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

From: Takashi Sakamoto
Date: Sun Aug 04 2024 - 09:05:33 EST


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