microblaze_v8: PVR support, cpuinfo support

Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Acked-by: John Linn <john.linn@xilinx.com>
Acked-by: John Williams <john.williams@petalogix.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/kernel/cpu/pvr.c b/arch/microblaze/kernel/cpu/pvr.c
new file mode 100644
index 0000000..c9a4340
--- /dev/null
+++ b/arch/microblaze/kernel/cpu/pvr.c
@@ -0,0 +1,81 @@
+/*
+ * Support for MicroBlaze PVR (processor version register)
+ *
+ * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2007-2009 PetaLogix
+ * Copyright (C) 2007 John Williams <john.williams@petalogix.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/compiler.h>
+#include <asm/system.h>
+#include <asm/exceptions.h>
+#include <asm/pvr.h>
+
+/*
+ * Until we get an assembler that knows about the pvr registers,
+ * this horrible cruft will have to do.
+ * That hardcoded opcode is mfs r3, rpvrNN
+ */
+
+#define get_single_pvr(pvrid, val)				\
+{								\
+	register unsigned tmp __asm__("r3");			\
+	tmp = 0x0;	/* Prevent warning about unused */	\
+	__asm__ __volatile__ (					\
+			".byte 0x94,0x60,0xa0, " #pvrid "\n\t"	\
+			: "=r" (tmp) : : "memory"); 		\
+	val = tmp;						\
+}
+
+/*
+ * Does the CPU support the PVR register?
+ * return value:
+ * 0: no PVR
+ * 1: simple PVR
+ * 2: full PVR
+ *
+ * This must work on all CPU versions, including those before the
+ * PVR was even an option.
+ */
+
+int cpu_has_pvr(void)
+{
+	unsigned flags;
+	unsigned pvr0;
+
+	local_save_flags(flags);
+
+	/* PVR bit in MSR tells us if there is any support */
+	if (!(flags & PVR_MSR_BIT))
+		return 0;
+
+	get_single_pvr(0x00, pvr0);
+	pr_debug("%s: pvr0 is 0x%08x\n", __func__, pvr0);
+
+	if (pvr0 & PVR0_PVR_FULL_MASK)
+		return 1;
+
+	/* for partial PVR use static cpuinfo */
+	return 2;
+}
+
+void get_pvr(struct pvr_s *p)
+{
+	get_single_pvr(0, p->pvr[0]);
+	get_single_pvr(1, p->pvr[1]);
+	get_single_pvr(2, p->pvr[2]);
+	get_single_pvr(3, p->pvr[3]);
+	get_single_pvr(4, p->pvr[4]);
+	get_single_pvr(5, p->pvr[5]);
+	get_single_pvr(6, p->pvr[6]);
+	get_single_pvr(7, p->pvr[7]);
+	get_single_pvr(8, p->pvr[8]);
+	get_single_pvr(9, p->pvr[9]);
+	get_single_pvr(10, p->pvr[10]);
+	get_single_pvr(11, p->pvr[11]);
+}