Commit 2a219b0e authored by David Daney's avatar David Daney Committed by Ralf Baechle
Browse files

MIPS: Cavium OCTEON multiplier state preservation. 



For OCTEON, implement a save and restore of the multiplier state
across context switches.

Signed-off-by: default avatarTomaso Paoletti <tpaoletti@caviumnetworks.com>
Signed-off-by: default avatarDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent ddcdb1b4

arch/mips/include/asm/stackframe.h

+17 −0
Original line number Diff line number Diff line
@@ -194,6 +194,19 @@ 
		LONG_S	$31, PT_R31(sp)

		ori	$28, sp, _THREAD_MASK

		xori	$28, _THREAD_MASK

#ifdef CONFIG_CPU_CAVIUM_OCTEON

		.set    mips64

		pref    0, 0($28)       /* Prefetch the current pointer */

		pref    0, PT_R31(sp)   /* Prefetch the $31(ra) */

		/* The Octeon multiplier state is affected by general multiply

		    instructions. It must be saved before and kernel code might

		    corrupt it */

		jal     octeon_mult_save

		LONG_L  v1, 0($28)  /* Load the current pointer */

			 /* Restore $31(ra) that was changed by the jal */

		LONG_L  ra, PT_R31(sp)

		pref    0, 0(v1)    /* Prefetch the current thread */

#endif

		.set	pop

		.endm
@@ -324,6 +337,10 @@ 
		DVPE	5				# dvpe a1

		jal	mips_ihb

#endif /* CONFIG_MIPS_MT_SMTC */

#ifdef CONFIG_CPU_CAVIUM_OCTEON

		/* Restore the Octeon multiplier state */

		jal	octeon_mult_restore

#endif

		mfc0	a0, CP0_STATUS

		ori	a0, STATMASK

		xori	a0, STATMASK

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