iwlwifi: pcie: prefer to load the firmware in one shot

Users complained about allocation failures, so we loaded
the firmware in small chunks (PAGE_SIZE). This makes the
firmware restart considerably slower.
So, always prefer to load it in one shot allocating a big
chunk of coherent, and use smaller chunks as a fallback
solution.

On my laptop, this reduces the fw loading time from 120ms
to 20ms.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-by: Moshe Island <moshe.island@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 14 insertions, 7 deletions

diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index 50ba0a468f94..e5365196e5fe 100644
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -405,20 +405,27 @@ static int iwl_pcie_load_section(struct iwl_trans *trans, u8 section_num,
 {
         u8 *v_addr;
         dma_addr_t p_addr;
-        u32 offset;
+        u32 offset, chunk_sz = section->len;
         int ret = 0;
 
         IWL_DEBUG_FW(trans, "[%d] uCode section being loaded...\n",
                      section_num);
 
-        v_addr = dma_alloc_coherent(trans->dev, PAGE_SIZE, &p_addr, GFP_KERNEL);
-        if (!v_addr)
-                return -ENOMEM;
+        v_addr = dma_alloc_coherent(trans->dev, chunk_sz, &p_addr,
+                                    GFP_KERNEL | __GFP_NOWARN);
+        if (!v_addr) {
+                IWL_DEBUG_INFO(trans, "Falling back to small chunks of DMA\n");
+                chunk_sz = PAGE_SIZE;
+                v_addr = dma_alloc_coherent(trans->dev, chunk_sz,
+                                            &p_addr, GFP_KERNEL);
+                if (!v_addr)
+                        return -ENOMEM;
+        }
 
-        for (offset = 0; offset < section->len; offset += PAGE_SIZE) {
+        for (offset = 0; offset < section->len; offset += chunk_sz) {
                 u32 copy_size;
 
-                copy_size = min_t(u32, PAGE_SIZE, section->len - offset);
+                copy_size = min_t(u32, chunk_sz, section->len - offset);
 
                 memcpy(v_addr, (u8 *)section->data + offset, copy_size);
                 ret = iwl_pcie_load_firmware_chunk(trans,
@@ -432,7 +439,7 @@ static int iwl_pcie_load_section(struct iwl_trans *trans, u8 section_num,
                 }
         }
 
-        dma_free_coherent(trans->dev, PAGE_SIZE, v_addr, p_addr);
+        dma_free_coherent(trans->dev, chunk_sz, v_addr, p_addr);
         return ret;
 }