firewire: ohci: use devres for list of isochronous contexts

The 1394 OHCI driver allocates the list of isochronous contexts as much
as the hardware supports.

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

Link: https://lore.kernel.org/r/20230604054451.161076-7-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

Author: takaswie

drivers/firewire/ohci.c

@@ -3666,7 +3666,11 @@ static int pci_probe(struct pci_dev *dev,
 	ohci->ir_context_mask = ohci->ir_context_support;
 	ohci->n_ir = hweight32(ohci->ir_context_mask);
 	size = sizeof(struct iso_context) * ohci->n_ir;
-	ohci->ir_context_list = kzalloc(size, GFP_KERNEL);
+	ohci->ir_context_list = devm_kzalloc(&dev->dev, size, GFP_KERNEL);
+	if (!ohci->ir_context_list) {
+		err = -ENOMEM;
+		goto fail_atresp_ctx;
+	}
 
 	reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
 	ohci->it_context_support = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
@@ -3679,11 +3683,10 @@ static int pci_probe(struct pci_dev *dev,
 	ohci->it_context_mask = ohci->it_context_support;
 	ohci->n_it = hweight32(ohci->it_context_mask);
 	size = sizeof(struct iso_context) * ohci->n_it;
-	ohci->it_context_list = kzalloc(size, GFP_KERNEL);
-
-	if (ohci->it_context_list == NULL || ohci->ir_context_list == NULL) {
+	ohci->it_context_list = devm_kzalloc(&dev->dev, size, GFP_KERNEL);
+	if (!ohci->it_context_list) {
 		err = -ENOMEM;
-		goto fail_contexts;
+		goto fail_atresp_ctx;
 	}
 
 	ohci->self_id     = ohci->misc_buffer     + PAGE_SIZE/2;
@@ -3721,9 +3724,7 @@ static int pci_probe(struct pci_dev *dev,
 
  fail_msi:
 	pci_disable_msi(dev);
- fail_contexts:
-	kfree(ohci->ir_context_list);
-	kfree(ohci->it_context_list);
+ fail_atresp_ctx:
 	context_release(&ohci->at_response_ctx);
  fail_atreq_ctx:
 	context_release(&ohci->at_request_ctx);
@@ -3767,8 +3768,6 @@ static void pci_remove(struct pci_dev *dev)
 	ar_context_release(&ohci->ar_response_ctx);
 	context_release(&ohci->at_request_ctx);
 	context_release(&ohci->at_response_ctx);
-	kfree(ohci->it_context_list);
-	kfree(ohci->ir_context_list);
 	pci_disable_msi(dev);
 
 	dev_notice(&dev->dev, "removing fw-ohci device\n");