2020-10-30 15:02:40

by Roja Rani Yarubandi

[permalink] [raw]
Subject: [PATCH V6 0/3] Implement Shutdown callback for geni-i2c

Roja Rani Yarubandi (3):
soc: qcom: geni: Remove "iova" check
i2c: i2c-qcom-geni: Store DMA mapping data in geni_i2c_dev struct
i2c: i2c-qcom-geni: Add shutdown callback for i2c

drivers/i2c/busses/i2c-qcom-geni.c | 104 ++++++++++++++++++++++++-----
drivers/soc/qcom/qcom-geni-se.c | 4 +-
2 files changed, 90 insertions(+), 18 deletions(-)

--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation


2020-10-30 15:02:48

by Roja Rani Yarubandi

[permalink] [raw]
Subject: [PATCH V6 1/3] soc: qcom: geni: Remove "iova" check

Remove "iova" check from geni_se_tx_dma_unprep and geni_se_rx_dma_unprep
functions as checking with dma_mapping_error() is enough.

Signed-off-by: Roja Rani Yarubandi <[email protected]>
---
Changes in V5:
- This is newly added patch in V5. As per Stephen's comments separted
this patch from shutdown callback patch.

Changes in V6:
- Fixed nit-picks in commit text.

drivers/soc/qcom/qcom-geni-se.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c
index d0e4f520cff8..0216b38c1e9a 100644
--- a/drivers/soc/qcom/qcom-geni-se.c
+++ b/drivers/soc/qcom/qcom-geni-se.c
@@ -705,7 +705,7 @@ void geni_se_tx_dma_unprep(struct geni_se *se, dma_addr_t iova, size_t len)
{
struct geni_wrapper *wrapper = se->wrapper;

- if (iova && !dma_mapping_error(wrapper->dev, iova))
+ if (!dma_mapping_error(wrapper->dev, iova))
dma_unmap_single(wrapper->dev, iova, len, DMA_TO_DEVICE);
}
EXPORT_SYMBOL(geni_se_tx_dma_unprep);
@@ -722,7 +722,7 @@ void geni_se_rx_dma_unprep(struct geni_se *se, dma_addr_t iova, size_t len)
{
struct geni_wrapper *wrapper = se->wrapper;

- if (iova && !dma_mapping_error(wrapper->dev, iova))
+ if (!dma_mapping_error(wrapper->dev, iova))
dma_unmap_single(wrapper->dev, iova, len, DMA_FROM_DEVICE);
}
EXPORT_SYMBOL(geni_se_rx_dma_unprep);
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation

2020-10-30 15:02:56

by Roja Rani Yarubandi

[permalink] [raw]
Subject: [PATCH V6 3/3] i2c: i2c-qcom-geni: Add shutdown callback for i2c

If the hardware is still accessing memory after SMMU translation
is disabled (as part of smmu shutdown callback), then the
IOVAs (I/O virtual address) which it was using will go on the bus
as the physical addresses which will result in unknown crashes
like NoC/interconnect errors.

So, implement shutdown callback to i2c driver to stop on-going transfer
and unmap DMA mappings during system "reboot" or "shutdown".

Fixes: 37692de5d523 ("i2c: i2c-qcom-geni: Add bus driver for the Qualcomm GENI I2C controller")
Signed-off-by: Roja Rani Yarubandi <[email protected]>
---
Changes in V2:
- As per Stephen's comments added seperate function for stop transfer,
fixed minor nitpicks.
- As per Stephen's comments, changed commit text.

Changes in V3:
- As per Stephen's comments, squashed patch 1 into patch 2, added Fixes tag.
- As per Akash's comments, included FIFO case in stop_xfer, fixed minor nitpicks.

Changes in V4:
- As per Stephen's comments cleaned up geni_i2c_stop_xfer function,
added dma_buf in geni_i2c_dev struct to call i2c_put_dma_safe_msg_buf()
from other functions, removed "iova" check in geni_se_rx_dma_unprep()
and geni_se_tx_dma_unprep() functions.
- Added two helper functions geni_i2c_rx_one_msg_done() and
geni_i2c_tx_one_msg_done() to unwrap the things after rx/tx FIFO/DMA
transfers, so that the same can be used in geni_i2c_stop_xfer() function
during shutdown callback. Updated commit text accordingly.
- Checking whether it is tx/rx transfer using I2C_M_RD which is valid for both
FIFO and DMA cases, so dropped DMA_RX_ACTIVE and DMA_TX_ACTIVE bit checking

Changes in V5:
- As per Stephen's comments, added spin_lock_irqsave & spin_unlock_irqsave in
geni_i2c_stop_xfer() function.

Changes in V6:
- As per Stephen's comments, taken care of unsafe lock order in
geni_i2c_stop_xfer().
- Moved spin_lock/unlock to geni_i2c_rx_msg_cleanup() and
geni_i2c_tx_msg_cleanup() functions.

drivers/i2c/busses/i2c-qcom-geni.c | 35 ++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)

diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index e3a4ae88ed31..0c35e3e27a01 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -385,6 +385,33 @@ static void geni_i2c_tx_msg_cleanup(struct geni_i2c_dev *gi2c,
spin_unlock_irqrestore(&gi2c->lock, flags);
}

+static void geni_i2c_stop_xfer(struct geni_i2c_dev *gi2c)
+{
+ int ret;
+ u32 geni_status;
+ struct i2c_msg *cur;
+
+ /* Resume device, as runtime suspend can happen anytime during transfer */
+ ret = pm_runtime_get_sync(gi2c->se.dev);
+ if (ret < 0) {
+ dev_err(gi2c->se.dev, "Failed to resume device: %d\n", ret);
+ return;
+ }
+
+ geni_status = readl_relaxed(gi2c->se.base + SE_GENI_STATUS);
+ if (!(geni_status & M_GENI_CMD_ACTIVE))
+ goto out;
+
+ cur = gi2c->cur;
+ geni_i2c_abort_xfer(gi2c);
+ if (cur->flags & I2C_M_RD)
+ geni_i2c_rx_msg_cleanup(gi2c, cur);
+ else
+ geni_i2c_tx_msg_cleanup(gi2c, cur);
+out:
+ pm_runtime_put_sync_suspend(gi2c->se.dev);
+}
+
static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
u32 m_param)
{
@@ -666,6 +693,13 @@ static int geni_i2c_remove(struct platform_device *pdev)
return 0;
}

+static void geni_i2c_shutdown(struct platform_device *pdev)
+{
+ struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev);
+
+ geni_i2c_stop_xfer(gi2c);
+}
+
static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev)
{
int ret;
@@ -730,6 +764,7 @@ MODULE_DEVICE_TABLE(of, geni_i2c_dt_match);
static struct platform_driver geni_i2c_driver = {
.probe = geni_i2c_probe,
.remove = geni_i2c_remove,
+ .shutdown = geni_i2c_shutdown,
.driver = {
.name = "geni_i2c",
.pm = &geni_i2c_pm_ops,
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation

2020-11-22 03:30:39

by Bjorn Andersson

[permalink] [raw]
Subject: Re: [PATCH V6 1/3] soc: qcom: geni: Remove "iova" check

On Fri 30 Oct 09:59 CDT 2020, Roja Rani Yarubandi wrote:

> Remove "iova" check from geni_se_tx_dma_unprep and geni_se_rx_dma_unprep
> functions as checking with dma_mapping_error() is enough.
>

Applied this patch towards v5.11.

Thank you,
Bjorn

> Signed-off-by: Roja Rani Yarubandi <[email protected]>
> ---
> Changes in V5:
> - This is newly added patch in V5. As per Stephen's comments separted
> this patch from shutdown callback patch.
>
> Changes in V6:
> - Fixed nit-picks in commit text.
>
> drivers/soc/qcom/qcom-geni-se.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c
> index d0e4f520cff8..0216b38c1e9a 100644
> --- a/drivers/soc/qcom/qcom-geni-se.c
> +++ b/drivers/soc/qcom/qcom-geni-se.c
> @@ -705,7 +705,7 @@ void geni_se_tx_dma_unprep(struct geni_se *se, dma_addr_t iova, size_t len)
> {
> struct geni_wrapper *wrapper = se->wrapper;
>
> - if (iova && !dma_mapping_error(wrapper->dev, iova))
> + if (!dma_mapping_error(wrapper->dev, iova))
> dma_unmap_single(wrapper->dev, iova, len, DMA_TO_DEVICE);
> }
> EXPORT_SYMBOL(geni_se_tx_dma_unprep);
> @@ -722,7 +722,7 @@ void geni_se_rx_dma_unprep(struct geni_se *se, dma_addr_t iova, size_t len)
> {
> struct geni_wrapper *wrapper = se->wrapper;
>
> - if (iova && !dma_mapping_error(wrapper->dev, iova))
> + if (!dma_mapping_error(wrapper->dev, iova))
> dma_unmap_single(wrapper->dev, iova, len, DMA_FROM_DEVICE);
> }
> EXPORT_SYMBOL(geni_se_rx_dma_unprep);
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation
>