* [PATCH RFC 0/2] scatterlist: add I/O variant of sg_pcopy & sg_copy and use them
@ 2021-06-28 12:34 Neil Armstrong
2021-06-28 12:34 ` [PATCH RFC 1/2] scatterlist: add I/O variant of sg_pcopy & sg_copy Neil Armstrong
2021-06-28 12:34 ` [PATCH RFC 2/2] mmc: meson-gx: use sg_copy_to/from_io instead of local version Neil Armstrong
0 siblings, 2 replies; 5+ messages in thread
From: Neil Armstrong @ 2021-06-28 12:34 UTC (permalink / raw)
To: jgg, leon, m.szyprowski, robin.murphy, ulf.hansson
Cc: torvalds, khilman, jbrunet, linux-mmc, linux-amlogic,
linux-arm-kernel, linux-kernel, Neil Armstrong
A local variant of sg_copy_buffer has been introduced in the meson-gx mmc driver [1] after
a mempcy optimization, fixing the iomem buffer manipulation and the reported system crash [2].
But, the fix is suboptimal in terms of performace/ugliness [3] and a proper I/O variant of
sg_copy_buffer should be added and used instead.
[1] https://lore.kernel.org/r/20210609150230.9291-1-narmstrong@baylibre.com
[2] https://lore.kernel.org/r/acb244ad-0759-5a96-c659-5c23003d3dcd@samsung.com
[3] https://lore.kernel.org/r/CAPDyKFrLSMpPJOgd5e4B1x3Vwfg4q23zgy4ESc8EmFL2MnyK7g@mail.gmail.com
Neil Armstrong (2):
scatterlist: add I/O variant of sg_pcopy & sg_copy
mmc: meson-gx: use sg_copy_to/from_io instead of local version
drivers/mmc/host/meson-gx-mmc.c | 53 +++-----------
include/linux/scatterlist.h | 14 ++++
lib/scatterlist.c | 119 ++++++++++++++++++++++++++++++++
3 files changed, 143 insertions(+), 43 deletions(-)
--
2.25.1
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^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH RFC 1/2] scatterlist: add I/O variant of sg_pcopy & sg_copy
2021-06-28 12:34 [PATCH RFC 0/2] scatterlist: add I/O variant of sg_pcopy & sg_copy and use them Neil Armstrong
@ 2021-06-28 12:34 ` Neil Armstrong
2021-06-28 13:40 ` Robin Murphy
2021-06-28 12:34 ` [PATCH RFC 2/2] mmc: meson-gx: use sg_copy_to/from_io instead of local version Neil Armstrong
1 sibling, 1 reply; 5+ messages in thread
From: Neil Armstrong @ 2021-06-28 12:34 UTC (permalink / raw)
To: jgg, leon, m.szyprowski, robin.murphy, ulf.hansson
Cc: torvalds, khilman, jbrunet, linux-mmc, linux-amlogic,
linux-arm-kernel, linux-kernel, Neil Armstrong
When copying from/to an iomem mapped memory, the current sg_copy & sg_pcopy can't
be used and lead to local variants in drivers like in [1] & [2].
This introduces an I/O variant to be used instead of the local variants.
[1] mv_cesa_sg_copy in drivers/crypto/marvell/cesa/tdma.c
[2] meson_mmc_copy_buffer in drivers/mmc/host/meson-gx-mmc.c
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
include/linux/scatterlist.h | 14 +++++
lib/scatterlist.c | 119 ++++++++++++++++++++++++++++++++++++
2 files changed, 133 insertions(+)
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index 6f70572b2938..6ef339ba5290 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -308,15 +308,29 @@ void sgl_free(struct scatterlist *sgl);
size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
size_t buflen, off_t skip, bool to_buffer);
+size_t sg_copy_io(struct scatterlist *sgl, unsigned int nents, void __iomem *buf,
+ size_t buflen, off_t skip, bool to_buffer);
+
size_t sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents,
const void *buf, size_t buflen);
size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents,
void *buf, size_t buflen);
+size_t sg_copy_from_io(struct scatterlist *sgl, unsigned int nents,
+ const void __iomem *buf, size_t buflen);
+size_t sg_copy_to_io(struct scatterlist *sgl, unsigned int nents,
+ void __iomem *buf, size_t buflen);
+
size_t sg_pcopy_from_buffer(struct scatterlist *sgl, unsigned int nents,
const void *buf, size_t buflen, off_t skip);
size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents,
void *buf, size_t buflen, off_t skip);
+
+size_t sg_pcopy_from_io(struct scatterlist *sgl, unsigned int nents,
+ const void __iomem *buf, size_t buflen, off_t skip);
+size_t sg_pcopy_to_io(struct scatterlist *sgl, unsigned int nents,
+ void __iomem *buf, size_t buflen, off_t skip);
+
size_t sg_zero_buffer(struct scatterlist *sgl, unsigned int nents,
size_t buflen, off_t skip);
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index a59778946404..e52f37b181fa 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -954,6 +954,55 @@ size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
}
EXPORT_SYMBOL(sg_copy_buffer);
+/**
+ * sg_copy_io - Copy data between an I/O mapped buffer and an SG list
+ * @sgl: The SG list
+ * @nents: Number of SG entries
+ * @buf: Where to copy from
+ * @buflen: The number of bytes to copy
+ * @skip: Number of bytes to skip before copying
+ * @to_buffer: transfer direction (true == from an sg list to a
+ * buffer, false == from a buffer to an sg list)
+ *
+ * Returns the number of copied bytes.
+ *
+ **/
+size_t sg_copy_io(struct scatterlist *sgl, unsigned int nents, void __iomem *buf,
+ size_t buflen, off_t skip, bool to_buffer)
+{
+ unsigned int offset = 0;
+ struct sg_mapping_iter miter;
+ unsigned int sg_flags = SG_MITER_ATOMIC;
+
+ if (to_buffer)
+ sg_flags |= SG_MITER_FROM_SG;
+ else
+ sg_flags |= SG_MITER_TO_SG;
+
+ sg_miter_start(&miter, sgl, nents, sg_flags);
+
+ if (!sg_miter_skip(&miter, skip))
+ return 0;
+
+ while ((offset < buflen) && sg_miter_next(&miter)) {
+ unsigned int len;
+
+ len = min(miter.length, buflen - offset);
+
+ if (to_buffer)
+ memcpy_toio(buf + offset, miter.addr, len);
+ else
+ memcpy_fromio(miter.addr, buf + offset, len);
+
+ offset += len;
+ }
+
+ sg_miter_stop(&miter);
+
+ return offset;
+}
+EXPORT_SYMBOL(sg_copy_io);
+
/**
* sg_copy_from_buffer - Copy from a linear buffer to an SG list
* @sgl: The SG list
@@ -988,6 +1037,40 @@ size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents,
}
EXPORT_SYMBOL(sg_copy_to_buffer);
+/**
+ * sg_copy_from_io - Copy from an I/O mapped buffer to an SG list
+ * @sgl: The SG list
+ * @nents: Number of SG entries
+ * @buf: Where to copy from
+ * @buflen: The number of bytes to copy
+ *
+ * Returns the number of copied bytes.
+ *
+ **/
+size_t sg_copy_from_io(struct scatterlist *sgl, unsigned int nents,
+ const void *buf, size_t buflen)
+{
+ return sg_copy_io(sgl, nents, (void __iomem *)buf, buflen, 0, false);
+}
+EXPORT_SYMBOL(sg_copy_from_io);
+
+/**
+ * sg_copy_to_io - Copy from an SG list to an I/O mapped buffer
+ * @sgl: The SG list
+ * @nents: Number of SG entries
+ * @buf: Where to copy to
+ * @buflen: The number of bytes to copy
+ *
+ * Returns the number of copied bytes.
+ *
+ **/
+size_t sg_copy_to_io(struct scatterlist *sgl, unsigned int nents,
+ void __iomem *buf, size_t buflen)
+{
+ return sg_copy_io(sgl, nents, buf, buflen, 0, true);
+}
+EXPORT_SYMBOL(sg_copy_to_io);
+
/**
* sg_pcopy_from_buffer - Copy from a linear buffer to an SG list
* @sgl: The SG list
@@ -1024,6 +1107,42 @@ size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents,
}
EXPORT_SYMBOL(sg_pcopy_to_buffer);
+/**
+ * sg_pcopy_from_io - Copy from an I/O mapped buffer to an SG list
+ * @sgl: The SG list
+ * @nents: Number of SG entries
+ * @buf: Where to copy from
+ * @buflen: The number of bytes to copy
+ * @skip: Number of bytes to skip before copying
+ *
+ * Returns the number of copied bytes.
+ *
+ **/
+size_t sg_pcopy_from_io(struct scatterlist *sgl, unsigned int nents,
+ const void __iomem *buf, size_t buflen, off_t skip)
+{
+ return sg_copy_io(sgl, nents, (void __iomem *)buf, buflen, skip, false);
+}
+EXPORT_SYMBOL(sg_pcopy_from_io);
+
+/**
+ * sg_pcopy_to_io - Copy from an SG list to an I/O mapped buffer
+ * @sgl: The SG list
+ * @nents: Number of SG entries
+ * @buf: Where to copy to
+ * @buflen: The number of bytes to copy
+ * @skip: Number of bytes to skip before copying
+ *
+ * Returns the number of copied bytes.
+ *
+ **/
+size_t sg_pcopy_to_io(struct scatterlist *sgl, unsigned int nents,
+ void __iomem *buf, size_t buflen, off_t skip)
+{
+ return sg_copy_io(sgl, nents, buf, buflen, skip, true);
+}
+EXPORT_SYMBOL(sg_pcopy_to_io);
+
/**
* sg_zero_buffer - Zero-out a part of a SG list
* @sgl: The SG list
--
2.25.1
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^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH RFC 2/2] mmc: meson-gx: use sg_copy_to/from_io instead of local version
2021-06-28 12:34 [PATCH RFC 0/2] scatterlist: add I/O variant of sg_pcopy & sg_copy and use them Neil Armstrong
2021-06-28 12:34 ` [PATCH RFC 1/2] scatterlist: add I/O variant of sg_pcopy & sg_copy Neil Armstrong
@ 2021-06-28 12:34 ` Neil Armstrong
2021-06-28 13:44 ` Robin Murphy
1 sibling, 1 reply; 5+ messages in thread
From: Neil Armstrong @ 2021-06-28 12:34 UTC (permalink / raw)
To: jgg, leon, m.szyprowski, robin.murphy, ulf.hansson
Cc: torvalds, khilman, jbrunet, linux-mmc, linux-amlogic,
linux-arm-kernel, linux-kernel, Neil Armstrong
Use the proper sg_copy_to_io & sg_copy_from_io instead of having a local
sg_copy_buffer variant to handle the I/O mapped buffer case.
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
drivers/mmc/host/meson-gx-mmc.c | 53 +++++++--------------------------
1 file changed, 10 insertions(+), 43 deletions(-)
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 3f28eb4d17fe..c13436efb414 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -746,47 +746,6 @@ static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
writel(start, host->regs + SD_EMMC_START);
}
-/* local sg copy to buffer version with _to/fromio usage for dram_access_quirk */
-static void meson_mmc_copy_buffer(struct meson_host *host, struct mmc_data *data,
- size_t buflen, bool to_buffer)
-{
- unsigned int sg_flags = SG_MITER_ATOMIC;
- struct scatterlist *sgl = data->sg;
- unsigned int nents = data->sg_len;
- struct sg_mapping_iter miter;
- unsigned int offset = 0;
-
- if (to_buffer)
- sg_flags |= SG_MITER_FROM_SG;
- else
- sg_flags |= SG_MITER_TO_SG;
-
- sg_miter_start(&miter, sgl, nents, sg_flags);
-
- while ((offset < buflen) && sg_miter_next(&miter)) {
- unsigned int len;
-
- len = min(miter.length, buflen - offset);
-
- /* When dram_access_quirk, the bounce buffer is a iomem mapping */
- if (host->dram_access_quirk) {
- if (to_buffer)
- memcpy_toio(host->bounce_iomem_buf + offset, miter.addr, len);
- else
- memcpy_fromio(miter.addr, host->bounce_iomem_buf + offset, len);
- } else {
- if (to_buffer)
- memcpy(host->bounce_buf + offset, miter.addr, len);
- else
- memcpy(miter.addr, host->bounce_buf + offset, len);
- }
-
- offset += len;
- }
-
- sg_miter_stop(&miter);
-}
-
static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
{
struct meson_host *host = mmc_priv(mmc);
@@ -830,7 +789,12 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
if (data->flags & MMC_DATA_WRITE) {
cmd_cfg |= CMD_CFG_DATA_WR;
WARN_ON(xfer_bytes > host->bounce_buf_size);
- meson_mmc_copy_buffer(host, data, xfer_bytes, true);
+ if (host->dram_access_quirk)
+ sg_copy_to_io(data->sg, data->sg_len,
+ host->bounce_iomem_buf, xfer_bytes);
+ else
+ sg_copy_to_buffer(data->sg, data->sg_len,
+ host->bounce_buf, xfer_bytes);
dma_wmb();
}
@@ -999,7 +963,10 @@ static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
if (meson_mmc_bounce_buf_read(data)) {
xfer_bytes = data->blksz * data->blocks;
WARN_ON(xfer_bytes > host->bounce_buf_size);
- meson_mmc_copy_buffer(host, data, xfer_bytes, false);
+ if (host->dram_access_quirk)
+ sg_copy_from_io(data->sg, data->sg_len, host->bounce_iomem_buf, xfer_bytes);
+ else
+ sg_copy_from_buffer(data->sg, data->sg_len, host->bounce_buf, xfer_bytes);
}
next_cmd = meson_mmc_get_next_command(cmd);
--
2.25.1
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^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH RFC 1/2] scatterlist: add I/O variant of sg_pcopy & sg_copy
2021-06-28 12:34 ` [PATCH RFC 1/2] scatterlist: add I/O variant of sg_pcopy & sg_copy Neil Armstrong
@ 2021-06-28 13:40 ` Robin Murphy
0 siblings, 0 replies; 5+ messages in thread
From: Robin Murphy @ 2021-06-28 13:40 UTC (permalink / raw)
To: Neil Armstrong, jgg, leon, m.szyprowski, ulf.hansson
Cc: torvalds, khilman, jbrunet, linux-mmc, linux-amlogic,
linux-arm-kernel, linux-kernel
On 2021-06-28 13:34, Neil Armstrong wrote:
> When copying from/to an iomem mapped memory, the current sg_copy & sg_pcopy can't
> be used and lead to local variants in drivers like in [1] & [2].
>
> This introduces an I/O variant to be used instead of the local variants.
>
> [1] mv_cesa_sg_copy in drivers/crypto/marvell/cesa/tdma.c
> [2] meson_mmc_copy_buffer in drivers/mmc/host/meson-gx-mmc.c
Other than one apparent typo below, this looks like what I imagined,
thanks for putting it together!
> Cc: Robin Murphy <robin.murphy@arm.com>
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
> include/linux/scatterlist.h | 14 +++++
> lib/scatterlist.c | 119 ++++++++++++++++++++++++++++++++++++
> 2 files changed, 133 insertions(+)
>
> diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
> index 6f70572b2938..6ef339ba5290 100644
> --- a/include/linux/scatterlist.h
> +++ b/include/linux/scatterlist.h
> @@ -308,15 +308,29 @@ void sgl_free(struct scatterlist *sgl);
> size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
> size_t buflen, off_t skip, bool to_buffer);
>
> +size_t sg_copy_io(struct scatterlist *sgl, unsigned int nents, void __iomem *buf,
> + size_t buflen, off_t skip, bool to_buffer);
> +
> size_t sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents,
> const void *buf, size_t buflen);
> size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents,
> void *buf, size_t buflen);
>
> +size_t sg_copy_from_io(struct scatterlist *sgl, unsigned int nents,
> + const void __iomem *buf, size_t buflen);
> +size_t sg_copy_to_io(struct scatterlist *sgl, unsigned int nents,
> + void __iomem *buf, size_t buflen);
> +
> size_t sg_pcopy_from_buffer(struct scatterlist *sgl, unsigned int nents,
> const void *buf, size_t buflen, off_t skip);
> size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents,
> void *buf, size_t buflen, off_t skip);
> +
> +size_t sg_pcopy_from_io(struct scatterlist *sgl, unsigned int nents,
> + const void __iomem *buf, size_t buflen, off_t skip);
> +size_t sg_pcopy_to_io(struct scatterlist *sgl, unsigned int nents,
> + void __iomem *buf, size_t buflen, off_t skip);
> +
> size_t sg_zero_buffer(struct scatterlist *sgl, unsigned int nents,
> size_t buflen, off_t skip);
>
> diff --git a/lib/scatterlist.c b/lib/scatterlist.c
> index a59778946404..e52f37b181fa 100644
> --- a/lib/scatterlist.c
> +++ b/lib/scatterlist.c
> @@ -954,6 +954,55 @@ size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
> }
> EXPORT_SYMBOL(sg_copy_buffer);
>
> +/**
> + * sg_copy_io - Copy data between an I/O mapped buffer and an SG list
> + * @sgl: The SG list
> + * @nents: Number of SG entries
> + * @buf: Where to copy from
> + * @buflen: The number of bytes to copy
> + * @skip: Number of bytes to skip before copying
> + * @to_buffer: transfer direction (true == from an sg list to a
> + * buffer, false == from a buffer to an sg list)
> + *
> + * Returns the number of copied bytes.
> + *
> + **/
> +size_t sg_copy_io(struct scatterlist *sgl, unsigned int nents, void __iomem *buf,
> + size_t buflen, off_t skip, bool to_buffer)
> +{
> + unsigned int offset = 0;
> + struct sg_mapping_iter miter;
> + unsigned int sg_flags = SG_MITER_ATOMIC;
> +
> + if (to_buffer)
> + sg_flags |= SG_MITER_FROM_SG;
> + else
> + sg_flags |= SG_MITER_TO_SG;
> +
> + sg_miter_start(&miter, sgl, nents, sg_flags);
> +
> + if (!sg_miter_skip(&miter, skip))
> + return 0;
> +
> + while ((offset < buflen) && sg_miter_next(&miter)) {
> + unsigned int len;
> +
> + len = min(miter.length, buflen - offset);
> +
> + if (to_buffer)
> + memcpy_toio(buf + offset, miter.addr, len);
> + else
> + memcpy_fromio(miter.addr, buf + offset, len);
> +
> + offset += len;
> + }
> +
> + sg_miter_stop(&miter);
> +
> + return offset;
> +}
> +EXPORT_SYMBOL(sg_copy_io);
> +
> /**
> * sg_copy_from_buffer - Copy from a linear buffer to an SG list
> * @sgl: The SG list
> @@ -988,6 +1037,40 @@ size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents,
> }
> EXPORT_SYMBOL(sg_copy_to_buffer);
>
> +/**
> + * sg_copy_from_io - Copy from an I/O mapped buffer to an SG list
> + * @sgl: The SG list
> + * @nents: Number of SG entries
> + * @buf: Where to copy from
> + * @buflen: The number of bytes to copy
> + *
> + * Returns the number of copied bytes.
> + *
> + **/
> +size_t sg_copy_from_io(struct scatterlist *sgl, unsigned int nents,
> + const void *buf, size_t buflen)
The __iomem annotation wants to be on buf here raher than cast in below,
to match the prototype (and everything else).
Cheers,
Robin.
> +{
> + return sg_copy_io(sgl, nents, (void __iomem *)buf, buflen, 0, false);
> +}
> +EXPORT_SYMBOL(sg_copy_from_io);
> +
> +/**
> + * sg_copy_to_io - Copy from an SG list to an I/O mapped buffer
> + * @sgl: The SG list
> + * @nents: Number of SG entries
> + * @buf: Where to copy to
> + * @buflen: The number of bytes to copy
> + *
> + * Returns the number of copied bytes.
> + *
> + **/
> +size_t sg_copy_to_io(struct scatterlist *sgl, unsigned int nents,
> + void __iomem *buf, size_t buflen)
> +{
> + return sg_copy_io(sgl, nents, buf, buflen, 0, true);
> +}
> +EXPORT_SYMBOL(sg_copy_to_io);
> +
> /**
> * sg_pcopy_from_buffer - Copy from a linear buffer to an SG list
> * @sgl: The SG list
> @@ -1024,6 +1107,42 @@ size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents,
> }
> EXPORT_SYMBOL(sg_pcopy_to_buffer);
>
> +/**
> + * sg_pcopy_from_io - Copy from an I/O mapped buffer to an SG list
> + * @sgl: The SG list
> + * @nents: Number of SG entries
> + * @buf: Where to copy from
> + * @buflen: The number of bytes to copy
> + * @skip: Number of bytes to skip before copying
> + *
> + * Returns the number of copied bytes.
> + *
> + **/
> +size_t sg_pcopy_from_io(struct scatterlist *sgl, unsigned int nents,
> + const void __iomem *buf, size_t buflen, off_t skip)
> +{
> + return sg_copy_io(sgl, nents, (void __iomem *)buf, buflen, skip, false);
> +}
> +EXPORT_SYMBOL(sg_pcopy_from_io);
> +
> +/**
> + * sg_pcopy_to_io - Copy from an SG list to an I/O mapped buffer
> + * @sgl: The SG list
> + * @nents: Number of SG entries
> + * @buf: Where to copy to
> + * @buflen: The number of bytes to copy
> + * @skip: Number of bytes to skip before copying
> + *
> + * Returns the number of copied bytes.
> + *
> + **/
> +size_t sg_pcopy_to_io(struct scatterlist *sgl, unsigned int nents,
> + void __iomem *buf, size_t buflen, off_t skip)
> +{
> + return sg_copy_io(sgl, nents, buf, buflen, skip, true);
> +}
> +EXPORT_SYMBOL(sg_pcopy_to_io);
> +
> /**
> * sg_zero_buffer - Zero-out a part of a SG list
> * @sgl: The SG list
>
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH RFC 2/2] mmc: meson-gx: use sg_copy_to/from_io instead of local version
2021-06-28 12:34 ` [PATCH RFC 2/2] mmc: meson-gx: use sg_copy_to/from_io instead of local version Neil Armstrong
@ 2021-06-28 13:44 ` Robin Murphy
0 siblings, 0 replies; 5+ messages in thread
From: Robin Murphy @ 2021-06-28 13:44 UTC (permalink / raw)
To: Neil Armstrong, jgg, leon, m.szyprowski, ulf.hansson
Cc: torvalds, khilman, jbrunet, linux-mmc, linux-amlogic,
linux-arm-kernel, linux-kernel
On 2021-06-28 13:34, Neil Armstrong wrote:
> Use the proper sg_copy_to_io & sg_copy_from_io instead of having a local
> sg_copy_buffer variant to handle the I/O mapped buffer case.
>
> Cc: Robin Murphy <robin.murphy@arm.com>
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
> drivers/mmc/host/meson-gx-mmc.c | 53 +++++++--------------------------
> 1 file changed, 10 insertions(+), 43 deletions(-)
>
> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
> index 3f28eb4d17fe..c13436efb414 100644
> --- a/drivers/mmc/host/meson-gx-mmc.c
> +++ b/drivers/mmc/host/meson-gx-mmc.c
> @@ -746,47 +746,6 @@ static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg)
> writel(start, host->regs + SD_EMMC_START);
> }
>
> -/* local sg copy to buffer version with _to/fromio usage for dram_access_quirk */
> -static void meson_mmc_copy_buffer(struct meson_host *host, struct mmc_data *data,
> - size_t buflen, bool to_buffer)
> -{
> - unsigned int sg_flags = SG_MITER_ATOMIC;
> - struct scatterlist *sgl = data->sg;
> - unsigned int nents = data->sg_len;
> - struct sg_mapping_iter miter;
> - unsigned int offset = 0;
> -
> - if (to_buffer)
> - sg_flags |= SG_MITER_FROM_SG;
> - else
> - sg_flags |= SG_MITER_TO_SG;
> -
> - sg_miter_start(&miter, sgl, nents, sg_flags);
> -
> - while ((offset < buflen) && sg_miter_next(&miter)) {
> - unsigned int len;
> -
> - len = min(miter.length, buflen - offset);
> -
> - /* When dram_access_quirk, the bounce buffer is a iomem mapping */
> - if (host->dram_access_quirk) {
> - if (to_buffer)
> - memcpy_toio(host->bounce_iomem_buf + offset, miter.addr, len);
> - else
> - memcpy_fromio(miter.addr, host->bounce_iomem_buf + offset, len);
> - } else {
> - if (to_buffer)
> - memcpy(host->bounce_buf + offset, miter.addr, len);
> - else
> - memcpy(miter.addr, host->bounce_buf + offset, len);
> - }
> -
> - offset += len;
> - }
> -
> - sg_miter_stop(&miter);
> -}
> -
> static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
> {
> struct meson_host *host = mmc_priv(mmc);
> @@ -830,7 +789,12 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
> if (data->flags & MMC_DATA_WRITE) {
> cmd_cfg |= CMD_CFG_DATA_WR;
> WARN_ON(xfer_bytes > host->bounce_buf_size);
> - meson_mmc_copy_buffer(host, data, xfer_bytes, true);
> + if (host->dram_access_quirk)
> + sg_copy_to_io(data->sg, data->sg_len,
> + host->bounce_iomem_buf, xfer_bytes);
Maybe you could just use host->regs + SD_EMMC_SRAM_DATA_BUF_OFF directly
here (and below) and save carrying host->bounce_iomem_buf around?
Robin.
> + else
> + sg_copy_to_buffer(data->sg, data->sg_len,
> + host->bounce_buf, xfer_bytes);
> dma_wmb();
> }
>
> @@ -999,7 +963,10 @@ static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
> if (meson_mmc_bounce_buf_read(data)) {
> xfer_bytes = data->blksz * data->blocks;
> WARN_ON(xfer_bytes > host->bounce_buf_size);
> - meson_mmc_copy_buffer(host, data, xfer_bytes, false);
> + if (host->dram_access_quirk)
> + sg_copy_from_io(data->sg, data->sg_len, host->bounce_iomem_buf, xfer_bytes);
> + else
> + sg_copy_from_buffer(data->sg, data->sg_len, host->bounce_buf, xfer_bytes);
> }
>
> next_cmd = meson_mmc_get_next_command(cmd);
>
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-- links below jump to the message on this page --
2021-06-28 12:34 [PATCH RFC 0/2] scatterlist: add I/O variant of sg_pcopy & sg_copy and use them Neil Armstrong
2021-06-28 12:34 ` [PATCH RFC 1/2] scatterlist: add I/O variant of sg_pcopy & sg_copy Neil Armstrong
2021-06-28 13:40 ` Robin Murphy
2021-06-28 12:34 ` [PATCH RFC 2/2] mmc: meson-gx: use sg_copy_to/from_io instead of local version Neil Armstrong
2021-06-28 13:44 ` Robin Murphy
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