MIPS: Document why RELOC_HIDE is there. (5707bf6b) · Commits · e / devices / android_kernel_xiaomi_markw

arch/mips/include/asm/page.h

+14 −0

Original line number	Diff line number	Diff line
		@@ -150,6 +150,20 @@ typedef struct { unsigned long pgprot; } pgprot_t;
		((unsigned long)(x) - PAGE_OFFSET + PHYS_OFFSET)
		#endif
		#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET - PHYS_OFFSET))

		/*
		* RELOC_HIDE was originally added by 6007b903dfe5f1d13e0c711ac2894bdd4a61b1ad
		* (lmo) rsp. 8431fd094d625b94d364fe393076ccef88e6ce18 (kernel.org). The
		* discussion can be found in lkml posting
		* <a2ebde260608230500o3407b108hc03debb9da6e62c@mail.gmail.com> which is
		* archived at http://lists.linuxcoding.com/kernel/2006-q3/msg17360.html
		*
		* It is unclear if the misscompilations mentioned in
		* http://lkml.org/lkml/2010/8/8/138 also affect MIPS so we keep this one
		* until GCC 3.x has been retired before we can apply
		* https://patchwork.linux-mips.org/patch/1541/
		*/

		#define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x), 0))

		#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)