Commit 733536b8 authored by Max Filippov's avatar Max Filippov Committed by Chris Zankel
Browse files

xtensa: save and restore scompare1 SR on kernel entry 



Although scompare1 may be saved/restored by xchal_ncp_{load,store}
macros, explicit save/restore of registers manipulated by the kernel
itself is considered more correct.

Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: default avatarChris Zankel <chris@zankel.net>
parent 2f6ea6a7

arch/xtensa/include/asm/ptrace.h

+1 −1
Original line number Diff line number Diff line
@@ -37,7 +37,7 @@ struct pt_regs { 
	unsigned long windowstart;	/*  52 */

	unsigned long syscall;		/*  56 */

	unsigned long icountlevel;	/*  60 */

	int reserved[1];		/*  64 */

	unsigned long scompare1;	/*  64 */



	/* Additional configurable registers that are used by the compiler. */

	xtregs_opt_t xtregs_opt;

arch/xtensa/kernel/asm-offsets.c

+1 −0
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ int main(void) 
	DEFINE(PT_SAR, offsetof (struct pt_regs, sar));

	DEFINE(PT_ICOUNTLEVEL, offsetof (struct pt_regs, icountlevel));

	DEFINE(PT_SYSCALL, offsetof (struct pt_regs, syscall));

	DEFINE(PT_SCOMPARE1, offsetof(struct pt_regs, scompare1));

	DEFINE(PT_AREG, offsetof (struct pt_regs, areg[0]));

	DEFINE(PT_AREG0, offsetof (struct pt_regs, areg[0]));

	DEFINE(PT_AREG1, offsetof (struct pt_regs, areg[1]));

arch/xtensa/kernel/entry.S

+13 −0
Original line number Diff line number Diff line
@@ -372,6 +372,13 @@ common_exception: 
	s32i	a2, a1, PT_LBEG

	s32i	a3, a1, PT_LEND



	/* Save SCOMPARE1 */



#if XCHAL_HAVE_S32C1I

	rsr     a2, scompare1

	s32i    a2, a1, PT_SCOMPARE1

#endif



	/* Save optional registers. */



	save_xtregs_opt a1 a2 a4 a5 a6 a7 PT_XTREGS_OPT
@@ -433,6 +440,12 @@ common_exception_return: 


	load_xtregs_opt a1 a2 a4 a5 a6 a7 PT_XTREGS_OPT



	/* Restore SCOMPARE1 */



#if XCHAL_HAVE_S32C1I

	l32i    a2, a1, PT_SCOMPARE1

	wsr     a2, scompare1

#endif

	wsr	a3, ps		/* disable interrupts */



	_bbci.l	a3, PS_UM_BIT, kernel_exception_exit

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