linux/drivers/xen/arm-device.c
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   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
  14static 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
  41static 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
  99unmap:
 100        xen_unmap_device_mmio(resources, i);
 101        return rc;
 102}
 103
 104static 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
 132static struct notifier_block platform_device_nb = {
 133        .notifier_call = xen_platform_notifier,
 134};
 135
 136static 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
 144arch_initcall(register_xen_platform_notifier);
 145
 146#ifdef CONFIG_ARM_AMBA
 147#include <linux/amba/bus.h>
 148
 149static 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
 174static struct notifier_block amba_device_nb = {
 175        .notifier_call = xen_amba_notifier,
 176};
 177
 178static 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
 186arch_initcall(register_xen_amba_notifier);
 187#endif
 188