bus: mhi: ep: Use slab allocator where applicable

[ Upstream commit 62210a26cd4f8ad52683a71c0226dfe85de1144d ]

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@linaro.org>
Link: https://lore.kernel.org/r/20231018122812.47261-1-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Stable-dep-of: 327ec5f70609 ("PCI: epf-mhi: Fix the DMA data direction of dma_unmap_single()")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
index e2513f5..5172796 100644 (file)
--- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -74,7 +74,7 @@ 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 +83,7 @@ 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 +93,7 @@ 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 +101,7 @@ 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 +111,7 @@ 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 +119,7 @@ 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 +130,7 @@ 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 +139,7 @@ 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 +451,7 @@ 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 +459,7 @@ 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 +471,7 @@ 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 +780,14 @@ 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 +799,12 @@ 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 +860,7 @@ 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 +1407,29 @@ 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 +1438,7 @@ 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 +1497,12 @@ err_ida_free:
        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 +1524,9 @@ 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 f198a8a..ce85d42 100644 (file)
--- 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,