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Commit 20bcfe09 authored by Mark Rutland's avatar Mark Rutland Committed by Greg Kroah-Hartman
Browse files

arm64: Move post_ttbr_update_workaround to C code 




From: Marc Zyngier <marc.zyngier@arm.com>

commit 95e3de3590e3f2358bb13f013911bc1bfa5d3f53 upstream.

We will soon need to invoke a CPU-specific function pointer after changing
page tables, so move post_ttbr_update_workaround out into C code to make
this possible.

Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com> [v4.9 backport]
Tested-by: default avatarGreg Hackmann <ghackmann@google.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 965924ee

arch/arm64/include/asm/assembler.h

+0 −13
Original line number Diff line number Diff line
@@ -435,17 +435,4 @@ alternative_endif 
	and	\phys, \pte, #(((1 << (48 - PAGE_SHIFT)) - 1) << PAGE_SHIFT)

	.endm



/*

 * Errata workaround post TTBR0_EL1 update.

 */

	.macro	post_ttbr0_update_workaround

#ifdef CONFIG_CAVIUM_ERRATUM_27456

alternative_if ARM64_WORKAROUND_CAVIUM_27456

	ic	iallu

	dsb	nsh

	isb

alternative_else_nop_endif

#endif

	.endm



#endif	/* __ASM_ASSEMBLER_H */

arch/arm64/mm/context.c

+9 −0
Original line number Diff line number Diff line
@@ -233,6 +233,15 @@ void check_and_switch_context(struct mm_struct *mm, unsigned int cpu) 
	cpu_switch_mm(mm->pgd, mm);

}



/* Errata workaround post TTBRx_EL1 update. */

asmlinkage void post_ttbr_update_workaround(void)

{

	asm(ALTERNATIVE("nop; nop; nop",

			"ic iallu; dsb nsh; isb",

			ARM64_WORKAROUND_CAVIUM_27456,

			CONFIG_CAVIUM_ERRATUM_27456));

}



static int asids_init(void)

{

	asid_bits = get_cpu_asid_bits();

arch/arm64/mm/proc.S

+1 −2
Original line number Diff line number Diff line
@@ -139,8 +139,7 @@ ENTRY(cpu_do_switch_mm) 
	isb

	msr	ttbr0_el1, x0			// now update TTBR0

	isb

	post_ttbr0_update_workaround

	ret

	b	post_ttbr_update_workaround	// Back to C code...

ENDPROC(cpu_do_switch_mm)



	.pushsection ".idmap.text", "awx"