5.15-stable review patch. If anyone has any objections, please let me know.
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From: Bhaumik Bhatt bbhatt@codeaurora.org
commit b89b6a863dd53bc70d8e52d50f9cfaef8ef5e9c9 upstream.
Protect WP accesses such that multiple threads queueing buffers for incoming data do not race.
Meanwhile, if CONFIG_TRACE_IRQFLAGS is enabled, irq will be enabled once __local_bh_enable_ip is called as part of write_unlock_bh. Hence, let's take irqsave lock after TRE is generated to avoid running write_unlock_bh when irqsave lock is held.
Cc: stable@vger.kernel.org Fixes: 189ff97cca53 ("bus: mhi: core: Add support for data transfer") Signed-off-by: Bhaumik Bhatt bbhatt@codeaurora.org Signed-off-by: Qiang Yu quic_qianyu@quicinc.com Reviewed-by: Jeffrey Hugo quic_jhugo@quicinc.com Tested-by: Jeffrey Hugo quic_jhugo@quicinc.com Reviewed-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Link: https://lore.kernel.org/r/1702276972-41296-2-git-send-email-quic_qianyu@quic... Signed-off-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/bus/mhi/host/main.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-)
--- a/drivers/bus/mhi/host/main.c +++ b/drivers/bus/mhi/host/main.c @@ -1114,17 +1114,15 @@ static int mhi_queue(struct mhi_device * if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state))) return -EIO;
- read_lock_irqsave(&mhi_cntrl->pm_lock, flags); - ret = mhi_is_ring_full(mhi_cntrl, tre_ring); - if (unlikely(ret)) { - ret = -EAGAIN; - goto exit_unlock; - } + if (unlikely(ret)) + return -EAGAIN;
ret = mhi_gen_tre(mhi_cntrl, mhi_chan, buf_info, mflags); if (unlikely(ret)) - goto exit_unlock; + return ret; + + read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
/* Packet is queued, take a usage ref to exit M3 if necessary * for host->device buffer, balanced put is done on buffer completion @@ -1144,7 +1142,6 @@ static int mhi_queue(struct mhi_device * if (dir == DMA_FROM_DEVICE) mhi_cntrl->runtime_put(mhi_cntrl);
-exit_unlock: read_unlock_irqrestore(&mhi_cntrl->pm_lock, flags);
return ret; @@ -1196,6 +1193,9 @@ int mhi_gen_tre(struct mhi_controller *m int eot, eob, chain, bei; int ret;
+ /* Protect accesses for reading and incrementing WP */ + write_lock_bh(&mhi_chan->lock); + buf_ring = &mhi_chan->buf_ring; tre_ring = &mhi_chan->tre_ring;
@@ -1213,8 +1213,10 @@ int mhi_gen_tre(struct mhi_controller *m
if (!info->pre_mapped) { ret = mhi_cntrl->map_single(mhi_cntrl, buf_info); - if (ret) + if (ret) { + write_unlock_bh(&mhi_chan->lock); return ret; + } }
eob = !!(flags & MHI_EOB); @@ -1231,6 +1233,8 @@ int mhi_gen_tre(struct mhi_controller *m mhi_add_ring_element(mhi_cntrl, tre_ring); mhi_add_ring_element(mhi_cntrl, buf_ring);
+ write_unlock_bh(&mhi_chan->lock); + return 0; }