usb: musb: host: Handle highmem in PIO mode
In case of USB bulk transfer, when himem page
is received, the usb_sg_init function sets the
urb transfer buffer to NULL. When such URB
transfer is handled, kernel crashes in PIO mode.
Handle this by mapping the highmem buffer in PIO mode.
Signed-off-by: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
Signed-off-by: Praveena NADAHALLY <praveen.nadahally@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index 2f6f9a8..d385e8a 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -823,9 +823,28 @@
if (load_count) {
/* PIO to load FIFO */
qh->segsize = load_count;
- musb_write_fifo(hw_ep, load_count, buf);
+ if (!buf) {
+ sg_miter_start(&qh->sg_miter, urb->sg, 1,
+ SG_MITER_ATOMIC
+ | SG_MITER_FROM_SG);
+ if (!sg_miter_next(&qh->sg_miter)) {
+ dev_err(musb->controller,
+ "error: sg"
+ "list empty\n");
+ sg_miter_stop(&qh->sg_miter);
+ goto finish;
+ }
+ buf = qh->sg_miter.addr + urb->sg->offset +
+ urb->actual_length;
+ load_count = min_t(u32, load_count,
+ qh->sg_miter.length);
+ musb_write_fifo(hw_ep, load_count, buf);
+ qh->sg_miter.consumed = load_count;
+ sg_miter_stop(&qh->sg_miter);
+ } else
+ musb_write_fifo(hw_ep, load_count, buf);
}
-
+finish:
/* re-enable interrupt */
musb_writew(mbase, MUSB_INTRTXE, int_txe);
@@ -1193,6 +1212,7 @@
void __iomem *mbase = musb->mregs;
struct dma_channel *dma;
bool transfer_pending = false;
+ static bool use_sg;
musb_ep_select(mbase, epnum);
tx_csr = musb_readw(epio, MUSB_TXCSR);
@@ -1247,6 +1267,7 @@
return;
}
+done:
if (status) {
if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
dma->status = MUSB_DMA_STATUS_CORE_ABORT;
@@ -1416,9 +1437,38 @@
length = qh->maxpacket;
/* Unmap the buffer so that CPU can use it */
usb_hcd_unmap_urb_for_dma(musb_to_hcd(musb), urb);
- musb_write_fifo(hw_ep, length, urb->transfer_buffer + offset);
+
+ /*
+ * We need to map sg if the transfer_buffer is
+ * NULL.
+ */
+ if (!urb->transfer_buffer)
+ use_sg = true;
+
+ if (use_sg) {
+ /* sg_miter_start is already done in musb_ep_program */
+ if (!sg_miter_next(&qh->sg_miter)) {
+ dev_err(musb->controller, "error: sg list empty\n");
+ sg_miter_stop(&qh->sg_miter);
+ status = -EINVAL;
+ goto done;
+ }
+ urb->transfer_buffer = qh->sg_miter.addr;
+ length = min_t(u32, length, qh->sg_miter.length);
+ musb_write_fifo(hw_ep, length, urb->transfer_buffer);
+ qh->sg_miter.consumed = length;
+ sg_miter_stop(&qh->sg_miter);
+ } else {
+ musb_write_fifo(hw_ep, length, urb->transfer_buffer + offset);
+ }
+
qh->segsize = length;
+ if (use_sg) {
+ if (offset + length >= urb->transfer_buffer_length)
+ use_sg = false;
+ }
+
musb_ep_select(mbase, epnum);
musb_writew(epio, MUSB_TXCSR,
MUSB_TXCSR_H_WZC_BITS | MUSB_TXCSR_TXPKTRDY);
@@ -1482,6 +1532,8 @@
bool done = false;
u32 status;
struct dma_channel *dma;
+ static bool use_sg;
+ unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
musb_ep_select(mbase, epnum);
@@ -1796,10 +1848,43 @@
#endif /* Mentor DMA */
if (!dma) {
+ unsigned int received_len;
+
/* Unmap the buffer so that CPU can use it */
usb_hcd_unmap_urb_for_dma(musb_to_hcd(musb), urb);
- done = musb_host_packet_rx(musb, urb,
- epnum, iso_err);
+
+ /*
+ * We need to map sg if the transfer_buffer is
+ * NULL.
+ */
+ if (!urb->transfer_buffer) {
+ use_sg = true;
+ sg_miter_start(&qh->sg_miter, urb->sg, 1,
+ sg_flags);
+ }
+
+ if (use_sg) {
+ if (!sg_miter_next(&qh->sg_miter)) {
+ dev_err(musb->controller, "error: sg list empty\n");
+ sg_miter_stop(&qh->sg_miter);
+ status = -EINVAL;
+ done = true;
+ goto finish;
+ }
+ urb->transfer_buffer = qh->sg_miter.addr;
+ received_len = urb->actual_length;
+ qh->offset = 0x0;
+ done = musb_host_packet_rx(musb, urb, epnum,
+ iso_err);
+ /* Calculate the number of bytes received */
+ received_len = urb->actual_length -
+ received_len;
+ qh->sg_miter.consumed = received_len;
+ sg_miter_stop(&qh->sg_miter);
+ } else {
+ done = musb_host_packet_rx(musb, urb,
+ epnum, iso_err);
+ }
dev_dbg(musb->controller, "read %spacket\n", done ? "last " : "");
}
}
@@ -1808,6 +1893,9 @@
urb->actual_length += xfer_len;
qh->offset += xfer_len;
if (done) {
+ if (use_sg)
+ use_sg = false;
+
if (urb->status == -EINPROGRESS)
urb->status = status;
musb_advance_schedule(musb, urb, hw_ep, USB_DIR_IN);
diff --git a/drivers/usb/musb/musb_host.h b/drivers/usb/musb/musb_host.h
index 622d09f..5a9c8fe 100644
--- a/drivers/usb/musb/musb_host.h
+++ b/drivers/usb/musb/musb_host.h
@@ -35,6 +35,8 @@
#ifndef _MUSB_HOST_H
#define _MUSB_HOST_H
+#include <linux/scatterlist.h>
+
static inline struct usb_hcd *musb_to_hcd(struct musb *musb)
{
return container_of((void *) musb, struct usb_hcd, hcd_priv);
@@ -71,6 +73,7 @@
u16 maxpacket;
u16 frame; /* for periodic schedule */
unsigned iso_idx; /* in urb->iso_frame_desc[] */
+ struct sg_mapping_iter sg_miter; /* for highmem in PIO mode */
};
/* map from control or bulk queue head to the first qh on that ring */