sparc64: Hibernation support

This patch adds CONFIG_HIBERNATION support for sparc64
architecture. The suspend function is the same as on another
platforms. The restore function uses Bypass feature of MMU
which allows to make the process more comfortable and plesant.

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
CC: David Miller <davem@davemloft.net>
CC: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/power/hibernate_asm.S

@@ -0,0 +1,131 @@
+/*
+ * hibernate_asm.S:  Hibernaton support specific for sparc64.
+ *
+ * Copyright (C) 2013 Kirill V Tkhai (tkhai@yandex.ru)
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/asm-offsets.h>
+#include <asm/cpudata.h>
+#include <asm/page.h>
+
+ENTRY(swsusp_arch_suspend)
+	save	%sp, -128, %sp
+	save	%sp, -128, %sp
+	flushw
+
+	setuw	saved_context, %g3
+
+	/* Save window regs */
+	rdpr	%cwp, %g2
+	stx	%g2, [%g3 + SC_REG_CWP]
+	rdpr	%wstate, %g2
+	stx	%g2, [%g3 + SC_REG_WSTATE]
+	stx	%fp, [%g3 + SC_REG_FP]
+
+	/* Save state regs */
+	rdpr	%tick, %g2
+	stx	%g2, [%g3 + SC_REG_TICK]
+	rdpr	%pstate, %g2
+	stx	%g2, [%g3 + SC_REG_PSTATE]
+
+	/* Save global regs */
+	stx	%g4, [%g3 + SC_REG_G4]
+	stx	%g5, [%g3 + SC_REG_G5]
+	stx	%g6, [%g3 + SC_REG_G6]
+
+	call	swsusp_save
+	 nop
+
+	mov	%o0, %i0
+	restore
+
+	mov	%o0, %i0
+	ret
+	 restore
+
+ENTRY(swsusp_arch_resume)
+	/* Write restore_pblist to %l0 */
+	sethi	%hi(restore_pblist), %l0
+	ldx	[%l0 + %lo(restore_pblist)], %l0
+
+	call	__flush_tlb_all
+	 nop
+
+	/* Write PAGE_OFFSET to %g7 */
+	sethi	%uhi(PAGE_OFFSET), %g7
+	sllx	%g7, 32, %g7
+
+	setuw	(PAGE_SIZE-8), %g3
+
+	/* Use MMU Bypass */
+	rd	%asi, %g1
+	wr	%g0, ASI_PHYS_USE_EC, %asi
+
+	ba	fill_itlb
+	 nop
+
+pbe_loop:
+	cmp	%l0, %g0
+	be	restore_ctx
+	 sub	%l0, %g7, %l0
+
+	ldxa	[%l0    ] %asi, %l1 /* address */
+	ldxa	[%l0 + 8] %asi, %l2 /* orig_address */
+
+	/* phys addr */
+	sub	%l1, %g7, %l1
+	sub	%l2, %g7, %l2
+
+	mov	%g3, %l3 /* PAGE_SIZE-8 */
+copy_loop:
+	ldxa	[%l1 + %l3] ASI_PHYS_USE_EC, %g2
+	stxa	%g2, [%l2 + %l3] ASI_PHYS_USE_EC
+	cmp	%l3, %g0
+	bne	copy_loop
+	 sub	%l3, 8, %l3
+
+	/* next pbe */
+	ba	pbe_loop
+	 ldxa	[%l0 + 16] %asi, %l0
+
+restore_ctx:
+	setuw	saved_context, %g3
+
+	/* Restore window regs */
+	wrpr    %g0, 0, %canrestore
+	wrpr    %g0, 0, %otherwin
+	wrpr	%g0, 6, %cansave
+	wrpr    %g0, 0, %cleanwin
+
+	ldxa	[%g3 + SC_REG_CWP] %asi, %g2
+	wrpr	%g2, %cwp
+	ldxa	[%g3 + SC_REG_WSTATE] %asi, %g2
+	wrpr	%g2, %wstate
+	ldxa	[%g3 + SC_REG_FP] %asi, %fp
+
+	/* Restore state regs */
+	ldxa	[%g3 + SC_REG_PSTATE] %asi, %g2
+	wrpr	%g2, %pstate
+	ldxa	[%g3 + SC_REG_TICK] %asi, %g2
+	wrpr	%g2, %tick
+
+	/* Restore global regs */
+	ldxa	[%g3 + SC_REG_G4] %asi, %g4
+	ldxa	[%g3 + SC_REG_G5] %asi, %g5
+	ldxa	[%g3 + SC_REG_G6] %asi, %g6
+
+	wr	%g1, %g0, %asi
+
+	restore
+	restore
+
+	wrpr	%g0, 14, %pil
+
+	retl
+	 mov	%g0, %o0
+
+fill_itlb:
+	ba	pbe_loop
+	 wrpr	%g0, 15, %pil