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scsi: zorro: Simplify storing pointers in device id struct

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Technically it is fine (on all current Linux architectures) to store a
pointer in an unsigned long variable. However this needs explicit casting
which is an easy source for type mismatches.

By replacing the plain unsigned long .driver_data in struct zorro_device_id
by an anonymous union, most of the casting can be dropped. There is still
some implicit casting involved (between a void * and a driver specific
pointer type), but that's better than the approach to store a pointer in an
unsigned long variable as this doesn't lose the information that the data
being pointed to is const.

All users of struct zorro_device_id are initialized in a way that is
compatible with the new definition, so no adaptions are needed there.

Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Max Staudt <max@enpas.org>
Acked-by: Helge Deller <deller@gmx.de>
Link: https://patch.msgid.link/49576a7501128c93ef318566ed7faefce163f1fd.1779803053.git.u.kleine-koenig@baylibre.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Uwe Kleine-König (The Capable Hub) 2026-05-26 16:17:32 +02:00 committed by Martin K. Petersen
parent 108e48a9a4
commit 841970b2f6
1 changed files with 5 additions and 1 deletions
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6
include/linux/mod_devicetable.h
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@ -640,7 +640,11 @@ struct mdio_device_id {
struct zorro_device_id {
__u32 id; /* Device ID or ZORRO_WILDCARD */
kernel_ulong_t driver_data; /* Data private to the driver */
union {
/* Data private to the driver */
kernel_ulong_t driver_data;
const void *driver_data_ptr;
};
};
#define ZORRO_WILDCARD (0xffffffff) /* not official */