[PATCH] powerpc: Unify udbg (#2)

This patch unifies udbg for both ppc32 and ppc64 when building the
merged achitecture. xmon now has a single "back end". The powermac udbg
stuff gets enriched with some ADB capabilities and btext output. In
addition, the early_init callback is now called on ppc32 as well,
approx. in the same order as ppc64 regarding device-tree manipulations.
The init sequences of ppc32 and ppc64 are getting closer, I'll unify
them in a later patch.

For now, you can force udbg to the scc using "sccdbg" or to btext using
"btextdbg" on powermacs. I'll implement a cleaner way of forcing udbg
output to something else than the autodetected OF output device in a
later patch.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/Kconfig

@@ -50,7 +50,7 @@ config PPC
 
 config EARLY_PRINTK
 	bool
-	default y if PPC64
+	default y
 
 config COMPAT
 	bool

arch/powerpc/kernel/Makefile

@@ -18,7 +18,7 @@ obj-y				+= vdso32/
 obj-$(CONFIG_PPC64)		+= setup_64.o binfmt_elf32.o sys_ppc32.o \
 				   signal_64.o ptrace32.o systbl.o \
 				   paca.o ioctl32.o cpu_setup_power4.o \
-				   firmware.o sysfs.o udbg.o idle_64.o
+				   firmware.o sysfs.o idle_64.o
 obj-$(CONFIG_PPC64)		+= vdso64/
 obj-$(CONFIG_ALTIVEC)		+= vecemu.o vector.o
 obj-$(CONFIG_POWER4)		+= idle_power4.o
@@ -46,7 +46,7 @@ extra-$(CONFIG_8xx)		:= head_8xx.o
 extra-y				+= vmlinux.lds
 
 obj-y				+= process.o init_task.o time.o \
-				   prom.o traps.o setup-common.o
+				   prom.o traps.o setup-common.o udbg.o
 obj-$(CONFIG_PPC32)		+= entry_32.o setup_32.o misc_32.o systbl.o
 obj-$(CONFIG_PPC64)		+= misc_64.o dma_64.o iommu.o
 obj-$(CONFIG_PPC_OF)		+= prom_init.o
@@ -56,8 +56,7 @@ obj-$(CONFIG_6xx)		+= idle_6xx.o
 obj-$(CONFIG_SMP)		+= smp.o
 obj-$(CONFIG_KPROBES)		+= kprobes.o
 obj-$(CONFIG_PPC_MULTIPLATFORM) += legacy_serial.o
-obj64-$(CONFIG_PPC_MULTIPLATFORM) += udbg_16550.o
-obj64-$(CONFIG_PPC_PMAC)	+= udbg_scc.o
+obj-$(CONFIG_PPC_MULTIPLATFORM) += udbg_16550.o
 module-$(CONFIG_PPC64)		+= module_64.o
 obj-$(CONFIG_MODULES)		+= $(module-y)
 

arch/powerpc/kernel/btext.c

@@ -31,23 +31,26 @@ static void draw_byte_32(unsigned char *bits, unsigned int *base, int rb);
 static void draw_byte_16(unsigned char *bits, unsigned int *base, int rb);
 static void draw_byte_8(unsigned char *bits, unsigned int *base, int rb);
 
-static int g_loc_X;
-static int g_loc_Y;
-static int g_max_loc_X;
-static int g_max_loc_Y;
+#define __force_data __attribute__((__section__(".data")))
 
-static int dispDeviceRowBytes;
-static int dispDeviceDepth;
-static int dispDeviceRect[4];
-static unsigned char *dispDeviceBase, *logicalDisplayBase;
+static int g_loc_X __force_data;
+static int g_loc_Y __force_data;
+static int g_max_loc_X __force_data;
+static int g_max_loc_Y __force_data;
+
+static int dispDeviceRowBytes __force_data;
+static int dispDeviceDepth  __force_data;
+static int dispDeviceRect[4] __force_data;
+static unsigned char *dispDeviceBase __force_data;
+static unsigned char *logicalDisplayBase __force_data;
 
 unsigned long disp_BAT[2] __initdata = {0, 0};
 
 #define cmapsz	(16*256)
 
 static unsigned char vga_font[cmapsz];
 
-int boot_text_mapped;
+int boot_text_mapped __force_data = 0;
 int force_printk_to_btext = 0;
 
 #ifdef CONFIG_PPC32
@@ -66,8 +69,7 @@ int force_printk_to_btext = 0;
  * is really badly aligned, but I didn't encounter this case
  * yet.
  */
-void __init
-btext_prepare_BAT(void)
+void __init btext_prepare_BAT(void)
 {
 	unsigned long vaddr = KERNELBASE + 0x10000000;
 	unsigned long addr;
@@ -95,12 +97,13 @@ btext_prepare_BAT(void)
 }
 #endif
 
-/* This function will enable the early boot text when doing OF booting. This
- * way, xmon output should work too
+
+/* This function can be used to enable the early boot text when doing
+ * OF booting or within bootx init. It must be followed by a btext_unmap()
+ * call before the logical address becomes unuseable
  */
-void __init
-btext_setup_display(int width, int height, int depth, int pitch,
-		    unsigned long address)
+void __init btext_setup_display(int width, int height, int depth, int pitch,
+				unsigned long address)
 {
 	g_loc_X = 0;
 	g_loc_Y = 0;
@@ -116,6 +119,11 @@ btext_setup_display(int width, int height, int depth, int pitch,
 	boot_text_mapped = 1;
 }
 
+void __init btext_unmap(void)
+{
+	boot_text_mapped = 0;
+}
+
 /* Here's a small text engine to use during early boot
  * or for debugging purposes
  *
@@ -127,7 +135,7 @@ btext_setup_display(int width, int height, int depth, int pitch,
  *    changes.
  */
 
-void map_boot_text(void)
+static void map_boot_text(void)
 {
 	unsigned long base, offset, size;
 	unsigned char *vbase;
@@ -175,16 +183,16 @@ int btext_initialize(struct device_node *np)
 	if (prop)
 		address = *prop;
 
-	/* FIXME: Add support for PCI reg properties */
-
+	/* FIXME: Add support for PCI reg properties. Right now, only
+	 * reliable on macs
+	 */
 	if (address == 0)
 		return -EINVAL;
 
 	g_loc_X = 0;
 	g_loc_Y = 0;
 	g_max_loc_X = width / 8;
 	g_max_loc_Y = height / 16;
-	logicalDisplayBase = (unsigned char *)address;
 	dispDeviceBase = (unsigned char *)address;
 	dispDeviceRowBytes = pitch;
 	dispDeviceDepth = depth;
@@ -197,7 +205,7 @@ int btext_initialize(struct device_node *np)
 	return 0;
 }
 
-void __init init_boot_display(void)
+int __init btext_find_display(int allow_nonstdout)
 {
 	char *name;
 	struct device_node *np = NULL; 
@@ -218,8 +226,8 @@ void __init init_boot_display(void)
 	}
 	if (np)
 		rc = btext_initialize(np);
-	if (rc == 0)
-		return;
+	if (rc == 0 || !allow_nonstdout)
+		return rc;
 
 	for (np = NULL; (np = of_find_node_by_type(np, "display"));) {
 		if (get_property(np, "linux,opened", NULL)) {
@@ -228,8 +236,9 @@ void __init init_boot_display(void)
 			printk("result: %d\n", rc);
 		}
 		if (rc == 0)
-			return;
+			break;
 	}
+	return rc;
 }
 
 /* Calc the base address of a given point (x,y) */
@@ -277,44 +286,83 @@ EXPORT_SYMBOL(btext_update_display);
 
 void btext_clearscreen(void)
 {
-	unsigned long *base	= (unsigned long *)calc_base(0, 0);
+	unsigned int *base	= (unsigned int *)calc_base(0, 0);
 	unsigned long width 	= ((dispDeviceRect[2] - dispDeviceRect[0]) *
-					(dispDeviceDepth >> 3)) >> 3;
+					(dispDeviceDepth >> 3)) >> 2;
 	int i,j;
 
 	for (i=0; i<(dispDeviceRect[3] - dispDeviceRect[1]); i++)
 	{
-		unsigned long *ptr = base;
+		unsigned int *ptr = base;
 		for(j=width; j; --j)
 			*(ptr++) = 0;
-		base += (dispDeviceRowBytes >> 3);
+		base += (dispDeviceRowBytes >> 2);
+	}
+}
+
+void btext_flushscreen(void)
+{
+	unsigned int *base	= (unsigned int *)calc_base(0, 0);
+	unsigned long width 	= ((dispDeviceRect[2] - dispDeviceRect[0]) *
+					(dispDeviceDepth >> 3)) >> 2;
+	int i,j;
+
+	for (i=0; i < (dispDeviceRect[3] - dispDeviceRect[1]); i++)
+	{
+		unsigned int *ptr = base;
+		for(j = width; j > 0; j -= 8) {
+			__asm__ __volatile__ ("dcbst 0,%0" :: "r" (ptr));
+			ptr += 8;
+		}
+		base += (dispDeviceRowBytes >> 2);
 	}
+	__asm__ __volatile__ ("sync" ::: "memory");
 }
 
+void btext_flushline(void)
+{
+	unsigned int *base	= (unsigned int *)calc_base(0, g_loc_Y << 4);
+	unsigned long width 	= ((dispDeviceRect[2] - dispDeviceRect[0]) *
+					(dispDeviceDepth >> 3)) >> 2;
+	int i,j;
+
+	for (i=0; i < 16; i++)
+	{
+		unsigned int *ptr = base;
+		for(j = width; j > 0; j -= 8) {
+			__asm__ __volatile__ ("dcbst 0,%0" :: "r" (ptr));
+			ptr += 8;
+		}
+		base += (dispDeviceRowBytes >> 2);
+	}
+	__asm__ __volatile__ ("sync" ::: "memory");
+}
+
+
 #ifndef NO_SCROLL
 static void scrollscreen(void)
 {
-	unsigned long *src     	= (unsigned long *)calc_base(0,16);
-	unsigned long *dst     	= (unsigned long *)calc_base(0,0);
+	unsigned int *src     	= (unsigned int *)calc_base(0,16);
+	unsigned int *dst     	= (unsigned int *)calc_base(0,0);
 	unsigned long width    	= ((dispDeviceRect[2] - dispDeviceRect[0]) *
-				   (dispDeviceDepth >> 3)) >> 3;
+				   (dispDeviceDepth >> 3)) >> 2;
 	int i,j;
 
 	for (i=0; i<(dispDeviceRect[3] - dispDeviceRect[1] - 16); i++)
 	{
-		unsigned long *src_ptr = src;
-		unsigned long *dst_ptr = dst;
+		unsigned int *src_ptr = src;
+		unsigned int *dst_ptr = dst;
 		for(j=width; j; --j)
 			*(dst_ptr++) = *(src_ptr++);
-		src += (dispDeviceRowBytes >> 3);
-		dst += (dispDeviceRowBytes >> 3);
+		src += (dispDeviceRowBytes >> 2);
+		dst += (dispDeviceRowBytes >> 2);
 	}
 	for (i=0; i<16; i++)
 	{
-		unsigned long *dst_ptr = dst;
+		unsigned int *dst_ptr = dst;
 		for(j=width; j; --j)
 			*(dst_ptr++) = 0;
-		dst += (dispDeviceRowBytes >> 3);
+		dst += (dispDeviceRowBytes >> 2);
 	}
 }
 #endif /* ndef NO_SCROLL */
@@ -377,6 +425,14 @@ void btext_drawstring(const char *c)
 		btext_drawchar(*c++);
 }
 
+void btext_drawtext(const char *c, unsigned int len)
+{
+	if (!boot_text_mapped)
+		return;
+	while (len--)
+		btext_drawchar(*c++);
+}
+
 void btext_drawhex(unsigned long v)
 {
 	char *hex_table = "0123456789abcdef";

arch/powerpc/kernel/head_32.S

@@ -153,6 +153,9 @@ __after_mmu_off:
 	bl	flush_tlbs
 
 	bl	initial_bats
+#if !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT)
+	bl	setup_disp_bat
+#endif
 
 /*
  * Call setup_cpu for CPU 0 and initialize 6xx Idle
@@ -1306,6 +1309,32 @@ initial_bats:
 	blr
 
 
+#if !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT)
+setup_disp_bat:
+	/*
+	 * setup the display bat prepared for us in prom.c
+	 */
+	mflr	r8
+	bl	reloc_offset
+	mtlr	r8
+	addis	r8,r3,disp_BAT@ha
+	addi	r8,r8,disp_BAT@l
+	cmpwi	cr0,r8,0
+	beqlr
+	lwz	r11,0(r8)
+	lwz	r8,4(r8)
+	mfspr	r9,SPRN_PVR
+	rlwinm	r9,r9,16,16,31		/* r9 = 1 for 601, 4 for 604 */
+	cmpwi	0,r9,1
+	beq	1f
+	mtspr	SPRN_DBAT3L,r8
+	mtspr	SPRN_DBAT3U,r11
+	blr
+1:	mtspr	SPRN_IBAT3L,r8
+	mtspr	SPRN_IBAT3U,r11
+	blr
+#endif /* !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT) */
+
 #ifdef CONFIG_8260
 /* Jump into the system reset for the rom.
  * We first disable the MMU, and then jump to the ROM reset address.

arch/powerpc/kernel/setup_32.c

@@ -40,6 +40,7 @@
 #include <asm/xmon.h>
 #include <asm/time.h>
 #include <asm/serial.h>
+#include <asm/udbg.h>
 
 #include "setup.h"
 
@@ -173,12 +174,23 @@ void __init platform_init(void)
  */
 void __init machine_init(unsigned long dt_ptr, unsigned long phys)
 {
+	/* If btext is enabled, we might have a BAT setup for early display,
+	 * thus we do enable some very basic udbg output
+	 */
+#ifdef CONFIG_BOOTX_TEXT
+	udbg_putc = btext_drawchar;
+#endif
+
+	/* Do some early initialization based on the flat device tree */
 	early_init_devtree(__va(dt_ptr));
 
+	/* Check default command line */
 #ifdef CONFIG_CMDLINE
-	strlcpy(cmd_line, CONFIG_CMDLINE, sizeof(cmd_line));
+	if (cmd_line[0] == 0)
+		strlcpy(cmd_line, CONFIG_CMDLINE, sizeof(cmd_line));
 #endif /* CONFIG_CMDLINE */
 
+	/* Base init based on machine type */
 	platform_init();
 
 #ifdef CONFIG_6xx
@@ -294,21 +306,11 @@ void __init setup_arch(char **cmdline_p)
 
 	smp_setup_cpu_maps();
 
-#ifdef CONFIG_BOOTX_TEXT
-	init_boot_display();
-#endif
-
-#ifdef CONFIG_PPC_PMAC
-	/* This could be called "early setup arch", it must be done
-	 * now because xmon need it
-	 */
-	if (_machine == _MACH_Pmac)
-		pmac_feature_init();	/* New cool way */
-#endif
-
 #ifdef CONFIG_XMON_DEFAULT
 	xmon_init(1);
 #endif
+	/* Register early console */
+	register_early_udbg_console();
 
 #if defined(CONFIG_KGDB)
 	if (ppc_md.kgdb_map_scc)

arch/powerpc/kernel/setup_64.c

@@ -474,10 +474,6 @@ void __init setup_system(void)
 	 */
 	finish_device_tree();
 
-#ifdef CONFIG_BOOTX_TEXT
-	init_boot_display();
-#endif
-
 	/*
 	 * Initialize xmon
 	 */