linux/drivers/xen/arm-device.c
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   1/*
   2 * Copyright (c) 2015, Linaro Limited, Shannon Zhao
   3 *
   4 * This program is free software; you can redistribute it and/or modify it
   5 * under the terms and conditions of the GNU General Public License,
   6 * version 2, as published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope it will be useful, but WITHOUT
   9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11 * more details.
  12 *
  13 * You should have received a copy of the GNU General Public License
  14 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15 */
  16
  17#include <linux/platform_device.h>
  18#include <linux/acpi.h>
  19#include <xen/xen.h>
  20#include <xen/page.h>
  21#include <xen/interface/memory.h>
  22#include <asm/xen/hypervisor.h>
  23#include <asm/xen/hypercall.h>
  24
  25static int xen_unmap_device_mmio(const struct resource *resources,
  26                                 unsigned int count)
  27{
  28        unsigned int i, j, nr;
  29        int rc = 0;
  30        const struct resource *r;
  31        struct xen_remove_from_physmap xrp;
  32
  33        for (i = 0; i < count; i++) {
  34                r = &resources[i];
  35                nr = DIV_ROUND_UP(resource_size(r), XEN_PAGE_SIZE);
  36                if ((resource_type(r) != IORESOURCE_MEM) || (nr == 0))
  37                        continue;
  38
  39                for (j = 0; j < nr; j++) {
  40                        xrp.domid = DOMID_SELF;
  41                        xrp.gpfn = XEN_PFN_DOWN(r->start) + j;
  42                        rc = HYPERVISOR_memory_op(XENMEM_remove_from_physmap,
  43                                                  &xrp);
  44                        if (rc)
  45                                return rc;
  46                }
  47        }
  48
  49        return rc;
  50}
  51
  52static int xen_map_device_mmio(const struct resource *resources,
  53                               unsigned int count)
  54{
  55        unsigned int i, j, nr;
  56        int rc = 0;
  57        const struct resource *r;
  58        xen_pfn_t *gpfns;
  59        xen_ulong_t *idxs;
  60        int *errs;
  61
  62        for (i = 0; i < count; i++) {
  63                struct xen_add_to_physmap_range xatp = {
  64                        .domid = DOMID_SELF,
  65                        .space = XENMAPSPACE_dev_mmio
  66                };
  67
  68                r = &resources[i];
  69                nr = DIV_ROUND_UP(resource_size(r), XEN_PAGE_SIZE);
  70                if ((resource_type(r) != IORESOURCE_MEM) || (nr == 0))
  71                        continue;
  72
  73                gpfns = kcalloc(nr, sizeof(xen_pfn_t), GFP_KERNEL);
  74                idxs = kcalloc(nr, sizeof(xen_ulong_t), GFP_KERNEL);
  75                errs = kcalloc(nr, sizeof(int), GFP_KERNEL);
  76                if (!gpfns || !idxs || !errs) {
  77                        kfree(gpfns);
  78                        kfree(idxs);
  79                        kfree(errs);
  80                        rc = -ENOMEM;
  81                        goto unmap;
  82                }
  83
  84                for (j = 0; j < nr; j++) {
  85                        /*
  86                         * The regions are always mapped 1:1 to DOM0 and this is
  87                         * fine because the memory map for DOM0 is the same as
  88                         * the host (except for the RAM).
  89                         */
  90                        gpfns[j] = XEN_PFN_DOWN(r->start) + j;
  91                        idxs[j] = XEN_PFN_DOWN(r->start) + j;
  92                }
  93
  94                xatp.size = nr;
  95
  96                set_xen_guest_handle(xatp.gpfns, gpfns);
  97                set_xen_guest_handle(xatp.idxs, idxs);
  98                set_xen_guest_handle(xatp.errs, errs);
  99
 100                rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
 101                kfree(gpfns);
 102                kfree(idxs);
 103                kfree(errs);
 104                if (rc)
 105                        goto unmap;
 106        }
 107
 108        return rc;
 109
 110unmap:
 111        xen_unmap_device_mmio(resources, i);
 112        return rc;
 113}
 114
 115static int xen_platform_notifier(struct notifier_block *nb,
 116                                 unsigned long action, void *data)
 117{
 118        struct platform_device *pdev = to_platform_device(data);
 119        int r = 0;
 120
 121        if (pdev->num_resources == 0 || pdev->resource == NULL)
 122                return NOTIFY_OK;
 123
 124        switch (action) {
 125        case BUS_NOTIFY_ADD_DEVICE:
 126                r = xen_map_device_mmio(pdev->resource, pdev->num_resources);
 127                break;
 128        case BUS_NOTIFY_DEL_DEVICE:
 129                r = xen_unmap_device_mmio(pdev->resource, pdev->num_resources);
 130                break;
 131        default:
 132                return NOTIFY_DONE;
 133        }
 134        if (r)
 135                dev_err(&pdev->dev, "Platform: Failed to %s device %s MMIO!\n",
 136                        action == BUS_NOTIFY_ADD_DEVICE ? "map" :
 137                        (action == BUS_NOTIFY_DEL_DEVICE ? "unmap" : "?"),
 138                        pdev->name);
 139
 140        return NOTIFY_OK;
 141}
 142
 143static struct notifier_block platform_device_nb = {
 144        .notifier_call = xen_platform_notifier,
 145};
 146
 147static int __init register_xen_platform_notifier(void)
 148{
 149        if (!xen_initial_domain() || acpi_disabled)
 150                return 0;
 151
 152        return bus_register_notifier(&platform_bus_type, &platform_device_nb);
 153}
 154
 155arch_initcall(register_xen_platform_notifier);
 156
 157#ifdef CONFIG_ARM_AMBA
 158#include <linux/amba/bus.h>
 159
 160static int xen_amba_notifier(struct notifier_block *nb,
 161                             unsigned long action, void *data)
 162{
 163        struct amba_device *adev = to_amba_device(data);
 164        int r = 0;
 165
 166        switch (action) {
 167        case BUS_NOTIFY_ADD_DEVICE:
 168                r = xen_map_device_mmio(&adev->res, 1);
 169                break;
 170        case BUS_NOTIFY_DEL_DEVICE:
 171                r = xen_unmap_device_mmio(&adev->res, 1);
 172                break;
 173        default:
 174                return NOTIFY_DONE;
 175        }
 176        if (r)
 177                dev_err(&adev->dev, "AMBA: Failed to %s device %s MMIO!\n",
 178                        action == BUS_NOTIFY_ADD_DEVICE ? "map" :
 179                        (action == BUS_NOTIFY_DEL_DEVICE ? "unmap" : "?"),
 180                        adev->dev.init_name);
 181
 182        return NOTIFY_OK;
 183}
 184
 185static struct notifier_block amba_device_nb = {
 186        .notifier_call = xen_amba_notifier,
 187};
 188
 189static int __init register_xen_amba_notifier(void)
 190{
 191        if (!xen_initial_domain() || acpi_disabled)
 192                return 0;
 193
 194        return bus_register_notifier(&amba_bustype, &amba_device_nb);
 195}
 196
 197arch_initcall(register_xen_amba_notifier);
 198#endif
 199