Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 726 insertions, 0 deletions

diff --git a/drivers/video/fbdev/offb.c b/drivers/video/fbdev/offb.c
new file mode 100644
index 000000000..166b2dff3
--- /dev/null
+++ b/drivers/video/fbdev/offb.c
@@ -0,0 +1,726 @@
+/*
+ *  linux/drivers/video/offb.c -- Open Firmware based frame buffer device
+ *
+ *	Copyright (C) 1997 Geert Uytterhoeven
+ *
+ *  This driver is partly based on the PowerMac console driver:
+ *
+ *	Copyright (C) 1996 Paul Mackerras
+ *
+ *  This file is subject to the terms and conditions of the GNU General Public
+ *  License. See the file COPYING in the main directory of this archive for
+ *  more details.
+ */
+
+#include <linux/aperture.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/interrupt.h>
+#include <linux/fb.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <asm/io.h>
+
+#ifdef CONFIG_PPC32
+#include <asm/bootx.h>
+#endif
+
+#include "macmodes.h"
+
+/* Supported palette hacks */
+enum {
+	cmap_unknown,
+	cmap_simple,		/* ATI Mach64 */
+	cmap_r128,		/* ATI Rage128 */
+	cmap_M3A,		/* ATI Rage Mobility M3 Head A */
+	cmap_M3B,		/* ATI Rage Mobility M3 Head B */
+	cmap_radeon,		/* ATI Radeon */
+	cmap_gxt2000,		/* IBM GXT2000 */
+	cmap_avivo,		/* ATI R5xx */
+	cmap_qemu,		/* qemu vga */
+};
+
+struct offb_par {
+	volatile void __iomem *cmap_adr;
+	volatile void __iomem *cmap_data;
+	int cmap_type;
+	int blanked;
+	u32 pseudo_palette[16];
+	resource_size_t base;
+	resource_size_t size;
+};
+
+#ifdef CONFIG_PPC32
+extern boot_infos_t *boot_infos;
+#endif
+
+/* Definitions used by the Avivo palette hack */
+#define AVIVO_DC_LUT_RW_SELECT                  0x6480
+#define AVIVO_DC_LUT_RW_MODE                    0x6484
+#define AVIVO_DC_LUT_RW_INDEX                   0x6488
+#define AVIVO_DC_LUT_SEQ_COLOR                  0x648c
+#define AVIVO_DC_LUT_PWL_DATA                   0x6490
+#define AVIVO_DC_LUT_30_COLOR                   0x6494
+#define AVIVO_DC_LUT_READ_PIPE_SELECT           0x6498
+#define AVIVO_DC_LUT_WRITE_EN_MASK              0x649c
+#define AVIVO_DC_LUT_AUTOFILL                   0x64a0
+
+#define AVIVO_DC_LUTA_CONTROL                   0x64c0
+#define AVIVO_DC_LUTA_BLACK_OFFSET_BLUE         0x64c4
+#define AVIVO_DC_LUTA_BLACK_OFFSET_GREEN        0x64c8
+#define AVIVO_DC_LUTA_BLACK_OFFSET_RED          0x64cc
+#define AVIVO_DC_LUTA_WHITE_OFFSET_BLUE         0x64d0
+#define AVIVO_DC_LUTA_WHITE_OFFSET_GREEN        0x64d4
+#define AVIVO_DC_LUTA_WHITE_OFFSET_RED          0x64d8
+
+#define AVIVO_DC_LUTB_CONTROL                   0x6cc0
+#define AVIVO_DC_LUTB_BLACK_OFFSET_BLUE         0x6cc4
+#define AVIVO_DC_LUTB_BLACK_OFFSET_GREEN        0x6cc8
+#define AVIVO_DC_LUTB_BLACK_OFFSET_RED          0x6ccc
+#define AVIVO_DC_LUTB_WHITE_OFFSET_BLUE         0x6cd0
+#define AVIVO_DC_LUTB_WHITE_OFFSET_GREEN        0x6cd4
+#define AVIVO_DC_LUTB_WHITE_OFFSET_RED          0x6cd8
+
+    /*
+     *  Set a single color register. The values supplied are already
+     *  rounded down to the hardware's capabilities (according to the
+     *  entries in the var structure). Return != 0 for invalid regno.
+     */
+
+static int offb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
+			  u_int transp, struct fb_info *info)
+{
+	struct offb_par *par = (struct offb_par *) info->par;
+
+	if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
+		u32 *pal = info->pseudo_palette;
+		u32 cr = red >> (16 - info->var.red.length);
+		u32 cg = green >> (16 - info->var.green.length);
+		u32 cb = blue >> (16 - info->var.blue.length);
+		u32 value;
+
+		if (regno >= 16)
+			return -EINVAL;
+
+		value = (cr << info->var.red.offset) |
+			(cg << info->var.green.offset) |
+			(cb << info->var.blue.offset);
+		if (info->var.transp.length > 0) {
+			u32 mask = (1 << info->var.transp.length) - 1;
+			mask <<= info->var.transp.offset;
+			value |= mask;
+		}
+		pal[regno] = value;
+		return 0;
+	}
+
+	if (regno > 255)
+		return -EINVAL;
+
+	red >>= 8;
+	green >>= 8;
+	blue >>= 8;
+
+	if (!par->cmap_adr)
+		return 0;
+
+	switch (par->cmap_type) {
+	case cmap_simple:
+		writeb(regno, par->cmap_adr);
+		writeb(red, par->cmap_data);
+		writeb(green, par->cmap_data);
+		writeb(blue, par->cmap_data);
+		break;
+	case cmap_M3A:
+		/* Clear PALETTE_ACCESS_CNTL in DAC_CNTL */
+		out_le32(par->cmap_adr + 0x58,
+			 in_le32(par->cmap_adr + 0x58) & ~0x20);
+		fallthrough;
+	case cmap_r128:
+		/* Set palette index & data */
+		out_8(par->cmap_adr + 0xb0, regno);
+		out_le32(par->cmap_adr + 0xb4,
+			 (red << 16 | green << 8 | blue));
+		break;
+	case cmap_M3B:
+		/* Set PALETTE_ACCESS_CNTL in DAC_CNTL */
+		out_le32(par->cmap_adr + 0x58,
+			 in_le32(par->cmap_adr + 0x58) | 0x20);
+		/* Set palette index & data */
+		out_8(par->cmap_adr + 0xb0, regno);
+		out_le32(par->cmap_adr + 0xb4, (red << 16 | green << 8 | blue));
+		break;
+	case cmap_radeon:
+		/* Set palette index & data (could be smarter) */
+		out_8(par->cmap_adr + 0xb0, regno);
+		out_le32(par->cmap_adr + 0xb4, (red << 16 | green << 8 | blue));
+		break;
+	case cmap_gxt2000:
+		out_le32(((unsigned __iomem *) par->cmap_adr) + regno,
+			 (red << 16 | green << 8 | blue));
+		break;
+	case cmap_avivo:
+		/* Write to both LUTs for now */
+		writel(1, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
+		writeb(regno, par->cmap_adr + AVIVO_DC_LUT_RW_INDEX);
+		writel(((red) << 22) | ((green) << 12) | ((blue) << 2),
+		       par->cmap_adr + AVIVO_DC_LUT_30_COLOR);
+		writel(0, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
+		writeb(regno, par->cmap_adr + AVIVO_DC_LUT_RW_INDEX);
+		writel(((red) << 22) | ((green) << 12) | ((blue) << 2),
+		       par->cmap_adr + AVIVO_DC_LUT_30_COLOR);
+		break;
+	}
+
+	return 0;
+}
+
+    /*
+     *  Blank the display.
+     */
+
+static int offb_blank(int blank, struct fb_info *info)
+{
+	struct offb_par *par = (struct offb_par *) info->par;
+	int i, j;
+
+	if (!par->cmap_adr)
+		return 0;
+
+	if (!par->blanked)
+		if (!blank)
+			return 0;
+
+	par->blanked = blank;
+
+	if (blank)
+		for (i = 0; i < 256; i++) {
+			switch (par->cmap_type) {
+			case cmap_simple:
+				writeb(i, par->cmap_adr);
+				for (j = 0; j < 3; j++)
+					writeb(0, par->cmap_data);
+				break;
+			case cmap_M3A:
+				/* Clear PALETTE_ACCESS_CNTL in DAC_CNTL */
+				out_le32(par->cmap_adr + 0x58,
+					 in_le32(par->cmap_adr + 0x58) & ~0x20);
+				fallthrough;
+			case cmap_r128:
+				/* Set palette index & data */
+				out_8(par->cmap_adr + 0xb0, i);
+				out_le32(par->cmap_adr + 0xb4, 0);
+				break;
+			case cmap_M3B:
+				/* Set PALETTE_ACCESS_CNTL in DAC_CNTL */
+				out_le32(par->cmap_adr + 0x58,
+					 in_le32(par->cmap_adr + 0x58) | 0x20);
+				/* Set palette index & data */
+				out_8(par->cmap_adr + 0xb0, i);
+				out_le32(par->cmap_adr + 0xb4, 0);
+				break;
+			case cmap_radeon:
+				out_8(par->cmap_adr + 0xb0, i);
+				out_le32(par->cmap_adr + 0xb4, 0);
+				break;
+			case cmap_gxt2000:
+				out_le32(((unsigned __iomem *) par->cmap_adr) + i,
+					 0);
+				break;
+			case cmap_avivo:
+				writel(1, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
+				writeb(i, par->cmap_adr + AVIVO_DC_LUT_RW_INDEX);
+				writel(0, par->cmap_adr + AVIVO_DC_LUT_30_COLOR);
+				writel(0, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
+				writeb(i, par->cmap_adr + AVIVO_DC_LUT_RW_INDEX);
+				writel(0, par->cmap_adr + AVIVO_DC_LUT_30_COLOR);
+				break;
+			}
+	} else
+		fb_set_cmap(&info->cmap, info);
+	return 0;
+}
+
+static int offb_set_par(struct fb_info *info)
+{
+	struct offb_par *par = (struct offb_par *) info->par;
+
+	/* On avivo, initialize palette control */
+	if (par->cmap_type == cmap_avivo) {
+		writel(0, par->cmap_adr + AVIVO_DC_LUTA_CONTROL);
+		writel(0, par->cmap_adr + AVIVO_DC_LUTA_BLACK_OFFSET_BLUE);
+		writel(0, par->cmap_adr + AVIVO_DC_LUTA_BLACK_OFFSET_GREEN);
+		writel(0, par->cmap_adr + AVIVO_DC_LUTA_BLACK_OFFSET_RED);
+		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTA_WHITE_OFFSET_BLUE);
+		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTA_WHITE_OFFSET_GREEN);
+		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTA_WHITE_OFFSET_RED);
+		writel(0, par->cmap_adr + AVIVO_DC_LUTB_CONTROL);
+		writel(0, par->cmap_adr + AVIVO_DC_LUTB_BLACK_OFFSET_BLUE);
+		writel(0, par->cmap_adr + AVIVO_DC_LUTB_BLACK_OFFSET_GREEN);
+		writel(0, par->cmap_adr + AVIVO_DC_LUTB_BLACK_OFFSET_RED);
+		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTB_WHITE_OFFSET_BLUE);
+		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTB_WHITE_OFFSET_GREEN);
+		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTB_WHITE_OFFSET_RED);
+		writel(1, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
+		writel(0, par->cmap_adr + AVIVO_DC_LUT_RW_MODE);
+		writel(0x0000003f, par->cmap_adr + AVIVO_DC_LUT_WRITE_EN_MASK);
+		writel(0, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
+		writel(0, par->cmap_adr + AVIVO_DC_LUT_RW_MODE);
+		writel(0x0000003f, par->cmap_adr + AVIVO_DC_LUT_WRITE_EN_MASK);
+	}
+	return 0;
+}
+
+static void offb_destroy(struct fb_info *info)
+{
+	struct offb_par *par = info->par;
+
+	if (info->screen_base)
+		iounmap(info->screen_base);
+	release_mem_region(par->base, par->size);
+	fb_dealloc_cmap(&info->cmap);
+	framebuffer_release(info);
+}
+
+static const struct fb_ops offb_ops = {
+	.owner		= THIS_MODULE,
+	FB_DEFAULT_IOMEM_OPS,
+	.fb_destroy	= offb_destroy,
+	.fb_setcolreg	= offb_setcolreg,
+	.fb_set_par	= offb_set_par,
+	.fb_blank	= offb_blank,
+};
+
+static void __iomem *offb_map_reg(struct device_node *np, int index,
+				  unsigned long offset, unsigned long size)
+{
+	const __be32 *addrp;
+	u64 asize, taddr;
+	unsigned int flags;
+
+	addrp = of_get_pci_address(np, index, &asize, &flags);
+	if (addrp == NULL)
+		addrp = of_get_address(np, index, &asize, &flags);
+	if (addrp == NULL)
+		return NULL;
+	if ((flags & (IORESOURCE_IO | IORESOURCE_MEM)) == 0)
+		return NULL;
+	if ((offset + size) > asize)
+		return NULL;
+	taddr = of_translate_address(np, addrp);
+	if (taddr == OF_BAD_ADDR)
+		return NULL;
+	return ioremap(taddr + offset, size);
+}
+
+static void offb_init_palette_hacks(struct fb_info *info, struct device_node *dp,
+				    unsigned long address)
+{
+	struct offb_par *par = (struct offb_par *) info->par;
+
+	if (of_node_name_prefix(dp, "ATY,Rage128")) {
+		par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
+		if (par->cmap_adr)
+			par->cmap_type = cmap_r128;
+	} else if (of_node_name_prefix(dp, "ATY,RageM3pA") ||
+		   of_node_name_prefix(dp, "ATY,RageM3p12A")) {
+		par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
+		if (par->cmap_adr)
+			par->cmap_type = cmap_M3A;
+	} else if (of_node_name_prefix(dp, "ATY,RageM3pB")) {
+		par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
+		if (par->cmap_adr)
+			par->cmap_type = cmap_M3B;
+	} else if (of_node_name_prefix(dp, "ATY,Rage6")) {
+		par->cmap_adr = offb_map_reg(dp, 1, 0, 0x1fff);
+		if (par->cmap_adr)
+			par->cmap_type = cmap_radeon;
+	} else if (of_node_name_prefix(dp, "ATY,")) {
+		unsigned long base = address & 0xff000000UL;
+		par->cmap_adr =
+			ioremap(base + 0x7ff000, 0x1000) + 0xcc0;
+		par->cmap_data = par->cmap_adr + 1;
+		par->cmap_type = cmap_simple;
+	} else if (dp && (of_device_is_compatible(dp, "pci1014,b7") ||
+			  of_device_is_compatible(dp, "pci1014,21c"))) {
+		par->cmap_adr = offb_map_reg(dp, 0, 0x6000, 0x1000);
+		if (par->cmap_adr)
+			par->cmap_type = cmap_gxt2000;
+	} else if (of_node_name_prefix(dp, "vga,Display-")) {
+		/* Look for AVIVO initialized by SLOF */
+		struct device_node *pciparent __free(device_node) = of_get_parent(dp);
+		const u32 *vid, *did;
+		vid = of_get_property(pciparent, "vendor-id", NULL);
+		did = of_get_property(pciparent, "device-id", NULL);
+		/* This will match most R5xx */
+		if (vid && did && *vid == 0x1002 &&
+		    ((*did >= 0x7100 && *did < 0x7800) ||
+		     (*did >= 0x9400))) {
+			par->cmap_adr = offb_map_reg(pciparent, 2, 0, 0x10000);
+			if (par->cmap_adr)
+				par->cmap_type = cmap_avivo;
+		}
+	} else if (dp && of_device_is_compatible(dp, "qemu,std-vga")) {
+#ifdef __BIG_ENDIAN
+		const __be32 io_of_addr[3] = { 0x01000000, 0x0, 0x0 };
+#else
+		const __be32 io_of_addr[3] = { 0x00000001, 0x0, 0x0 };
+#endif
+		u64 io_addr = of_translate_address(dp, io_of_addr);
+		if (io_addr != OF_BAD_ADDR) {
+			par->cmap_adr = ioremap(io_addr + 0x3c8, 2);
+			if (par->cmap_adr) {
+				par->cmap_type = cmap_simple;
+				par->cmap_data = par->cmap_adr + 1;
+			}
+		}
+	}
+	info->fix.visual = (par->cmap_type != cmap_unknown) ?
+		FB_VISUAL_PSEUDOCOLOR : FB_VISUAL_STATIC_PSEUDOCOLOR;
+}
+
+static void offb_init_fb(struct platform_device *parent, const char *name,
+			 int width, int height, int depth,
+			 int pitch, unsigned long address,
+			 int foreign_endian, struct device_node *dp)
+{
+	unsigned long res_size = pitch * height;
+	unsigned long res_start = address;
+	struct fb_fix_screeninfo *fix;
+	struct fb_var_screeninfo *var;
+	struct fb_info *info;
+	struct offb_par *par;
+
+	if (!request_mem_region(res_start, res_size, "offb"))
+		return;
+
+	printk(KERN_INFO
+	       "Using unsupported %dx%d %s at %lx, depth=%d, pitch=%d\n",
+	       width, height, name, address, depth, pitch);
+	if (depth != 8 && depth != 15 && depth != 16 && depth != 32) {
+		printk(KERN_ERR "%pOF: can't use depth = %d\n", dp, depth);
+		release_mem_region(res_start, res_size);
+		return;
+	}
+
+	info = framebuffer_alloc(sizeof(*par), &parent->dev);
+	if (!info) {
+		release_mem_region(res_start, res_size);
+		return;
+	}
+	platform_set_drvdata(parent, info);
+	par = info->par;
+	fix = &info->fix;
+	var = &info->var;
+
+	if (name)
+		snprintf(fix->id, sizeof(fix->id), "OFfb %s", name);
+	else
+		snprintf(fix->id, sizeof(fix->id), "OFfb %pOFn", dp);
+
+
+	var->xres = var->xres_virtual = width;
+	var->yres = var->yres_virtual = height;
+	fix->line_length = pitch;
+
+	fix->smem_start = address;
+	fix->smem_len = pitch * height;
+	fix->type = FB_TYPE_PACKED_PIXELS;
+	fix->type_aux = 0;
+
+	par->cmap_type = cmap_unknown;
+	if (depth == 8)
+		offb_init_palette_hacks(info, dp, address);
+	else
+		fix->visual = FB_VISUAL_TRUECOLOR;
+
+	var->xoffset = var->yoffset = 0;
+	switch (depth) {
+	case 8:
+		var->bits_per_pixel = 8;
+		var->red.offset = 0;
+		var->red.length = 8;
+		var->green.offset = 0;
+		var->green.length = 8;
+		var->blue.offset = 0;
+		var->blue.length = 8;
+		var->transp.offset = 0;
+		var->transp.length = 0;
+		break;
+	case 15:		/* RGB 555 */
+		var->bits_per_pixel = 16;
+		var->red.offset = 10;
+		var->red.length = 5;
+		var->green.offset = 5;
+		var->green.length = 5;
+		var->blue.offset = 0;
+		var->blue.length = 5;
+		var->transp.offset = 0;
+		var->transp.length = 0;
+		break;
+	case 16:		/* RGB 565 */
+		var->bits_per_pixel = 16;
+		var->red.offset = 11;
+		var->red.length = 5;
+		var->green.offset = 5;
+		var->green.length = 6;
+		var->blue.offset = 0;
+		var->blue.length = 5;
+		var->transp.offset = 0;
+		var->transp.length = 0;
+		break;
+	case 32:		/* RGB 888 */
+		var->bits_per_pixel = 32;
+		var->red.offset = 16;
+		var->red.length = 8;
+		var->green.offset = 8;
+		var->green.length = 8;
+		var->blue.offset = 0;
+		var->blue.length = 8;
+		var->transp.offset = 24;
+		var->transp.length = 8;
+		break;
+	}
+	var->red.msb_right = var->green.msb_right = var->blue.msb_right =
+	    var->transp.msb_right = 0;
+	var->grayscale = 0;
+	var->nonstd = 0;
+	var->activate = 0;
+	var->height = var->width = -1;
+	var->pixclock = 10000;
+	var->left_margin = var->right_margin = 16;
+	var->upper_margin = var->lower_margin = 16;
+	var->hsync_len = var->vsync_len = 8;
+	var->sync = 0;
+	var->vmode = FB_VMODE_NONINTERLACED;
+
+	par->base = address;
+	par->size = fix->smem_len;
+
+	info->fbops = &offb_ops;
+	info->screen_base = ioremap(address, fix->smem_len);
+	info->pseudo_palette = par->pseudo_palette;
+	info->flags = foreign_endian;
+
+	fb_alloc_cmap(&info->cmap, 256, 0);
+
+	if (devm_aperture_acquire_for_platform_device(parent, par->base, par->size) < 0)
+		goto out_err;
+	if (register_framebuffer(info) < 0)
+		goto out_err;
+
+	fb_info(info, "Open Firmware frame buffer device on %pOF\n", dp);
+	return;
+
+out_err:
+	fb_dealloc_cmap(&info->cmap);
+	iounmap(info->screen_base);
+	iounmap(par->cmap_adr);
+	par->cmap_adr = NULL;
+	framebuffer_release(info);
+	release_mem_region(res_start, res_size);
+}
+
+
+static void offb_init_nodriver(struct platform_device *parent, struct device_node *dp,
+			       int no_real_node)
+{
+	unsigned int len;
+	int i, width = 640, height = 480, depth = 8, pitch = 640;
+	unsigned int flags, rsize, addr_prop = 0;
+	unsigned long max_size = 0;
+	u64 rstart, address = OF_BAD_ADDR;
+	const __be32 *pp, *addrp, *up;
+	u64 asize;
+	int foreign_endian = 0;
+
+#ifdef __BIG_ENDIAN
+	if (of_property_read_bool(dp, "little-endian"))
+		foreign_endian = FBINFO_FOREIGN_ENDIAN;
+#else
+	if (of_property_read_bool(dp, "big-endian"))
+		foreign_endian = FBINFO_FOREIGN_ENDIAN;
+#endif
+
+	pp = of_get_property(dp, "linux,bootx-depth", &len);
+	if (pp == NULL)
+		pp = of_get_property(dp, "depth", &len);
+	if (pp && len == sizeof(u32))
+		depth = be32_to_cpup(pp);
+
+	pp = of_get_property(dp, "linux,bootx-width", &len);
+	if (pp == NULL)
+		pp = of_get_property(dp, "width", &len);
+	if (pp && len == sizeof(u32))
+		width = be32_to_cpup(pp);
+
+	pp = of_get_property(dp, "linux,bootx-height", &len);
+	if (pp == NULL)
+		pp = of_get_property(dp, "height", &len);
+	if (pp && len == sizeof(u32))
+		height = be32_to_cpup(pp);
+
+	pp = of_get_property(dp, "linux,bootx-linebytes", &len);
+	if (pp == NULL)
+		pp = of_get_property(dp, "linebytes", &len);
+	if (pp && len == sizeof(u32) && (*pp != 0xffffffffu))
+		pitch = be32_to_cpup(pp);
+	else
+		pitch = width * ((depth + 7) / 8);
+
+	rsize = (unsigned long)pitch * (unsigned long)height;
+
+	/* Ok, now we try to figure out the address of the framebuffer.
+	 *
+	 * Unfortunately, Open Firmware doesn't provide a standard way to do
+	 * so. All we can do is a dodgy heuristic that happens to work in
+	 * practice. On most machines, the "address" property contains what
+	 * we need, though not on Matrox cards found in IBM machines. What I've
+	 * found that appears to give good results is to go through the PCI
+	 * ranges and pick one that is both big enough and if possible encloses
+	 * the "address" property. If none match, we pick the biggest
+	 */
+	up = of_get_property(dp, "linux,bootx-addr", &len);
+	if (up == NULL)
+		up = of_get_property(dp, "address", &len);
+	if (up && len == sizeof(u32))
+		addr_prop = *up;
+
+	/* Hack for when BootX is passing us */
+	if (no_real_node)
+		goto skip_addr;
+
+	for (i = 0; (addrp = of_get_address(dp, i, &asize, &flags))
+		     != NULL; i++) {
+		int match_addrp = 0;
+
+		if (!(flags & IORESOURCE_MEM))
+			continue;
+		if (asize < rsize)
+			continue;
+		rstart = of_translate_address(dp, addrp);
+		if (rstart == OF_BAD_ADDR)
+			continue;
+		if (addr_prop && (rstart <= addr_prop) &&
+		    ((rstart + asize) >= (addr_prop + rsize)))
+			match_addrp = 1;
+		if (match_addrp) {
+			address = addr_prop;
+			break;
+		}
+		if (rsize > max_size) {
+			max_size = rsize;
+			address = OF_BAD_ADDR;
+ 		}
+
+		if (address == OF_BAD_ADDR)
+			address = rstart;
+	}
+ skip_addr:
+	if (address == OF_BAD_ADDR && addr_prop)
+		address = (u64)addr_prop;
+	if (address != OF_BAD_ADDR) {
+#ifdef CONFIG_PCI
+		const __be32 *vidp, *didp;
+		u32 vid, did;
+		struct pci_dev *pdev;
+
+		vidp = of_get_property(dp, "vendor-id", NULL);
+		didp = of_get_property(dp, "device-id", NULL);
+		if (vidp && didp) {
+			vid = be32_to_cpup(vidp);
+			did = be32_to_cpup(didp);
+			pdev = pci_get_device(vid, did, NULL);
+			if (!pdev)
+				return;
+
+			if (pci_enable_device(pdev)) {
+				pci_dev_put(pdev);
+				return;
+			}
+		}
+#endif
+		/* kludge for valkyrie */
+		if (of_node_name_eq(dp, "valkyrie"))
+			address += 0x1000;
+		offb_init_fb(parent, no_real_node ? "bootx" : NULL,
+			     width, height, depth, pitch, address,
+			     foreign_endian, no_real_node ? NULL : dp);
+	}
+}
+
+static void offb_remove(struct platform_device *pdev)
+{
+	struct fb_info *info = platform_get_drvdata(pdev);
+
+	if (info)
+		unregister_framebuffer(info);
+}
+
+static int offb_probe_bootx_noscreen(struct platform_device *pdev)
+{
+	offb_init_nodriver(pdev, of_chosen, 1);
+
+	return 0;
+}
+
+static struct platform_driver offb_driver_bootx_noscreen = {
+	.driver = {
+		.name = "bootx-noscreen",
+	},
+	.probe = offb_probe_bootx_noscreen,
+	.remove = offb_remove,
+};
+
+static int offb_probe_display(struct platform_device *pdev)
+{
+	offb_init_nodriver(pdev, pdev->dev.of_node, 0);
+
+	return 0;
+}
+
+static const struct of_device_id offb_of_match_display[] = {
+	{ .compatible = "display", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, offb_of_match_display);
+
+static struct platform_driver offb_driver_display = {
+	.driver = {
+		.name = "of-display",
+		.of_match_table = offb_of_match_display,
+	},
+	.probe = offb_probe_display,
+	.remove = offb_remove,
+};
+
+static int __init offb_init(void)
+{
+	if (fb_get_options("offb", NULL))
+		return -ENODEV;
+
+	platform_driver_register(&offb_driver_bootx_noscreen);
+	platform_driver_register(&offb_driver_display);
+
+	return 0;
+}
+module_init(offb_init);
+
+static void __exit offb_exit(void)
+{
+	platform_driver_unregister(&offb_driver_display);
+	platform_driver_unregister(&offb_driver_bootx_noscreen);
+}
+module_exit(offb_exit);
+
+MODULE_DESCRIPTION("Open Firmware frame buffer device driver");
+MODULE_LICENSE("GPL");