ath10k: do not use coherent memory for allocated device memory chunks

Coherent memory is more expensive to allocate (and constrained on some
architectures where it has to be pre-allocated). It is also completely
unnecessary, since the host has no reason to even access these allocated
memory spaces

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

diff --git a/drivers/net/wireless/ath/ath10k/wmi.c b/drivers/net/wireless/ath/ath10k/wmi.c
index 2a44d63..a7c3d29 100644 (file)
--- a/drivers/net/wireless/ath/ath10k/wmi.c
+++ b/drivers/net/wireless/ath/ath10k/wmi.c
@@ -4312,34 +4312,58 @@ void ath10k_wmi_event_vdev_resume_req(struct ath10k *ar, struct sk_buff *skb)
        ath10k_dbg(ar, ATH10K_DBG_WMI, "WMI_VDEV_RESUME_REQ_EVENTID\n");
 }
 
-static int ath10k_wmi_alloc_host_mem(struct ath10k *ar, u32 req_id,
-                                    u32 num_units, u32 unit_len)
+static int ath10k_wmi_alloc_chunk(struct ath10k *ar, u32 req_id,
+                                 u32 num_units, u32 unit_len)
 {
        dma_addr_t paddr;
-       u32 pool_size;
+       u32 pool_size = 0;
        int idx = ar->wmi.num_mem_chunks;
+       void *vaddr = NULL;
 
-       pool_size = num_units * round_up(unit_len, 4);
+       if (ar->wmi.num_mem_chunks == ARRAY_SIZE(ar->wmi.mem_chunks))
+               return -ENOMEM;
 
-       if (!pool_size)
-               return -EINVAL;
+       while (!vaddr && num_units) {
+               pool_size = num_units * round_up(unit_len, 4);
+               if (!pool_size)
+                       return -EINVAL;
 
-       ar->wmi.mem_chunks[idx].vaddr = dma_alloc_coherent(ar->dev,
-                                                          pool_size,
-                                                          &paddr,
-                                                          GFP_KERNEL);
-       if (!ar->wmi.mem_chunks[idx].vaddr) {
-               ath10k_warn(ar, "failed to allocate memory chunk\n");
-               return -ENOMEM;
+               vaddr = kzalloc(pool_size, GFP_KERNEL | __GFP_NOWARN);
+               if (!vaddr)
+                       num_units /= 2;
        }
 
-       memset(ar->wmi.mem_chunks[idx].vaddr, 0, pool_size);
+       if (!num_units)
+               return -ENOMEM;
+
+       paddr = dma_map_single(ar->dev, vaddr, pool_size, DMA_TO_DEVICE);
+       if (dma_mapping_error(ar->dev, paddr)) {
+               kfree(vaddr);
+               return -ENOMEM;
+       }
 
+       ar->wmi.mem_chunks[idx].vaddr = vaddr;
        ar->wmi.mem_chunks[idx].paddr = paddr;
        ar->wmi.mem_chunks[idx].len = pool_size;
        ar->wmi.mem_chunks[idx].req_id = req_id;
        ar->wmi.num_mem_chunks++;
 
+       return num_units;
+}
+
+static int ath10k_wmi_alloc_host_mem(struct ath10k *ar, u32 req_id,
+                                    u32 num_units, u32 unit_len)
+{
+       int ret;
+
+       while (num_units) {
+               ret = ath10k_wmi_alloc_chunk(ar, req_id, num_units, unit_len);
+               if (ret < 0)
+                       return ret;
+
+               num_units -= ret;
+       }
+
        return 0;
 }
 
@@ -7717,10 +7741,11 @@ void ath10k_wmi_free_host_mem(struct ath10k *ar)
 
        /* free the host memory chunks requested by firmware */
        for (i = 0; i < ar->wmi.num_mem_chunks; i++) {
-               dma_free_coherent(ar->dev,
-                                 ar->wmi.mem_chunks[i].len,
-                                 ar->wmi.mem_chunks[i].vaddr,
-                                 ar->wmi.mem_chunks[i].paddr);
+               dma_unmap_single(ar->dev,
+                                ar->wmi.mem_chunks[i].paddr,
+                                ar->wmi.mem_chunks[i].len,
+                                DMA_TO_DEVICE);
+               kfree(ar->wmi.mem_chunks[i].vaddr);
        }
 
        ar->wmi.num_mem_chunks = 0;