target/linux/brcm2708/patches-4.19/950-0295-usb-dwc_otg-Use-dma-allocation-for-mphi-dummy_send-b.patch

   1 From f0d93c5098283f88ea1de3af152a190177da8f36 Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.org>
   3 Date: Wed, 30 Jan 2019 17:47:51 +0000
   4 Subject: [PATCH] usb: dwc_otg: Use dma allocation for mphi dummy_send
   5  buffer
   6
   7 The FIQ driver used a kzalloc'ed buffer for dummy_send,
   8 passing a kernel virtual address to the hardware block.
   9 The buffer is only ever used for a dummy read, so it
  10 should be harmless, but there is the chance that it will
  11 cause exceptions.
  12
  13 Use a dma allocation so that we have a genuine bus address,
  14 and read from that.
  15 Free the allocation when done for good measure.
  16
  17 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
  18 ---
  19  drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c | 4 ++--
  20  drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.h | 1 +
  21  drivers/usb/host/dwc_otg/dwc_otg_hcd.c     | 5 ++++-
  22  3 files changed, 7 insertions(+), 3 deletions(-)
  23
  24 --- a/drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c
  25 +++ b/drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.c
  26 @@ -1347,7 +1347,7 @@ void notrace dwc_otg_fiq_fsm(struct fiq_
  27         /* We got an interrupt, didn't handle it. */
  28         if (kick_irq) {
  29                 state->mphi_int_count++;
  30 -               FIQ_WRITE(state->mphi_regs.outdda, (int) state->dummy_send);
  31 +               FIQ_WRITE(state->mphi_regs.outdda, state->dummy_send_dma);
  32                 FIQ_WRITE(state->mphi_regs.outddb, (1<<29));
  33
  34         }
  35 @@ -1408,7 +1408,7 @@ void notrace dwc_otg_fiq_nop(struct fiq_
  36                 FIQ_WRITE(state->dwc_regs_base + GINTMSK, gintmsk.d32);
  37                 /* Force a clear before another dummy send */
  38                 FIQ_WRITE(state->mphi_regs.intstat, (1<<29));
  39 -               FIQ_WRITE(state->mphi_regs.outdda, (int) state->dummy_send);
  40 +               FIQ_WRITE(state->mphi_regs.outdda, state->dummy_send_dma);
  41                 FIQ_WRITE(state->mphi_regs.outddb, (1<<29));
  42
  43         }
  44 --- a/drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.h
  45 +++ b/drivers/usb/host/dwc_otg/dwc_otg_fiq_fsm.h
  46 @@ -352,6 +352,7 @@ struct fiq_state {
  47         dma_addr_t dma_base;
  48         struct fiq_dma_blob *fiq_dmab;
  49         void *dummy_send;
  50 +       dma_addr_t dummy_send_dma;
  51         gintmsk_data_t gintmsk_saved;
  52         haintmsk_data_t haintmsk_saved;
  53         int mphi_int_count;
  54 --- a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
  55 +++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
  56 @@ -929,6 +929,8 @@ static void dwc_otg_hcd_free(dwc_otg_hcd
  57         DWC_TIMER_FREE(dwc_otg_hcd->conn_timer);
  58         DWC_TASK_FREE(dwc_otg_hcd->reset_tasklet);
  59         DWC_TASK_FREE(dwc_otg_hcd->completion_tasklet);
  60 +       DWC_DMA_FREE(dev, 16, dwc_otg_hcd->fiq_state->dummy_send,
  61 +                    dwc_otg_hcd->fiq_state->dummy_send_dma);
  62         DWC_FREE(dwc_otg_hcd->fiq_state);
  63
  64  #ifdef DWC_DEV_SRPCAP
  65 @@ -1021,7 +1023,8 @@ int dwc_otg_hcd_init(dwc_otg_hcd_t * hcd
  66                 for (i = 0; i < num_channels; i++) {
  67                         hcd->fiq_state->channel[i].fsm = FIQ_PASSTHROUGH;
  68                 }
  69 -               hcd->fiq_state->dummy_send = DWC_ALLOC_ATOMIC(16);
  70 +               hcd->fiq_state->dummy_send = DWC_DMA_ALLOC_ATOMIC(dev, 16,
  71 +                                                        &hcd->fiq_state->dummy_send_dma);
  72
  73                 hcd->fiq_stack = DWC_ALLOC(sizeof(struct fiq_stack));
  74                 if (!hcd->fiq_stack) {