[PATCH 16/17] firewire: ohci: use guard macro to maintain image of configuration ROM

[Takashi Sakamoto]

The 1394 OHCI driver uses spinlock for the process to update local
configuration ROM.

This commit uses guard macro to maintain the spinlock.

Signed-off-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>
---
 drivers/firewire/ohci.c | 116 +++++++++++++++++-----------------------
 1 file changed, 49 insertions(+), 67 deletions(-)

diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 5cb7c7603c2c..368420e4b414 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -2139,53 +2139,42 @@ static void bus_reset_work(struct work_struct *work)
 	at_context_flush(&ohci->at_request_ctx);
 	at_context_flush(&ohci->at_response_ctx);
 
-	spin_lock_irq(&ohci->lock);
-
-	ohci->generation = generation;
-	reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);
-	reg_write(ohci, OHCI1394_IntMaskSet, OHCI1394_busReset);
-
-	if (ohci->quirks & QUIRK_RESET_PACKET)
-		ohci->request_generation = generation;
-
-	/*
-	 * This next bit is unrelated to the AT context stuff but we
-	 * have to do it under the spinlock also.  If a new config rom
-	 * was set up before this reset, the old one is now no longer
-	 * in use and we can free it. Update the config rom pointers
-	 * to point to the current config rom and clear the
-	 * next_config_rom pointer so a new update can take place.
-	 */
-
-	if (ohci->next_config_rom != NULL) {
-		if (ohci->next_config_rom != ohci->config_rom) {
-			free_rom      = ohci->config_rom;
-			free_rom_bus  = ohci->config_rom_bus;
+	scoped_guard(spinlock_irq, &ohci->lock) {
+		ohci->generation = generation;
+		reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);
+		reg_write(ohci, OHCI1394_IntMaskSet, OHCI1394_busReset);
+
+		if (ohci->quirks & QUIRK_RESET_PACKET)
+			ohci->request_generation = generation;
+
+		// This next bit is unrelated to the AT context stuff but we have to do it under the
+		// spinlock also. If a new config rom was set up before this reset, the old one is
+		// now no longer in use and we can free it. Update the config rom pointers to point
+		// to the current config rom and clear the next_config_rom pointer so a new update
+		// can take place.
+		if (ohci->next_config_rom != NULL) {
+			if (ohci->next_config_rom != ohci->config_rom) {
+				free_rom      = ohci->config_rom;
+				free_rom_bus  = ohci->config_rom_bus;
+			}
+			ohci->config_rom      = ohci->next_config_rom;
+			ohci->config_rom_bus  = ohci->next_config_rom_bus;
+			ohci->next_config_rom = NULL;
+
+			// Restore config_rom image and manually update config_rom registers.
+			// Writing the header quadlet will indicate that the config rom is ready,
+			// so we do that last.
+			reg_write(ohci, OHCI1394_BusOptions, be32_to_cpu(ohci->config_rom[2]));
+			ohci->config_rom[0] = ohci->next_header;
+			reg_write(ohci, OHCI1394_ConfigROMhdr, be32_to_cpu(ohci->next_header));
 		}
-		ohci->config_rom      = ohci->next_config_rom;
-		ohci->config_rom_bus  = ohci->next_config_rom_bus;
-		ohci->next_config_rom = NULL;
 
-		/*
-		 * Restore config_rom image and manually update
-		 * config_rom registers.  Writing the header quadlet
-		 * will indicate that the config rom is ready, so we
-		 * do that last.
-		 */
-		reg_write(ohci, OHCI1394_BusOptions,
-			  be32_to_cpu(ohci->config_rom[2]));
-		ohci->config_rom[0] = ohci->next_header;
-		reg_write(ohci, OHCI1394_ConfigROMhdr,
-			  be32_to_cpu(ohci->next_header));
-	}
-
-	if (param_remote_dma) {
-		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
-		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
+		if (param_remote_dma) {
+			reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
+			reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
+		}
 	}
 
-	spin_unlock_irq(&ohci->lock);
-
 	if (free_rom)
 		dmam_free_coherent(ohci->card.device, CONFIG_ROM_SIZE, free_rom, free_rom_bus);
 
@@ -2626,33 +2615,26 @@ static int ohci_set_config_rom(struct fw_card *card,
 	if (next_config_rom == NULL)
 		return -ENOMEM;
 
-	spin_lock_irq(&ohci->lock);
-
-	/*
-	 * If there is not an already pending config_rom update,
-	 * push our new allocation into the ohci->next_config_rom
-	 * and then mark the local variable as null so that we
-	 * won't deallocate the new buffer.
-	 *
-	 * OTOH, if there is a pending config_rom update, just
-	 * use that buffer with the new config_rom data, and
-	 * let this routine free the unused DMA allocation.
-	 */
-
-	if (ohci->next_config_rom == NULL) {
-		ohci->next_config_rom = next_config_rom;
-		ohci->next_config_rom_bus = next_config_rom_bus;
-		next_config_rom = NULL;
-	}
+	scoped_guard(spinlock_irq, &ohci->lock) {
+		// If there is not an already pending config_rom update, push our new allocation
+		// into the ohci->next_config_rom and then mark the local variable as null so that
+		// we won't deallocate the new buffer.
+		//
+		// OTOH, if there is a pending config_rom update, just use that buffer with the new
+		// config_rom data, and let this routine free the unused DMA allocation.
+		if (ohci->next_config_rom == NULL) {
+			ohci->next_config_rom = next_config_rom;
+			ohci->next_config_rom_bus = next_config_rom_bus;
+			next_config_rom = NULL;
+		}
 
-	copy_config_rom(ohci->next_config_rom, config_rom, length);
+		copy_config_rom(ohci->next_config_rom, config_rom, length);
 
-	ohci->next_header = config_rom[0];
-	ohci->next_config_rom[0] = 0;
+		ohci->next_header = config_rom[0];
+		ohci->next_config_rom[0] = 0;
 
-	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
-
-	spin_unlock_irq(&ohci->lock);
+		reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
+	}
 
 	/* If we didn't use the DMA allocation, delete it. */
 	if (next_config_rom != NULL) {
-- 
2.43.0