ae57857b9b
To avoid "performing pointer subtraction with a null pointer has undefined behavior" compiler warnings, use uintptr_t and offsetof() that are always available during Linux kernel builds to define acpi_uintptr_t and the ACPI_TO_INTEGER() and ACPI_OFFSET() macros. Based on earlier proposal from Arnd Bergmann. Link: https://lore.kernel.org/linux-acpi/20210927121338.938994-1-arnd@kernel.org Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de>