[PATCH] bus: mhi: ep: Use slab allocator where applicable
From: Manivannan Sadhasivam
Date: Wed Oct 18 2023 - 08:28:33 EST
Use slab allocator for allocating the memory for objects used frequently
and are of fixed size. This reduces the overheard associated with
kmalloc().
Suggested-by: Alex Elder <elder@xxxxxxxxxx>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
---
drivers/bus/mhi/ep/main.c | 70 +++++++++++++++++++++++++++++----------
include/linux/mhi_ep.h | 3 ++
2 files changed, 56 insertions(+), 17 deletions(-)
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
index 66ca470bf302..834e7afadd64 100644
--- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -71,7 +71,8 @@ static int mhi_ep_send_event(struct mhi_ep_cntrl *mhi_cntrl, u32 ring_idx,
static int mhi_ep_send_completion_event(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_ring *ring,
struct mhi_ring_element *tre, u32 len, enum mhi_ev_ccs code)
{
- struct mhi_ring_element *event = kzalloc(sizeof(struct mhi_ring_element), GFP_KERNEL);
+ struct mhi_ring_element *event = kmem_cache_zalloc(mhi_cntrl->ev_ring_el_cache,
+ GFP_KERNEL | GFP_DMA);
int ret;
event->ptr = cpu_to_le64(ring->rbase + ring->rd_offset * sizeof(*tre));
@@ -79,42 +80,45 @@ static int mhi_ep_send_completion_event(struct mhi_ep_cntrl *mhi_cntrl, struct m
event->dword[1] = MHI_TRE_EV_DWORD1(ring->ch_id, MHI_PKT_TYPE_TX_EVENT);
ret = mhi_ep_send_event(mhi_cntrl, ring->er_index, event, MHI_TRE_DATA_GET_BEI(tre));
- kfree(event);
+ kmem_cache_free(mhi_cntrl->ev_ring_el_cache, event);
return ret;
}
int mhi_ep_send_state_change_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_state state)
{
- struct mhi_ring_element *event = kzalloc(sizeof(struct mhi_ring_element), GFP_KERNEL);
+ struct mhi_ring_element *event = kmem_cache_zalloc(mhi_cntrl->ev_ring_el_cache,
+ GFP_KERNEL | GFP_DMA);
int ret;
event->dword[0] = MHI_SC_EV_DWORD0(state);
event->dword[1] = MHI_SC_EV_DWORD1(MHI_PKT_TYPE_STATE_CHANGE_EVENT);
ret = mhi_ep_send_event(mhi_cntrl, 0, event, 0);
- kfree(event);
+ kmem_cache_free(mhi_cntrl->ev_ring_el_cache, event);
return ret;
}
int mhi_ep_send_ee_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_ee_type exec_env)
{
- struct mhi_ring_element *event = kzalloc(sizeof(struct mhi_ring_element), GFP_KERNEL);
+ struct mhi_ring_element *event = kmem_cache_zalloc(mhi_cntrl->ev_ring_el_cache,
+ GFP_KERNEL | GFP_DMA);
int ret;
event->dword[0] = MHI_EE_EV_DWORD0(exec_env);
event->dword[1] = MHI_SC_EV_DWORD1(MHI_PKT_TYPE_EE_EVENT);
ret = mhi_ep_send_event(mhi_cntrl, 0, event, 0);
- kfree(event);
+ kmem_cache_free(mhi_cntrl->ev_ring_el_cache, event);
return ret;
}
static int mhi_ep_send_cmd_comp_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_ev_ccs code)
{
- struct mhi_ring_element *event = kzalloc(sizeof(struct mhi_ring_element), GFP_KERNEL);
+ struct mhi_ring_element *event = kmem_cache_zalloc(mhi_cntrl->ev_ring_el_cache,
+ GFP_KERNEL | GFP_DMA);
struct mhi_ep_ring *ring = &mhi_cntrl->mhi_cmd->ring;
int ret;
@@ -123,7 +127,7 @@ static int mhi_ep_send_cmd_comp_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_e
event->dword[1] = MHI_CC_EV_DWORD1(MHI_PKT_TYPE_CMD_COMPLETION_EVENT);
ret = mhi_ep_send_event(mhi_cntrl, 0, event, 0);
- kfree(event);
+ kmem_cache_free(mhi_cntrl->ev_ring_el_cache, event);
return ret;
}
@@ -435,7 +439,7 @@ static int mhi_ep_process_ch_ring(struct mhi_ep_ring *ring, struct mhi_ring_elem
mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
} else {
/* UL channel */
- result.buf_addr = kzalloc(len, GFP_KERNEL);
+ result.buf_addr = kmem_cache_zalloc(mhi_cntrl->tre_buf_cache, GFP_KERNEL | GFP_DMA);
if (!result.buf_addr)
return -ENOMEM;
@@ -443,7 +447,7 @@ static int mhi_ep_process_ch_ring(struct mhi_ep_ring *ring, struct mhi_ring_elem
ret = mhi_ep_read_channel(mhi_cntrl, ring, &result, len);
if (ret < 0) {
dev_err(&mhi_chan->mhi_dev->dev, "Failed to read channel\n");
- kfree(result.buf_addr);
+ kmem_cache_free(mhi_cntrl->tre_buf_cache, result.buf_addr);
return ret;
}
@@ -455,7 +459,7 @@ static int mhi_ep_process_ch_ring(struct mhi_ep_ring *ring, struct mhi_ring_elem
/* Read until the ring becomes empty */
} while (!mhi_ep_queue_is_empty(mhi_chan->mhi_dev, DMA_TO_DEVICE));
- kfree(result.buf_addr);
+ kmem_cache_free(mhi_cntrl->tre_buf_cache, result.buf_addr);
}
return 0;
@@ -764,14 +768,14 @@ static void mhi_ep_ch_ring_worker(struct work_struct *work)
if (ret) {
dev_err(dev, "Error updating write offset for ring\n");
mutex_unlock(&chan->lock);
- kfree(itr);
+ kmem_cache_free(mhi_cntrl->ring_item_cache, itr);
continue;
}
/* Sanity check to make sure there are elements in the ring */
if (ring->rd_offset == ring->wr_offset) {
mutex_unlock(&chan->lock);
- kfree(itr);
+ kmem_cache_free(mhi_cntrl->ring_item_cache, itr);
continue;
}
@@ -783,12 +787,12 @@ static void mhi_ep_ch_ring_worker(struct work_struct *work)
dev_err(dev, "Error processing ring for channel (%u): %d\n",
ring->ch_id, ret);
mutex_unlock(&chan->lock);
- kfree(itr);
+ kmem_cache_free(mhi_cntrl->ring_item_cache, itr);
continue;
}
mutex_unlock(&chan->lock);
- kfree(itr);
+ kmem_cache_free(mhi_cntrl->ring_item_cache, itr);
}
}
@@ -844,7 +848,7 @@ static void mhi_ep_queue_channel_db(struct mhi_ep_cntrl *mhi_cntrl, unsigned lon
u32 ch_id = ch_idx + i;
ring = &mhi_cntrl->mhi_chan[ch_id].ring;
- item = kzalloc(sizeof(*item), GFP_ATOMIC);
+ item = kmem_cache_zalloc(mhi_cntrl->ring_item_cache, GFP_ATOMIC);
if (!item)
return;
@@ -1391,6 +1395,29 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl,
goto err_free_ch;
}
+ mhi_cntrl->ev_ring_el_cache = kmem_cache_create("mhi_ep_event_ring_el",
+ sizeof(struct mhi_ring_element), 0,
+ SLAB_CACHE_DMA, NULL);
+ if (!mhi_cntrl->ev_ring_el_cache) {
+ ret = -ENOMEM;
+ goto err_free_cmd;
+ }
+
+ mhi_cntrl->tre_buf_cache = kmem_cache_create("mhi_ep_tre_buf", MHI_EP_DEFAULT_MTU, 0,
+ SLAB_CACHE_DMA, NULL);
+ if (!mhi_cntrl->tre_buf_cache) {
+ ret = -ENOMEM;
+ goto err_destroy_ev_ring_el_cache;
+ }
+
+ mhi_cntrl->ring_item_cache = kmem_cache_create("mhi_ep_ring_item",
+ sizeof(struct mhi_ep_ring_item), 0,
+ 0, NULL);
+ if (!mhi_cntrl->ev_ring_el_cache) {
+ ret = -ENOMEM;
+ goto err_destroy_tre_buf_cache;
+ }
+
INIT_WORK(&mhi_cntrl->state_work, mhi_ep_state_worker);
INIT_WORK(&mhi_cntrl->reset_work, mhi_ep_reset_worker);
INIT_WORK(&mhi_cntrl->cmd_ring_work, mhi_ep_cmd_ring_worker);
@@ -1399,7 +1426,7 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl,
mhi_cntrl->wq = alloc_workqueue("mhi_ep_wq", 0, 0);
if (!mhi_cntrl->wq) {
ret = -ENOMEM;
- goto err_free_cmd;
+ goto err_destroy_ring_item_cache;
}
INIT_LIST_HEAD(&mhi_cntrl->st_transition_list);
@@ -1458,6 +1485,12 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl,
ida_free(&mhi_ep_cntrl_ida, mhi_cntrl->index);
err_destroy_wq:
destroy_workqueue(mhi_cntrl->wq);
+err_destroy_ring_item_cache:
+ kmem_cache_destroy(mhi_cntrl->ring_item_cache);
+err_destroy_ev_ring_el_cache:
+ kmem_cache_destroy(mhi_cntrl->ev_ring_el_cache);
+err_destroy_tre_buf_cache:
+ kmem_cache_destroy(mhi_cntrl->tre_buf_cache);
err_free_cmd:
kfree(mhi_cntrl->mhi_cmd);
err_free_ch:
@@ -1479,6 +1512,9 @@ void mhi_ep_unregister_controller(struct mhi_ep_cntrl *mhi_cntrl)
free_irq(mhi_cntrl->irq, mhi_cntrl);
+ kmem_cache_destroy(mhi_cntrl->tre_buf_cache);
+ kmem_cache_destroy(mhi_cntrl->ev_ring_el_cache);
+ kmem_cache_destroy(mhi_cntrl->ring_item_cache);
kfree(mhi_cntrl->mhi_cmd);
kfree(mhi_cntrl->mhi_chan);
diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h
index f198a8ac7ee7..ce85d42b685d 100644
--- a/include/linux/mhi_ep.h
+++ b/include/linux/mhi_ep.h
@@ -128,6 +128,9 @@ struct mhi_ep_cntrl {
struct work_struct reset_work;
struct work_struct cmd_ring_work;
struct work_struct ch_ring_work;
+ struct kmem_cache *ring_item_cache;
+ struct kmem_cache *ev_ring_el_cache;
+ struct kmem_cache *tre_buf_cache;
void (*raise_irq)(struct mhi_ep_cntrl *mhi_cntrl, u32 vector);
int (*alloc_map)(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr, phys_addr_t *phys_ptr,
--
2.25.1