[PATCH v6 1/8] bus: mhi: core: Refactor mhi queue APIs

Bhaumik Bhatt
2020-05-05T22:47:36Z

From: Hemant Kumar <hemantk@codeaurora.org>

Move all the common code to generate TRE from mhi_queue_buf,
mhi_queue_dma and mhi_queue_skb to mhi_gen_tre. This helps
to centralize the TRE generation code which makes any future
bug fixing easier to manage in these APIs.

Suggested-by: Jeffrey Hugo <jhugo@codeaurora.org>
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>
Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
---
drivers/bus/mhi/core/internal.h | 3 +-
drivers/bus/mhi/core/main.c | 107 +++++++++++++++++-----------------------
2 files changed, 47 insertions(+), 63 deletions(-)

diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
index 095d95b..40c47f9 100644
--- a/drivers/bus/mhi/core/internal.h
+++ b/drivers/bus/mhi/core/internal.h
@@ -670,8 +670,7 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl,
irqreturn_t mhi_intvec_handler(int irq_number, void *dev);

int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
- void *buf, void *cb, size_t buf_len, enum mhi_flags flags);
-
+ struct mhi_buf_info *info, enum mhi_flags flags);
int mhi_map_single_no_bb(struct mhi_controller *mhi_cntrl,
struct mhi_buf_info *buf_info);
int mhi_map_single_use_bb(struct mhi_controller *mhi_cntrl,
diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index c26eed0..605640c 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -919,9 +919,7 @@ int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir,
struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ? mhi_dev->ul_chan :
mhi_dev->dl_chan;
struct mhi_ring *tre_ring = &mhi_chan->tre_ring;
- struct mhi_ring *buf_ring = &mhi_chan->buf_ring;
- struct mhi_buf_info *buf_info;
- struct mhi_tre *mhi_tre;
+ struct mhi_buf_info buf_info = { };
int ret;

/* If MHI host pre-allocates buffers then client drivers cannot queue */
@@ -946,27 +944,15 @@ int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir,
/* Toggle wake to exit out of M2 */
mhi_cntrl->wake_toggle(mhi_cntrl);

- /* Generate the TRE */
- buf_info = buf_ring->wp;
-
- buf_info->v_addr = skb->data;
- buf_info->cb_buf = skb;
- buf_info->wp = tre_ring->wp;
- buf_info->dir = mhi_chan->dir;
- buf_info->len = len;
- ret = mhi_cntrl->map_single(mhi_cntrl, buf_info);
- if (ret)
- goto map_error;
-
- mhi_tre = tre_ring->wp;
-
- mhi_tre->ptr = MHI_TRE_DATA_PTR(buf_info->p_addr);
- mhi_tre->dword[0] = MHI_TRE_DATA_DWORD0(buf_info->len);
- mhi_tre->dword[1] = MHI_TRE_DATA_DWORD1(1, 1, 0, 0);
+ buf_info.v_addr = skb->data;
+ buf_info.cb_buf = skb;
+ buf_info.len = len;

- /* increment WP */
- mhi_add_ring_element(mhi_cntrl, tre_ring);
- mhi_add_ring_element(mhi_cntrl, buf_ring);
+ ret = mhi_gen_tre(mhi_cntrl, mhi_chan, &buf_info, mflags);
+ if (unlikely(ret)) {
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+ return ret;
+ }

if (mhi_chan->dir == DMA_TO_DEVICE)
atomic_inc(&mhi_cntrl->pending_pkts);
@@ -980,11 +966,6 @@ int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir,
read_unlock_bh(&mhi_cntrl->pm_lock);

return 0;
-
-map_error:
- read_unlock_bh(&mhi_cntrl->pm_lock);
-
- return ret;
}
EXPORT_SYMBOL_GPL(mhi_queue_skb);

@@ -996,9 +977,8 @@ int mhi_queue_dma(struct mhi_device *mhi_dev, enum dma_data_direction dir,
mhi_dev->dl_chan;
struct device *dev = &mhi_cntrl->mhi_dev->dev;
struct mhi_ring *tre_ring = &mhi_chan->tre_ring;
- struct mhi_ring *buf_ring = &mhi_chan->buf_ring;
- struct mhi_buf_info *buf_info;
- struct mhi_tre *mhi_tre;
+ struct mhi_buf_info buf_info = { };
+ int ret;

/* If MHI host pre-allocates buffers then client drivers cannot queue */
if (mhi_chan->pre_alloc)
@@ -1025,25 +1005,16 @@ int mhi_queue_dma(struct mhi_device *mhi_dev, enum dma_data_direction dir,
/* Toggle wake to exit out of M2 */
mhi_cntrl->wake_toggle(mhi_cntrl);

- /* Generate the TRE */
- buf_info = buf_ring->wp;
- WARN_ON(buf_info->used);
- buf_info->p_addr = mhi_buf->dma_addr;
- buf_info->pre_mapped = true;
- buf_info->cb_buf = mhi_buf;
- buf_info->wp = tre_ring->wp;
- buf_info->dir = mhi_chan->dir;
- buf_info->len = len;
-
- mhi_tre = tre_ring->wp;
-
- mhi_tre->ptr = MHI_TRE_DATA_PTR(buf_info->p_addr);
- mhi_tre->dword[0] = MHI_TRE_DATA_DWORD0(buf_info->len);
- mhi_tre->dword[1] = MHI_TRE_DATA_DWORD1(1, 1, 0, 0);
+ buf_info.p_addr = mhi_buf->dma_addr;
+ buf_info.cb_buf = mhi_buf;
+ buf_info.pre_mapped = true;
+ buf_info.len = len;

- /* increment WP */
- mhi_add_ring_element(mhi_cntrl, tre_ring);
- mhi_add_ring_element(mhi_cntrl, buf_ring);
+ ret = mhi_gen_tre(mhi_cntrl, mhi_chan, &buf_info, mflags);
+ if (unlikely(ret)) {
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+ return ret;
+ }

if (mhi_chan->dir == DMA_TO_DEVICE)
atomic_inc(&mhi_cntrl->pending_pkts);
@@ -1061,7 +1032,7 @@ int mhi_queue_dma(struct mhi_device *mhi_dev, enum dma_data_direction dir,
EXPORT_SYMBOL_GPL(mhi_queue_dma);

int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
- void *buf, void *cb, size_t buf_len, enum mhi_flags flags)
+ struct mhi_buf_info *info, enum mhi_flags flags)
{
struct mhi_ring *buf_ring, *tre_ring;
struct mhi_tre *mhi_tre;
@@ -1073,15 +1044,22 @@ int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
tre_ring = &mhi_chan->tre_ring;

buf_info = buf_ring->wp;
- buf_info->v_addr = buf;
- buf_info->cb_buf = cb;
+ WARN_ON(buf_info->used);
+ buf_info->pre_mapped = info->pre_mapped;
+ if (info->pre_mapped)
+ buf_info->p_addr = info->p_addr;
+ else
+ buf_info->v_addr = info->v_addr;
+ buf_info->cb_buf = info->cb_buf;
buf_info->wp = tre_ring->wp;
buf_info->dir = mhi_chan->dir;
- buf_info->len = buf_len;
+ buf_info->len = info->len;

- ret = mhi_cntrl->map_single(mhi_cntrl, buf_info);
- if (ret)
- return ret;
+ if (!info->pre_mapped) {
+ ret = mhi_cntrl->map_single(mhi_cntrl, buf_info);
+ if (ret)
+ return ret;
+ }

eob = !!(flags & MHI_EOB);
eot = !!(flags & MHI_EOT);
@@ -1090,7 +1068,7 @@ int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,

mhi_tre = tre_ring->wp;
mhi_tre->ptr = MHI_TRE_DATA_PTR(buf_info->p_addr);
- mhi_tre->dword[0] = MHI_TRE_DATA_DWORD0(buf_len);
+ mhi_tre->dword[0] = MHI_TRE_DATA_DWORD0(info->len);
mhi_tre->dword[1] = MHI_TRE_DATA_DWORD1(bei, eot, eob, chain);

/* increment WP */
@@ -1107,6 +1085,7 @@ int mhi_queue_buf(struct mhi_device *mhi_dev, enum dma_data_direction dir,
struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ? mhi_dev->ul_chan :
mhi_dev->dl_chan;
struct mhi_ring *tre_ring;
+ struct mhi_buf_info buf_info = { };
unsigned long flags;
int ret;

@@ -1122,7 +1101,11 @@ int mhi_queue_buf(struct mhi_device *mhi_dev, enum dma_data_direction dir,
if (mhi_is_ring_full(mhi_cntrl, tre_ring))
return -ENOMEM;

- ret = mhi_gen_tre(mhi_cntrl, mhi_chan, buf, buf, len, mflags);
+ buf_info.v_addr = buf;
+ buf_info.cb_buf = buf;
+ buf_info.len = len;
+
+ ret = mhi_gen_tre(mhi_cntrl, mhi_chan, &buf_info, mflags);
if (unlikely(ret))
return ret;

@@ -1323,7 +1306,7 @@ int mhi_prepare_channel(struct mhi_controller *mhi_cntrl,

while (nr_el--) {
void *buf;
-
+ struct mhi_buf_info info = { };
buf = kmalloc(len, GFP_KERNEL);
if (!buf) {
ret = -ENOMEM;
@@ -1331,8 +1314,10 @@ int mhi_prepare_channel(struct mhi_controller *mhi_cntrl,
}

/* Prepare transfer descriptors */
- ret = mhi_gen_tre(mhi_cntrl, mhi_chan, buf, buf,
- len, MHI_EOT);
+ info.v_addr = buf;
+ info.cb_buf = buf;
+ info.len = len;
+ ret = mhi_gen_tre(mhi_cntrl, mhi_chan, &info, MHI_EOT);
if (ret) {
kfree(buf);
goto error_pre_alloc;