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Commit edfbcb32 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Greg Kroah-Hartman
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usb: add a hcd_uses_dma helper 



The USB buffer allocation code is the only place in the usb core (and in
fact the whole kernel) that uses is_device_dma_capable, while the URB
mapping code uses the uses_dma flag in struct usb_bus.  Switch the buffer
allocation to use the uses_dma flag used by the rest of the USB code,
and create a helper in hcd.h that checks this flag as well as the
CONFIG_HAS_DMA to simplify the caller a bit.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20190811080520.21712-3-hch@lst.de


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent dd3ecf17

drivers/usb/core/buffer.c

+3 −7
Original line number Diff line number Diff line
@@ -66,9 +66,7 @@ int hcd_buffer_create(struct usb_hcd *hcd) 
	char		name[16];

	int		i, size;



	if (hcd->localmem_pool ||

	    !IS_ENABLED(CONFIG_HAS_DMA) ||

	    !is_device_dma_capable(hcd->self.sysdev))

	if (hcd->localmem_pool || !hcd_uses_dma(hcd))

		return 0;



	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
@@ -129,8 +127,7 @@ void *hcd_buffer_alloc( 
		return gen_pool_dma_alloc(hcd->localmem_pool, size, dma);



	/* some USB hosts just use PIO */

	if (!IS_ENABLED(CONFIG_HAS_DMA) ||

	    !is_device_dma_capable(bus->sysdev)) {

	if (!hcd_uses_dma(hcd)) {

		*dma = ~(dma_addr_t) 0;

		return kmalloc(size, mem_flags);

	}
@@ -160,8 +157,7 @@ void hcd_buffer_free( 
		return;

	}



	if (!IS_ENABLED(CONFIG_HAS_DMA) ||

	    !is_device_dma_capable(bus->sysdev)) {

	if (!hcd_uses_dma(hcd)) {

		kfree(addr);

		return;

	}

drivers/usb/core/hcd.c

+2 −2
Original line number Diff line number Diff line
@@ -1412,7 +1412,7 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, 
	if (usb_endpoint_xfer_control(&urb->ep->desc)) {

		if (hcd->self.uses_pio_for_control)

			return ret;

		if (IS_ENABLED(CONFIG_HAS_DMA) && hcd->self.uses_dma) {

		if (hcd_uses_dma(hcd)) {

			if (is_vmalloc_addr(urb->setup_packet)) {

				WARN_ONCE(1, "setup packet is not dma capable\n");

				return -EAGAIN;
@@ -1446,7 +1446,7 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, 
	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;

	if (urb->transfer_buffer_length != 0

	    && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {

		if (IS_ENABLED(CONFIG_HAS_DMA) && hcd->self.uses_dma) {

		if (hcd_uses_dma(hcd)) {

			if (urb->num_sgs) {

				int n;

drivers/usb/dwc2/hcd.c

+1 −1
Original line number Diff line number Diff line
@@ -4608,7 +4608,7 @@ static int _dwc2_hcd_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, 


	buf = urb->transfer_buffer;



	if (hcd->self.uses_dma) {

	if (hcd_uses_dma(hcd)) {

		if (!buf && (urb->transfer_dma & 3)) {

			dev_err(hsotg->dev,

				"%s: unaligned transfer with no transfer_buffer",

include/linux/usb.h

+1 −1
Original line number Diff line number Diff line
@@ -1457,7 +1457,7 @@ typedef void (*usb_complete_t)(struct urb *); 
 * field rather than determining a dma address themselves.

 *

 * Note that transfer_buffer must still be set if the controller

 * does not support DMA (as indicated by bus.uses_dma) and when talking

 * does not support DMA (as indicated by hcd_uses_dma()) and when talking

 * to root hub. If you have to trasfer between highmem zone and the device

 * on such controller, create a bounce buffer or bail out with an error.

 * If transfer_buffer cannot be set (is in highmem) and the controller is DMA

include/linux/usb/hcd.h

+3 −0
Original line number Diff line number Diff line
@@ -422,6 +422,9 @@ static inline bool hcd_periodic_completion_in_progress(struct usb_hcd *hcd, 
	return hcd->high_prio_bh.completing_ep == ep;

}



#define hcd_uses_dma(hcd) \

	(IS_ENABLED(CONFIG_HAS_DMA) && (hcd)->self.uses_dma)



extern int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb);

extern int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,

		int status);