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17 May 2024, 11:00:25 UTC
Revision 46fe18b16c4656969347fc0a3d83a034e47d9119 authored by Jens Axboe on 04 March 2021, 19:39:36 UTC, committed by Jens Axboe on 05 March 2021, 15:43:01 UTC 
io_uring: move to using create_io_thread()
 
This allows us to do task creation and setup without needing to use
completions to try and synchronize with the starting thread. Get rid of
the old io_wq_fork_thread() wrapper, and the 'wq' and 'worker' startup
completion events - we can now do setup before the task is running.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
1 parent cc440e8
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Tip revision: 46fe18b16c4656969347fc0a3d83a034e47d9119 authored by Jens Axboe on 04 March 2021, 19:39:36 UTC
io_uring: move to using create_io_thread()
Tip revision: 46fe18b
devmem_is_allowed.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>

/*
 * 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 << PAGE_SHIFT))
		return 0;
	if (!page_is_ram(pfn))
		return 1;
	return 0;
}
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