releases/4.19.46/intel_th-msu-fix-single-mode-with-iommu.patch

   1 From 4e0eaf239fb33ebc671303e2b736fa043462e2f4 Mon Sep 17 00:00:00 2001
   2 From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
   3 Date: Fri, 3 May 2019 11:44:34 +0300
   4 Subject: intel_th: msu: Fix single mode with IOMMU
   5
   6 From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
   7
   8 commit 4e0eaf239fb33ebc671303e2b736fa043462e2f4 upstream.
   9
  10 Currently, the pages that are allocated for the single mode of MSC are not
  11 mapped into the device's dma space and the code is incorrectly using
  12 *_to_phys() in place of a dma address. This fails with IOMMU enabled and
  13 is otherwise bad practice.
  14
  15 Fix the single mode buffer allocation to map the pages into the device's
  16 DMA space.
  17
  18 Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
  19 Fixes: ba82664c134e ("intel_th: Add Memory Storage Unit driver")
  20 Cc: stable@vger.kernel.org # v4.4+
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22
  23 ---
  24  drivers/hwtracing/intel_th/msu.c |   35 ++++++++++++++++++++++++++++++++---
  25  1 file changed, 32 insertions(+), 3 deletions(-)
  26
  27 --- a/drivers/hwtracing/intel_th/msu.c
  28 +++ b/drivers/hwtracing/intel_th/msu.c
  29 @@ -84,6 +84,7 @@ struct msc_iter {
  30   * @reg_base:          register window base address
  31   * @thdev:             intel_th_device pointer
  32   * @win_list:          list of windows in multiblock mode
  33 + * @single_sgt:                single mode buffer
  34   * @nr_pages:          total number of pages allocated for this buffer
  35   * @single_sz:         amount of data in single mode
  36   * @single_wrap:       single mode wrap occurred
  37 @@ -104,6 +105,7 @@ struct msc {
  38         struct intel_th_device  *thdev;
  39
  40         struct list_head        win_list;
  41 +       struct sg_table         single_sgt;
  42         unsigned long           nr_pages;
  43         unsigned long           single_sz;
  44         unsigned int            single_wrap : 1;
  45 @@ -617,22 +619,45 @@ static void intel_th_msc_deactivate(stru
  46   */
  47  static int msc_buffer_contig_alloc(struct msc *msc, unsigned long size)
  48  {
  49 +       unsigned long nr_pages = size >> PAGE_SHIFT;
  50         unsigned int order = get_order(size);
  51         struct page *page;
  52 +       int ret;
  53
  54         if (!size)
  55                 return 0;
  56
  57 +       ret = sg_alloc_table(&msc->single_sgt, 1, GFP_KERNEL);
  58 +       if (ret)
  59 +               goto err_out;
  60 +
  61 +       ret = -ENOMEM;
  62         page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
  63         if (!page)
  64 -               return -ENOMEM;
  65 +               goto err_free_sgt;
  66
  67         split_page(page, order);
  68 -       msc->nr_pages = size >> PAGE_SHIFT;
  69 +       sg_set_buf(msc->single_sgt.sgl, page_address(page), size);
  70 +
  71 +       ret = dma_map_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl, 1,
  72 +                        DMA_FROM_DEVICE);
  73 +       if (ret < 0)
  74 +               goto err_free_pages;
  75 +
  76 +       msc->nr_pages = nr_pages;
  77         msc->base = page_address(page);
  78 -       msc->base_addr = page_to_phys(page);
  79 +       msc->base_addr = sg_dma_address(msc->single_sgt.sgl);
  80
  81         return 0;
  82 +
  83 +err_free_pages:
  84 +       __free_pages(page, order);
  85 +
  86 +err_free_sgt:
  87 +       sg_free_table(&msc->single_sgt);
  88 +
  89 +err_out:
  90 +       return ret;
  91  }
  92
  93  /**
  94 @@ -643,6 +668,10 @@ static void msc_buffer_contig_free(struc
  95  {
  96         unsigned long off;
  97
  98 +       dma_unmap_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl,
  99 +                    1, DMA_FROM_DEVICE);
 100 +       sg_free_table(&msc->single_sgt);
 101 +
 102         for (off = 0; off < msc->nr_pages << PAGE_SHIFT; off += PAGE_SIZE) {
 103                 struct page *page = virt_to_page(msc->base + off);
 104