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>

3 files changed, 176 insertions, 0 deletions

diff --git a/arch/sparc/power/Makefile b/arch/sparc/power/Makefile
new file mode 100644
index 000000000000..3201ace0ddbd
--- /dev/null
+++ b/arch/sparc/power/Makefile
@@ -0,0 +1,3 @@
+# Makefile for Sparc-specific hibernate files.
+
+obj-$(CONFIG_HIBERNATION)       += hibernate.o hibernate_asm.o
diff --git a/arch/sparc/power/hibernate.c b/arch/sparc/power/hibernate.c
new file mode 100644
index 000000000000..42b0b8ce699a
--- /dev/null
+++ b/arch/sparc/power/hibernate.c
@@ -0,0 +1,42 @@
+/*
+ * hibernate.c:  Hibernaton support specific for sparc64.
+ *
+ * Copyright (C) 2013 Kirill V Tkhai (tkhai@yandex.ru)
+ */
+
+#include <linux/mm.h>
+
+#include <asm/hibernate.h>
+#include <asm/visasm.h>
+#include <asm/page.h>
+#include <asm/tlb.h>
+
+/* References to section boundaries */
+extern const void __nosave_begin, __nosave_end;
+
+struct saved_context saved_context;
+
+/*
+ *      pfn_is_nosave - check if given pfn is in the 'nosave' section
+ */
+
+int pfn_is_nosave(unsigned long pfn)
+{
+        unsigned long nosave_begin_pfn = PFN_DOWN((unsigned long)&__nosave_begin);
+        unsigned long nosave_end_pfn = PFN_DOWN((unsigned long)&__nosave_end);
+
+        return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
+}
+
+void save_processor_state(void)
+{
+        save_and_clear_fpu();
+}
+
+void restore_processor_state(void)
+{
+        struct mm_struct *mm = current->active_mm;
+
+        load_secondary_context(mm);
+        tsb_context_switch(mm);
+}
diff --git a/arch/sparc/power/hibernate_asm.S b/arch/sparc/power/hibernate_asm.S
new file mode 100644
index 000000000000..79942166df84
--- /dev/null
+++ b/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