sparc64: Get rid of indirect p1275 PROM call buffer.

This is based upon a report by Meelis Roos showing that it's possible
that we'll try to fetch a property that is 32K in size with some
devices.  With the current fixed 3K buffer we use for moving data in
and out of the firmware during PROM calls, that simply won't work.

In fact, it will scramble random kernel data during bootup.

The reasoning behind the temporary buffer is entirely historical.  It
used to be the case that we had problems referencing dynamic kernel
memory (including the stack) early in the boot process before we
explicitly told the firwmare to switch us over to the kernel trap
table.

So what we did was always give the firmware buffers that were locked
into the main kernel image.

But we no longer have problems like that, so get rid of all of this
indirect bounce buffering.

Besides fixing Meelis's bug, this also makes the kernel data about 3K
smaller.

It was also discovered during these conversions that the
implementation of prom_retain() was completely wrong, so that was
fixed here as well.  Currently that interface is not in use.

Reported-by: Meelis Roos <mroos@linux.ee>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 99 deletions

diff --git a/arch/sparc/prom/p1275.c b/arch/sparc/prom/p1275.c
index 2d8b70d..fa6e4e2 100644
--- a/arch/sparc/prom/p1275.c
+++ b/arch/sparc/prom/p1275.c
@@ -22,13 +22,11 @@ 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);
 
-extern void prom_cif_interface(void);
+extern void prom_cif_direct(unsigned long *args);
 extern void prom_cif_callback(void);
 
 /*
@@ -36,114 +34,20 @@ extern void prom_cif_callback(void);
  */
 DEFINE_RAW_SPINLOCK(prom_entry_lock);
 
-long p1275_cmd(const char *service, long fmt, ...)
+void p1275_cmd_direct(unsigned long *args)
 {
-	char *p, *q;
 	unsigned long flags;
-	int nargs, nrets, i;
-	va_list list;
-	long attrs, x;
-	
-	p = p1275buf.prom_buffer;
 
 	raw_local_save_flags(flags);
 	raw_local_irq_restore(PIL_NMI);
 	raw_spin_lock(&prom_entry_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_cif_direct(args);
 	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];
-
 	raw_spin_unlock(&prom_entry_lock);
 	raw_local_irq_restore(flags);
-
-	return x;
 }
 
 void prom_cif_init(void *cif_handler, void *cif_stack)