[PATCH 1/2] ath10k: do not use coherent memory for allocated device memory chunks
Felix Fietkau
nbd at openwrt.org
Mon Nov 23 05:18:48 PST 2015
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 at openwrt.org>
---
drivers/net/wireless/ath/ath10k/wmi.c | 59 +++++++++++++++++++++++++----------
1 file changed, 42 insertions(+), 17 deletions(-)
diff --git a/drivers/net/wireless/ath/ath10k/wmi.c b/drivers/net/wireless/ath/ath10k/wmi.c
index 9021079..6cd097c 100644
--- a/drivers/net/wireless/ath/ath10k/wmi.c
+++ b/drivers/net/wireless/ath/ath10k/wmi.c
@@ -4300,34 +4300,58 @@ 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;
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;
}
@@ -7705,10 +7729,11 @@ 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;
--
2.2.2
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