target/linux/bcm27xx/patches-5.10/950-0253-staging-vchiq_arm-Clean-up-40-bit-DMA-support.patch

   1 From 461092c036303037c0efe37002079ce6e9ed8ba5 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 staging: vchiq_arm: Use g_dma_dev for dma_unmap_sg
  15
  16 Commit "staging: vchiq_arm: Clean up 40-bit DMA support" failed to
  17 change one of the calls to dma_unmap_sg to pass in g_dma_dev (rather
  18 than g_dev). Correct that oversight.
  19
  20 See: https://github.com/raspberrypi/linux/issues/3647
  21
  22 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
  23 ---
  24  .../interface/vchiq_arm/vchiq_2835_arm.c      | 42 ++++++++++++-------
  25  .../interface/vchiq_arm/vchiq_arm.c           | 14 -------
  26  2 files changed, 27 insertions(+), 29 deletions(-)
  27
  28 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
  29 +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
  30 @@ -16,8 +16,6 @@
  31  #include <soc/bcm2835/raspberrypi-firmware.h>
  32
  33  #define TOTAL_SLOTS (VCHIQ_SLOT_ZERO_SLOTS + 2 * 32)
  34 -#define VC_SAFE(x) (g_use_36bit_addrs ? ((u32)(x) | 0xc0000000) : (u32)(x))
  35 -#define IS_VC_SAFE(x) (g_use_36bit_addrs ? !((x) & ~0x3fffffffull) : 1)
  36
  37  #include "vchiq_arm.h"
  38  #include "vchiq_connected.h"
  39 @@ -66,6 +64,7 @@ static char *g_fragments_base;
  40  static char *g_free_fragments;
  41  static struct semaphore g_free_fragments_sema;
  42  static struct device *g_dev;
  43 +static struct device *g_dma_dev;
  44
  45  static DEFINE_SEMAPHORE(g_free_fragments_mutex);
  46
  47 @@ -82,6 +81,7 @@ free_pagelist(struct vchiq_pagelist_info
  48  int vchiq_platform_init(struct platform_device *pdev, struct vchiq_state *state)
  49  {
  50         struct device *dev = &pdev->dev;
  51 +       struct device *dma_dev = NULL;
  52         struct vchiq_drvdata *drvdata = platform_get_drvdata(pdev);
  53         struct rpi_firmware *fw = drvdata->fw;
  54         struct vchiq_slot_zero *vchiq_slot_zero;
  55 @@ -103,7 +103,23 @@ int vchiq_platform_init(struct platform_
  56         g_cache_line_size = drvdata->cache_line_size;
  57         g_fragments_size = 2 * g_cache_line_size;
  58
  59 -       g_use_36bit_addrs = (dev->dma_pfn_offset == 0);
  60 +       if (drvdata->use_36bit_addrs) {
  61 +               struct device_node *dma_node =
  62 +                       of_find_compatible_node(NULL, NULL, "brcm,bcm2711-dma");
  63 +
  64 +               if (dma_node) {
  65 +                       struct platform_device *pdev;
  66 +
  67 +                       pdev = of_find_device_by_node(dma_node);
  68 +                       if (pdev)
  69 +                               dma_dev = &pdev->dev;
  70 +                       of_node_put(dma_node);
  71 +                       g_use_36bit_addrs = true;
  72 +               } else {
  73 +                       dev_err(dev, "40-bit DMA controller not found\n");
  74 +                       return -EINVAL;
  75 +               }
  76 +       }
  77
  78         /* Allocate space for the channels in coherent memory */
  79         slot_mem_size = PAGE_ALIGN(TOTAL_SLOTS * VCHIQ_SLOT_SIZE);
  80 @@ -116,14 +132,8 @@ int vchiq_platform_init(struct platform_
  81                 return -ENOMEM;
  82         }
  83
  84 -       if (!IS_VC_SAFE(slot_phys)) {
  85 -               dev_err(dev, "allocated DMA memory %pad is not VC-safe\n",
  86 -                       &slot_phys);
  87 -               return -ENOMEM;
  88 -       }
  89 -
  90         WARN_ON(((unsigned long)slot_mem & (PAGE_SIZE - 1)) != 0);
  91 -       channelbase = VC_SAFE(slot_phys);
  92 +       channelbase = slot_phys;
  93
  94         vchiq_slot_zero = vchiq_init_slots(slot_mem, slot_mem_size);
  95         if (!vchiq_slot_zero)
  96 @@ -171,6 +181,8 @@ int vchiq_platform_init(struct platform_
  97         }
  98
  99         g_dev = dev;
 100 +       g_dma_dev = dma_dev ?: dev;
 101 +
 102         vchiq_log_info(vchiq_arm_log_level,
 103                 "vchiq_init - done (slots %pK, phys %pad)",
 104                 vchiq_slot_zero, &slot_phys);
 105 @@ -240,7 +252,7 @@ vchiq_prepare_bulk_data(struct vchiq_bul
 106         if (!pagelistinfo)
 107                 return VCHIQ_ERROR;
 108
 109 -       bulk->data = (void *)VC_SAFE(pagelistinfo->dma_addr);
 110 +       bulk->data = pagelistinfo->dma_addr;
 111
 112         /*
 113          * Store the pagelistinfo address in remote_data,
 114 @@ -295,7 +307,7 @@ static void
 115  cleanup_pagelistinfo(struct vchiq_pagelist_info *pagelistinfo)
 116  {
 117         if (pagelistinfo->scatterlist_mapped) {
 118 -               dma_unmap_sg(g_dev, pagelistinfo->scatterlist,
 119 +               dma_unmap_sg(g_dma_dev, pagelistinfo->scatterlist,
 120                              pagelistinfo->num_pages, pagelistinfo->dma_dir);
 121         }
 122
 123 @@ -444,7 +456,7 @@ create_pagelist(char *buf, char __user *
 124                 count -= len;
 125         }
 126
 127 -       dma_buffers = dma_map_sg(g_dev,
 128 +       dma_buffers = dma_map_sg(g_dma_dev,
 129                                  scatterlist,
 130                                  num_pages,
 131                                  pagelistinfo->dma_dir);
 132 @@ -494,7 +506,7 @@ create_pagelist(char *buf, char __user *
 133         } else {
 134                 for_each_sg(scatterlist, sg, dma_buffers, i) {
 135                         u32 len = sg_dma_len(sg);
 136 -                       u32 addr = VC_SAFE(sg_dma_address(sg));
 137 +                       u32 addr = sg_dma_address(sg);
 138                         u32 new_pages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 139
 140                         /* Note: addrs is the address + page_count - 1
 141 @@ -555,7 +567,7 @@ free_pagelist(struct vchiq_pagelist_info
 142          * NOTE: dma_unmap_sg must be called before the
 143          * cpu can touch any of the data/pages.
 144          */
 145 -       dma_unmap_sg(g_dev, pagelistinfo->scatterlist,
 146 +       dma_unmap_sg(g_dma_dev, pagelistinfo->scatterlist,
 147                      pagelistinfo->num_pages, pagelistinfo->dma_dir);
 148         pagelistinfo->scatterlist_mapped = 0;
 149
 150 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
 151 +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
 152 @@ -2720,22 +2720,8 @@ vchiq_register_child(struct platform_dev
 153
 154         child->dev.of_node = np;
 155
 156 -       /*
 157 -        * We want the dma-ranges etc to be copied from a device with the
 158 -        * correct dma-ranges for the VPU.
 159 -        * VCHIQ on Pi4 is now under scb which doesn't get those dma-ranges.
 160 -        * Take the "dma" node as going to be suitable as it sees the world
 161 -        * through the same eyes as the VPU.
 162 -        */
 163 -       np = of_find_node_by_path("dma");
 164 -       if (!np)
 165 -               np = pdev->dev.of_node;
 166 -
 167         of_dma_configure(&child->dev, np, true);
 168
 169 -       if (np != pdev->dev.of_node)
 170 -               of_node_put(np);
 171 -
 172         return child;
 173  }
 174