iwlwifi: pcie: limit fw chunk sizes given to fh

New FW has chunks that are larger than the size limit of the
FH's DMA. To make sure we don't crash it - actively limit the
max size of each chunk.
Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/iwl-fh.h

@@ -310,6 +310,7 @@ static inline unsigned int FH_MEM_CBBC_QUEUE(unsigned int chnl)
 #define FH_RSSR_CHNL0_RX_STATUS_CHNL_IDLE	(0x01000000)
 
 #define FH_MEM_TFDIB_REG1_ADDR_BITSHIFT	28
+#define FH_MEM_TB_MAX_LENGTH			(0x00020000)
 
 /* TFDB  Area - TFDs buffer table */
 #define FH_MEM_TFDIB_DRAM_ADDR_LSB_MSK      (0xFFFFFFFF)

drivers/net/wireless/iwlwifi/pcie/trans.c

@@ -614,7 +614,7 @@ static int iwl_pcie_load_section(struct iwl_trans *trans, u8 section_num,
 {
 	u8 *v_addr;
 	dma_addr_t p_addr;
-	u32 offset, chunk_sz = section->len;
+	u32 offset, chunk_sz = min_t(u32, FH_MEM_TB_MAX_LENGTH, section->len);
 	int ret = 0;
 
 	IWL_DEBUG_FW(trans, "[%d] uCode section being loaded...\n",