arm_get_dma_map_ops(dev->archdata.dma_coherent));
+	set_dma_ops(dev, NULL);
 
 	pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev));
 }
 EXPORT_SYMBOL_GPL(arm_iommu_detach_device);
 
-static const struct dma_map_ops *arm_get_iommu_dma_map_ops(bool coherent)
-{
-	return coherent ? &iommu_coherent_ops : &iommu_ops;
-}
-
-static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,
-				    const struct iommu_ops *iommu)
+static void arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,
+				    const struct iommu_ops *iommu, bool coherent)
 {
 	struct dma_iommu_mapping *mapping;
 
-	if (!iommu)
-		return false;
-
 	mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);
 	if (IS_ERR(mapping)) {
 		pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n",
 				size, dev_name(dev));
-		return false;
+		return;
 	}
 
 	if (__arm_iommu_attach_device(dev, mapping)) {
 		pr_warn("Failed to attached device %s to IOMMU_mapping\n",
 				dev_name(dev));
 		arm_iommu_release_mapping(mapping);
-		return false;
+		return;
 	}
 
-	return true;
+	if (coherent)
+		set_dma_ops(dev, &iommu_coherent_ops);
+	else
+		set_dma_ops(dev, &iommu_ops);
 }
 
 static void arm_teardown_iommu_dma_ops(struct device *dev)
@@ -2242,27 +1920,20 @@ static void arm_teardown_iommu_dma_ops(struct device *dev)
 
 #else
 
-static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,
-				    const struct iommu_ops *iommu)
+static void arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,
+				    const struct iommu_ops *iommu, bool coherent)
 {
-	return false;
 }
 
 static void arm_teardown_iommu_dma_ops(struct device *dev) { }
 
-#define arm_get_iommu_dma_map_ops arm_get_dma_map_ops
-
 #endif	/* CONFIG_ARM_DMA_USE_IOMMU */
 
 void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 			const struct iommu_ops *iommu, bool coherent)
 {
-	const struct dma_map_ops *dma_ops;
-
 	dev->archdata.dma_coherent = coherent;
-#ifdef CONFIG_SWIOTLB
 	dev->dma_coherent = coherent;
-#endif
 
 	/*
 	 * Don't override the dma_ops if they have already been set. Ideally
@@ -2272,12 +1943,8 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 	if (dev->dma_ops)
 		return;
 
-	if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu))
-		dma_ops = arm_get_iommu_dma_map_ops(coherent);
-	else
-		dma_ops = arm_get_dma_map_ops(coherent);
-
-	set_dma_ops(dev, dma_ops);
+	if (iommu)
+		arm_setup_iommu_dma_ops(dev, dma_base, size, iommu, coherent);
 
 #ifdef CONFIG_XEN
 	if (xen_initial_domain())
@@ -2296,7 +1963,6 @@ void arch_teardown_dma_ops(struct device *dev)
 	set_dma_ops(dev, NULL);
 }
 
-#ifdef CONFIG_SWIOTLB
 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
 		enum dma_data_direction dir)
 {
@@ -2324,4 +1990,3 @@ void arch_dma_free(struct device *dev, size_t size, void *cpu_addr,
 {
 	__arm_dma_free(dev, size, cpu_addr, dma_handle, attrs, false);
 }
-#endif /* CONFIG_SWIOTLB */
-- 
2.30.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 7/7] ARM: use dma-direct unconditionally

[Arnd Bergmann]

On Thu, Apr 21, 2022 at 9:42 AM Christoph Hellwig <hch@lst.de> wrote:
>
> Use dma-direct unconditionally on arm.  It has already been used for
> some time for LPAE and nommu configurations.
>
> This mostly changes the streaming mapping implementation and the (simple)
> coherent allocator for device that are DMA coherent.  The existing
> complex allocator for uncached mappings for non-coherent devices is still
> used as is using the arch_dma_alloc/arch_dma_free hooks.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  arch/arm/Kconfig                   |   4 +-
>  arch/arm/include/asm/dma-mapping.h |  24 --
>  arch/arm/mach-highbank/highbank.c  |   2 +-
>  arch/arm/mach-mvebu/coherency.c    |   2 +-
>  arch/arm/mm/dma-mapping.c          | 365 ++---------------------------
>  5 files changed, 19 insertions(+), 378 deletions(-)
>  delete mode 100644 arch/arm/include/asm/dma-mapping.h

The diffstat looks really nice!

I can't really tell from looking at the code if this is an equivalent
conversion,
so I have to trust you on that. I did make sure this passes the basic tests
on kernelci.org, which tests a large number of machines, which is a good
sign.

Tested-by: Arnd Bergmann <arnd@arndb.de>

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: fully convert arm to use dma-direct

[Arnd Bergmann]

On Thu, Apr 21, 2022 at 9:41 AM Christoph Hellwig <hch@lst.de> wrote:
>
> Hi all,
>
> arm is the last platform not using the dma-direct code for directly
> mapped DMA.  With the dmaboune removal from Arnd we can easily switch
> arm to always use dma-direct now (it already does for LPAE configs
> and nommu).  I'd love to merge this series through the dma-mapping tree
> as it gives us the opportunity for additional core dma-mapping
> improvements.

Thanks a lot for completing this, it looks all good to me, and I hope that
Russell can test my assabet patch to make sure this doesn't break
anything.

I saw one opportunity for an additional cleanup patch that I commented
on, but that does not stop the rest from getting merged.

I also made sure that this passes the basic kernelci tests across all
arm machines.

     Arnd

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: fully convert arm to use dma-direct

[Andre Przywara]

On Thu, 21 Apr 2022 09:41:57 +0200
Christoph Hellwig <hch@lst.de> wrote:

Hi,

> arm is the last platform not using the dma-direct code for directly
> mapped DMA.  With the dmaboune removal from Arnd we can easily switch
> arm to always use dma-direct now (it already does for LPAE configs
> and nommu).  I'd love to merge this series through the dma-mapping tree
> as it gives us the opportunity for additional core dma-mapping
> improvements.
> 
> Diffstat:
>  arch/arm/common/dmabounce.c                          |  582 -------------------
>  arch/arm/include/asm/dma-mapping.h                   |  128 ----
>  b/arch/arm/Kconfig                                   |    5 
>  b/arch/arm/common/Kconfig                            |    6 
>  b/arch/arm/common/Makefile                           |    1 
>  b/arch/arm/common/sa1111.c                           |   64 --
>  b/arch/arm/include/asm/device.h                      |    3 
>  b/arch/arm/include/asm/dma-direct.h                  |   49 -
>  b/arch/arm/include/asm/memory.h                      |    2 
>  b/arch/arm/mach-footbridge/Kconfig                   |    1 
>  b/arch/arm/mach-footbridge/common.c                  |   19 
>  b/arch/arm/mach-footbridge/include/mach/dma-direct.h |    8 
>  b/arch/arm/mach-footbridge/include/mach/memory.h     |    4 
>  b/arch/arm/mach-highbank/highbank.c                  |    2 

FWIW, I applied this on top of 5.18-rc3 and pushed my Midway (the Highbank
successor) a bit with it (scp-ing GBs forth and back to a SATA SSD). Not a
really conclusive test, but so far it looks all fine.

So for the Highbank part:
Acked-by: Andre Przywara <andre.przywara@arm.com>

Cheers,
Andre


>  b/arch/arm/mach-mvebu/coherency.c                    |    2 
>  b/arch/arm/mm/dma-mapping.c                          |  381 ------------
>  b/drivers/usb/core/hcd.c                             |   17 
>  b/drivers/usb/host/ohci-sa1111.c                     |   25 
>  18 files changed, 84 insertions(+), 1215 deletions(-)


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: fully convert arm to use dma-direct

[Linus Walleij]

On Thu, Apr 21, 2022 at 9:42 AM Christoph Hellwig <hch@lst.de> wrote:

> arm is the last platform not using the dma-direct code for directly
> mapped DMA.  With the dmaboune removal from Arnd we can easily switch
> arm to always use dma-direct now (it already does for LPAE configs
> and nommu).  I'd love to merge this series through the dma-mapping tree
> as it gives us the opportunity for additional core dma-mapping
> improvements.
(...)

>  b/arch/arm/mach-footbridge/Kconfig                   |    1
>  b/arch/arm/mach-footbridge/common.c                  |   19
>  b/arch/arm/mach-footbridge/include/mach/dma-direct.h |    8
>  b/arch/arm/mach-footbridge/include/mach/memory.h     |    4

I think Marc Z has a Netwinder that he can test this on. Marc?
I have one too, just not much in my office because of parental leave.

Yours,
Linus Walleij

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: fully convert arm to use dma-direct

[Marc Zyngier]

On 2022-04-22 22:17, Linus Walleij wrote:
> On Thu, Apr 21, 2022 at 9:42 AM Christoph Hellwig <hch@lst.de> wrote:
> 
>> arm is the last platform not using the dma-direct code for directly
>> mapped DMA.  With the dmaboune removal from Arnd we can easily switch
>> arm to always use dma-direct now (it already does for LPAE configs
>> and nommu).  I'd love to merge this series through the dma-mapping 
>> tree
>> as it gives us the opportunity for additional core dma-mapping
>> improvements.
> (...)
> 
>>  b/arch/arm/mach-footbridge/Kconfig                   |    1
>>  b/arch/arm/mach-footbridge/common.c                  |   19
>>  b/arch/arm/mach-footbridge/include/mach/dma-direct.h |    8
>>  b/arch/arm/mach-footbridge/include/mach/memory.h     |    4
> 
> I think Marc Z has a Netwinder that he can test this on. Marc?
> I have one too, just not much in my office because of parental leave.

I'm about to travel for a week. Can this wait until I'm back?
This is one of the few boxes that isn't hooked up to the PDU,
so I can't operate it remotely.

         M.
-- 
Jazz is not dead. It just smells funny...

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: fully convert arm to use dma-direct

[Christoph Hellwig]

On Sat, Apr 23, 2022 at 11:27:13AM +0100, Marc Zyngier wrote:
>> I think Marc Z has a Netwinder that he can test this on. Marc?
>> I have one too, just not much in my office because of parental leave.
>
> I'm about to travel for a week. Can this wait until I'm back?
> This is one of the few boxes that isn't hooked up to the PDU,
> so I can't operate it remotely.

No rush at all from my side except that I;d love to get it into
5.19.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: fully convert arm to use dma-direct

[Marc Zyngier]

On Fri, 22 Apr 2022 22:17:20 +0100,
Linus Walleij <linus.walleij@linaro.org> wrote:
> 
> On Thu, Apr 21, 2022 at 9:42 AM Christoph Hellwig <hch@lst.de> wrote:
> 
> > arm is the last platform not using the dma-direct code for directly
> > mapped DMA.  With the dmaboune removal from Arnd we can easily switch
> > arm to always use dma-direct now (it already does for LPAE configs
> > and nommu).  I'd love to merge this series through the dma-mapping tree
> > as it gives us the opportunity for additional core dma-mapping
> > improvements.
> (...)
> 
> >  b/arch/arm/mach-footbridge/Kconfig                   |    1
> >  b/arch/arm/mach-footbridge/common.c                  |   19
> >  b/arch/arm/mach-footbridge/include/mach/dma-direct.h |    8
> >  b/arch/arm/mach-footbridge/include/mach/memory.h     |    4
> 
> I think Marc Z has a Netwinder that he can test this on. Marc?
> I have one too, just not much in my office because of parental leave.

Finally found some time to hook the machine up and throw a new kernel
at it. Booted at its usual glacial speed, so FWIW:

Tested-by: Marc Zyngier <maz@kernel.org>

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: fully convert arm to use dma-direct

[Christoph Hellwig]

On Fri, May 06, 2022 at 01:06:14PM +0100, Marc Zyngier wrote:
> > I think Marc Z has a Netwinder that he can test this on. Marc?
> > I have one too, just not much in my office because of parental leave.
> 
> Finally found some time to hook the machine up and throw a new kernel
> at it. Booted at its usual glacial speed, so FWIW:
> 
> Tested-by: Marc Zyngier <maz@kernel.org>

Thanks.  I've not heard anything from Russell and we're pretty late
in the merge window, so I'm tempted to wait until the next merge
window.  I'd like to pull in ASAP for that though as I have other
changes that are just waiting for it.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: fully convert arm to use dma-direct

[Russell King (Oracle)]

On Fri, Apr 22, 2022 at 11:17:20PM +0200, Linus Walleij wrote:
> On Thu, Apr 21, 2022 at 9:42 AM Christoph Hellwig <hch@lst.de> wrote:
> 
> > arm is the last platform not using the dma-direct code for directly
> > mapped DMA.  With the dmaboune removal from Arnd we can easily switch
> > arm to always use dma-direct now (it already does for LPAE configs
> > and nommu).  I'd love to merge this series through the dma-mapping tree
> > as it gives us the opportunity for additional core dma-mapping
> > improvements.
> (...)
> 
> >  b/arch/arm/mach-footbridge/Kconfig                   |    1
> >  b/arch/arm/mach-footbridge/common.c                  |   19
> >  b/arch/arm/mach-footbridge/include/mach/dma-direct.h |    8
> >  b/arch/arm/mach-footbridge/include/mach/memory.h     |    4
> 
> I think Marc Z has a Netwinder that he can test this on. Marc?
> I have one too, just not much in my office because of parental leave.

Netwinder is just more of a PC-but-with-ARM - it doesn't make use of any
of the dmabounce code.

Assabet is what needs testing for that, or one of the SA1110 machines.
I'm away from home on my boat (and have been for the last two and a bit
weeks) so can't test. Sorry.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: fully convert arm to use dma-direct

[Linus Walleij]

On Mon, May 9, 2022 at 5:44 PM Russell King (Oracle)
<linux@armlinux.org.uk> wrote:

> Assabet is what needs testing for that, or one of the SA1110 machines.
> I'm away from home on my boat (and have been for the last two and a bit
> weeks) so can't test. Sorry.

Hm I actually have an Assabet, but I never even powered it up. I'm
on parental leave for another week but after that I could actually
try to get that machine up, but it'd be a bit late for this merge window
indeed.

BR
Linus Walleij

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel