Re: [PATCH v1 4/4] usb: xhci: Add virt_to_phys() to support mapped platforms

[Stefan Roese]

Hi Bin,

On 17.07.20 07:57, Bin Meng wrote:

Hi Stefan,

On Thu, Jul 2, 2020 at 4:47 PM Stefan Roese <s...@denx.de> wrote:

Some platforms, like MIPS Octeon, use mapped addresses (virtual address
!= physical address). On these platforms we need to make sure, that the
local virtual addresses are converted to physical (DMA) addresses for
the xHCI controller. This patch adds the missing virt_to_phys() calls,
so that the correct addresses are used.

Signed-off-by: Stefan Roese <s...@denx.de>
Cc: Bin Meng <bmeng...@gmail.com>
Cc: Marek Vasut <ma...@denx.de>

---

  drivers/usb/host/xhci-mem.c  | 19 +++++++++----------
  drivers/usb/host/xhci-ring.c |  8 ++++----
  drivers/usb/host/xhci.c      |  3 +--
  3 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 3b805ecb9e..874caf4761 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -224,7 +224,7 @@ static void xhci_link_segments(struct xhci_segment *prev,
                 return;
         prev->next = next;
         if (link_trbs) {
-               val_64 = (uintptr_t)next->trbs;
+               val_64 = virt_to_phys(next->trbs);
                 prev->trbs[TRBS_PER_SEGMENT-1].link.segment_ptr =
                         cpu_to_le64(val_64);

@@ -484,7 +484,7 @@ int xhci_alloc_virt_device(struct xhci_ctrl *ctrl, unsigned 
int slot_id)
         /* Allocate endpoint 0 ring */
         virt_dev->eps[0].ring = xhci_ring_alloc(1, true);

-       byte_64 = (uintptr_t)(virt_dev->out_ctx->bytes);
+       byte_64 = virt_to_phys(virt_dev->out_ctx->bytes);

         /* Point to output device context in dcbaa. */
         ctrl->dcbaa->dev_context_ptrs[slot_id] = cpu_to_le64(byte_64);
@@ -509,7 +509,7 @@ int xhci_mem_init(struct xhci_ctrl *ctrl, struct xhci_hccr 
*hccr,
         uint64_t val_64;
         uint64_t trb_64;
         uint32_t val;
-       unsigned long deq;
+       uint64_t deq;

This change seems unnecessary?

In most (all other?) places, the variable containing these 64 bit
addresses has the type uint64_t in this driver. So I wanted to make the
code more consistant here. Or do you see a problem with this change?

         int i;
         struct xhci_segment *seg;

@@ -521,7 +521,7 @@ int xhci_mem_init(struct xhci_ctrl *ctrl, struct xhci_hccr 
*hccr,
                 return -ENOMEM;
         }

-       val_64 = (uintptr_t)ctrl->dcbaa;
+       val_64 = virt_to_phys(ctrl->dcbaa);
         /* Set the pointer in DCBAA register */
         xhci_writeq(&hcor->or_dcbaap, val_64);

@@ -529,7 +529,7 @@ int xhci_mem_init(struct xhci_ctrl *ctrl, struct xhci_hccr 
*hccr,
         ctrl->cmd_ring = xhci_ring_alloc(1, true);

         /* Set the address in the Command Ring Control register */
-       trb_64 = (uintptr_t)ctrl->cmd_ring->first_seg->trbs;
+       trb_64 = virt_to_phys(ctrl->cmd_ring->first_seg->trbs);
         val_64 = xhci_readq(&hcor->or_crcr);
         val_64 = (val_64 & (u64) CMD_RING_RSVD_BITS) |
                 (trb_64 & (u64) ~CMD_RING_RSVD_BITS) |
@@ -559,8 +559,7 @@ int xhci_mem_init(struct xhci_ctrl *ctrl, struct xhci_hccr 
*hccr,
         for (val = 0, seg = ctrl->event_ring->first_seg;
                         val < ERST_NUM_SEGS;
                         val++) {
-               trb_64 = 0;
-               trb_64 = (uintptr_t)seg->trbs;
+               trb_64 = virt_to_phys(seg->trbs);
                 struct xhci_erst_entry *entry = &ctrl->erst.entries[val];
                 entry->seg_addr = cpu_to_le64(trb_64);
                 entry->seg_size = cpu_to_le32(TRBS_PER_SEGMENT);
@@ -570,7 +569,7 @@ int xhci_mem_init(struct xhci_ctrl *ctrl, struct xhci_hccr 
*hccr,
         xhci_flush_cache((uintptr_t)ctrl->erst.entries,
                          ERST_NUM_SEGS * sizeof(struct xhci_erst_entry));

-       deq = (unsigned long)ctrl->event_ring->dequeue;
+       deq = virt_to_phys(ctrl->event_ring->dequeue);

         /* Update HC event ring dequeue pointer */
         xhci_writeq(&ctrl->ir_set->erst_dequeue,
@@ -585,7 +584,7 @@ int xhci_mem_init(struct xhci_ctrl *ctrl, struct xhci_hccr 
*hccr,
         /* this is the event ring segment table pointer */
         val_64 = xhci_readq(&ctrl->ir_set->erst_base);
         val_64 &= ERST_PTR_MASK;
-       val_64 |= ((uintptr_t)(ctrl->erst.entries) & ~ERST_PTR_MASK);
+       val_64 |= virt_to_phys(ctrl->erst.entries) & ~ERST_PTR_MASK;

         xhci_writeq(&ctrl->ir_set->erst_base, val_64);

@@ -853,7 +852,7 @@ void xhci_setup_addressable_virt_dev(struct xhci_ctrl *ctrl,
                         cpu_to_le32(((0 & MAX_BURST_MASK) << MAX_BURST_SHIFT) |
                         ((3 & ERROR_COUNT_MASK) << ERROR_COUNT_SHIFT));

-       trb_64 = (uintptr_t)virt_dev->eps[0].ring->first_seg->trbs;
+       trb_64 = virt_to_phys(virt_dev->eps[0].ring->first_seg->trbs);
         ep0_ctx->deq = cpu_to_le64(trb_64 | 
virt_dev->eps[0].ring->cycle_state);

         /*
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 86aeaab412..092ed6eaf1 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -275,7 +275,7 @@ void xhci_queue_command(struct xhci_ctrl *ctrl, u8 *ptr, 
u32 slot_id,
                         u32 ep_index, trb_type cmd)
  {
         u32 fields[4];
-       u64 val_64 = (uintptr_t)ptr;
+       u64 val_64 = virt_to_phys(ptr);

         BUG_ON(prepare_ring(ctrl, ctrl->cmd_ring, EP_STATE_RUNNING));

@@ -399,7 +399,7 @@ void xhci_acknowledge_event(struct xhci_ctrl *ctrl)

         /* Inform the hardware */
         xhci_writeq(&ctrl->ir_set->erst_dequeue,
-               (uintptr_t)ctrl->event_ring->dequeue | ERST_EHB);
+                   virt_to_phys(ctrl->event_ring->dequeue) | ERST_EHB);
  }

  /**
@@ -577,7 +577,7 @@ int xhci_bulk_tx(struct usb_device *udev, unsigned long 
pipe,
         u64 addr;
         int ret;
         u32 trb_fields[4];
-       u64 val_64 = (uintptr_t)buffer;
+       u64 val_64 = virt_to_phys(buffer);

         debug("dev=%p, pipe=%lx, buffer=%p, length=%d\n",
                 udev, pipe, buffer, length);
@@ -876,7 +876,7 @@ int xhci_ctrl_tx(struct usb_device *udev, unsigned long 
pipe,
         if (length > 0) {
                 if (req->requesttype & USB_DIR_IN)
                         field |= TRB_DIR_IN;
-               buf_64 = (uintptr_t)buffer;
+               buf_64 = virt_to_phys(buffer);

                 trb_fields[0] = lower_32_bits(buf_64);
                 trb_fields[1] = upper_32_bits(buf_64);
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index ebd2954571..f89e274b0d 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -600,8 +600,7 @@ static int xhci_set_configuration(struct usb_device *udev)
                         cpu_to_le32(MAX_BURST(max_burst) |
                         ERROR_COUNT(err_count));

-               trb_64 = (uintptr_t)
-                               virt_dev->eps[ep_index].ring->enqueue;
+               trb_64 = virt_to_phys(virt_dev->eps[ep_index].ring->enqueue);
                 ep_ctx[ep_index]->deq = cpu_to_le64(trb_64 |
                                 virt_dev->eps[ep_index].ring->cycle_state);

--

Other than above,
Reviewed-by: Bin Meng <bmeng...@gmail.com>

Regards,
Bin

Thanks,
Stefan