drivers/misc/ocxl/sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 // Copyright 2017 IBM Corp.
   3 #include <linux/sysfs.h>
   4 #include "ocxl_internal.h"
   5
   6 static inline struct ocxl_afu *to_afu(struct device *device)
   7 {
   8         struct ocxl_file_info *info = container_of(device, struct ocxl_file_info, dev);
   9
  10         return info->afu;
  11 }
  12
  13 static ssize_t global_mmio_size_show(struct device *device,
  14                                 struct device_attribute *attr,
  15                                 char *buf)
  16 {
  17         struct ocxl_afu *afu = to_afu(device);
  18
  19         return scnprintf(buf, PAGE_SIZE, "%d\n",
  20                         afu->config.global_mmio_size);
  21 }
  22
  23 static ssize_t pp_mmio_size_show(struct device *device,
  24                                 struct device_attribute *attr,
  25                                 char *buf)
  26 {
  27         struct ocxl_afu *afu = to_afu(device);
  28
  29         return scnprintf(buf, PAGE_SIZE, "%d\n",
  30                         afu->config.pp_mmio_stride);
  31 }
  32
  33 static ssize_t afu_version_show(struct device *device,
  34                                 struct device_attribute *attr,
  35                                 char *buf)
  36 {
  37         struct ocxl_afu *afu = to_afu(device);
  38
  39         return scnprintf(buf, PAGE_SIZE, "%hhu:%hhu\n",
  40                         afu->config.version_major,
  41                         afu->config.version_minor);
  42 }
  43
  44 static ssize_t contexts_show(struct device *device,
  45                 struct device_attribute *attr,
  46                 char *buf)
  47 {
  48         struct ocxl_afu *afu = to_afu(device);
  49
  50         return scnprintf(buf, PAGE_SIZE, "%d/%d\n",
  51                         afu->pasid_count, afu->pasid_max);
  52 }
  53
  54 static struct device_attribute afu_attrs[] = {
  55         __ATTR_RO(global_mmio_size),
  56         __ATTR_RO(pp_mmio_size),
  57         __ATTR_RO(afu_version),
  58         __ATTR_RO(contexts),
  59 };
  60
  61 static ssize_t global_mmio_read(struct file *filp, struct kobject *kobj,
  62                                 struct bin_attribute *bin_attr, char *buf,
  63                                 loff_t off, size_t count)
  64 {
  65         struct ocxl_afu *afu = to_afu(kobj_to_dev(kobj));
  66
  67         if (count == 0 || off < 0 ||
  68                 off >= afu->config.global_mmio_size)
  69                 return 0;
  70         memcpy_fromio(buf, afu->global_mmio_ptr + off, count);
  71         return count;
  72 }
  73
  74 static vm_fault_t global_mmio_fault(struct vm_fault *vmf)
  75 {
  76         struct vm_area_struct *vma = vmf->vma;
  77         struct ocxl_afu *afu = vma->vm_private_data;
  78         unsigned long offset;
  79
  80         if (vmf->pgoff >= (afu->config.global_mmio_size >> PAGE_SHIFT))
  81                 return VM_FAULT_SIGBUS;
  82
  83         offset = vmf->pgoff;
  84         offset += (afu->global_mmio_start >> PAGE_SHIFT);
  85         return vmf_insert_pfn(vma, vmf->address, offset);
  86 }
  87
  88 static const struct vm_operations_struct global_mmio_vmops = {
  89         .fault = global_mmio_fault,
  90 };
  91
  92 static int global_mmio_mmap(struct file *filp, struct kobject *kobj,
  93                         struct bin_attribute *bin_attr,
  94                         struct vm_area_struct *vma)
  95 {
  96         struct ocxl_afu *afu = to_afu(kobj_to_dev(kobj));
  97
  98         if ((vma_pages(vma) + vma->vm_pgoff) >
  99                 (afu->config.global_mmio_size >> PAGE_SHIFT))
 100                 return -EINVAL;
 101
 102         vma->vm_flags |= VM_IO | VM_PFNMAP;
 103         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 104         vma->vm_ops = &global_mmio_vmops;
 105         vma->vm_private_data = afu;
 106         return 0;
 107 }
 108
 109 int ocxl_sysfs_register_afu(struct ocxl_file_info *info)
 110 {
 111         int i, rc;
 112
 113         for (i = 0; i < ARRAY_SIZE(afu_attrs); i++) {
 114                 rc = device_create_file(&info->dev, &afu_attrs[i]);
 115                 if (rc)
 116                         goto err;
 117         }
 118
 119         sysfs_attr_init(&info->attr_global_mmio.attr);
 120         info->attr_global_mmio.attr.name = "global_mmio_area";
 121         info->attr_global_mmio.attr.mode = 0600;
 122         info->attr_global_mmio.size = info->afu->config.global_mmio_size;
 123         info->attr_global_mmio.read = global_mmio_read;
 124         info->attr_global_mmio.mmap = global_mmio_mmap;
 125         rc = device_create_bin_file(&info->dev, &info->attr_global_mmio);
 126         if (rc) {
 127                 dev_err(&info->dev, "Unable to create global mmio attr for afu: %d\n", rc);
 128                 goto err;
 129         }
 130
 131         return 0;
 132
 133 err:
 134         for (i--; i >= 0; i--)
 135                 device_remove_file(&info->dev, &afu_attrs[i]);
 136
 137         return rc;
 138 }
 139
 140 void ocxl_sysfs_unregister_afu(struct ocxl_file_info *info)
 141 {
 142         int i;
 143
 144         /*
 145          * device_remove_bin_file is safe to call if the file is not added as
 146          * the files are removed by name, and early exit if not found
 147          */
 148         for (i = 0; i < ARRAY_SIZE(afu_attrs); i++)
 149                 device_remove_file(&info->dev, &afu_attrs[i]);
 150         device_remove_bin_file(&info->dev, &info->attr_global_mmio);
 151 }