[PATCH v7 06/17] Xen: ARM: Add support for mapping platform device mmio

Shannon Zhao
2016-03-24T14:50:56Z

Add a bus_notifier for platform bus device in order to map the device
mmio regions when DOM0 booting with ACPI.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
drivers/xen/Makefile | 1 +
drivers/xen/arm-device.c | 141 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 142 insertions(+)
create mode 100644 drivers/xen/arm-device.c

diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 9b7a35c..415f286 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -9,6 +9,7 @@ CFLAGS_features.o := $(nostackp)

CFLAGS_efi.o += -fshort-wchar

+dom0-$(CONFIG_ARM64) += arm-device.o
dom0-$(CONFIG_PCI) += pci.o
dom0-$(CONFIG_USB_SUPPORT) += dbgp.o
dom0-$(CONFIG_XEN_ACPI) += acpi.o $(xen-pad-y)
diff --git a/drivers/xen/arm-device.c b/drivers/xen/arm-device.c
new file mode 100644
index 0000000..76e26e5
--- /dev/null
+++ b/drivers/xen/arm-device.c
@@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 2015, Linaro Limited, Shannon Zhao
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/acpi.h>
+#include <xen/xen.h>
+#include <xen/page.h>
+#include <xen/interface/memory.h>
+#include <asm/xen/hypervisor.h>
+#include <asm/xen/hypercall.h>
+
+static int xen_unmap_device_mmio(struct resource *resource, unsigned int count)
+{
+ unsigned int i, j, nr;
+ int rc = 0;
+ struct resource *r;
+ struct xen_remove_from_physmap xrp;
+
+ for (i = 0; i < count; i++) {
+ r = &resource[i];
+ nr = DIV_ROUND_UP(resource_size(r), XEN_PAGE_SIZE);
+ if ((resource_type(r) != IORESOURCE_MEM) || (nr == 0))
+ continue;
+
+ for (j = 0; j < nr; j++) {
+ xrp.domid = DOMID_SELF;
+ xrp.gpfn = XEN_PFN_DOWN(r->start) + j;
+ rc = HYPERVISOR_memory_op(XENMEM_remove_from_physmap,
+ &xrp);
+ if (rc)
+ return rc;
+ }
+ }
+
+ return rc;
+}
+
+static int xen_map_device_mmio(struct resource *resource, unsigned int count)
+{
+ unsigned int i, j, nr;
+ int rc = 0;
+ struct resource *r;
+ xen_pfn_t *gpfns;
+ xen_ulong_t *idxs;
+ int *errs;
+ struct xen_add_to_physmap_range xatp;
+
+ for (i = 0; i < count; i++) {
+ r = &resource[i];
+ nr = DIV_ROUND_UP(resource_size(r), XEN_PAGE_SIZE);
+ if ((resource_type(r) != IORESOURCE_MEM) || (nr == 0))
+ continue;
+
+ gpfns = kzalloc(sizeof(xen_pfn_t) * nr, GFP_KERNEL);
+ idxs = kzalloc(sizeof(xen_ulong_t) * nr, GFP_KERNEL);
+ errs = kzalloc(sizeof(int) * nr, GFP_KERNEL);
+ if (!gpfns || !idxs || !errs) {
+ kfree(gpfns);
+ kfree(idxs);
+ kfree(errs);
+ return -ENOMEM;
+ }
+
+ for (j = 0; j < nr; j++) {
+ gpfns[j] = XEN_PFN_DOWN(r->start) + j;
+ idxs[j] = XEN_PFN_DOWN(r->start) + j;
+ }
+
+ xatp.domid = DOMID_SELF;
+ xatp.size = nr;
+ xatp.space = XENMAPSPACE_dev_mmio;
+
+ set_xen_guest_handle(xatp.gpfns, gpfns);
+ set_xen_guest_handle(xatp.idxs, idxs);
+ set_xen_guest_handle(xatp.errs, errs);
+
+ rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
+ kfree(gpfns);
+ kfree(idxs);
+ kfree(errs);
+ if (rc)
+ return rc;
+ }
+
+ return rc;
+}
+
+static int xen_platform_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct platform_device *pdev = to_platform_device(data);
+ int r = 0;
+
+ if (pdev->num_resources == 0 || pdev->resource == NULL)
+ return NOTIFY_OK;
+
+ switch (action) {
+ case BUS_NOTIFY_ADD_DEVICE:
+ r = xen_map_device_mmio(pdev->resource, pdev->num_resources);
+ break;
+ case BUS_NOTIFY_DEL_DEVICE:
+ r = xen_unmap_device_mmio(pdev->resource, pdev->num_resources);
+ break;
+ default:
+ return NOTIFY_DONE;
+ }
+ if (r)
+ dev_err(&pdev->dev, "Platform: Failed to %s device %s MMIO!\n",
+ action == BUS_NOTIFY_ADD_DEVICE ? "map" :
+ (action == BUS_NOTIFY_DEL_DEVICE ? "unmap" : "?"),
+ pdev->name);
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block platform_device_nb = {
+ .notifier_call = xen_platform_notifier,
+};
+
+static int __init register_xen_platform_notifier(void)
+{
+ if (!xen_initial_domain() || acpi_disabled)
+ return 0;
+
+ return bus_register_notifier(&platform_bus_type, &platform_device_nb);
+}
+
+arch_initcall(register_xen_platform_notifier);
--
2.1.4