powerpc: Merge xmon

The merged version follows the ppc64 version pretty closely mostly,
and in fact ARCH=ppc64 now uses the arch/powerpc/xmon version.
The main difference for ppc64 is that the 'p' command to call
show_state (which was always pretty dodgy) has been replaced by
the ppc32 'p' command, which calls a given procedure (so in fact
the old 'p' command behaviour can be achieved with 'p $show_state').
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/Makefile

@@ -131,7 +131,7 @@ core-y				+= arch/powerpc/kernel/ \
 				   arch/powerpc/sysdev/ \
 				   arch/powerpc/platforms/
 core-$(CONFIG_MATH_EMULATION)	+= arch/ppc/math-emu/
-#core-$(CONFIG_XMON)		+= arch/powerpc/xmon/
+core-$(CONFIG_XMON)		+= arch/powerpc/xmon/
 core-$(CONFIG_APUS)		+= arch/ppc/amiga/
 drivers-$(CONFIG_8xx)		+= arch/ppc/8xx_io/
 drivers-$(CONFIG_4xx)		+= arch/ppc/4xx_io/

arch/powerpc/kernel/head_32.S

@@ -271,6 +271,9 @@ __secondary_hold_acknowledge:
 	li	r10,MSR_KERNEL & ~(MSR_IR|MSR_DR); /* can take exceptions */ \
 	MTMSRD(r10);			/* (except for mach check in rtas) */ \
 	stw	r0,GPR0(r11);	\
+	lis	r10,0x7265;		/* put exception frame marker */ \
+	addi	r10,r10,0x6773;	\
+	stw	r10,8(r11);	\
 	SAVE_4GPRS(3, r11);	\
 	SAVE_2GPRS(7, r11)
 

arch/powerpc/kernel/ppc_ksyms.c

@@ -44,7 +44,6 @@
 #include <asm/cputable.h>
 #include <asm/btext.h>
 #include <asm/div64.h>
-#include <asm/xmon.h>
 
 #ifdef  CONFIG_8xx
 #include <asm/commproc.h>
@@ -238,10 +237,6 @@ EXPORT_SYMBOL(console_drivers);
 EXPORT_SYMBOL(cacheable_memcpy);
 #endif
 
-#ifdef CONFIG_XMON
-EXPORT_SYMBOL(xmon);
-EXPORT_SYMBOL(xmon_printf);
-#endif
 EXPORT_SYMBOL(__up);
 EXPORT_SYMBOL(__down);
 EXPORT_SYMBOL(__down_interruptible);

arch/powerpc/kernel/setup_32.c

@@ -302,8 +302,10 @@ void __init setup_arch(char **cmdline_p)
 
 #ifdef CONFIG_XMON
 	xmon_map_scc();
-	if (strstr(cmd_line, "xmon"))
-		xmon(NULL);
+	if (strstr(cmd_line, "xmon")) {
+		xmon_init(1);
+		debugger(NULL);
+	}
 #endif /* CONFIG_XMON */
 	if ( ppc_md.progress ) ppc_md.progress("setup_arch: enter", 0x3eab);
 

arch/powerpc/kernel/setup_64.c

@@ -59,6 +59,7 @@
 #include <asm/iSeries/ItLpNaca.h>
 #include <asm/firmware.h>
 #include <asm/systemcfg.h>
+#include <asm/xmon.h>
 
 #ifdef DEBUG
 #define DBG(fmt...) udbg_printf(fmt)

arch/powerpc/lib/Makefile

@@ -11,6 +11,8 @@ obj-$(CONFIG_PPC32)	+= div64.o copy_32.o checksum_32.o
 obj-$(CONFIG_PPC64)	+= checksum_64.o copypage_64.o copyuser_64.o \
 			   memcpy_64.o usercopy_64.o mem_64.o
 obj-$(CONFIG_PPC_ISERIES) += e2a.o
+obj-$(CONFIG_XMON)	+= sstep.o
+
 ifeq ($(CONFIG_PPC64),y)
 obj-$(CONFIG_SMP)	+= locks.o
 obj-$(CONFIG_DEBUG_KERNEL) += sstep.o

arch/powerpc/xmon/Makefile

+# Makefile for xmon
+
+ifdef CONFIG_PPC64
+EXTRA_CFLAGS += -mno-minimal-toc
+endif
+
+obj-$(CONFIG_8xx)	+= start_8xx.o
+obj-$(CONFIG_6xx)	+= start_32.o
+obj-$(CONFIG_4xx)	+= start_32.o
+obj-$(CONFIG_PPC64)	+= start_64.o
+obj-y			+= xmon.o ppc-dis.o ppc-opc.o subr_prf.o setjmp.o

arch/powerpc/xmon/setjmp.S

+/*
+ * Copyright (C) 1996 Paul Mackerras.
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ *
+ * NOTE: assert(sizeof(buf) > 23 * sizeof(long))
+ */
+#include <asm/processor.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+
+_GLOBAL(xmon_setjmp)
+	mflr	r0
+	STL	r0,0(r3)
+	STL	r1,SZL(r3)
+	STL	r2,2*SZL(r3)
+	mfcr	r0
+	STL	r0,3*SZL(r3)
+	STL	r13,4*SZL(r3)
+	STL	r14,5*SZL(r3)
+	STL	r15,6*SZL(r3)
+	STL	r16,7*SZL(r3)
+	STL	r17,8*SZL(r3)
+	STL	r18,9*SZL(r3)
+	STL	r19,10*SZL(r3)
+	STL	r20,11*SZL(r3)
+	STL	r21,12*SZL(r3)
+	STL	r22,13*SZL(r3)
+	STL	r23,14*SZL(r3)
+	STL	r24,15*SZL(r3)
+	STL	r25,16*SZL(r3)
+	STL	r26,17*SZL(r3)
+	STL	r27,18*SZL(r3)
+	STL	r28,19*SZL(r3)
+	STL	r29,20*SZL(r3)
+	STL	r30,21*SZL(r3)
+	STL	r31,22*SZL(r3)
+	li	r3,0
+	blr
+
+_GLOBAL(xmon_longjmp)
+	CMPI	r4,0
+	bne	1f
+	li	r4,1
+1:	LDL	r13,4*SZL(r3)
+	LDL	r14,5*SZL(r3)
+	LDL	r15,6*SZL(r3)
+	LDL	r16,7*SZL(r3)
+	LDL	r17,8*SZL(r3)
+	LDL	r18,9*SZL(r3)
+	LDL	r19,10*SZL(r3)
+	LDL	r20,11*SZL(r3)
+	LDL	r21,12*SZL(r3)
+	LDL	r22,13*SZL(r3)
+	LDL	r23,14*SZL(r3)
+	LDL	r24,15*SZL(r3)
+	LDL	r25,16*SZL(r3)
+	LDL	r26,17*SZL(r3)
+	LDL	r27,18*SZL(r3)
+	LDL	r28,19*SZL(r3)
+	LDL	r29,20*SZL(r3)
+	LDL	r30,21*SZL(r3)
+	LDL	r31,22*SZL(r3)
+	LDL	r0,3*SZL(r3)
+	mtcrf	0x38,r0
+	LDL	r0,0(r3)
+	LDL	r1,SZL(r3)
+	LDL	r2,2*SZL(r3)
+	mtlr	r0
+	mr	r3,r4
+	blr
+
+/*
+ * Grab the register values as they are now.
+ * This won't do a particularily good job because we really
+ * want our caller's caller's registers, and our caller has
+ * already executed its prologue.
+ * ToDo: We could reach back into the caller's save area to do
+ * a better job of representing the caller's state (note that
+ * that will be different for 32-bit and 64-bit, because of the
+ * different ABIs, though).
+ */
+_GLOBAL(xmon_save_regs)
+	STL	r0,0*SZL(r3)
+	STL	r2,2*SZL(r3)
+	STL	r3,3*SZL(r3)
+	STL	r4,4*SZL(r3)
+	STL	r5,5*SZL(r3)
+	STL	r6,6*SZL(r3)
+	STL	r7,7*SZL(r3)
+	STL	r8,8*SZL(r3)
+	STL	r9,9*SZL(r3)
+	STL	r10,10*SZL(r3)
+	STL	r11,11*SZL(r3)
+	STL	r12,12*SZL(r3)
+	STL	r13,13*SZL(r3)
+	STL	r14,14*SZL(r3)
+	STL	r15,15*SZL(r3)
+	STL	r16,16*SZL(r3)
+	STL	r17,17*SZL(r3)
+	STL	r18,18*SZL(r3)
+	STL	r19,19*SZL(r3)
+	STL	r20,20*SZL(r3)
+	STL	r21,21*SZL(r3)
+	STL	r22,22*SZL(r3)
+	STL	r23,23*SZL(r3)
+	STL	r24,24*SZL(r3)
+	STL	r25,25*SZL(r3)
+	STL	r26,26*SZL(r3)
+	STL	r27,27*SZL(r3)
+	STL	r28,28*SZL(r3)
+	STL	r29,29*SZL(r3)
+	STL	r30,30*SZL(r3)
+	STL	r31,31*SZL(r3)
+	/* go up one stack frame for SP */
+	LDL	r4,0(r1)
+	STL	r4,1*SZL(r3)
+	/* get caller's LR */
+	LDL	r0,LRSAVE(r4)
+	STL	r0,_NIP-STACK_FRAME_OVERHEAD(r3)
+	STL	r0,_LINK-STACK_FRAME_OVERHEAD(r3)
+	mfmsr	r0
+	STL	r0,_MSR-STACK_FRAME_OVERHEAD(r3)
+	mfctr	r0
+	STL	r0,_CTR-STACK_FRAME_OVERHEAD(r3)
+	mfxer	r0
+	STL	r0,_XER-STACK_FRAME_OVERHEAD(r3)
+	mfcr	r0
+	STL	r0,_CCR-STACK_FRAME_OVERHEAD(r3)
+	li	r0,0
+	STL	r0,_TRAP-STACK_FRAME_OVERHEAD(r3)
+	blr

arch/powerpc/xmon/start_8xx.c

+/*
+ * Copyright (C) 1996 Paul Mackerras.
+ * Copyright (C) 2000 Dan Malek.
+ * Quick hack of Paul's code to make XMON work on 8xx processors.  Lots
+ * of assumptions, like the SMC1 is used, it has been initialized by the
+ * loader at some point, and we can just stuff and suck bytes.
+ * We rely upon the 8xx uart driver to support us, as the interface
+ * changes between boot up and operational phases of the kernel.
+ */
+#include <linux/string.h>
+#include <asm/machdep.h>
+#include <asm/io.h>
+#include <asm/page.h>
+#include <linux/kernel.h>
+#include <asm/8xx_immap.h>
+#include <asm/mpc8xx.h>
+#include <asm/commproc.h>
+
+extern void xmon_printf(const char *fmt, ...);
+extern int xmon_8xx_write(char *str, int nb);
+extern int xmon_8xx_read_poll(void);
+extern int xmon_8xx_read_char(void);
+void prom_drawhex(uint);
+void prom_drawstring(const char *str);
+
+static int use_screen = 1; /* default */
+
+#define TB_SPEED	25000000
+
+static inline unsigned int readtb(void)
+{
+	unsigned int ret;
+
+	asm volatile("mftb %0" : "=r" (ret) :);
+	return ret;
+}
+
+void buf_access(void)
+{
+}
+
+void
+xmon_map_scc(void)
+{
+
+	cpmp = (cpm8xx_t *)&(((immap_t *)IMAP_ADDR)->im_cpm);
+	use_screen = 0;
+	
+	prom_drawstring("xmon uses serial port\n");
+}
+
+static int scc_initialized = 0;
+
+void xmon_init_scc(void);
+
+int
+xmon_write(void *handle, void *ptr, int nb)
+{
+	char *p = ptr;
+	int i, c, ct;
+
+	if (!scc_initialized)
+		xmon_init_scc();
+
+	return(xmon_8xx_write(ptr, nb));
+}
+
+int xmon_wants_key;
+
+int
+xmon_read(void *handle, void *ptr, int nb)
+{
+	char *p = ptr;
+	int i;
+
+	if (!scc_initialized)
+		xmon_init_scc();
+
+	for (i = 0; i < nb; ++i) {
+		*p++ = xmon_8xx_read_char();
+	}
+	return i;
+}
+
+int
+xmon_read_poll(void)
+{
+	return(xmon_8xx_read_poll());
+}
+
+void
+xmon_init_scc()
+{
+	scc_initialized = 1;
+}
+
+#if 0
+extern int (*prom_entry)(void *);
+
+int
+xmon_exit(void)
+{
+    struct prom_args {
+	char *service;
+    } args;
+
+    for (;;) {
+	args.service = "exit";
+	(*prom_entry)(&args);
+    }
+}
+#endif
+
+void *xmon_stdin;
+void *xmon_stdout;
+void *xmon_stderr;
+
+void
+xmon_init(void)
+{
+}
+
+int
+xmon_putc(int c, void *f)
+{
+    char ch = c;
+
+    if (c == '\n')
+	xmon_putc('\r', f);
+    return xmon_write(f, &ch, 1) == 1? c: -1;
+}
+
+int
+xmon_putchar(int c)
+{
+    return xmon_putc(c, xmon_stdout);
+}
+
+int
+xmon_fputs(char *str, void *f)
+{
+    int n = strlen(str);
+
+    return xmon_write(f, str, n) == n? 0: -1;
+}
+
+int
+xmon_readchar(void)
+{
+    char ch;
+
+    for (;;) {
+	switch (xmon_read(xmon_stdin, &ch, 1)) {
+	case 1:
+	    return ch;
+	case -1:
+	    xmon_printf("read(stdin) returned -1\r\n", 0, 0);
+	    return -1;
+	}
+    }
+}
+
+static char line[256];
+static char *lineptr;
+static int lineleft;
+
+#if 0
+int xmon_expect(const char *str, unsigned int timeout)
+{
+	int c;
+	unsigned int t0;
+
+	timeout *= TB_SPEED;
+	t0 = readtb();
+	do {
+		lineptr = line;
+		for (;;) {
+			c = xmon_read_poll();
+			if (c == -1) {
+				if (readtb() - t0 > timeout)
+					return 0;
+				continue;
+			}
+			if (c == '\n')
+				break;
+			if (c != '\r' && lineptr < &line[sizeof(line) - 1])
+				*lineptr++ = c;
+		}
+		*lineptr = 0;
+	} while (strstr(line, str) == NULL);
+	return 1;
+}
+#endif
+
+int
+xmon_getchar(void)
+{
+    int c;
+
+    if (lineleft == 0) {
+	lineptr = line;
+	for (;;) {
+	    c = xmon_readchar();
+	    if (c == -1 || c == 4)
+		break;
+	    if (c == '\r' || c == '\n') {
+		*lineptr++ = '\n';
+		xmon_putchar('\n');
+		break;
+	    }
+	    switch (c) {
+	    case 0177:
+	    case '\b':
+		if (lineptr > line) {
+		    xmon_putchar('\b');
+		    xmon_putchar(' ');
+		    xmon_putchar('\b');
+		    --lineptr;
+		}
+		break;
+	    case 'U' & 0x1F:
+		while (lineptr > line) {
+		    xmon_putchar('\b');
+		    xmon_putchar(' ');
+		    xmon_putchar('\b');
+		    --lineptr;
+		}
+		break;
+	    default:
+		if (lineptr >= &line[sizeof(line) - 1])
+		    xmon_putchar('\a');
+		else {
+		    xmon_putchar(c);
+		    *lineptr++ = c;
+		}
+	    }
+	}
+	lineleft = lineptr - line;
+	lineptr = line;
+    }
+    if (lineleft == 0)
+	return -1;
+    --lineleft;
+    return *lineptr++;
+}
+
+char *
+xmon_fgets(char *str, int nb, void *f)
+{
+    char *p;
+    int c;
+
+    for (p = str; p < str + nb - 1; ) {
+	c = xmon_getchar();
+	if (c == -1) {
+	    if (p == str)
+		return 0;
+	    break;
+	}
+	*p++ = c;
+	if (c == '\n')
+	    break;
+    }
+    *p = 0;
+    return str;
+}
+
+void
+prom_drawhex(uint val)
+{
+	unsigned char buf[10];
+
+	int i;
+	for (i = 7;  i >= 0;  i--)
+	{
+		buf[i] = "0123456789abcdef"[val & 0x0f];
+		val >>= 4;
+	}
+	buf[8] = '\0';
+	xmon_fputs(buf, xmon_stdout);
+}
+
+void
+prom_drawstring(const char *str)
+{
+	xmon_fputs(str, xmon_stdout);
+}

arch/ppc64/xmon/subr_prf.c → arch/powerpc/xmon/subr_prf.c

@@ -18,13 +18,13 @@
 
 #include <linux/kernel.h>
 #include <linux/string.h>
+#include <linux/module.h>
 #include <stdarg.h>
 #include "nonstdio.h"
 
 extern int xmon_write(void *, void *, int);
 
-void
-xmon_vfprintf(void *f, const char *fmt, va_list ap)
+void xmon_vfprintf(void *f, const char *fmt, va_list ap)
 {
 	static char xmon_buf[2048];
 	int n;
@@ -33,8 +33,7 @@ xmon_vfprintf(void *f, const char *fmt, va_list ap)
 	xmon_write(f, xmon_buf, n);
 }
 
-void
-xmon_printf(const char *fmt, ...)
+void xmon_printf(const char *fmt, ...)
 {
 	va_list ap;
 
@@ -42,9 +41,9 @@ xmon_printf(const char *fmt, ...)
 	xmon_vfprintf(stdout, fmt, ap);
 	va_end(ap);
 }
+EXPORT_SYMBOL(xmon_printf);
 
-void
-xmon_fprintf(void *f, const char *fmt, ...)
+void xmon_fprintf(void *f, const char *fmt, ...)
 {
 	va_list ap;
 

arch/ppc64/Makefile

@@ -89,7 +89,7 @@ core-y				+= arch/powerpc/mm/
 core-y				+= arch/powerpc/sysdev/
 core-y				+= arch/powerpc/platforms/
 core-y				+= arch/powerpc/lib/
-core-$(CONFIG_XMON)		+= arch/ppc64/xmon/
+core-$(CONFIG_XMON)		+= arch/powerpc/xmon/
 drivers-$(CONFIG_OPROFILE)	+= arch/powerpc/oprofile/
 
 boot := arch/ppc64/boot

arch/ppc64/xmon/Makefile

-# Makefile for xmon
-
-EXTRA_CFLAGS += -mno-minimal-toc
-
-obj-y := start.o xmon.o ppc-dis.o ppc-opc.o subr_prf.o setjmp.o

arch/ppc64/xmon/setjmp.S

-/*
- * Copyright (C) 1996 Paul Mackerras.
- *
- *      This program is free software; you can redistribute it and/or
- *      modify it under the terms of the GNU General Public License
- *      as published by the Free Software Foundation; either version
- *      2 of the License, or (at your option) any later version.
- *
- * NOTE: assert(sizeof(buf) > 184)
- */
-#include <asm/processor.h>
-#include <asm/ppc_asm.h>
-
-_GLOBAL(xmon_setjmp)
-	mflr    r0
-	std     r0,0(r3)
-	std     r1,8(r3)
-	std     r2,16(r3)
-	mfcr    r0
-	std     r0,24(r3)
-	std     r13,32(r3)
-	std     r14,40(r3)
-	std     r15,48(r3)
-	std     r16,56(r3)
-	std     r17,64(r3)
-	std     r18,72(r3)
-	std     r19,80(r3)
-	std     r20,88(r3)
-	std     r21,96(r3)
-	std     r22,104(r3)
-	std     r23,112(r3)
-	std     r24,120(r3)
-	std     r25,128(r3)
-	std     r26,136(r3)
-	std     r27,144(r3)
-	std     r28,152(r3)
-	std     r29,160(r3)
-	std     r30,168(r3)
-	std     r31,176(r3)
-	li      r3,0
-	blr
-
-_GLOBAL(xmon_longjmp)
-	cmpdi   r4,0
-	bne     1f
-	li      r4,1
-1:	ld      r13,32(r3)
-	ld      r14,40(r3)
-	ld      r15,48(r3)
-	ld      r16,56(r3)
-	ld      r17,64(r3)
-	ld      r18,72(r3)
-	ld      r19,80(r3)
-	ld      r20,88(r3)
-	ld      r21,96(r3)
-	ld      r22,104(r3)
-	ld      r23,112(r3)
-	ld      r24,120(r3)
-	ld      r25,128(r3)
-	ld      r26,136(r3)
-	ld      r27,144(r3)
-	ld      r28,152(r3)
-	ld      r29,160(r3)
-	ld      r30,168(r3)
-	ld      r31,176(r3)
-	ld      r0,24(r3)
-	mtcrf   56,r0
-	ld      r0,0(r3)
-	ld      r1,8(r3)
-	ld      r2,16(r3)
-	mtlr    r0
-	mr      r3,r4
-	blr

include/asm-powerpc/ppc_asm.h

@@ -188,6 +188,10 @@ n:
 #define LDL	ld
 #define STL	std
 #define CMPI	cmpdi
+#define SZL	8
+
+/* offsets for stack frame layout */
+#define LRSAVE	16
 
 #else /* 32-bit */
 #define LOADADDR(rn,name) \
@@ -203,6 +207,10 @@ n:
 #define LDL	lwz
 #define STL	stw
 #define CMPI	cmpwi
+#define SZL	4
+
+/* offsets for stack frame layout */
+#define LRSAVE	4
 
 #endif
 

include/asm-powerpc/reg.h

@@ -546,6 +546,7 @@
 #define __mtmsrd(v, l)	asm volatile("mtmsrd %0," __stringify(l) \
 				     : : "r" (v))
 #define mtmsrd(v)	__mtmsrd((v), 0)
+#define mtmsr(v)	mtmsrd(v)
 #else
 #define mtmsr(v)	asm volatile("mtmsr %0" : : "r" (v))
 #endif

include/asm-powerpc/xmon.h

@@ -4,7 +4,7 @@
 
 struct pt_regs;
 
-extern void xmon(struct pt_regs *excp);
+extern int xmon(struct pt_regs *excp);
 extern void xmon_printf(const char *fmt, ...);
 extern void xmon_init(int);