MIPS: Save MSA extended context around signals

It is desirable for signal handlers to be allowed to make use of MSA,
particularly if auto vectorisation is used when compiling a program.
The MSA context must therefore be saved & restored before & after
invoking the signal handler. Make use of the extended context structs
defined in the preceding patch to save MSA context after the sigframe
when appropriate.

[ralf@linux-mips.org: Fixed conflicts.]

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-kernel@vger.kernel.org
Cc: Richard Weinberger <richard@nod.at>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Maciej W. Rozycki <macro@codesourcery.com>
Patchwork: https://patchwork.linux-mips.org/patch/10796/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/r4k_fpu.S

@@ -236,6 +236,124 @@ LEAF(\name)
 	op_msa_wr	write_msa_wr_w, ld_w
 	op_msa_wr	write_msa_wr_d, ld_d
 
+#endif /* CONFIG_CPU_HAS_MSA */
+
+#ifdef CONFIG_CPU_HAS_MSA
+
+	.macro	save_msa_upper	wr, off, base
+	.set	push
+	.set	noat
+#ifdef CONFIG_64BIT
+	copy_u_d \wr, 1
+	EX sd	$1, \off(\base)
+#elif defined(CONFIG_CPU_LITTLE_ENDIAN)
+	copy_u_w \wr, 2
+	EX sw	$1, \off(\base)
+	copy_u_w \wr, 3
+	EX sw	$1, (\off+4)(\base)
+#else /* CONFIG_CPU_BIG_ENDIAN */
+	copy_u_w \wr, 2
+	EX sw	$1, (\off+4)(\base)
+	copy_u_w \wr, 3
+	EX sw	$1, \off(\base)
+#endif
+	.set	pop
+	.endm
+
+LEAF(_save_msa_all_upper)
+	save_msa_upper	0, 0x00, a0
+	save_msa_upper	1, 0x08, a0
+	save_msa_upper	2, 0x10, a0
+	save_msa_upper	3, 0x18, a0
+	save_msa_upper	4, 0x20, a0
+	save_msa_upper	5, 0x28, a0
+	save_msa_upper	6, 0x30, a0
+	save_msa_upper	7, 0x38, a0
+	save_msa_upper	8, 0x40, a0
+	save_msa_upper	9, 0x48, a0
+	save_msa_upper	10, 0x50, a0
+	save_msa_upper	11, 0x58, a0
+	save_msa_upper	12, 0x60, a0
+	save_msa_upper	13, 0x68, a0
+	save_msa_upper	14, 0x70, a0
+	save_msa_upper	15, 0x78, a0
+	save_msa_upper	16, 0x80, a0
+	save_msa_upper	17, 0x88, a0
+	save_msa_upper	18, 0x90, a0
+	save_msa_upper	19, 0x98, a0
+	save_msa_upper	20, 0xa0, a0
+	save_msa_upper	21, 0xa8, a0
+	save_msa_upper	22, 0xb0, a0
+	save_msa_upper	23, 0xb8, a0
+	save_msa_upper	24, 0xc0, a0
+	save_msa_upper	25, 0xc8, a0
+	save_msa_upper	26, 0xd0, a0
+	save_msa_upper	27, 0xd8, a0
+	save_msa_upper	28, 0xe0, a0
+	save_msa_upper	29, 0xe8, a0
+	save_msa_upper	30, 0xf0, a0
+	save_msa_upper	31, 0xf8, a0
+	jr	ra
+	 li	v0, 0
+	END(_save_msa_all_upper)
+
+	.macro	restore_msa_upper	wr, off, base
+	.set	push
+	.set	noat
+#ifdef CONFIG_64BIT
+	EX ld	$1, \off(\base)
+	insert_d \wr, 1
+#elif defined(CONFIG_CPU_LITTLE_ENDIAN)
+	EX lw	$1, \off(\base)
+	insert_w \wr, 2
+	EX lw	$1, (\off+4)(\base)
+	insert_w \wr, 3
+#else /* CONFIG_CPU_BIG_ENDIAN */
+	EX lw	$1, (\off+4)(\base)
+	insert_w \wr, 2
+	EX lw	$1, \off(\base)
+	insert_w \wr, 3
+#endif
+	.set	pop
+	.endm
+
+LEAF(_restore_msa_all_upper)
+	restore_msa_upper	0, 0x00, a0
+	restore_msa_upper	1, 0x08, a0
+	restore_msa_upper	2, 0x10, a0
+	restore_msa_upper	3, 0x18, a0
+	restore_msa_upper	4, 0x20, a0
+	restore_msa_upper	5, 0x28, a0
+	restore_msa_upper	6, 0x30, a0
+	restore_msa_upper	7, 0x38, a0
+	restore_msa_upper	8, 0x40, a0
+	restore_msa_upper	9, 0x48, a0
+	restore_msa_upper	10, 0x50, a0
+	restore_msa_upper	11, 0x58, a0
+	restore_msa_upper	12, 0x60, a0
+	restore_msa_upper	13, 0x68, a0
+	restore_msa_upper	14, 0x70, a0
+	restore_msa_upper	15, 0x78, a0
+	restore_msa_upper	16, 0x80, a0
+	restore_msa_upper	17, 0x88, a0
+	restore_msa_upper	18, 0x90, a0
+	restore_msa_upper	19, 0x98, a0
+	restore_msa_upper	20, 0xa0, a0
+	restore_msa_upper	21, 0xa8, a0
+	restore_msa_upper	22, 0xb0, a0
+	restore_msa_upper	23, 0xb8, a0
+	restore_msa_upper	24, 0xc0, a0
+	restore_msa_upper	25, 0xc8, a0
+	restore_msa_upper	26, 0xd0, a0
+	restore_msa_upper	27, 0xd8, a0
+	restore_msa_upper	28, 0xe0, a0
+	restore_msa_upper	29, 0xe8, a0
+	restore_msa_upper	30, 0xf0, a0
+	restore_msa_upper	31, 0xf8, a0
+	jr	ra
+	 li	v0, 0
+	END(_restore_msa_all_upper)
+
 #endif /* CONFIG_CPU_HAS_MSA */
 
 	.set	reorder

arch/mips/kernel/signal-common.h

@@ -37,4 +37,7 @@ _save_fp_context(void __user *fpregs, void __user *csr);
 extern asmlinkage int
 _restore_fp_context(void __user *fpregs, void __user *csr);
 
+extern asmlinkage int _save_msa_all_upper(void __user *buf);
+extern asmlinkage int _restore_msa_all_upper(void __user *buf);
+
 #endif	/* __SIGNAL_COMMON_H */