[PATCH 1/2] spi: Fix mapping from vmalloc-ed buffer to scatter list

[PATCH 1/2] spi: Fix mapping from vmalloc-ed buffer to scatter list

[Charles Keepax]

We can only use page_address on memory that has been mapped using kmap,
when the buffer passed to the SPI has been allocated by vmalloc the page
has not necessarily been mapped through kmap. This means sometimes
page_address will return NULL causing the pointer we pass to sg_set_buf
to be invalid.

As we only call page_address such that we can pass a virtual address to
sg_set_buf which will then immediately call virt_to_page on it, fix this
by calling sg_set_page directly rather then relying on the sg_set_buf
helper.

Signed-off-by: Charles Keepax <ckeepax-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org>
---
 drivers/spi/spi.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index ebcb33d..50f20f2 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -615,13 +615,13 @@ static int spi_map_buf(struct spi_master *master, struct device *dev,
 				sg_free_table(sgt);
 				return -ENOMEM;
 			}
-			sg_buf = page_address(vm_page) +
-				((size_t)buf & ~PAGE_MASK);
+			sg_set_page(&sgt->sgl[i], vm_page,
+				    min, offset_in_page(buf));
 		} else {
 			sg_buf = buf;
+			sg_set_buf(&sgt->sgl[i], sg_buf, min);
 		}
 
-		sg_set_buf(&sgt->sgl[i], sg_buf, min);
 
 		buf += min;
 		len -= min;
-- 
1.7.2.5

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[PATCH 2/2] ASoC: wm_adsp: Use vmalloc to allocate firmware download buffer

[Charles Keepax]

Use vmalloc to allocate the buffer for firmware/coefficient download and
rely on the SPI core to split this up into DMA-able chunks. This should
give better performance and means we no longer need to manually split
the download into page size chunks to avoid allocating overly large
continuous memory regions.

Signed-off-by: Charles Keepax <ckeepax-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org>
---
 sound/soc/codecs/wm_adsp.c |   58 +++++++++++++++++--------------------------
 1 files changed, 23 insertions(+), 35 deletions(-)

diff --git a/sound/soc/codecs/wm_adsp.c b/sound/soc/codecs/wm_adsp.c
index f412a99..0a08ef5e 100644
--- a/sound/soc/codecs/wm_adsp.c
+++ b/sound/soc/codecs/wm_adsp.c
@@ -21,6 +21,7 @@
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
+#include <linux/vmalloc.h>
 #include <linux/workqueue.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
@@ -169,11 +170,12 @@ static struct wm_adsp_buf *wm_adsp_buf_alloc(const void *src, size_t len,
 	if (buf == NULL)
 		return NULL;
 
-	buf->buf = kmemdup(src, len, GFP_KERNEL | GFP_DMA);
+	buf->buf = vmalloc(len);
 	if (!buf->buf) {
-		kfree(buf);
+		vfree(buf);
 		return NULL;
 	}
+	memcpy(buf->buf, src, len);
 
 	if (list)
 		list_add_tail(&buf->list, list);
@@ -188,7 +190,7 @@ static void wm_adsp_buf_free(struct list_head *list)
 							   struct wm_adsp_buf,
 							   list);
 		list_del(&buf->list);
-		kfree(buf->buf);
+		vfree(buf->buf);
 		kfree(buf);
 	}
 }
@@ -684,38 +686,24 @@ static int wm_adsp_load(struct wm_adsp *dsp)
 		}
 
 		if (reg) {
-			size_t to_write = PAGE_SIZE;
-			size_t remain = le32_to_cpu(region->len);
-			const u8 *data = region->data;
-
-			while (remain > 0) {
-				if (remain < PAGE_SIZE)
-					to_write = remain;
-
-				buf = wm_adsp_buf_alloc(data,
-							to_write,
-							&buf_list);
-				if (!buf) {
-					adsp_err(dsp, "Out of memory\n");
-					ret = -ENOMEM;
-					goto out_fw;
-				}
-
-				ret = regmap_raw_write_async(regmap, reg,
-							     buf->buf,
-							     to_write);
-				if (ret != 0) {
-					adsp_err(dsp,
-						"%s.%d: Failed to write %zd bytes at %d in %s: %d\n",
-						file, regions,
-						to_write, offset,
-						region_name, ret);
-					goto out_fw;
-				}
+			buf = wm_adsp_buf_alloc(region->data,
+						le32_to_cpu(region->len),
+						&buf_list);
+			if (!buf) {
+				adsp_err(dsp, "Out of memory\n");
+				ret = -ENOMEM;
+				goto out_fw;
+			}
 
-				data += to_write;
-				reg += to_write / 2;
-				remain -= to_write;
+			ret = regmap_raw_write_async(regmap, reg, buf->buf,
+						     le32_to_cpu(region->len));
+			if (ret != 0) {
+				adsp_err(dsp,
+					"%s.%d: Failed to write %d bytes at %d in %s: %d\n",
+					file, regions,
+					le32_to_cpu(region->len), offset,
+					region_name, ret);
+				goto out_fw;
 			}
 		}
 
-- 
1.7.2.5

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Re: [PATCH 1/2] spi: Fix mapping from vmalloc-ed buffer to scatter list

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 568 bytes --]

On Fri, Nov 14, 2014 at 03:40:44PM +0000, Charles Keepax wrote:
> We can only use page_address on memory that has been mapped using kmap,
> when the buffer passed to the SPI has been allocated by vmalloc the page
> has not necessarily been mapped through kmap. This means sometimes
> page_address will return NULL causing the pointer we pass to sg_set_buf
> to be invalid.

Hrm, this is a bug in the mxs driver (which is where we copied the core
code from) - care to fix that too?

> As we only call page_address such that we can pass a virtual address to

s/such/so/

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Re: [PATCH 1/2] spi: Fix mapping from vmalloc-ed buffer to scatter list

[Charles Keepax]

On Fri, Nov 14, 2014 at 03:52:22PM +0000, Mark Brown wrote:
> On Fri, Nov 14, 2014 at 03:40:44PM +0000, Charles Keepax wrote:
> > We can only use page_address on memory that has been mapped using kmap,
> > when the buffer passed to the SPI has been allocated by vmalloc the page
> > has not necessarily been mapped through kmap. This means sometimes
> > page_address will return NULL causing the pointer we pass to sg_set_buf
> > to be invalid.
> 
> Hrm, this is a bug in the mxs driver (which is where we copied the core
> code from) - care to fix that too?

Yeah no problem, won't be able to test it, but should be a fairly
trivial change and hopefully someone else can test.

> 
> > As we only call page_address such that we can pass a virtual address to
> 
> s/such/so/

Will ping a respin and include the mxs fixup too.

Thanks,
Charles


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Re: [PATCH 1/2] spi: Fix mapping from vmalloc-ed buffer to scatter list

[Charles Keepax]

On Fri, Nov 14, 2014 at 04:06:07PM +0000, Charles Keepax wrote:
> On Fri, Nov 14, 2014 at 03:52:22PM +0000, Mark Brown wrote:
> > On Fri, Nov 14, 2014 at 03:40:44PM +0000, Charles Keepax wrote:
> > > We can only use page_address on memory that has been mapped using kmap,
> > > when the buffer passed to the SPI has been allocated by vmalloc the page
> > > has not necessarily been mapped through kmap. This means sometimes
> > > page_address will return NULL causing the pointer we pass to sg_set_buf
> > > to be invalid.
> > 
> > Hrm, this is a bug in the mxs driver (which is where we copied the core
> > code from) - care to fix that too?
> 
> Yeah no problem, won't be able to test it, but should be a fairly
> trivial change and hopefully someone else can test.

Ah... ok I think I see the difference here. The MXS architecture
has CONFIG_HIGHMEM=n whereas Arndale has CONFIG_HIGHMEM=y. So
that means on MXS all the pages will always be in low mem so I
think will always be mapped into the kernel logical address space
hence no problems. Not sure if it would be worth updating the
driver or not, what do you think?

Thanks,
Charles
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Re: [PATCH 1/2] spi: Fix mapping from vmalloc-ed buffer to scatter list

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 637 bytes --]

On Fri, Nov 14, 2014 at 05:11:33PM +0000, Charles Keepax wrote:

> Ah... ok I think I see the difference here. The MXS architecture
> has CONFIG_HIGHMEM=n whereas Arndale has CONFIG_HIGHMEM=y. So
> that means on MXS all the pages will always be in low mem so I
> think will always be mapped into the kernel logical address space
> hence no problems. Not sure if it would be worth updating the
> driver or not, what do you think?

This is a user configurable option, it's not something that depends on
the architecture (and in any case it's better not to leave people
wondering why things are different when they consider consolidation).

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Re: [PATCH 2/2] ASoC: wm_adsp: Use vmalloc to allocate firmware download buffer

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 402 bytes --]

On Fri, Nov 14, 2014 at 03:40:45PM +0000, Charles Keepax wrote:
> Use vmalloc to allocate the buffer for firmware/coefficient download and
> rely on the SPI core to split this up into DMA-able chunks. This should
> give better performance and means we no longer need to manually split
> the download into page size chunks to avoid allocating overly large
> continuous memory regions.

Applied, thanks.

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Re: [PATCH 1/2] spi: Fix mapping from vmalloc-ed buffer to scatter list

[Charles Keepax]

On Fri, Nov 14, 2014 at 05:26:26PM +0000, Mark Brown wrote:
> On Fri, Nov 14, 2014 at 05:11:33PM +0000, Charles Keepax wrote:
> 
> > Ah... ok I think I see the difference here. The MXS architecture
> > has CONFIG_HIGHMEM=n whereas Arndale has CONFIG_HIGHMEM=y. So
> > that means on MXS all the pages will always be in low mem so I
> > think will always be mapped into the kernel logical address space
> > hence no problems. Not sure if it would be worth updating the
> > driver or not, what do you think?
> 
> This is a user configurable option, it's not something that depends on
> the architecture (and in any case it's better not to leave people
> wondering why things are different when they consider consolidation).

Cool, I will do the respin then.

Thanks,
Charles
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[PATCH 1/2] spi: Fix mapping from vmalloc-ed buffer to scatter list

[Charles Keepax]

We can only use page_address on memory that has been mapped using kmap,
when the buffer passed to the SPI has been allocated by vmalloc the page
has not necessarily been mapped through kmap. This means sometimes
page_address will return NULL causing the pointer we pass to sg_set_buf
to be invalid.

As we only call page_address so that we can pass a virtual address to
sg_set_buf which will then immediately call virt_to_page on it, fix this
by calling sg_set_page directly rather then relying on the sg_set_buf
helper.

Signed-off-by: Charles Keepax <ckeepax-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org>
---
 drivers/spi/spi.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index ebcb33d..50f20f2 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -615,13 +615,13 @@ static int spi_map_buf(struct spi_master *master, struct device *dev,
 				sg_free_table(sgt);
 				return -ENOMEM;
 			}
-			sg_buf = page_address(vm_page) +
-				((size_t)buf & ~PAGE_MASK);
+			sg_set_page(&sgt->sgl[i], vm_page,
+				    min, offset_in_page(buf));
 		} else {
 			sg_buf = buf;
+			sg_set_buf(&sgt->sgl[i], sg_buf, min);
 		}
 
-		sg_set_buf(&sgt->sgl[i], sg_buf, min);
 
 		buf += min;
 		len -= min;
-- 
1.7.2.5

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Re: [PATCH 1/2] spi: Fix mapping from vmalloc-ed buffer to scatter list

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 391 bytes --]

On Mon, Nov 17, 2014 at 09:14:31AM +0000, Charles Keepax wrote:
> We can only use page_address on memory that has been mapped using kmap,
> when the buffer passed to the SPI has been allocated by vmalloc the page
> has not necessarily been mapped through kmap. This means sometimes
> page_address will return NULL causing the pointer we pass to sg_set_buf
> to be invalid.

Applied, thanks.

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