drivers/xen/arm-device.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2015, Linaro Limited, Shannon Zhao
   4  */
   5
   6 #include <linux/platform_device.h>
   7 #include <linux/acpi.h>
   8 #include <xen/xen.h>
   9 #include <xen/page.h>
  10 #include <xen/interface/memory.h>
  11 #include <asm/xen/hypervisor.h>
  12 #include <asm/xen/hypercall.h>
  13
  14 static int xen_unmap_device_mmio(const struct resource *resources,
  15                                  unsigned int count)
  16 {
  17         unsigned int i, j, nr;
  18         int rc = 0;
  19         const struct resource *r;
  20         struct xen_remove_from_physmap xrp;
  21
  22         for (i = 0; i < count; i++) {
  23                 r = &resources[i];
  24                 nr = DIV_ROUND_UP(resource_size(r), XEN_PAGE_SIZE);
  25                 if ((resource_type(r) != IORESOURCE_MEM) || (nr == 0))
  26                         continue;
  27
  28                 for (j = 0; j < nr; j++) {
  29                         xrp.domid = DOMID_SELF;
  30                         xrp.gpfn = XEN_PFN_DOWN(r->start) + j;
  31                         rc = HYPERVISOR_memory_op(XENMEM_remove_from_physmap,
  32                                                   &xrp);
  33                         if (rc)
  34                                 return rc;
  35                 }
  36         }
  37
  38         return rc;
  39 }
  40
  41 static int xen_map_device_mmio(const struct resource *resources,
  42                                unsigned int count)
  43 {
  44         unsigned int i, j, nr;
  45         int rc = 0;
  46         const struct resource *r;
  47         xen_pfn_t *gpfns;
  48         xen_ulong_t *idxs;
  49         int *errs;
  50
  51         for (i = 0; i < count; i++) {
  52                 struct xen_add_to_physmap_range xatp = {
  53                         .domid = DOMID_SELF,
  54                         .space = XENMAPSPACE_dev_mmio
  55                 };
  56
  57                 r = &resources[i];
  58                 nr = DIV_ROUND_UP(resource_size(r), XEN_PAGE_SIZE);
  59                 if ((resource_type(r) != IORESOURCE_MEM) || (nr == 0))
  60                         continue;
  61
  62                 gpfns = kcalloc(nr, sizeof(xen_pfn_t), GFP_KERNEL);
  63                 idxs = kcalloc(nr, sizeof(xen_ulong_t), GFP_KERNEL);
  64                 errs = kcalloc(nr, sizeof(int), GFP_KERNEL);
  65                 if (!gpfns || !idxs || !errs) {
  66                         kfree(gpfns);
  67                         kfree(idxs);
  68                         kfree(errs);
  69                         rc = -ENOMEM;
  70                         goto unmap;
  71                 }
  72
  73                 for (j = 0; j < nr; j++) {
  74                         /*
  75                          * The regions are always mapped 1:1 to DOM0 and this is
  76                          * fine because the memory map for DOM0 is the same as
  77                          * the host (except for the RAM).
  78                          */
  79                         gpfns[j] = XEN_PFN_DOWN(r->start) + j;
  80                         idxs[j] = XEN_PFN_DOWN(r->start) + j;
  81                 }
  82
  83                 xatp.size = nr;
  84
  85                 set_xen_guest_handle(xatp.gpfns, gpfns);
  86                 set_xen_guest_handle(xatp.idxs, idxs);
  87                 set_xen_guest_handle(xatp.errs, errs);
  88
  89                 rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
  90                 kfree(gpfns);
  91                 kfree(idxs);
  92                 kfree(errs);
  93                 if (rc)
  94                         goto unmap;
  95         }
  96
  97         return rc;
  98
  99 unmap:
 100         xen_unmap_device_mmio(resources, i);
 101         return rc;
 102 }
 103
 104 static int xen_platform_notifier(struct notifier_block *nb,
 105                                  unsigned long action, void *data)
 106 {
 107         struct platform_device *pdev = to_platform_device(data);
 108         int r = 0;
 109
 110         if (pdev->num_resources == 0 || pdev->resource == NULL)
 111                 return NOTIFY_OK;
 112
 113         switch (action) {
 114         case BUS_NOTIFY_ADD_DEVICE:
 115                 r = xen_map_device_mmio(pdev->resource, pdev->num_resources);
 116                 break;
 117         case BUS_NOTIFY_DEL_DEVICE:
 118                 r = xen_unmap_device_mmio(pdev->resource, pdev->num_resources);
 119                 break;
 120         default:
 121                 return NOTIFY_DONE;
 122         }
 123         if (r)
 124                 dev_err(&pdev->dev, "Platform: Failed to %s device %s MMIO!\n",
 125                         action == BUS_NOTIFY_ADD_DEVICE ? "map" :
 126                         (action == BUS_NOTIFY_DEL_DEVICE ? "unmap" : "?"),
 127                         pdev->name);
 128
 129         return NOTIFY_OK;
 130 }
 131
 132 static struct notifier_block platform_device_nb = {
 133         .notifier_call = xen_platform_notifier,
 134 };
 135
 136 static int __init register_xen_platform_notifier(void)
 137 {
 138         if (!xen_initial_domain() || acpi_disabled)
 139                 return 0;
 140
 141         return bus_register_notifier(&platform_bus_type, &platform_device_nb);
 142 }
 143
 144 arch_initcall(register_xen_platform_notifier);
 145
 146 #ifdef CONFIG_ARM_AMBA
 147 #include <linux/amba/bus.h>
 148
 149 static int xen_amba_notifier(struct notifier_block *nb,
 150                              unsigned long action, void *data)
 151 {
 152         struct amba_device *adev = to_amba_device(data);
 153         int r = 0;
 154
 155         switch (action) {
 156         case BUS_NOTIFY_ADD_DEVICE:
 157                 r = xen_map_device_mmio(&adev->res, 1);
 158                 break;
 159         case BUS_NOTIFY_DEL_DEVICE:
 160                 r = xen_unmap_device_mmio(&adev->res, 1);
 161                 break;
 162         default:
 163                 return NOTIFY_DONE;
 164         }
 165         if (r)
 166                 dev_err(&adev->dev, "AMBA: Failed to %s device %s MMIO!\n",
 167                         action == BUS_NOTIFY_ADD_DEVICE ? "map" :
 168                         (action == BUS_NOTIFY_DEL_DEVICE ? "unmap" : "?"),
 169                         adev->dev.init_name);
 170
 171         return NOTIFY_OK;
 172 }
 173
 174 static struct notifier_block amba_device_nb = {
 175         .notifier_call = xen_amba_notifier,
 176 };
 177
 178 static int __init register_xen_amba_notifier(void)
 179 {
 180         if (!xen_initial_domain() || acpi_disabled)
 181                 return 0;
 182
 183         return bus_register_notifier(&amba_bustype, &amba_device_nb);
 184 }
 185
 186 arch_initcall(register_xen_amba_notifier);
 187 #endif