firewire: ohci: use devres for content of configuration ROM

The 1394 OHCI driver allocates DMA coherent buffer to transfer content
of configuration ROM.

This commit utilizes managed device resource to maintain the lifetime of
buffer.

Link: https://lore.kernel.org/r/20230604054451.161076-9-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

drivers/firewire/ohci.c

@@ -2052,8 +2052,7 @@ static void bus_reset_work(struct work_struct *work)
 	spin_unlock_irq(&ohci->lock);
 
 	if (free_rom)
-		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
-				  free_rom, free_rom_bus);
+		dmam_free_coherent(ohci->card.device, CONFIG_ROM_SIZE, free_rom, free_rom_bus);
 
 	log_selfids(ohci, generation, self_id_count);
 
@@ -2385,10 +2384,8 @@ static int ohci_enable(struct fw_card *card,
 	 */
 
 	if (config_rom) {
-		ohci->next_config_rom =
-			dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
-					   &ohci->next_config_rom_bus,
-					   GFP_KERNEL);
+		ohci->next_config_rom = dmam_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
+							    &ohci->next_config_rom_bus, GFP_KERNEL);
 		if (ohci->next_config_rom == NULL)
 			return -ENOMEM;
 
@@ -2480,9 +2477,8 @@ static int ohci_set_config_rom(struct fw_card *card,
 	 * ohci->next_config_rom to NULL (see bus_reset_work).
 	 */
 
-	next_config_rom =
-		dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
-				   &next_config_rom_bus, GFP_KERNEL);
+	next_config_rom = dmam_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
+					      &next_config_rom_bus, GFP_KERNEL);
 	if (next_config_rom == NULL)
 		return -ENOMEM;
 
@@ -2515,9 +2511,10 @@ static int ohci_set_config_rom(struct fw_card *card,
 	spin_unlock_irq(&ohci->lock);
 
 	/* If we didn't use the DMA allocation, delete it. */
-	if (next_config_rom != NULL)
-		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
-				  next_config_rom, next_config_rom_bus);
+	if (next_config_rom != NULL) {
+		dmam_free_coherent(ohci->card.device, CONFIG_ROM_SIZE, next_config_rom,
+				   next_config_rom_bus);
+	}
 
 	/*
 	 * Now initiate a bus reset to have the changes take
@@ -3753,12 +3750,6 @@ static void pci_remove(struct pci_dev *dev)
 
 	software_reset(ohci);
 
-	if (ohci->next_config_rom && ohci->next_config_rom != ohci->config_rom)
-		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
-				  ohci->next_config_rom, ohci->next_config_rom_bus);
-	if (ohci->config_rom)
-		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
-				  ohci->config_rom, ohci->config_rom_bus);
 	ar_context_release(&ohci->ar_request_ctx);
 	ar_context_release(&ohci->ar_response_ctx);
 	pci_disable_msi(dev);