target/linux/layerscape/patches-5.4/821-vfio-0009-vfio-fsl-mc-Add-read-write-support-for-fsl-mc-device.patch

   1 From c4fbb93e85b13edc174fa6fc3105341f646305e4 Mon Sep 17 00:00:00 2001
   2 From: Diana Craciun <diana.craciun@nxp.com>
   3 Date: Wed, 2 Oct 2019 11:14:52 +0300
   4 Subject: [PATCH] vfio/fsl-mc: Add read/write support for fsl-mc devices
   5
   6 This patch adds support to read and write ioctls for
   7 fsl-mc devices. Only read-write to DPRC/DPMCP devices
   8 are supported while read writes on other fsl-mc devices
   9 is not supported by this patch.
  10
  11 Also current patch limits userspace to write complete
  12 64byte command once and read 64byte response by one ioctl.
  13
  14 Signed-off-by: Bharat Bhushan <Bharat.Bhushan@nxp.com>
  15 Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
  16 ---
  17  drivers/vfio/fsl-mc/vfio_fsl_mc.c         | 125 +++++++++++++++++++++++++++++-
  18  drivers/vfio/fsl-mc/vfio_fsl_mc_private.h |   1 +
  19  2 files changed, 124 insertions(+), 2 deletions(-)
  20
  21 --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
  22 +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
  23 @@ -12,6 +12,7 @@
  24  #include <linux/types.h>
  25  #include <linux/vfio.h>
  26  #include <linux/fsl/mc.h>
  27 +#include <linux/delay.h>
  28
  29  #include "vfio_fsl_mc_private.h"
  30
  31 @@ -112,6 +113,11 @@ static int vfio_fsl_mc_regions_init(stru
  32  }
  33  static void vfio_fsl_mc_regions_cleanup(struct vfio_fsl_mc_device *vdev)
  34  {
  35 +       int i;
  36 +
  37 +       for (i = 0; i < vdev->num_regions; i++)
  38 +               iounmap(vdev->regions[i].ioaddr);
  39 +
  40         vdev->num_regions = 0;
  41         kfree(vdev->regions);
  42  }
  43 @@ -308,13 +314,128 @@ static long vfio_fsl_mc_ioctl(void *devi
  44  static ssize_t vfio_fsl_mc_read(void *device_data, char __user *buf,
  45                                 size_t count, loff_t *ppos)
  46  {
  47 -       return -EINVAL;
  48 +       struct vfio_fsl_mc_device *vdev = device_data;
  49 +       unsigned int index = VFIO_FSL_MC_OFFSET_TO_INDEX(*ppos);
  50 +       loff_t off = *ppos & VFIO_FSL_MC_OFFSET_MASK;
  51 +       struct vfio_fsl_mc_region *region;
  52 +       uint64_t data[8];
  53 +       int i;
  54 +
  55 +       /* Read ioctl supported only for DPRC and DPMCP device */
  56 +       if (strcmp(vdev->mc_dev->obj_desc.type, "dprc") &&
  57 +           strcmp(vdev->mc_dev->obj_desc.type, "dpmcp"))
  58 +               return -EINVAL;
  59 +
  60 +       if (index >= vdev->num_regions)
  61 +               return -EINVAL;
  62 +
  63 +       region = &vdev->regions[index];
  64 +
  65 +       if (!(region->flags & VFIO_REGION_INFO_FLAG_READ))
  66 +               return -EINVAL;
  67 +
  68 +
  69 +       if (!region->ioaddr) {
  70 +               region->ioaddr = ioremap_nocache(region->addr, region->size);
  71 +               if (!region->ioaddr)
  72 +                       return -ENOMEM;
  73 +       }
  74 +
  75 +       if (count != 64 || off != 0)
  76 +               return -EINVAL;
  77 +
  78 +       for (i = 7; i >= 0; i--)
  79 +               data[i] = readq(region->ioaddr + i * sizeof(uint64_t));
  80 +
  81 +       if (copy_to_user(buf, data, 64))
  82 +               return -EFAULT;
  83 +
  84 +       return count;
  85  }
  86
  87 +#define MC_CMD_COMPLETION_TIMEOUT_MS    5000
  88 +#define MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS    500
  89 +
  90 +static int vfio_fsl_mc_send_command(void __iomem *ioaddr, uint64_t *cmd_data)
  91 +{
  92 +       int i;
  93 +       enum mc_cmd_status status;
  94 +       unsigned long timeout_usecs = MC_CMD_COMPLETION_TIMEOUT_MS * 1000;
  95 +
  96 +       /* Write at command parameter into portal */
  97 +       for (i = 7; i >= 1; i--)
  98 +               writeq_relaxed(cmd_data[i], ioaddr + i * sizeof(uint64_t));
  99 +
 100 +       /* Write command header in the end */
 101 +       writeq(cmd_data[0], ioaddr);
 102 +
 103 +       /* Wait for response before returning to user-space
 104 +        * This can be optimized in future to even prepare response
 105 +        * before returning to user-space and avoid read ioctl.
 106 +        */
 107 +       for (;;) {
 108 +               u64 header;
 109 +               struct mc_cmd_header *resp_hdr;
 110 +
 111 +               header = cpu_to_le64(readq_relaxed(ioaddr));
 112 +
 113 +               resp_hdr = (struct mc_cmd_header *)&header;
 114 +               status = (enum mc_cmd_status)resp_hdr->status;
 115 +               if (status != MC_CMD_STATUS_READY)
 116 +                       break;
 117 +
 118 +               udelay(MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
 119 +               timeout_usecs -= MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS;
 120 +               if (timeout_usecs == 0)
 121 +                       return -ETIMEDOUT;
 122 +       }
 123 +
 124 +       return 0;
 125 +}
 126 +
 127 +
 128  static ssize_t vfio_fsl_mc_write(void *device_data, const char __user *buf,
 129                                  size_t count, loff_t *ppos)
 130  {
 131 -       return -EINVAL;
 132 +       struct vfio_fsl_mc_device *vdev = device_data;
 133 +       unsigned int index = VFIO_FSL_MC_OFFSET_TO_INDEX(*ppos);
 134 +       loff_t off = *ppos & VFIO_FSL_MC_OFFSET_MASK;
 135 +       struct vfio_fsl_mc_region *region;
 136 +       uint64_t data[8];
 137 +       int ret;
 138 +
 139 +
 140 +       /* Write ioctl supported only for DPRC and DPMCP device */
 141 +       if (strcmp(vdev->mc_dev->obj_desc.type, "dprc") &&
 142 +           strcmp(vdev->mc_dev->obj_desc.type, "dpmcp"))
 143 +               return -EINVAL;
 144 +
 145 +       if (index >= vdev->num_regions)
 146 +               return -EINVAL;
 147 +
 148 +       region = &vdev->regions[index];
 149 +
 150 +       if (!(region->flags & VFIO_REGION_INFO_FLAG_WRITE))
 151 +               return -EINVAL;
 152 +
 153 +       if (!region->ioaddr) {
 154 +               region->ioaddr = ioremap_nocache(region->addr, region->size);
 155 +               if (!region->ioaddr)
 156 +                       return -ENOMEM;
 157 +       }
 158 +
 159 +       if (count != 64 || off != 0)
 160 +               return -EINVAL;
 161 +
 162 +       if (copy_from_user(&data, buf, 64))
 163 +               return -EFAULT;
 164 +
 165 +       ret = vfio_fsl_mc_send_command(region->ioaddr, data);
 166 +       if (ret)
 167 +               return ret;
 168 +
 169 +       return count;
 170 +
 171  }
 172
 173  static int vfio_fsl_mc_mmap_mmio(struct vfio_fsl_mc_region region,
 174 --- a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
 175 +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
 176 @@ -32,6 +32,7 @@ struct vfio_fsl_mc_region {
 177         u32                     type;
 178         u64                     addr;
 179         resource_size_t         size;
 180 +       void __iomem            *ioaddr;
 181  };
 182
 183  struct vfio_fsl_mc_device {