/* $Id: p1275.c,v 1.20 1999/11/23 23:47:56 davem Exp $
 * p1275.c: Sun IEEE 1275 PROM low level interface routines
 *
 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/string.h>
#include <linux/spinlock.h>

#include <asm/openprom.h>
#include <asm/oplib.h>
#include <asm/system.h>
#include <asm/spitfire.h>
#include <asm/pstate.h>

struct {
	long prom_callback;			/* 0x00 */
	void (*prom_cif_handler)(long *);	/* 0x08 */
	unsigned long prom_cif_stack;		/* 0x10 */
	unsigned long prom_args [23];		/* 0x18 */
	char prom_buffer [3000];
} p1275buf;

extern void prom_world(int);

void prom_cif_interface (void)
{
	__asm__ __volatile__ ("
	mov	%0, %%o0
	ldx	[%%o0 + 0x010], %%o1	! prom_cif_stack
	save	%%o1, -0x190, %%sp
	ldx	[%%i0 + 0x008], %%l2	! prom_cif_handler
	rdpr	%%pstate, %%l4
	wrpr	%%g0, 0x15, %%pstate	! save alternate globals
	stx	%%g1, [%%sp + 2047 + 0x0b0]
	stx	%%g2, [%%sp + 2047 + 0x0b8]
	stx	%%g3, [%%sp + 2047 + 0x0c0]
	stx	%%g4, [%%sp + 2047 + 0x0c8]
	stx	%%g5, [%%sp + 2047 + 0x0d0]
	stx	%%g6, [%%sp + 2047 + 0x0d8]
	stx	%%g7, [%%sp + 2047 + 0x0e0]
	wrpr	%%g0, 0x814, %%pstate	! save interrupt globals
	stx	%%g1, [%%sp + 2047 + 0x0e8]
	stx	%%g2, [%%sp + 2047 + 0x0f0]
	stx	%%g3, [%%sp + 2047 + 0x0f8]
	stx	%%g4, [%%sp + 2047 + 0x100]
	stx	%%g5, [%%sp + 2047 + 0x108]
	stx	%%g6, [%%sp + 2047 + 0x110]
	stx	%%g7, [%%sp + 2047 + 0x118]
	wrpr	%%g0, 0x14, %%pstate	! save normal globals
	stx	%%g1, [%%sp + 2047 + 0x120]
	stx	%%g2, [%%sp + 2047 + 0x128]
	stx	%%g3, [%%sp + 2047 + 0x130]
	stx	%%g4, [%%sp + 2047 + 0x138]
	stx	%%g5, [%%sp + 2047 + 0x140]
	stx	%%g6, [%%sp + 2047 + 0x148]
	stx	%%g7, [%%sp + 2047 + 0x150]
	wrpr	%%g0, 0x414, %%pstate	! save mmu globals
	stx	%%g1, [%%sp + 2047 + 0x158]
	stx	%%g2, [%%sp + 2047 + 0x160]
	stx	%%g3, [%%sp + 2047 + 0x168]
	stx	%%g4, [%%sp + 2047 + 0x170]
	stx	%%g5, [%%sp + 2047 + 0x178]
	stx	%%g6, [%%sp + 2047 + 0x180]
	stx	%%g7, [%%sp + 2047 + 0x188]
	mov	%%g1, %%l0		! also save to locals, so we can handle
	mov	%%g2, %%l1		! tlb faults later on, when accessing
	mov	%%g3, %%l3		! the stack.
	mov	%%g7, %%l5
	wrpr	%%l4, %1, %%pstate	! turn off interrupts
	call	%%l2
	 add	%%i0, 0x018, %%o0	! prom_args
	wrpr	%%g0, 0x414, %%pstate	! restore mmu globals
	mov	%%l0, %%g1
	mov	%%l1, %%g2
	mov	%%l3, %%g3
	mov	%%l5, %%g7
	wrpr	%%g0, 0x14, %%pstate	! restore normal globals
	ldx	[%%sp + 2047 + 0x120], %%g1
	ldx	[%%sp + 2047 + 0x128], %%g2
	ldx	[%%sp + 2047 + 0x130], %%g3
	ldx	[%%sp + 2047 + 0x138], %%g4
	ldx	[%%sp + 2047 + 0x140], %%g5
	ldx	[%%sp + 2047 + 0x148], %%g6
	ldx	[%%sp + 2047 + 0x150], %%g7
	wrpr	%%g0, 0x814, %%pstate	! restore interrupt globals
	ldx	[%%sp + 2047 + 0x0e8], %%g1
	ldx	[%%sp + 2047 + 0x0f0], %%g2
	ldx	[%%sp + 2047 + 0x0f8], %%g3
	ldx	[%%sp + 2047 + 0x100], %%g4
	ldx	[%%sp + 2047 + 0x108], %%g5
	ldx	[%%sp + 2047 + 0x110], %%g6
	ldx	[%%sp + 2047 + 0x118], %%g7
	wrpr	%%g0, 0x15, %%pstate	! restore alternate globals
	ldx	[%%sp + 2047 + 0x0b0], %%g1
	ldx	[%%sp + 2047 + 0x0b8], %%g2
	ldx	[%%sp + 2047 + 0x0c0], %%g3
	ldx	[%%sp + 2047 + 0x0c8], %%g4
	ldx	[%%sp + 2047 + 0x0d0], %%g5
	ldx	[%%sp + 2047 + 0x0d8], %%g6
	ldx	[%%sp + 2047 + 0x0e0], %%g7
	wrpr	%%l4, 0, %%pstate	! restore original pstate
	ret
	 restore
	" : : "r" (&p1275buf), "i" (PSTATE_IE));
}

void prom_cif_callback(void)
{
	__asm__ __volatile__ ("
	mov	%0, %%o1
	save	%%sp, -0x270, %%sp
	rdpr	%%pstate, %%l4
	wrpr	%%g0, 0x15, %%pstate	! save PROM alternate globals
	stx	%%g1, [%%sp + 2047 + 0x0b0]
	stx	%%g2, [%%sp + 2047 + 0x0b8]
	stx	%%g3, [%%sp + 2047 + 0x0c0]
	stx	%%g4, [%%sp + 2047 + 0x0c8]
	stx	%%g5, [%%sp + 2047 + 0x0d0]
	stx	%%g6, [%%sp + 2047 + 0x0d8]
	stx	%%g7, [%%sp + 2047 + 0x0e0]
					! restore Linux alternate globals
	ldx	[%%sp + 2047 + 0x190], %%g1
	ldx	[%%sp + 2047 + 0x198], %%g2
	ldx	[%%sp + 2047 + 0x1a0], %%g3
	ldx	[%%sp + 2047 + 0x1a8], %%g4
	ldx	[%%sp + 2047 + 0x1b0], %%g5
	ldx	[%%sp + 2047 + 0x1b8], %%g6
	ldx	[%%sp + 2047 + 0x1c0], %%g7
	wrpr	%%g0, 0x814, %%pstate	! save PROM interrupt globals
	stx	%%g1, [%%sp + 2047 + 0x0e8]
	stx	%%g2, [%%sp + 2047 + 0x0f0]
	stx	%%g3, [%%sp + 2047 + 0x0f8]
	stx	%%g4, [%%sp + 2047 + 0x100]
	stx	%%g5, [%%sp + 2047 + 0x108]
	stx	%%g6, [%%sp + 2047 + 0x110]
	stx	%%g7, [%%sp + 2047 + 0x118]
					! restore Linux interrupt globals
	ldx	[%%sp + 2047 + 0x1c8], %%g1
	ldx	[%%sp + 2047 + 0x1d0], %%g2
	ldx	[%%sp + 2047 + 0x1d8], %%g3
	ldx	[%%sp + 2047 + 0x1e0], %%g4
	ldx	[%%sp + 2047 + 0x1e8], %%g5
	ldx	[%%sp + 2047 + 0x1f0], %%g6
	ldx	[%%sp + 2047 + 0x1f8], %%g7
	wrpr	%%g0, 0x14, %%pstate	! save PROM normal globals
	stx	%%g1, [%%sp + 2047 + 0x120]
	stx	%%g2, [%%sp + 2047 + 0x128]
	stx	%%g3, [%%sp + 2047 + 0x130]
	stx	%%g4, [%%sp + 2047 + 0x138]
	stx	%%g5, [%%sp + 2047 + 0x140]
	stx	%%g6, [%%sp + 2047 + 0x148]
	stx	%%g7, [%%sp + 2047 + 0x150]
					! restore Linux normal globals
	ldx	[%%sp + 2047 + 0x200], %%g1
	ldx	[%%sp + 2047 + 0x208], %%g2
	ldx	[%%sp + 2047 + 0x210], %%g3
	ldx	[%%sp + 2047 + 0x218], %%g4
	ldx	[%%sp + 2047 + 0x220], %%g5
	ldx	[%%sp + 2047 + 0x228], %%g6
	ldx	[%%sp + 2047 + 0x230], %%g7
	wrpr	%%g0, 0x414, %%pstate	! save PROM mmu globals
	stx	%%g1, [%%sp + 2047 + 0x158]
	stx	%%g2, [%%sp + 2047 + 0x160]
	stx	%%g3, [%%sp + 2047 + 0x168]
	stx	%%g4, [%%sp + 2047 + 0x170]
	stx	%%g5, [%%sp + 2047 + 0x178]
	stx	%%g6, [%%sp + 2047 + 0x180]
	stx	%%g7, [%%sp + 2047 + 0x188]
					! restore Linux mmu globals
	ldx	[%%sp + 2047 + 0x238], %%o0
	ldx	[%%sp + 2047 + 0x240], %%o1
	ldx	[%%sp + 2047 + 0x248], %%l2
	ldx	[%%sp + 2047 + 0x250], %%l3
	ldx	[%%sp + 2047 + 0x258], %%l5
	ldx	[%%sp + 2047 + 0x260], %%l6
	ldx	[%%sp + 2047 + 0x268], %%l7
					! switch to Linux tba
	sethi	%%hi(sparc64_ttable_tl0), %%l1
	rdpr	%%tba, %%l0		! save PROM tba
	mov	%%o0, %%g1
	mov	%%o1, %%g2
	mov	%%l2, %%g3
	mov	%%l3, %%g4
	mov	%%l5, %%g5
	mov	%%l6, %%g6
	mov	%%l7, %%g7
	wrpr	%%l1, %%tba		! install Linux tba
	wrpr	%%l4, 0, %%pstate	! restore PSTATE
	call	prom_world
	 mov	%%g0, %%o0
	ldx	[%%i1 + 0x000], %%l2
	call	%%l2
	 mov	%%i0, %%o0
	mov	%%o0, %%l1
	call	prom_world
	 or	%%g0, 1, %%o0
	wrpr	%%g0, 0x14, %%pstate	! interrupts off
					! restore PROM mmu globals
	ldx	[%%sp + 2047 + 0x158], %%o0
	ldx	[%%sp + 2047 + 0x160], %%o1
	ldx	[%%sp + 2047 + 0x168], %%l2
	ldx	[%%sp + 2047 + 0x170], %%l3
	ldx	[%%sp + 2047 + 0x178], %%l5
	ldx	[%%sp + 2047 + 0x180], %%l6
	ldx	[%%sp + 2047 + 0x188], %%l7
	wrpr	%%g0, 0x414, %%pstate	! restore PROM mmu globals
	mov	%%o0, %%g1
	mov	%%o1, %%g2
	mov	%%l2, %%g3
	mov	%%l3, %%g4
	mov	%%l5, %%g5
	mov	%%l6, %%g6
	mov	%%l7, %%g7
	wrpr	%%l0, %%tba		! restore PROM tba
	wrpr	%%g0, 0x14, %%pstate	! restore PROM normal globals
	ldx	[%%sp + 2047 + 0x120], %%g1
	ldx	[%%sp + 2047 + 0x128], %%g2
	ldx	[%%sp + 2047 + 0x130], %%g3
	ldx	[%%sp + 2047 + 0x138], %%g4
	ldx	[%%sp + 2047 + 0x140], %%g5
	ldx	[%%sp + 2047 + 0x148], %%g6
	ldx	[%%sp + 2047 + 0x150], %%g7
	wrpr	%%g0, 0x814, %%pstate	! restore PROM interrupt globals
	ldx	[%%sp + 2047 + 0x0e8], %%g1
	ldx	[%%sp + 2047 + 0x0f0], %%g2
	ldx	[%%sp + 2047 + 0x0f8], %%g3
	ldx	[%%sp + 2047 + 0x100], %%g4
	ldx	[%%sp + 2047 + 0x108], %%g5
	ldx	[%%sp + 2047 + 0x110], %%g6
	ldx	[%%sp + 2047 + 0x118], %%g7
	wrpr	%%g0, 0x15, %%pstate	! restore PROM alternate globals
	ldx	[%%sp + 2047 + 0x0b0], %%g1
	ldx	[%%sp + 2047 + 0x0b8], %%g2
	ldx	[%%sp + 2047 + 0x0c0], %%g3
	ldx	[%%sp + 2047 + 0x0c8], %%g4
	ldx	[%%sp + 2047 + 0x0d0], %%g5
	ldx	[%%sp + 2047 + 0x0d8], %%g6
	ldx	[%%sp + 2047 + 0x0e0], %%g7
	wrpr	%%l4, 0, %%pstate
	ret
	 restore %%l1, 0, %%o0
	" : : "r" (&p1275buf), "i" (PSTATE_PRIV));
}

/* We need some SMP protection here.  But be careful as
 * prom callback code can call into here too, this is why
 * the counter is needed.  -DaveM
 */
static int prom_entry_depth = 0;
spinlock_t prom_entry_lock = SPIN_LOCK_UNLOCKED;

static __inline__ unsigned long prom_get_lock(void)
{
	unsigned long flags;

	__save_and_cli(flags);
	if (prom_entry_depth == 0) {
		spin_lock(&prom_entry_lock);

#if 1 /* DEBUGGING */
		if (prom_entry_depth != 0)
			panic("prom_get_lock");
#endif
	}
	prom_entry_depth++;

	return flags;
}

static __inline__ void prom_release_lock(unsigned long flags)
{
	if (--prom_entry_depth == 0)
		spin_unlock(&prom_entry_lock);

	__restore_flags(flags);
}

long p1275_cmd (char *service, long fmt, ...)
{
	char *p, *q;
	unsigned long flags;
	int nargs, nrets, i;
	va_list list;
	long attrs, x;
	long ctx = 0;
	
	p = p1275buf.prom_buffer;
	ctx = spitfire_get_primary_context ();
	if (ctx) {
		flushw_user ();
		spitfire_set_primary_context (0);
	}

	flags = prom_get_lock();

	p1275buf.prom_args[0] = (unsigned long)p;		/* service */
	strcpy (p, service);
	p = (char *)(((long)(strchr (p, 0) + 8)) & ~7);
	p1275buf.prom_args[1] = nargs = (fmt & 0x0f);		/* nargs */
	p1275buf.prom_args[2] = nrets = ((fmt & 0xf0) >> 4); 	/* nrets */
	attrs = fmt >> 8;
	va_start(list, fmt);
	for (i = 0; i < nargs; i++, attrs >>= 3) {
		switch (attrs & 0x7) {
		case P1275_ARG_NUMBER:
			p1275buf.prom_args[i + 3] =
						(unsigned)va_arg(list, long);
			break;
		case P1275_ARG_IN_64B:
			p1275buf.prom_args[i + 3] =
				va_arg(list, unsigned long);
			break;
		case P1275_ARG_IN_STRING:
			strcpy (p, va_arg(list, char *));
			p1275buf.prom_args[i + 3] = (unsigned long)p;
			p = (char *)(((long)(strchr (p, 0) + 8)) & ~7);
			break;
		case P1275_ARG_OUT_BUF:
			(void) va_arg(list, char *);
			p1275buf.prom_args[i + 3] = (unsigned long)p;
			x = va_arg(list, long);
			i++; attrs >>= 3;
			p = (char *)(((long)(p + (int)x + 7)) & ~7);
			p1275buf.prom_args[i + 3] = x;
			break;
		case P1275_ARG_IN_BUF:
			q = va_arg(list, char *);
			p1275buf.prom_args[i + 3] = (unsigned long)p;
			x = va_arg(list, long);
			i++; attrs >>= 3;
			memcpy (p, q, (int)x);
			p = (char *)(((long)(p + (int)x + 7)) & ~7);
			p1275buf.prom_args[i + 3] = x;
			break;
		case P1275_ARG_OUT_32B:
			(void) va_arg(list, char *);
			p1275buf.prom_args[i + 3] = (unsigned long)p;
			p += 32;
			break;
		case P1275_ARG_IN_FUNCTION:
			p1275buf.prom_args[i + 3] =
					(unsigned long)prom_cif_callback;
			p1275buf.prom_callback = va_arg(list, long);
			break;
		}
	}
	va_end(list);

	prom_world(1);
	prom_cif_interface();
	prom_world(0);

	attrs = fmt >> 8;
	va_start(list, fmt);
	for (i = 0; i < nargs; i++, attrs >>= 3) {
		switch (attrs & 0x7) {
		case P1275_ARG_NUMBER:
			(void) va_arg(list, long);
			break;
		case P1275_ARG_IN_STRING:
			(void) va_arg(list, char *);
			break;
		case P1275_ARG_IN_FUNCTION:
			(void) va_arg(list, long);
			break;
		case P1275_ARG_IN_BUF:
			(void) va_arg(list, char *);
			(void) va_arg(list, long);
			i++; attrs >>= 3;
			break;
		case P1275_ARG_OUT_BUF:
			p = va_arg(list, char *);
			x = va_arg(list, long);
			memcpy (p, (char *)(p1275buf.prom_args[i + 3]), (int)x);
			i++; attrs >>= 3;
			break;
		case P1275_ARG_OUT_32B:
			p = va_arg(list, char *);
			memcpy (p, (char *)(p1275buf.prom_args[i + 3]), 32);
			break;
		}
	}
	va_end(list);
	x = p1275buf.prom_args [nargs + 3];

	prom_release_lock(flags);

	if (ctx)
		spitfire_set_primary_context (ctx);

	return x;
}

void prom_cif_init(void *cif_handler, void *cif_stack)
{
	p1275buf.prom_cif_handler = (void (*)(long *))cif_handler;
	p1275buf.prom_cif_stack = (unsigned long)cif_stack;
}