usb: xhci: use array_size() when allocating and freeing memory

Replace size_mul() with array_size() in memory allocation and freeing
processes, it fits better semantically.

Macro array_size() is identical to size_mult(), which clamps the max size,
so it's imperative that array_size() is used when freeing said memory.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20240429140245.3955523-8-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Epicurius

drivers/usb/host/xhci-mem.c

@@ -536,7 +536,7 @@ static void xhci_free_stream_ctx(struct xhci_hcd *xhci,
 		struct xhci_stream_ctx *stream_ctx, dma_addr_t dma)
 {
 	struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
-	size_t size = sizeof(struct xhci_stream_ctx) * num_stream_ctxs;
+	size_t size = array_size(sizeof(struct xhci_stream_ctx), num_stream_ctxs);
 
 	if (size > MEDIUM_STREAM_ARRAY_SIZE)
 		dma_free_coherent(dev, size, stream_ctx, dma);
@@ -561,7 +561,7 @@ static struct xhci_stream_ctx *xhci_alloc_stream_ctx(struct xhci_hcd *xhci,
 		gfp_t mem_flags)
 {
 	struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
-	size_t size = size_mul(sizeof(struct xhci_stream_ctx), num_stream_ctxs);
+	size_t size = array_size(sizeof(struct xhci_stream_ctx), num_stream_ctxs);
 
 	if (size > MEDIUM_STREAM_ARRAY_SIZE)
 		return dma_alloc_coherent(dev, size, dma, mem_flags);
@@ -1638,7 +1638,7 @@ static int scratchpad_alloc(struct xhci_hcd *xhci, gfp_t flags)
 		goto fail_sp;
 
 	xhci->scratchpad->sp_array = dma_alloc_coherent(dev,
-				     size_mul(sizeof(u64), num_sp),
+				     array_size(sizeof(u64), num_sp),
 				     &xhci->scratchpad->sp_dma, flags);
 	if (!xhci->scratchpad->sp_array)
 		goto fail_sp2;
@@ -1671,7 +1671,7 @@ static int scratchpad_alloc(struct xhci_hcd *xhci, gfp_t flags)
 	kfree(xhci->scratchpad->sp_buffers);
 
  fail_sp3:
-	dma_free_coherent(dev, num_sp * sizeof(u64),
+	dma_free_coherent(dev, array_size(sizeof(u64), num_sp),
 			    xhci->scratchpad->sp_array,
 			    xhci->scratchpad->sp_dma);
 
@@ -1700,7 +1700,7 @@ static void scratchpad_free(struct xhci_hcd *xhci)
 				    xhci->scratchpad->sp_array[i]);
 	}
 	kfree(xhci->scratchpad->sp_buffers);
-	dma_free_coherent(dev, num_sp * sizeof(u64),
+	dma_free_coherent(dev, array_size(sizeof(u64), num_sp),
 			    xhci->scratchpad->sp_array,
 			    xhci->scratchpad->sp_dma);
 	kfree(xhci->scratchpad);
@@ -1778,7 +1778,7 @@ static int xhci_alloc_erst(struct xhci_hcd *xhci,
 	struct xhci_segment *seg;
 	struct xhci_erst_entry *entry;
 
-	size = size_mul(sizeof(struct xhci_erst_entry), evt_ring->num_segs);
+	size = array_size(sizeof(struct xhci_erst_entry), evt_ring->num_segs);
 	erst->entries = dma_alloc_coherent(xhci_to_hcd(xhci)->self.sysdev,
 					   size, &erst->erst_dma_addr, flags);
 	if (!erst->entries)
@@ -1829,7 +1829,7 @@ xhci_free_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir)
 	if (!ir)
 		return;
 
-	erst_size = sizeof(struct xhci_erst_entry) * ir->erst.num_entries;
+	erst_size = array_size(sizeof(struct xhci_erst_entry), ir->erst.num_entries);
 	if (ir->erst.entries)
 		dma_free_coherent(dev, erst_size,
 				  ir->erst.entries,