ARM: head.S: use PC relative insn sequence to calculate PHYS_OFFSET (3bcf906b) · Commits · 戴 / test

Replace the open coded arithmetic with a simple adr_l/sub pair. This removes some open coded arithmetic involving virtual addresses, avoids literal pools on v7+, and slightly reduces the footprint of the code. Reviewed-by:

Nicolas Pitre <nico@fluxnic.net> Signed-off-by:

Ard Biesheuvel <ardb@kernel.org>

arch/arm/kernel/head.S

+2 −8

Original line number	Diff line number	Diff line
		@@ -103,10 +103,8 @@ ENTRY(stext)
		#endif

		#ifndef CONFIG_XIP_KERNEL
		adr r3, 2f
		ldmia r3, {r4, r8}
		sub r4, r3, r4 @ (PHYS_OFFSET - PAGE_OFFSET)
		add r8, r8, r4 @ PHYS_OFFSET
		adr_l r8, _text @ __pa(_text)
		sub r8, r8, #TEXT_OFFSET @ PHYS_OFFSET
		#else
		ldr r8, =PLAT_PHYS_OFFSET @ always constant in this case
		#endif
		@@ -158,10 +156,6 @@ ENTRY(stext)
		1: b __enable_mmu
		ENDPROC(stext)
		.ltorg
		#ifndef CONFIG_XIP_KERNEL
		2: .long .
		.long PAGE_OFFSET
		#endif

		/*
		* Setup the initial page tables. We only setup the barest

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