https://github.com/torvalds/linux
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Tip revision: af2d861d4cd2a4da5137f795ee3509e6f944a25b authored by Linus Torvalds on 24 April 2022, 21:51:22 UTC
Linux 5.18-rc4
Tip revision: af2d861
physaddr.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/bug.h>
#include <linux/export.h>
#include <linux/types.h>
#include <linux/mmdebug.h>
#include <linux/mm.h>

#include <asm/sections.h>
#include <asm/io.h>
#include <asm/page.h>
#include <asm/dma.h>

static inline bool __debug_virt_addr_valid(unsigned long x)
{
	/* high_memory does not get immediately defined, and there
	 * are early callers of __pa() against PAGE_OFFSET
	 */
	if (!high_memory && x >= PAGE_OFFSET)
		return true;

	if (high_memory && x >= PAGE_OFFSET && x < (unsigned long)high_memory)
		return true;

	/*
	 * MAX_DMA_ADDRESS is a virtual address that may not correspond to an
	 * actual physical address. Enough code relies on
	 * virt_to_phys(MAX_DMA_ADDRESS) that we just need to work around it
	 * and always return true.
	 */
	if (x == MAX_DMA_ADDRESS)
		return true;

	return false;
}

phys_addr_t __virt_to_phys(volatile const void *x)
{
	WARN(!__debug_virt_addr_valid((unsigned long)x),
	     "virt_to_phys used for non-linear address: %pK (%pS)\n",
	     x, x);

	return __virt_to_phys_nodebug(x);
}
EXPORT_SYMBOL(__virt_to_phys);

phys_addr_t __phys_addr_symbol(unsigned long x)
{
	/* This is bounds checking against the kernel image only.
	 * __pa_symbol should only be used on kernel symbol addresses.
	 */
	VIRTUAL_BUG_ON(x < (unsigned long)_text ||
		       x > (unsigned long)_end);

	return __pa_symbol_nodebug(x);
}
EXPORT_SYMBOL(__phys_addr_symbol);
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