[06/13] Xen: ARM: Add support for mapping amba device mmio

Message ID 1447754231-7772-7-git-send-email-shannon.zhao@linaro.org
State New
Headers show

Commit Message

Shannon Zhao Nov. 17, 2015, 9:57 a.m.
From: Shannon Zhao <shannon.zhao@linaro.org>


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

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>

---
 drivers/xen/Makefile |  1 +
 drivers/xen/amba.c   | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 100 insertions(+)
 create mode 100644 drivers/xen/amba.c

-- 
2.1.0

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Comments

Shannon Zhao Nov. 18, 2015, 1:15 p.m. | #1
On 2015/11/18 20:27, Julien Grall wrote:
> On 18/11/15 06:03, Shannon Zhao wrote:

>>>

>>> What about the removal of a bus device? No need to handle that?

>>>

>> I have thought about removal before. I think there is little(or no)

>> chance for AMBA and platform bus devices to be removed. It's not like

>> the PCI devices which will be hot-unplug.

>> Maybe I'm not right. If so, it's fine to add a case to handle the removal.

>

> What about the platform device passthrough case?

>

No, it will add the platform passthrough device at booting step while 
it's only removed when Dom0 shutdowns unless it supports platform device 
hot-unplug.

> In anycase, if the AMBA platform provides a removal method, there is

> harmless to implement it.

>

Sure, as you said, it's harmless to add.

Thanks,
-- 
Shannon
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Patch

diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 2f867e7..139bd0b 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -12,6 +12,7 @@  CFLAGS_features.o			:= $(nostackp)
 CFLAGS_efi.o				+= -fshort-wchar
 
 dom0-$(CONFIG_ARM64) += platform.o
+dom0-$(CONFIG_ARM_AMBA) += amba.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/amba.c b/drivers/xen/amba.c
new file mode 100644
index 0000000..e491c8e
--- /dev/null
+++ b/drivers/xen/amba.c
@@ -0,0 +1,99 @@ 
+/*
+ * Copyright (c) 2015, Linaro Limited.
+ *
+ * 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, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * Author: Shannon Zhao <shannon.zhao@linaro.org>
+ */
+
+#include <linux/amba/bus.h>
+#include <linux/acpi.h>
+#include <xen/xen.h>
+#include <xen/interface/memory.h>
+#include <asm/xen/hypervisor.h>
+#include <asm/xen/hypercall.h>
+
+static int xen_map_amba_device_mmio(struct amba_device *adev)
+{
+	int rc = 0;
+	struct resource *r = &adev->res;
+
+	if (resource_type(r) == IORESOURCE_MEM)
+	{
+		int j;
+		int nr = DIV_ROUND_UP(resource_size(r), PAGE_SIZE);
+		xen_pfn_t *gpfns = kmalloc(sizeof(xen_pfn_t) * nr, GFP_KERNEL);
+		xen_ulong_t *idxs = kmalloc(sizeof(xen_ulong_t) * nr,
+					    GFP_KERNEL);
+		int *errs = kmalloc(sizeof(int) * nr, GFP_KERNEL);
+		struct xen_add_to_physmap_range xatp;
+
+		for (j = 0; j < nr; j++) {
+			gpfns[j] = (r->start >> PAGE_SHIFT) + j;
+			idxs[j] = (r->start >> PAGE_SHIFT) + j;
+			errs[j] = 0;
+		}
+
+		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 != 0)
+			return rc;
+	}
+
+	return rc;
+}
+
+static int xen_amba_notifier(struct notifier_block *nb,
+			     unsigned long action, void *data)
+{
+	struct amba_device *adev = to_amba_device(data);
+	int r = 0;
+
+	if (!acpi_disabled && (action == BUS_NOTIFY_ADD_DEVICE))
+		r = xen_map_amba_device_mmio(adev);
+
+	if (r)
+	{
+		dev_err(&adev->dev, "Failed to add_to_physmap device (%s) mmio!\n",
+			adev->dev.init_name);
+		return NOTIFY_OK;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block amba_device_nb = {
+	.notifier_call = xen_amba_notifier,
+};
+
+static int __init register_xen_amba_notifier(void)
+{
+	if (!xen_initial_domain())
+		return 0;
+
+	return bus_register_notifier(&amba_bustype, &amba_device_nb);
+}
+
+arch_initcall(register_xen_amba_notifier);