mirror of
https://github.com/torvalds/linux.git
synced 2024-11-30 16:11:38 +00:00
6b76ca2ab9
The devmem_is_allowed() function is defined in a file of the same name, but the declaration is in asm/io.h, which is not included there, causing a W=1 warning: lib/devmem_is_allowed.c:20:5: error: no previous prototype for 'devmem_is_allowed' [-Werror=missing-prototypes] Include the appropriate header to avoid the warning. Link: https://lkml.kernel.org/r/20230517131102.934196-6-arnd@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Eric Paris <eparis@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
29 lines
705 B
C
29 lines
705 B
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* A generic version of devmem_is_allowed.
|
|
*
|
|
* Based on arch/arm64/mm/mmap.c
|
|
*
|
|
* Copyright (C) 2020 Google, Inc.
|
|
* Copyright (C) 2012 ARM Ltd.
|
|
*/
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/ioport.h>
|
|
#include <linux/io.h>
|
|
|
|
/*
|
|
* devmem_is_allowed() checks to see if /dev/mem access to a certain address
|
|
* is valid. The argument is a physical page number. We mimic x86 here by
|
|
* disallowing access to system RAM as well as device-exclusive MMIO regions.
|
|
* This effectively disable read()/write() on /dev/mem.
|
|
*/
|
|
int devmem_is_allowed(unsigned long pfn)
|
|
{
|
|
if (iomem_is_exclusive(PFN_PHYS(pfn)))
|
|
return 0;
|
|
if (!page_is_ram(pfn))
|
|
return 1;
|
|
return 0;
|
|
}
|