sparc64: Add Niagara2 RNG driver.

With feedback and suggestions from Sam Ravnborg.

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/char/hw_random/n2-asm.S

@@ -0,0 +1,79 @@
+/* n2-asm.S: Niagara2 RNG hypervisor call assembler.
+ *
+ * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
+ */
+#include <linux/linkage.h>
+#include <asm/hypervisor.h>
+#include "n2rng.h"
+
+	.text
+
+ENTRY(sun4v_rng_get_diag_ctl)
+	mov	HV_FAST_RNG_GET_DIAG_CTL, %o5
+	ta	HV_FAST_TRAP
+	retl
+	 nop
+ENDPROC(sun4v_rng_get_diag_ctl)
+
+ENTRY(sun4v_rng_ctl_read_v1)
+	mov	%o1, %o3
+	mov	%o2, %o4
+	mov	HV_FAST_RNG_CTL_READ, %o5
+	ta	HV_FAST_TRAP
+	stx	%o1, [%o3]
+	retl
+	 stx	%o2, [%o4]
+ENDPROC(sun4v_rng_ctl_read_v1)
+
+ENTRY(sun4v_rng_ctl_read_v2)
+	save	%sp, -192, %sp
+	mov	%i0, %o0
+	mov	%i1, %o1
+	mov	HV_FAST_RNG_CTL_READ, %o5
+	ta	HV_FAST_TRAP
+	stx	%o1, [%i2]
+	stx	%o2, [%i3]
+	stx	%o3, [%i4]
+	stx	%o4, [%i5]
+	ret
+	restore	%g0, %o0, %o0
+ENDPROC(sun4v_rng_ctl_read_v2)
+
+ENTRY(sun4v_rng_ctl_write_v1)
+	mov	%o3, %o4
+	mov	HV_FAST_RNG_CTL_WRITE, %o5
+	ta	HV_FAST_TRAP
+	retl
+	 stx	%o1, [%o4]
+ENDPROC(sun4v_rng_ctl_write_v1)
+
+ENTRY(sun4v_rng_ctl_write_v2)
+	mov	HV_FAST_RNG_CTL_WRITE, %o5
+	ta	HV_FAST_TRAP
+	retl
+	 nop
+ENDPROC(sun4v_rng_ctl_write_v2)
+
+ENTRY(sun4v_rng_data_read_diag_v1)
+	mov	%o2, %o4
+	mov	HV_FAST_RNG_DATA_READ_DIAG, %o5
+	ta	HV_FAST_TRAP
+	retl
+	 stx	%o1, [%o4]
+ENDPROC(sun4v_rng_data_read_diag_v1)
+
+ENTRY(sun4v_rng_data_read_diag_v2)
+	mov	%o3, %o4
+	mov	HV_FAST_RNG_DATA_READ_DIAG, %o5
+	ta	HV_FAST_TRAP
+	retl
+	 stx	%o1, [%o4]
+ENDPROC(sun4v_rng_data_read_diag_v2)
+
+ENTRY(sun4v_rng_data_read)
+	mov	%o1, %o4
+	mov	HV_FAST_RNG_DATA_READ, %o5
+	ta	HV_FAST_TRAP
+	retl
+	 stx	%o1, [%o4]
+ENDPROC(sun4v_rng_data_read)