It has been reported that usage of memcpy() to/from an iomem mapping is invalid,
and and recent arm64 memcpy update [1] triggers a memory abort when dram-access-quirk
is used on the G12A/G12B platforms.
This adds a local sg_copy_to_buffer which makes usage of io versions of memcpy
when dram-access-quirk is enabled.
Fixes: acdc8e71d9bb ("mmc: meson-gx: add dram-access-quirk")
Reported-by: Marek Szyprowski <[email protected]>
Suggested-by: Mark Rutland <[email protected]>
Signed-off-by: Neil Armstrong <[email protected]>
[1] 285133040e6c ("arm64: Import latest memcpy()/memmove() implementation")
Signed-off-by: Neil Armstrong <[email protected]>
---
Hi Ulf, Marek, Mark,
I haven't tested the patch yet, but should fix issue reported at [2].
Neil
[2] https://lore.kernel.org/r/[email protected]
drivers/mmc/host/meson-gx-mmc.c | 48 ++++++++++++++++++++++++++++++---
1 file changed, 44 insertions(+), 4 deletions(-)
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index b8b771b643cc..89ff6038092d 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -742,6 +742,48 @@ 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;
+ void *buf = host->bounce_buf;
+ 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(buf + offset, miter.addr, len);
+ else
+ memcpy_fromio(miter.addr, buf + offset, len);
+ } else {
+ if (to_buffer)
+ memcpy(buf + offset, miter.addr, len);
+ else
+ memcpy(miter.addr, 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);
@@ -785,8 +827,7 @@ 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);
- sg_copy_to_buffer(data->sg, data->sg_len,
- host->bounce_buf, xfer_bytes);
+ meson_mmc_copy_buffer(host, data, xfer_bytes, true);
dma_wmb();
}
@@ -955,8 +996,7 @@ 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);
- sg_copy_from_buffer(data->sg, data->sg_len,
- host->bounce_buf, xfer_bytes);
+ meson_mmc_copy_buffer(host, data, xfer_bytes, false);
}
next_cmd = meson_mmc_get_next_command(cmd);
--
2.25.1
Hi
On 08.06.2021 17:33, Neil Armstrong wrote:
> It has been reported that usage of memcpy() to/from an iomem mapping is invalid,
> and and recent arm64 memcpy update [1] triggers a memory abort when dram-access-quirk
> is used on the G12A/G12B platforms.
>
> This adds a local sg_copy_to_buffer which makes usage of io versions of memcpy
> when dram-access-quirk is enabled.
>
> Fixes: acdc8e71d9bb ("mmc: meson-gx: add dram-access-quirk")
> Reported-by: Marek Szyprowski <[email protected]>
> Suggested-by: Mark Rutland <[email protected]>
> Signed-off-by: Neil Armstrong <[email protected]>
>
> [1] 285133040e6c ("arm64: Import latest memcpy()/memmove() implementation")
>
> Signed-off-by: Neil Armstrong <[email protected]>
> ---
> Hi Ulf, Marek, Mark,
>
> I haven't tested the patch yet, but should fix issue reported at [2].
Works fine here and fixed the issue.
Tested-by: Marek Szyprowski <[email protected]>
> Neil
>
> [2] https://lore.kernel.org/r/[email protected]
>
> drivers/mmc/host/meson-gx-mmc.c | 48 ++++++++++++++++++++++++++++++---
> 1 file changed, 44 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
> index b8b771b643cc..89ff6038092d 100644
> --- a/drivers/mmc/host/meson-gx-mmc.c
> +++ b/drivers/mmc/host/meson-gx-mmc.c
> @@ -742,6 +742,48 @@ 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;
> + void *buf = host->bounce_buf;
> + 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(buf + offset, miter.addr, len);
> + else
> + memcpy_fromio(miter.addr, buf + offset, len);
> + } else {
> + if (to_buffer)
> + memcpy(buf + offset, miter.addr, len);
> + else
> + memcpy(miter.addr, 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);
> @@ -785,8 +827,7 @@ 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);
> - sg_copy_to_buffer(data->sg, data->sg_len,
> - host->bounce_buf, xfer_bytes);
> + meson_mmc_copy_buffer(host, data, xfer_bytes, true);
> dma_wmb();
> }
>
> @@ -955,8 +996,7 @@ 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);
> - sg_copy_from_buffer(data->sg, data->sg_len,
> - host->bounce_buf, xfer_bytes);
> + meson_mmc_copy_buffer(host, data, xfer_bytes, false);
> }
>
> next_cmd = meson_mmc_get_next_command(cmd);
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
On 2021-06-09 14:07, Neil Armstrong wrote:
> Hi,
>
> On 08/06/2021 17:50, Marek Szyprowski wrote:
>> Hi
>>
>> On 08.06.2021 17:33, Neil Armstrong wrote:
>>> It has been reported that usage of memcpy() to/from an iomem mapping is invalid,
>>> and and recent arm64 memcpy update [1] triggers a memory abort when dram-access-quirk
>>> is used on the G12A/G12B platforms.
>>>
>>> This adds a local sg_copy_to_buffer which makes usage of io versions of memcpy
>>> when dram-access-quirk is enabled.
>>>
>>> Fixes: acdc8e71d9bb ("mmc: meson-gx: add dram-access-quirk")
>>> Reported-by: Marek Szyprowski <[email protected]>
>>> Suggested-by: Mark Rutland <[email protected]>
>>> Signed-off-by: Neil Armstrong <[email protected]>
>>>
>>> [1] 285133040e6c ("arm64: Import latest memcpy()/memmove() implementation")
>>>
>>> Signed-off-by: Neil Armstrong <[email protected]>
>>> ---
>>> Hi Ulf, Marek, Mark,
>>>
>>> I haven't tested the patch yet, but should fix issue reported at [2].
>>
>> Works fine here and fixed the issue.
>>
>> Tested-by: Marek Szyprowski <[email protected]>
>
> Thanks, I'll need to rework to pass an __iomem pointer to memcpy_to/fromio so sparse doesn't scream anymore.
Hmm, might it be worth factoring out general sg_copy_{to,from}_iomem()
helpers? From a quick grep I found at least mv_cesa_sg_copy() already
doing essentially the same thing as meson_mmc_copy_buffer().
Robin.
>
> Neil
>
>>
>>> Neil
>>>
>>> [2] https://lore.kernel.org/r/[email protected]
>>>
>>> drivers/mmc/host/meson-gx-mmc.c | 48 ++++++++++++++++++++++++++++++---
>>> 1 file changed, 44 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
>>> index b8b771b643cc..89ff6038092d 100644
>>> --- a/drivers/mmc/host/meson-gx-mmc.c
>>> +++ b/drivers/mmc/host/meson-gx-mmc.c
>>> @@ -742,6 +742,48 @@ 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;
>>> + void *buf = host->bounce_buf;
>>> + 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(buf + offset, miter.addr, len);
>>> + else
>>> + memcpy_fromio(miter.addr, buf + offset, len);
>>> + } else {
>>> + if (to_buffer)
>>> + memcpy(buf + offset, miter.addr, len);
>>> + else
>>> + memcpy(miter.addr, 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);
>>> @@ -785,8 +827,7 @@ 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);
>>> - sg_copy_to_buffer(data->sg, data->sg_len,
>>> - host->bounce_buf, xfer_bytes);
>>> + meson_mmc_copy_buffer(host, data, xfer_bytes, true);
>>> dma_wmb();
>>> }
>>>
>>> @@ -955,8 +996,7 @@ 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);
>>> - sg_copy_from_buffer(data->sg, data->sg_len,
>>> - host->bounce_buf, xfer_bytes);
>>> + meson_mmc_copy_buffer(host, data, xfer_bytes, false);
>>> }
>>>
>>> next_cmd = meson_mmc_get_next_command(cmd);
>>
>> Best regards
>>
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
Hi Robin,
On 09/06/2021 16:45, Robin Murphy wrote:
> On 2021-06-09 14:07, Neil Armstrong wrote:
>> Hi,
>>
>> On 08/06/2021 17:50, Marek Szyprowski wrote:
>>> Hi
>>>
>>> On 08.06.2021 17:33, Neil Armstrong wrote:
>>>> It has been reported that usage of memcpy() to/from an iomem mapping is invalid,
>>>> and and recent arm64 memcpy update [1] triggers a memory abort when dram-access-quirk
>>>> is used on the G12A/G12B platforms.
>>>>
>>>> This adds a local sg_copy_to_buffer which makes usage of io versions of memcpy
>>>> when dram-access-quirk is enabled.
>>>>
>>>> Fixes: acdc8e71d9bb ("mmc: meson-gx: add dram-access-quirk")
>>>> Reported-by: Marek Szyprowski <[email protected]>
>>>> Suggested-by: Mark Rutland <[email protected]>
>>>> Signed-off-by: Neil Armstrong <[email protected]>
>>>>
>>>> [1] 285133040e6c ("arm64: Import latest memcpy()/memmove() implementation")
>>>>
>>>> Signed-off-by: Neil Armstrong <[email protected]>
>>>> ---
>>>> Hi Ulf, Marek, Mark,
>>>>
>>>> I haven't tested the patch yet, but should fix issue reported at [2].
>>>
>>> Works fine here and fixed the issue.
>>>
>>> Tested-by: Marek Szyprowski <[email protected]>
>>
>> Thanks, I'll need to rework to pass an __iomem pointer to memcpy_to/fromio so sparse doesn't scream anymore.
>
> Hmm, might it be worth factoring out general sg_copy_{to,from}_iomem() helpers? From a quick grep I found at least mv_cesa_sg_copy() already doing essentially the same thing as meson_mmc_copy_buffer().
It's definitely worth it, but since we need a quick fix, we should have meson_mmc_copy_buffer() as a fix then we should definitely move to sg_copy_{to,from}_iomem() helpers
Neil
>
> Robin.
>
>>
>> Neil
>>
>>>
>>>> Neil
>>>>
>>>> [2] https://lore.kernel.org/r/[email protected]
>>>>
>>>> drivers/mmc/host/meson-gx-mmc.c | 48 ++++++++++++++++++++++++++++++---
>>>> 1 file changed, 44 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
>>>> index b8b771b643cc..89ff6038092d 100644
>>>> --- a/drivers/mmc/host/meson-gx-mmc.c
>>>> +++ b/drivers/mmc/host/meson-gx-mmc.c
>>>> @@ -742,6 +742,48 @@ 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;
>>>> + void *buf = host->bounce_buf;
>>>> + 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(buf + offset, miter.addr, len);
>>>> + else
>>>> + memcpy_fromio(miter.addr, buf + offset, len);
>>>> + } else {
>>>> + if (to_buffer)
>>>> + memcpy(buf + offset, miter.addr, len);
>>>> + else
>>>> + memcpy(miter.addr, 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);
>>>> @@ -785,8 +827,7 @@ 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);
>>>> - sg_copy_to_buffer(data->sg, data->sg_len,
>>>> - host->bounce_buf, xfer_bytes);
>>>> + meson_mmc_copy_buffer(host, data, xfer_bytes, true);
>>>> dma_wmb();
>>>> }
>>>> @@ -955,8 +996,7 @@ 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);
>>>> - sg_copy_from_buffer(data->sg, data->sg_len,
>>>> - host->bounce_buf, xfer_bytes);
>>>> + meson_mmc_copy_buffer(host, data, xfer_bytes, false);
>>>> }
>>>> next_cmd = meson_mmc_get_next_command(cmd);
>>>
>>> Best regards
>>>
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> [email protected]
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>
On 2021-06-09 15:55, Neil Armstrong wrote:
> Hi Robin,
>
> On 09/06/2021 16:45, Robin Murphy wrote:
>> On 2021-06-09 14:07, Neil Armstrong wrote:
>>> Hi,
>>>
>>> On 08/06/2021 17:50, Marek Szyprowski wrote:
>>>> Hi
>>>>
>>>> On 08.06.2021 17:33, Neil Armstrong wrote:
>>>>> It has been reported that usage of memcpy() to/from an iomem mapping is invalid,
>>>>> and and recent arm64 memcpy update [1] triggers a memory abort when dram-access-quirk
>>>>> is used on the G12A/G12B platforms.
>>>>>
>>>>> This adds a local sg_copy_to_buffer which makes usage of io versions of memcpy
>>>>> when dram-access-quirk is enabled.
>>>>>
>>>>> Fixes: acdc8e71d9bb ("mmc: meson-gx: add dram-access-quirk")
>>>>> Reported-by: Marek Szyprowski <[email protected]>
>>>>> Suggested-by: Mark Rutland <[email protected]>
>>>>> Signed-off-by: Neil Armstrong <[email protected]>
>>>>>
>>>>> [1] 285133040e6c ("arm64: Import latest memcpy()/memmove() implementation")
>>>>>
>>>>> Signed-off-by: Neil Armstrong <[email protected]>
>>>>> ---
>>>>> Hi Ulf, Marek, Mark,
>>>>>
>>>>> I haven't tested the patch yet, but should fix issue reported at [2].
>>>>
>>>> Works fine here and fixed the issue.
>>>>
>>>> Tested-by: Marek Szyprowski <[email protected]>
>>>
>>> Thanks, I'll need to rework to pass an __iomem pointer to memcpy_to/fromio so sparse doesn't scream anymore.
>>
>> Hmm, might it be worth factoring out general sg_copy_{to,from}_iomem() helpers? From a quick grep I found at least mv_cesa_sg_copy() already doing essentially the same thing as meson_mmc_copy_buffer().
>
> It's definitely worth it, but since we need a quick fix, we should have meson_mmc_copy_buffer() as a fix then we should definitely move to sg_copy_{to,from}_iomem() helpers
Oh, that makes sense for sure - I was just doing some general thinking
out loud before I forget about the whole thing :)
Cheers,
Robin.
Hi,
On 08/06/2021 17:50, Marek Szyprowski wrote:
> Hi
>
> On 08.06.2021 17:33, Neil Armstrong wrote:
>> It has been reported that usage of memcpy() to/from an iomem mapping is invalid,
>> and and recent arm64 memcpy update [1] triggers a memory abort when dram-access-quirk
>> is used on the G12A/G12B platforms.
>>
>> This adds a local sg_copy_to_buffer which makes usage of io versions of memcpy
>> when dram-access-quirk is enabled.
>>
>> Fixes: acdc8e71d9bb ("mmc: meson-gx: add dram-access-quirk")
>> Reported-by: Marek Szyprowski <[email protected]>
>> Suggested-by: Mark Rutland <[email protected]>
>> Signed-off-by: Neil Armstrong <[email protected]>
>>
>> [1] 285133040e6c ("arm64: Import latest memcpy()/memmove() implementation")
>>
>> Signed-off-by: Neil Armstrong <[email protected]>
>> ---
>> Hi Ulf, Marek, Mark,
>>
>> I haven't tested the patch yet, but should fix issue reported at [2].
>
> Works fine here and fixed the issue.
>
> Tested-by: Marek Szyprowski <[email protected]>
Thanks, I'll need to rework to pass an __iomem pointer to memcpy_to/fromio so sparse doesn't scream anymore.
Neil
>
>> Neil
>>
>> [2] https://lore.kernel.org/r/[email protected]
>>
>> drivers/mmc/host/meson-gx-mmc.c | 48 ++++++++++++++++++++++++++++++---
>> 1 file changed, 44 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
>> index b8b771b643cc..89ff6038092d 100644
>> --- a/drivers/mmc/host/meson-gx-mmc.c
>> +++ b/drivers/mmc/host/meson-gx-mmc.c
>> @@ -742,6 +742,48 @@ 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;
>> + void *buf = host->bounce_buf;
>> + 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(buf + offset, miter.addr, len);
>> + else
>> + memcpy_fromio(miter.addr, buf + offset, len);
>> + } else {
>> + if (to_buffer)
>> + memcpy(buf + offset, miter.addr, len);
>> + else
>> + memcpy(miter.addr, 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);
>> @@ -785,8 +827,7 @@ 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);
>> - sg_copy_to_buffer(data->sg, data->sg_len,
>> - host->bounce_buf, xfer_bytes);
>> + meson_mmc_copy_buffer(host, data, xfer_bytes, true);
>> dma_wmb();
>> }
>>
>> @@ -955,8 +996,7 @@ 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);
>> - sg_copy_from_buffer(data->sg, data->sg_len,
>> - host->bounce_buf, xfer_bytes);
>> + meson_mmc_copy_buffer(host, data, xfer_bytes, false);
>> }
>>
>> next_cmd = meson_mmc_get_next_command(cmd);
>
> Best regards
>