target/linux/bcm27xx/patches-5.4/950-0756-staging-vchiq_arm-Clean-up-40-bit-DMA-support.patch

   1 From d8cbdaa729d5d3e9a1c18150bf4de69335a85a40 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.com>
   3 Date: Wed, 20 May 2020 16:36:33 +0100
   4 Subject: [PATCH] staging: vchiq_arm: Clean up 40-bit DMA support
   5
   6 Manage the split between addresses for the VPU and addresses for the
   7 40-bit DMA controller with a dedicated DMA device pointer that on non-
   8 BCM2711 platforms is the same as the main VCHIQ device. This allows
   9 the VCHIQ node to stay in the usual place in the DT, and removes the
  10 ugly VC_SAFE macros.
  11
  12 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
  13 ---
  14  .../interface/vchiq_arm/vchiq_2835_arm.c      | 39 ++++++++++++-------
  15  .../interface/vchiq_arm/vchiq_arm.c           | 14 -------
  16  2 files changed, 25 insertions(+), 28 deletions(-)
  17
  18 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
  19 +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
  20 @@ -16,8 +16,6 @@
  21  #include <soc/bcm2835/raspberrypi-firmware.h>
  22
  23  #define TOTAL_SLOTS (VCHIQ_SLOT_ZERO_SLOTS + 2 * 32)
  24 -#define VC_SAFE(x) (g_use_36bit_addrs ? ((u32)(x) | 0xc0000000) : (u32)(x))
  25 -#define IS_VC_SAFE(x) (g_use_36bit_addrs ? !((x) & ~0x3fffffffull) : 1)
  26
  27  #include "vchiq_arm.h"
  28  #include "vchiq_connected.h"
  29 @@ -71,6 +69,7 @@ static char *g_fragments_base;
  30  static char *g_free_fragments;
  31  static struct semaphore g_free_fragments_sema;
  32  static struct device *g_dev;
  33 +static struct device *g_dma_dev;
  34
  35  static DEFINE_SEMAPHORE(g_free_fragments_mutex);
  36
  37 @@ -87,6 +86,7 @@ free_pagelist(struct vchiq_pagelist_info
  38  int vchiq_platform_init(struct platform_device *pdev, struct vchiq_state *state)
  39  {
  40         struct device *dev = &pdev->dev;
  41 +       struct device *dma_dev = NULL;
  42         struct vchiq_drvdata *drvdata = platform_get_drvdata(pdev);
  43         struct rpi_firmware *fw = drvdata->fw;
  44         struct vchiq_slot_zero *vchiq_slot_zero;
  45 @@ -109,7 +109,23 @@ int vchiq_platform_init(struct platform_
  46         g_cache_line_size = drvdata->cache_line_size;
  47         g_fragments_size = 2 * g_cache_line_size;
  48
  49 -       g_use_36bit_addrs = (dev->dma_pfn_offset == 0);
  50 +       if (drvdata->use_36bit_addrs) {
  51 +               struct device_node *dma_node =
  52 +                       of_find_compatible_node(NULL, NULL, "brcm,bcm2711-dma");
  53 +
  54 +               if (dma_node) {
  55 +                       struct platform_device *pdev;
  56 +
  57 +                       pdev = of_find_device_by_node(dma_node);
  58 +                       if (pdev)
  59 +                               dma_dev = &pdev->dev;
  60 +                       of_node_put(dma_node);
  61 +                       g_use_36bit_addrs = true;
  62 +               } else {
  63 +                       dev_err(dev, "40-bit DMA controller not found\n");
  64 +                       return -EINVAL;
  65 +               }
  66 +       }
  67
  68         /* Allocate space for the channels in coherent memory */
  69         slot_mem_size = PAGE_ALIGN(TOTAL_SLOTS * VCHIQ_SLOT_SIZE);
  70 @@ -122,14 +138,8 @@ int vchiq_platform_init(struct platform_
  71                 return -ENOMEM;
  72         }
  73
  74 -       if (!IS_VC_SAFE(slot_phys)) {
  75 -               dev_err(dev, "allocated DMA memory %pad is not VC-safe\n",
  76 -                       &slot_phys);
  77 -               return -ENOMEM;
  78 -       }
  79 -
  80         WARN_ON(((unsigned long)slot_mem & (PAGE_SIZE - 1)) != 0);
  81 -       channelbase = VC_SAFE(slot_phys);
  82 +       channelbase = slot_phys;
  83
  84         vchiq_slot_zero = vchiq_init_slots(slot_mem, slot_mem_size);
  85         if (!vchiq_slot_zero)
  86 @@ -178,6 +188,7 @@ int vchiq_platform_init(struct platform_
  87         }
  88
  89         g_dev = dev;
  90 +       g_dma_dev = dma_dev ?: dev;
  91         g_dma_pool = dmam_pool_create("vchiq_scatter_pool", dev,
  92                                       VCHIQ_DMA_POOL_SIZE, g_cache_line_size,
  93                                       0);
  94 @@ -255,7 +266,7 @@ vchiq_prepare_bulk_data(struct vchiq_bul
  95         if (!pagelistinfo)
  96                 return VCHIQ_ERROR;
  97
  98 -       bulk->data = (void *)(uintptr_t)VC_SAFE(pagelistinfo->dma_addr);
  99 +       bulk->data = (void *)(uintptr_t)pagelistinfo->dma_addr;
 100
 101         /*
 102          * Store the pagelistinfo address in remote_data,
 103 @@ -354,7 +365,7 @@ static void
 104  cleanup_pagelistinfo(struct vchiq_pagelist_info *pagelistinfo)
 105  {
 106         if (pagelistinfo->scatterlist_mapped) {
 107 -               dma_unmap_sg(g_dev, pagelistinfo->scatterlist,
 108 +               dma_unmap_sg(g_dma_dev, pagelistinfo->scatterlist,
 109                              pagelistinfo->num_pages, pagelistinfo->dma_dir);
 110         }
 111
 112 @@ -519,7 +530,7 @@ create_pagelist(char __user *buf, size_t
 113                 count -= len;
 114         }
 115
 116 -       dma_buffers = dma_map_sg(g_dev,
 117 +       dma_buffers = dma_map_sg(g_dma_dev,
 118                                  scatterlist,
 119                                  num_pages,
 120                                  pagelistinfo->dma_dir);
 121 @@ -569,7 +580,7 @@ create_pagelist(char __user *buf, size_t
 122         } else {
 123                 for_each_sg(scatterlist, sg, dma_buffers, i) {
 124                         u32 len = sg_dma_len(sg);
 125 -                       u32 addr = VC_SAFE(sg_dma_address(sg));
 126 +                       u32 addr = sg_dma_address(sg);
 127                         u32 new_pages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 128
 129                         /* Note: addrs is the address + page_count - 1
 130 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
 131 +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
 132 @@ -3205,22 +3205,8 @@ vchiq_register_child(struct platform_dev
 133
 134         child->dev.of_node = np;
 135
 136 -       /*
 137 -        * We want the dma-ranges etc to be copied from a device with the
 138 -        * correct dma-ranges for the VPU.
 139 -        * VCHIQ on Pi4 is now under scb which doesn't get those dma-ranges.
 140 -        * Take the "dma" node as going to be suitable as it sees the world
 141 -        * through the same eyes as the VPU.
 142 -        */
 143 -       np = of_find_node_by_path("dma");
 144 -       if (!np)
 145 -               np = pdev->dev.of_node;
 146 -
 147         of_dma_configure(&child->dev, np, true);
 148
 149 -       if (np != pdev->dev.of_node)
 150 -               of_node_put(np);
 151 -
 152         return child;
 153  }
 154