Remove the device initialization code from `xen/arch/arm/device.c`
and move it to the common code to avoid duplication and make it accessible
for both ARM and other architectures.
device_get_class(), device_init(), _sdevice[] and _edevice[] are wrapped by
"#ifdef CONFIG_HAS_DEVICE_TREE" for the case if an arch doesn't support
device tree.

Remove unnecessary inclusions of <asm/device.h> and <xen/init.h> from
`xen/arch/arm/device.c` as no code in the file relies on these headers.
Fix the inclusion order by moving <asm/setup.h> after <xen/*> headers to
resolve a compilation error:
   ./include/public/xen.h:968:35: error: unknown type name 'uint64_t'
    968 | __DEFINE_XEN_GUEST_HANDLE(uint64, uint64_t);
        |                                   ^~~~~~~~
   ./include/public/arch-arm.h:191:21: note: in definition of macro '___DEFINE_XEN_GUEST_HANDLE'
   191 |     typedef union { type *p; uint64_aligned_t q; }              \
       |                     ^~~~
   ./include/public/xen.h:968:1: note: in expansion of macro '__DEFINE_XEN_GUEST_HANDLE'
   968 | __DEFINE_XEN_GUEST_HANDLE(uint64, uint64_t);
because <asm/setup.h> includes <public/version.h>, which in turn includes
"xen.h", which requires <xen/types.h> to be processed correctly.
Additionally, add <xen/device_tree.h> to `device.c` as functions from this
header are used within the file.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
Changes in V4:
 - add Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
Changes in V3:
 - drop DEVICE_INIT config.
 - update the commit message.
---
 xen/arch/arm/device.c | 71 ++-----------------------------------
 xen/common/Makefile   |  2 ++
 xen/common/device.c   | 82 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 86 insertions(+), 69 deletions(-)
 create mode 100644 xen/common/device.c

diff --git a/xen/arch/arm/device.c b/xen/arch/arm/device.c
index 3e02cff008..5610cddcba 100644
--- a/xen/arch/arm/device.c
+++ b/xen/arch/arm/device.c
@@ -8,79 +8,12 @@
  * Copyright (C) 2013 Linaro Limited.
  */
 
-#include <asm/device.h>
-#include <asm/setup.h>
+#include <xen/device_tree.h>
 #include <xen/errno.h>
-#include <xen/init.h>
 #include <xen/iocap.h>
 #include <xen/lib.h>
 
-extern const struct device_desc _sdevice[], _edevice[];
-
-#ifdef CONFIG_ACPI
-extern const struct acpi_device_desc _asdevice[], _aedevice[];
-#endif
-
-int __init device_init(struct dt_device_node *dev, enum device_class class,
-                       const void *data)
-{
-    const struct device_desc *desc;
-
-    ASSERT(dev != NULL);
-
-    if ( !dt_device_is_available(dev) || dt_device_for_passthrough(dev) )
-        return  -ENODEV;
-
-    for ( desc = _sdevice; desc != _edevice; desc++ )
-    {
-        if ( desc->class != class )
-            continue;
-
-        if ( dt_match_node(desc->dt_match, dev) )
-        {
-            ASSERT(desc->init != NULL);
-
-            return desc->init(dev, data);
-        }
-
-    }
-
-    return -EBADF;
-}
-
-#ifdef CONFIG_ACPI
-int __init acpi_device_init(enum device_class class, const void *data, int class_type)
-{
-    const struct acpi_device_desc *desc;
-
-    for ( desc = _asdevice; desc != _aedevice; desc++ )
-    {
-        if ( ( desc->class != class ) || ( desc->class_type != class_type ) )
-            continue;
-
-        ASSERT(desc->init != NULL);
-
-        return desc->init(data);
-    }
-
-    return -EBADF;
-}
-#endif
-
-enum device_class device_get_class(const struct dt_device_node *dev)
-{
-    const struct device_desc *desc;
-
-    ASSERT(dev != NULL);
-
-    for ( desc = _sdevice; desc != _edevice; desc++ )
-    {
-        if ( dt_match_node(desc->dt_match, dev) )
-            return desc->class;
-    }
-
-    return DEVICE_UNKNOWN;
-}
+#include <asm/setup.h>
 
 int map_irq_to_domain(struct domain *d, unsigned int irq,
                       bool need_mapping, const char *devname)
diff --git a/xen/common/Makefile b/xen/common/Makefile
index fc52e0857d..9d962069f7 100644
--- a/xen/common/Makefile
+++ b/xen/common/Makefile
@@ -6,6 +6,8 @@ obj-$(CONFIG_HYPFS_CONFIG) += config_data.o
 obj-$(CONFIG_CORE_PARKING) += core_parking.o
 obj-y += cpu.o
 obj-$(CONFIG_DEBUG_TRACE) += debugtrace.o
+obj-$(CONFIG_HAS_DEVICE_TREE) += device.o
+obj-$(filter-out $(CONFIG_X86),$(CONFIG_ACPI)) += device.o
 obj-$(CONFIG_HAS_DEVICE_TREE) += device-tree/
 obj-$(CONFIG_IOREQ_SERVER) += dm.o
 obj-y += domain.o
diff --git a/xen/common/device.c b/xen/common/device.c
new file mode 100644
index 0000000000..33e0d58f2f
--- /dev/null
+++ b/xen/common/device.c
@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Based on the code from:
+ *   xen/arch/arm/device.c
+ */
+
+#include <xen/bug.h>
+#include <xen/device_tree.h>
+#include <xen/errno.h>
+#include <xen/init.h>
+
+#include <asm/device.h>
+
+#ifdef CONFIG_HAS_DEVICE_TREE
+
+extern const struct device_desc _sdevice[], _edevice[];
+
+int __init device_init(struct dt_device_node *dev, enum device_class class,
+                       const void *data)
+{
+    const struct device_desc *desc;
+
+    ASSERT(dev != NULL);
+
+    if ( !dt_device_is_available(dev) || dt_device_for_passthrough(dev) )
+        return  -ENODEV;
+
+    for ( desc = _sdevice; desc != _edevice; desc++ )
+    {
+        if ( desc->class != class )
+            continue;
+
+        if ( dt_match_node(desc->dt_match, dev) )
+        {
+            ASSERT(desc->init != NULL);
+
+            return desc->init(dev, data);
+        }
+    }
+
+    return -EBADF;
+}
+
+enum device_class device_get_class(const struct dt_device_node *dev)
+{
+    const struct device_desc *desc;
+
+    ASSERT(dev != NULL);
+
+    for ( desc = _sdevice; desc != _edevice; desc++ )
+    {
+        if ( dt_match_node(desc->dt_match, dev) )
+            return desc->class;
+    }
+
+    return DEVICE_UNKNOWN;
+}
+
+#endif
+
+#ifdef CONFIG_ACPI
+
+extern const struct acpi_device_desc _asdevice[], _aedevice[];
+
+int __init acpi_device_init(enum device_class class, const void *data, int class_type)
+{
+    const struct acpi_device_desc *desc;
+
+    for ( desc = _asdevice; desc != _aedevice; desc++ )
+    {
+        if ( ( desc->class != class ) || ( desc->class_type != class_type ) )
+            continue;
+
+        ASSERT(desc->init != NULL);
+
+        return desc->init(data);
+    }
+
+    return -EBADF;
+}
+
+#endif
-- 
2.46.1

On 26/09/2024 18:54, Oleksii Kurochko wrote:
> 
> 
> Remove the device initialization code from `xen/arch/arm/device.c`
> and move it to the common code to avoid duplication and make it accessible
> for both ARM and other architectures.
> device_get_class(), device_init(), _sdevice[] and _edevice[] are wrapped by
> "#ifdef CONFIG_HAS_DEVICE_TREE" for the case if an arch doesn't support
> device tree.
> 
> Remove unnecessary inclusions of <asm/device.h> and <xen/init.h> from
> `xen/arch/arm/device.c` as no code in the file relies on these headers.
> Fix the inclusion order by moving <asm/setup.h> after <xen/*> headers to
> resolve a compilation error:
>    ./include/public/xen.h:968:35: error: unknown type name 'uint64_t'
>     968 | __DEFINE_XEN_GUEST_HANDLE(uint64, uint64_t);
>         |                                   ^~~~~~~~
>    ./include/public/arch-arm.h:191:21: note: in definition of macro '___DEFINE_XEN_GUEST_HANDLE'
>    191 |     typedef union { type *p; uint64_aligned_t q; }              \
>        |                     ^~~~
>    ./include/public/xen.h:968:1: note: in expansion of macro '__DEFINE_XEN_GUEST_HANDLE'
>    968 | __DEFINE_XEN_GUEST_HANDLE(uint64, uint64_t);
> because <asm/setup.h> includes <public/version.h>, which in turn includes
> "xen.h", which requires <xen/types.h> to be processed correctly.
> Additionally, add <xen/device_tree.h> to `device.c` as functions from this
> header are used within the file.
> 
> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
> Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>

~Michal