From: Alan Stern Date: Fri, 2 Apr 2010 17:27:28 +0000 (-0400) Subject: USB: fix usbmon and DMA mapping for scatter-gather URBs X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ff9c895f07d36193c75533bda8193bde8ca99d02;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git USB: fix usbmon and DMA mapping for scatter-gather URBs This patch (as1368) fixes a rather obscure bug in usbmon: When tracing URBs sent by the scatter-gather library, it accesses the data buffers while they are still mapped for DMA. The solution is to move the mapping and unmapping out of the s-g library and into the usual place in hcd.c. This requires the addition of new URB flag bits to describe the kind of mapping needed, since we have to call dma_map_sg() if the HCD supports native scatter-gather operation and dma_map_page() if it doesn't. The nice thing about having the new flags is that they simplify the testing for unmapping. The patch removes the only caller of usb_buffer_[un]map_sg(), so those functions are #if'ed out. A later patch will remove them entirely. As a result of this change, urb->sg will be set in situations where it wasn't set previously. Hence the xhci and whci drivers are adjusted to test urb->num_sgs instead, which retains its original meaning and is nonzero only when the HCD has to handle a scatterlist. Finally, even when a submission error occurs we don't want to hand URBs to usbmon before they are unmapped. The submission path is rearranged so that map_urb_for_dma() is called only for non-root-hub URBs and unmap_urb_for_dma() is called immediately after a submission error. This simplifies the error handling. Signed-off-by: Alan Stern CC: Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 38d4700926f7..6a05e6934455 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -1259,6 +1259,51 @@ static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle, *dma_handle = 0; } +static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb) +{ + enum dma_data_direction dir; + + if (urb->transfer_flags & URB_SETUP_MAP_SINGLE) + dma_unmap_single(hcd->self.controller, + urb->setup_dma, + sizeof(struct usb_ctrlrequest), + DMA_TO_DEVICE); + else if (urb->transfer_flags & URB_SETUP_MAP_LOCAL) + hcd_free_coherent(urb->dev->bus, + &urb->setup_dma, + (void **) &urb->setup_packet, + sizeof(struct usb_ctrlrequest), + DMA_TO_DEVICE); + + dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE; + if (urb->transfer_flags & URB_DMA_MAP_SG) + dma_unmap_sg(hcd->self.controller, + urb->sg->sg, + urb->num_sgs, + dir); + else if (urb->transfer_flags & URB_DMA_MAP_PAGE) + dma_unmap_page(hcd->self.controller, + urb->transfer_dma, + urb->transfer_buffer_length, + dir); + else if (urb->transfer_flags & URB_DMA_MAP_SINGLE) + dma_unmap_single(hcd->self.controller, + urb->transfer_dma, + urb->transfer_buffer_length, + dir); + else if (urb->transfer_flags & URB_MAP_LOCAL) + hcd_free_coherent(urb->dev->bus, + &urb->transfer_dma, + &urb->transfer_buffer, + urb->transfer_buffer_length, + dir); + + /* Make it safe to call this routine more than once */ + urb->transfer_flags &= ~(URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL | + URB_DMA_MAP_SG | URB_DMA_MAP_PAGE | + URB_DMA_MAP_SINGLE | URB_MAP_LOCAL); +} + static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags) { @@ -1270,8 +1315,6 @@ static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, * unless it uses pio or talks to another transport, * or uses the provided scatter gather list for bulk. */ - if (is_root_hub(urb->dev)) - return 0; if (usb_endpoint_xfer_control(&urb->ep->desc) && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) { @@ -1284,6 +1327,7 @@ static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, if (dma_mapping_error(hcd->self.controller, urb->setup_dma)) return -EAGAIN; + urb->transfer_flags |= URB_SETUP_MAP_SINGLE; } else if (hcd->driver->flags & HCD_LOCAL_MEM) ret = hcd_alloc_coherent( urb->dev->bus, mem_flags, @@ -1291,20 +1335,57 @@ static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, (void **)&urb->setup_packet, sizeof(struct usb_ctrlrequest), DMA_TO_DEVICE); + if (ret) + return ret; + urb->transfer_flags |= URB_SETUP_MAP_LOCAL; } dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE; - if (ret == 0 && urb->transfer_buffer_length != 0 + if (urb->transfer_buffer_length != 0 && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) { if (hcd->self.uses_dma) { - urb->transfer_dma = dma_map_single ( - hcd->self.controller, - urb->transfer_buffer, - urb->transfer_buffer_length, - dir); - if (dma_mapping_error(hcd->self.controller, + if (urb->num_sgs) { + int n = dma_map_sg( + hcd->self.controller, + urb->sg->sg, + urb->num_sgs, + dir); + if (n <= 0) + ret = -EAGAIN; + else + urb->transfer_flags |= URB_DMA_MAP_SG; + if (n != urb->num_sgs) { + urb->num_sgs = n; + urb->transfer_flags |= + URB_DMA_SG_COMBINED; + } + } else if (urb->sg) { + struct scatterlist *sg; + + sg = (struct scatterlist *) urb->sg; + urb->transfer_dma = dma_map_page( + hcd->self.controller, + sg_page(sg), + sg->offset, + urb->transfer_buffer_length, + dir); + if (dma_mapping_error(hcd->self.controller, urb->transfer_dma)) - return -EAGAIN; + ret = -EAGAIN; + else + urb->transfer_flags |= URB_DMA_MAP_PAGE; + } else { + urb->transfer_dma = dma_map_single( + hcd->self.controller, + urb->transfer_buffer, + urb->transfer_buffer_length, + dir); + if (dma_mapping_error(hcd->self.controller, + urb->transfer_dma)) + ret = -EAGAIN; + else + urb->transfer_flags |= URB_DMA_MAP_SINGLE; + } } else if (hcd->driver->flags & HCD_LOCAL_MEM) { ret = hcd_alloc_coherent( urb->dev->bus, mem_flags, @@ -1312,55 +1393,16 @@ static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, &urb->transfer_buffer, urb->transfer_buffer_length, dir); - - if (ret && usb_endpoint_xfer_control(&urb->ep->desc) - && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) - hcd_free_coherent(urb->dev->bus, - &urb->setup_dma, - (void **)&urb->setup_packet, - sizeof(struct usb_ctrlrequest), - DMA_TO_DEVICE); + if (ret == 0) + urb->transfer_flags |= URB_MAP_LOCAL; } + if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE | + URB_SETUP_MAP_LOCAL))) + unmap_urb_for_dma(hcd, urb); } return ret; } -static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb) -{ - enum dma_data_direction dir; - - if (is_root_hub(urb->dev)) - return; - - if (usb_endpoint_xfer_control(&urb->ep->desc) - && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) { - if (hcd->self.uses_dma) - dma_unmap_single(hcd->self.controller, urb->setup_dma, - sizeof(struct usb_ctrlrequest), - DMA_TO_DEVICE); - else if (hcd->driver->flags & HCD_LOCAL_MEM) - hcd_free_coherent(urb->dev->bus, &urb->setup_dma, - (void **)&urb->setup_packet, - sizeof(struct usb_ctrlrequest), - DMA_TO_DEVICE); - } - - 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 (hcd->self.uses_dma) - dma_unmap_single(hcd->self.controller, - urb->transfer_dma, - urb->transfer_buffer_length, - dir); - else if (hcd->driver->flags & HCD_LOCAL_MEM) - hcd_free_coherent(urb->dev->bus, &urb->transfer_dma, - &urb->transfer_buffer, - urb->transfer_buffer_length, - dir); - } -} - /*-------------------------------------------------------------------------*/ /* may be called in any context with a valid urb->dev usecount @@ -1389,21 +1431,20 @@ int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags) * URBs must be submitted in process context with interrupts * enabled. */ - status = map_urb_for_dma(hcd, urb, mem_flags); - if (unlikely(status)) { - usbmon_urb_submit_error(&hcd->self, urb, status); - goto error; - } - if (is_root_hub(urb->dev)) + if (is_root_hub(urb->dev)) { status = rh_urb_enqueue(hcd, urb); - else - status = hcd->driver->urb_enqueue(hcd, urb, mem_flags); + } else { + status = map_urb_for_dma(hcd, urb, mem_flags); + if (likely(status == 0)) { + status = hcd->driver->urb_enqueue(hcd, urb, mem_flags); + if (unlikely(status)) + unmap_urb_for_dma(hcd, urb); + } + } if (unlikely(status)) { usbmon_urb_submit_error(&hcd->self, urb, status); - unmap_urb_for_dma(hcd, urb); - error: urb->hcpriv = NULL; INIT_LIST_HEAD(&urb->urb_list); atomic_dec(&urb->use_count); diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index 619c44fb8a96..79d1cdf4a635 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -259,9 +259,6 @@ static void sg_clean(struct usb_sg_request *io) kfree(io->urbs); io->urbs = NULL; } - if (io->dev->dev.dma_mask != NULL) - usb_buffer_unmap_sg(io->dev, usb_pipein(io->pipe), - io->sg, io->nents); io->dev = NULL; } @@ -364,7 +361,6 @@ int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev, { int i; int urb_flags; - int dma; int use_sg; if (!io || !dev || !sg @@ -378,21 +374,9 @@ int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev, io->pipe = pipe; io->sg = sg; io->nents = nents; - - /* not all host controllers use DMA (like the mainstream pci ones); - * they can use PIO (sl811) or be software over another transport. - */ - dma = (dev->dev.dma_mask != NULL); - if (dma) - io->entries = usb_buffer_map_sg(dev, usb_pipein(pipe), - sg, nents); - else - io->entries = nents; + io->entries = nents; /* initialize all the urbs we'll use */ - if (io->entries <= 0) - return io->entries; - if (dev->bus->sg_tablesize > 0) { io->urbs = kmalloc(sizeof *io->urbs, mem_flags); use_sg = true; @@ -404,8 +388,6 @@ int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev, goto nomem; urb_flags = 0; - if (dma) - urb_flags |= URB_NO_TRANSFER_DMA_MAP; if (usb_pipein(pipe)) urb_flags |= URB_SHORT_NOT_OK; @@ -423,12 +405,13 @@ int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev, io->urbs[0]->complete = sg_complete; io->urbs[0]->context = io; + /* A length of zero means transfer the whole sg list */ io->urbs[0]->transfer_buffer_length = length; if (length == 0) { for_each_sg(sg, sg, io->entries, i) { io->urbs[0]->transfer_buffer_length += - sg_dma_len(sg); + sg->length; } } io->urbs[0]->sg = io; @@ -454,26 +437,16 @@ int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev, io->urbs[i]->context = io; /* - * Some systems need to revert to PIO when DMA is temporarily - * unavailable. For their sakes, both transfer_buffer and - * transfer_dma are set when possible. - * - * Note that if IOMMU coalescing occurred, we cannot - * trust sg_page anymore, so check if S/G list shrunk. + * Some systems can't use DMA; they use PIO instead. + * For their sakes, transfer_buffer is set whenever + * possible. */ - if (io->nents == io->entries && !PageHighMem(sg_page(sg))) + if (!PageHighMem(sg_page(sg))) io->urbs[i]->transfer_buffer = sg_virt(sg); else io->urbs[i]->transfer_buffer = NULL; - if (dma) { - io->urbs[i]->transfer_dma = sg_dma_address(sg); - len = sg_dma_len(sg); - } else { - /* hc may use _only_ transfer_buffer */ - len = sg->length; - } - + len = sg->length; if (length) { len = min_t(unsigned, len, length); length -= len; @@ -481,6 +454,8 @@ int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev, io->entries = i + 1; } io->urbs[i]->transfer_buffer_length = len; + + io->urbs[i]->sg = (struct usb_sg_request *) sg; } io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT; } diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c index 2532a0917f8c..a760e46871c5 100644 --- a/drivers/usb/core/urb.c +++ b/drivers/usb/core/urb.c @@ -333,9 +333,12 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags) is_out = usb_endpoint_dir_out(&ep->desc); } - /* Cache the direction for later use */ - urb->transfer_flags = (urb->transfer_flags & ~URB_DIR_MASK) | - (is_out ? URB_DIR_OUT : URB_DIR_IN); + /* Clear the internal flags and cache the direction for later use */ + urb->transfer_flags &= ~(URB_DIR_MASK | URB_DMA_MAP_SINGLE | + URB_DMA_MAP_PAGE | URB_DMA_MAP_SG | URB_MAP_LOCAL | + URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL | + URB_DMA_SG_COMBINED); + urb->transfer_flags |= (is_out ? URB_DIR_OUT : URB_DIR_IN); if (xfertype != USB_ENDPOINT_XFER_CONTROL && dev->state < USB_STATE_CONFIGURED) diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index 097172e2ba06..8180ce533ebf 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -881,6 +881,7 @@ void usb_buffer_unmap(struct urb *urb) EXPORT_SYMBOL_GPL(usb_buffer_unmap); #endif /* 0 */ +#if 0 /** * usb_buffer_map_sg - create scatterlist DMA mapping(s) for an endpoint * @dev: device to which the scatterlist will be mapped @@ -924,6 +925,7 @@ int usb_buffer_map_sg(const struct usb_device *dev, int is_in, is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE) ? : -ENOMEM; } EXPORT_SYMBOL_GPL(usb_buffer_map_sg); +#endif /* XXX DISABLED, no users currently. If you wish to re-enable this * XXX please determine whether the sync is to transfer ownership of @@ -960,6 +962,7 @@ void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in, EXPORT_SYMBOL_GPL(usb_buffer_dmasync_sg); #endif +#if 0 /** * usb_buffer_unmap_sg - free DMA mapping(s) for a scatterlist * @dev: device to which the scatterlist will be mapped @@ -985,6 +988,7 @@ void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in, is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } EXPORT_SYMBOL_GPL(usb_buffer_unmap_sg); +#endif /* To disable USB, kernel command line is 'nousb' not 'usbcore.nousb' */ #ifdef MODULE diff --git a/drivers/usb/host/whci/qset.c b/drivers/usb/host/whci/qset.c index 141d049beb3e..b388dd1fb4c4 100644 --- a/drivers/usb/host/whci/qset.c +++ b/drivers/usb/host/whci/qset.c @@ -646,7 +646,7 @@ int qset_add_urb(struct whc *whc, struct whc_qset *qset, struct urb *urb, wurb->urb = urb; INIT_WORK(&wurb->dequeue_work, urb_dequeue_work); - if (urb->sg) { + if (urb->num_sgs) { ret = qset_add_urb_sg(whc, qset, urb, mem_flags); if (ret == -EINVAL) { qset_free_stds(qset, urb); diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 407d33fb5e84..c1359ed310b5 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1962,7 +1962,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, int running_total, trb_buff_len, ret; u64 addr; - if (urb->sg) + if (urb->num_sgs) return queue_bulk_sg_tx(xhci, mem_flags, urb, slot_id, ep_index); ep_ring = xhci->devs[slot_id]->eps[ep_index].ring; diff --git a/drivers/usb/mon/mon_bin.c b/drivers/usb/mon/mon_bin.c index ddf7f9a1b336..8a7968df278f 100644 --- a/drivers/usb/mon/mon_bin.c +++ b/drivers/usb/mon/mon_bin.c @@ -416,7 +416,7 @@ static unsigned int mon_bin_get_data(const struct mon_reader_bin *rp, } else { /* If IOMMU coalescing occurred, we cannot trust sg_page */ - if (urb->sg->nents != urb->num_sgs) { + if (urb->transfer_flags & URB_DMA_SG_COMBINED) { *flag = 'D'; return length; } diff --git a/drivers/usb/mon/mon_text.c b/drivers/usb/mon/mon_text.c index 4d0be130f49b..d56260280f54 100644 --- a/drivers/usb/mon/mon_text.c +++ b/drivers/usb/mon/mon_text.c @@ -161,9 +161,7 @@ static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb, } else { struct scatterlist *sg = urb->sg->sg; - /* If IOMMU coalescing occurred, we cannot trust sg_page */ - if (urb->sg->nents != urb->num_sgs || - PageHighMem(sg_page(sg))) + if (PageHighMem(sg_page(sg))) return 'D'; /* For the text interface we copy only the first sg buffer */ diff --git a/include/linux/usb.h b/include/linux/usb.h index 739f1fd1cc15..99833029e5a8 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -965,10 +965,19 @@ extern int usb_disabled(void); * needed */ #define URB_FREE_BUFFER 0x0100 /* Free transfer buffer with the URB */ +/* The following flags are used internally by usbcore and HCDs */ #define URB_DIR_IN 0x0200 /* Transfer from device to host */ #define URB_DIR_OUT 0 #define URB_DIR_MASK URB_DIR_IN +#define URB_DMA_MAP_SINGLE 0x00010000 /* Non-scatter-gather mapping */ +#define URB_DMA_MAP_PAGE 0x00020000 /* HCD-unsupported S-G */ +#define URB_DMA_MAP_SG 0x00040000 /* HCD-supported S-G */ +#define URB_MAP_LOCAL 0x00080000 /* HCD-local-memory mapping */ +#define URB_SETUP_MAP_SINGLE 0x00100000 /* Setup packet DMA mapped */ +#define URB_SETUP_MAP_LOCAL 0x00200000 /* HCD-local setup packet */ +#define URB_DMA_SG_COMBINED 0x00400000 /* S-G entries were combined */ + struct usb_iso_packet_descriptor { unsigned int offset; unsigned int length; /* expected length */