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/Kconfig

@@ -59,6 +59,19 @@ config HW_RANDOM_GEODE
 
 	  If unsure, say Y.
 
+config HW_RANDOM_N2RNG
+	tristate "Niagara2 Random Number Generator support"
+	depends on HW_RANDOM && SPARC64
+	default HW_RANDOM
+	---help---
+	  This driver provides kernel-side support for the Random Number
+	  Generator hardware found on Niagara2 cpus.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called n2-rng.
+
+	  If unsure, say Y.
+
 config HW_RANDOM_VIA
 	tristate "VIA HW Random Number Generator support"
 	depends on HW_RANDOM && X86_32

drivers/char/hw_random/Makefile

@@ -7,6 +7,8 @@ rng-core-y := core.o
 obj-$(CONFIG_HW_RANDOM_INTEL) += intel-rng.o
 obj-$(CONFIG_HW_RANDOM_AMD) += amd-rng.o
 obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o
+obj-$(CONFIG_HW_RANDOM_N2RNG) += n2-rng.o
+n2-rng-y := n2-drv.o n2-asm.o
 obj-$(CONFIG_HW_RANDOM_VIA) += via-rng.o
 obj-$(CONFIG_HW_RANDOM_IXP4XX) += ixp4xx-rng.o
 obj-$(CONFIG_HW_RANDOM_OMAP) += omap-rng.o

drivers/char/hw_random/n2-asm.S

+/* 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)

drivers/char/hw_random/n2rng.h

+/* n2rng.h: Niagara2 RNG defines.
+ *
+ * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
+ */
+
+#ifndef _N2RNG_H
+#define _N2RNG_H
+
+#define RNG_CTL_WAIT       0x0000000001fffe00ULL /* Minimum wait time       */
+#define RNG_CTL_WAIT_SHIFT 9
+#define RNG_CTL_BYPASS     0x0000000000000100ULL /* VCO voltage source      */
+#define RNG_CTL_VCO        0x00000000000000c0ULL /* VCO rate control        */
+#define RNG_CTL_VCO_SHIFT  6
+#define RNG_CTL_ASEL       0x0000000000000030ULL /* Analog MUX select       */
+#define RNG_CTL_ASEL_SHIFT 4
+#define RNG_CTL_LFSR       0x0000000000000008ULL /* Use LFSR or plain shift */
+#define RNG_CTL_ES3        0x0000000000000004ULL /* Enable entropy source 3 */
+#define RNG_CTL_ES2        0x0000000000000002ULL /* Enable entropy source 2 */
+#define RNG_CTL_ES1        0x0000000000000001ULL /* Enable entropy source 1 */
+
+#define HV_FAST_RNG_GET_DIAG_CTL	0x130
+#define HV_FAST_RNG_CTL_READ		0x131
+#define HV_FAST_RNG_CTL_WRITE		0x132
+#define HV_FAST_RNG_DATA_READ_DIAG	0x133
+#define HV_FAST_RNG_DATA_READ		0x134
+
+#define HV_RNG_STATE_UNCONFIGURED	0
+#define HV_RNG_STATE_CONFIGURED		1
+#define HV_RNG_STATE_HEALTHCHECK	2
+#define HV_RNG_STATE_ERROR		3
+
+#define HV_RNG_NUM_CONTROL		4
+
+#ifndef __ASSEMBLY__
+extern unsigned long sun4v_rng_get_diag_ctl(void);
+extern unsigned long sun4v_rng_ctl_read_v1(unsigned long ctl_regs_ra,
+					   unsigned long *state,
+					   unsigned long *tick_delta);
+extern unsigned long sun4v_rng_ctl_read_v2(unsigned long ctl_regs_ra,
+					   unsigned long unit,
+					   unsigned long *state,
+					   unsigned long *tick_delta,
+					   unsigned long *watchdog,
+					   unsigned long *write_status);
+extern unsigned long sun4v_rng_ctl_write_v1(unsigned long ctl_regs_ra,
+					    unsigned long state,
+					    unsigned long write_timeout,
+					    unsigned long *tick_delta);
+extern unsigned long sun4v_rng_ctl_write_v2(unsigned long ctl_regs_ra,
+					    unsigned long state,
+					    unsigned long write_timeout,
+					    unsigned long unit);
+extern unsigned long sun4v_rng_data_read_diag_v1(unsigned long data_ra,
+						 unsigned long len,
+						 unsigned long *tick_delta);
+extern unsigned long sun4v_rng_data_read_diag_v2(unsigned long data_ra,
+						 unsigned long len,
+						 unsigned long unit,
+						 unsigned long *tick_delta);
+extern unsigned long sun4v_rng_data_read(unsigned long data_ra,
+					 unsigned long *tick_delta);
+
+struct n2rng_unit {
+	u64			control[HV_RNG_NUM_CONTROL];
+};
+
+struct n2rng {
+	struct of_device	*op;
+
+	unsigned long		flags;
+#define N2RNG_FLAG_VF		0x00000001 /* Victoria Falls RNG, else N2 */
+#define N2RNG_FLAG_CONTROL	0x00000002 /* Operating in control domain */
+#define N2RNG_FLAG_READY	0x00000008 /* Ready for hw-rng layer      */
+#define N2RNG_FLAG_SHUTDOWN	0x00000010 /* Driver unregistering        */
+#define N2RNG_FLAG_BUFFER_VALID	0x00000020 /* u32 buffer holds valid data */
+
+	int			num_units;
+	struct n2rng_unit	*units;
+
+	struct hwrng		hwrng;
+	u32			buffer;
+
+	/* Registered hypervisor group API major and minor version.  */
+	unsigned long		hvapi_major;
+	unsigned long		hvapi_minor;
+
+	struct delayed_work	work;
+
+	unsigned long		hv_state; /* HV_RNG_STATE_foo */
+
+	unsigned long		health_check_sec;
+	unsigned long		accum_cycles;
+	unsigned long		wd_timeo;
+#define N2RNG_HEALTH_CHECK_SEC_DEFAULT	0
+#define N2RNG_ACCUM_CYCLES_DEFAULT	2048
+#define N2RNG_WD_TIMEO_DEFAULT		0
+
+	u64			scratch_control[HV_RNG_NUM_CONTROL];
+
+#define SELFTEST_TICKS		38859
+#define SELFTEST_VAL		((u64)0xB8820C7BD387E32C)
+#define SELFTEST_POLY		((u64)0x231DCEE91262B8A3)
+#define SELFTEST_MATCH_GOAL	6
+#define SELFTEST_LOOPS_MAX	40000
+#define SELFTEST_BUFFER_WORDS	8
+
+	u64			test_data;
+	u64			test_control[HV_RNG_NUM_CONTROL];
+	u64			test_buffer[SELFTEST_BUFFER_WORDS];
+};
+
+#define N2RNG_BLOCK_LIMIT	60000
+#define N2RNG_BUSY_LIMIT	100
+#define N2RNG_HCHECK_LIMIT	100
+
+#endif /* !(__ASSEMBLY__) */
+
+#endif /* _N2RNG_H */