[PATCH v2] bus: mhi: ep: Use slab allocator where applicable

From: Manivannan Sadhasivam
Date: Thu Oct 26 2023 - 00:50:36 EST

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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>
---

Changes in v2:

* Rebased on top of mhi-next.

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 e2513f5f47a6..b5af23f0e65a 100644
--- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -74,7 +74,8 @@ static int mhi_ep_send_completion_event(struct mhi_ep_cntrl *mhi_cntrl, struct m
struct mhi_ring_element *event;
int ret;

- event = kzalloc(sizeof(struct mhi_ring_element), GFP_KERNEL);
+ event = kmem_cache_zalloc(mhi_cntrl->ev_ring_el_cache,
+ GFP_KERNEL | GFP_DMA);
if (!event)
return -ENOMEM;

@@ -83,7 +84,7 @@ 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;
}
@@ -93,7 +94,8 @@ int mhi_ep_send_state_change_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_stat
struct mhi_ring_element *event;
int ret;

- event = kzalloc(sizeof(struct mhi_ring_element), GFP_KERNEL);
+ event = kmem_cache_zalloc(mhi_cntrl->ev_ring_el_cache,
+ GFP_KERNEL | GFP_DMA);
if (!event)
return -ENOMEM;

@@ -101,7 +103,7 @@ int mhi_ep_send_state_change_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_stat
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;
}
@@ -111,7 +113,8 @@ int mhi_ep_send_ee_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_ee_type exec_e
struct mhi_ring_element *event;
int ret;

- event = kzalloc(sizeof(struct mhi_ring_element), GFP_KERNEL);
+ event = kmem_cache_zalloc(mhi_cntrl->ev_ring_el_cache,
+ GFP_KERNEL | GFP_DMA);
if (!event)
return -ENOMEM;

@@ -119,7 +122,7 @@ int mhi_ep_send_ee_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_ee_type exec_e
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;
}
@@ -130,7 +133,8 @@ static int mhi_ep_send_cmd_comp_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_e
struct mhi_ring_element *event;
int ret;

- event = kzalloc(sizeof(struct mhi_ring_element), GFP_KERNEL);
+ event = kmem_cache_zalloc(mhi_cntrl->ev_ring_el_cache,
+ GFP_KERNEL | GFP_DMA);
if (!event)
return -ENOMEM;

@@ -139,7 +143,7 @@ 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;
}
@@ -451,7 +455,7 @@ 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;

@@ -459,7 +463,7 @@ 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;
}

@@ -471,7 +475,7 @@ 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;
@@ -780,14 +784,14 @@ 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;
}

@@ -799,12 +803,12 @@ 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);
}
}

@@ -860,7 +864,7 @@ 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;

@@ -1407,6 +1411,29 @@ 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);
@@ -1415,7 +1442,7 @@ 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);
@@ -1474,6 +1501,12 @@ 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:
@@ -1495,6 +1528,9 @@ 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,

base-commit: 12606ba1d46b34a241eb3d0956727e5379f0f626
--
2.25.1

Next message: Anshuman Khandual: "Re: [PATCH] arm64: mm: drop tlb flush operation when clearing the access bit"
Previous message: Vijayanand Jitta: "Re: [PATCH 4/9] dma-buf: heaps: Initialise MediaTek secure heap"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]