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, 847 insertions, 0 deletions

diff --git a/drivers/mtd/devices/pmc551.c b/drivers/mtd/devices/pmc551.c
new file mode 100644
index 000000000..dc0ebfeb8
--- /dev/null
+++ b/drivers/mtd/devices/pmc551.c
@@ -0,0 +1,847 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PMC551 PCI Mezzanine Ram Device
+ *
+ * Author:
+ *	Mark Ferrell <mferrell@mvista.com>
+ *	Copyright 1999,2000 Nortel Networks
+ *
+ * Description:
+ *	This driver is intended to support the PMC551 PCI Ram device
+ *	from Ramix Inc.  The PMC551 is a PMC Mezzanine module for
+ *	cPCI embedded systems.  The device contains a single SROM
+ *	that initially programs the V370PDC chipset onboard the
+ *	device, and various banks of DRAM/SDRAM onboard.  This driver
+ *	implements this PCI Ram device as an MTD (Memory Technology
+ *	Device) so that it can be used to hold a file system, or for
+ *	added swap space in embedded systems.  Since the memory on
+ *	this board isn't as fast as main memory we do not try to hook
+ *	it into main memory as that would simply reduce performance
+ *	on the system.  Using it as a block device allows us to use
+ *	it as high speed swap or for a high speed disk device of some
+ *	sort.  Which becomes very useful on diskless systems in the
+ *	embedded market I might add.
+ *
+ * Notes:
+ *	Due to what I assume is more buggy SROM, the 64M PMC551 I
+ *	have available claims that all 4 of its DRAM banks have 64MiB
+ *	of ram configured (making a grand total of 256MiB onboard).
+ *	This is slightly annoying since the BAR0 size reflects the
+ *	aperture size, not the dram size, and the V370PDC supplies no
+ *	other method for memory size discovery.  This problem is
+ *	mostly only relevant when compiled as a module, as the
+ *	unloading of the module with an aperture size smaller than
+ *	the ram will cause the driver to detect the onboard memory
+ *	size to be equal to the aperture size when the module is
+ *	reloaded.  Soooo, to help, the module supports an msize
+ *	option to allow the specification of the onboard memory, and
+ *	an asize option, to allow the specification of the aperture
+ *	size.  The aperture must be equal to or less then the memory
+ *	size, the driver will correct this if you screw it up.  This
+ *	problem is not relevant for compiled in drivers as compiled
+ *	in drivers only init once.
+ *
+ * Credits:
+ *	Saeed Karamooz <saeed@ramix.com> of Ramix INC. for the
+ *	initial example code of how to initialize this device and for
+ *	help with questions I had concerning operation of the device.
+ *
+ *	Most of the MTD code for this driver was originally written
+ *	for the slram.o module in the MTD drivers package which
+ *	allows the mapping of system memory into an MTD device.
+ *	Since the PMC551 memory module is accessed in the same
+ *	fashion as system memory, the slram.c code became a very nice
+ *	fit to the needs of this driver.  All we added was PCI
+ *	detection/initialization to the driver and automatically figure
+ *	out the size via the PCI detection.o, later changes by Corey
+ *	Minyard set up the card to utilize a 1M sliding apature.
+ *
+ *	Corey Minyard <minyard@nortelnetworks.com>
+ *	* Modified driver to utilize a sliding aperture instead of
+ *	 mapping all memory into kernel space which turned out to
+ *	 be very wasteful.
+ *	* Located a bug in the SROM's initialization sequence that
+ *	 made the memory unusable, added a fix to code to touch up
+ *	 the DRAM some.
+ *
+ * Bugs/FIXMEs:
+ *	* MUST fix the init function to not spin on a register
+ *	waiting for it to set .. this does not safely handle busted
+ *	devices that never reset the register correctly which will
+ *	cause the system to hang w/ a reboot being the only chance at
+ *	recover. [sort of fixed, could be better]
+ *	* Add I2C handling of the SROM so we can read the SROM's information
+ *	about the aperture size.  This should always accurately reflect the
+ *	onboard memory size.
+ *	* Comb the init routine.  It's still a bit cludgy on a few things.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/major.h>
+#include <linux/fs.h>
+#include <linux/ioctl.h>
+#include <asm/io.h>
+#include <linux/pci.h>
+#include <linux/mtd/mtd.h>
+
+#define PMC551_VERSION \
+	"Ramix PMC551 PCI Mezzanine Ram Driver. (C) 1999,2000 Nortel Networks.\n"
+
+#define PCI_VENDOR_ID_V3_SEMI 0x11b0
+#define PCI_DEVICE_ID_V3_SEMI_V370PDC 0x0200
+
+#define PMC551_PCI_MEM_MAP0 0x50
+#define PMC551_PCI_MEM_MAP1 0x54
+#define PMC551_PCI_MEM_MAP_MAP_ADDR_MASK 0x3ff00000
+#define PMC551_PCI_MEM_MAP_APERTURE_MASK 0x000000f0
+#define PMC551_PCI_MEM_MAP_REG_EN 0x00000002
+#define PMC551_PCI_MEM_MAP_ENABLE 0x00000001
+
+#define PMC551_SDRAM_MA  0x60
+#define PMC551_SDRAM_CMD 0x62
+#define PMC551_DRAM_CFG  0x64
+#define PMC551_SYS_CTRL_REG 0x78
+
+#define PMC551_DRAM_BLK0 0x68
+#define PMC551_DRAM_BLK1 0x6c
+#define PMC551_DRAM_BLK2 0x70
+#define PMC551_DRAM_BLK3 0x74
+#define PMC551_DRAM_BLK_GET_SIZE(x) (524288 << ((x >> 4) & 0x0f))
+#define PMC551_DRAM_BLK_SET_COL_MUX(x, v) (((x) & ~0x00007000) | (((v) & 0x7) << 12))
+#define PMC551_DRAM_BLK_SET_ROW_MUX(x, v) (((x) & ~0x00000f00) | (((v) & 0xf) << 8))
+
+struct mypriv {
+	struct pci_dev *dev;
+	u_char *start;
+	u32 base_map0;
+	u32 curr_map0;
+	u32 asize;
+	struct mtd_info *nextpmc551;
+};
+
+static struct mtd_info *pmc551list;
+
+static int pmc551_point(struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, void **virt, resource_size_t *phys);
+
+static int pmc551_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct mypriv *priv = mtd->priv;
+	u32 soff_hi;		/* start address offset hi */
+	u32 eoff_hi, eoff_lo;	/* end address offset hi/lo */
+	unsigned long end;
+	u_char *ptr;
+	size_t retlen;
+
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_erase(pos:%ld, len:%ld)\n", (long)instr->addr,
+		(long)instr->len);
+#endif
+
+	end = instr->addr + instr->len - 1;
+	eoff_hi = end & ~(priv->asize - 1);
+	soff_hi = instr->addr & ~(priv->asize - 1);
+	eoff_lo = end & (priv->asize - 1);
+
+	pmc551_point(mtd, instr->addr, instr->len, &retlen,
+		     (void **)&ptr, NULL);
+
+	if (soff_hi == eoff_hi || mtd->size == priv->asize) {
+		/* The whole thing fits within one access, so just one shot
+		   will do it. */
+		memset(ptr, 0xff, instr->len);
+	} else {
+		/* We have to do multiple writes to get all the data
+		   written. */
+		while (soff_hi != eoff_hi) {
+#ifdef CONFIG_MTD_PMC551_DEBUG
+			printk(KERN_DEBUG "pmc551_erase() soff_hi: %ld, "
+				"eoff_hi: %ld\n", (long)soff_hi, (long)eoff_hi);
+#endif
+			memset(ptr, 0xff, priv->asize);
+			if (soff_hi + priv->asize >= mtd->size) {
+				goto out;
+			}
+			soff_hi += priv->asize;
+			pmc551_point(mtd, (priv->base_map0 | soff_hi),
+				     priv->asize, &retlen,
+				     (void **)&ptr, NULL);
+		}
+		memset(ptr, 0xff, eoff_lo);
+	}
+
+      out:
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_erase() done\n");
+#endif
+
+	return 0;
+}
+
+static int pmc551_point(struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, void **virt, resource_size_t *phys)
+{
+	struct mypriv *priv = mtd->priv;
+	u32 soff_hi;
+	u32 soff_lo;
+
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_point(%ld, %ld)\n", (long)from, (long)len);
+#endif
+
+	soff_hi = from & ~(priv->asize - 1);
+	soff_lo = from & (priv->asize - 1);
+
+	/* Cheap hack optimization */
+	if (priv->curr_map0 != from) {
+		pci_write_config_dword(priv->dev, PMC551_PCI_MEM_MAP0,
+					(priv->base_map0 | soff_hi));
+		priv->curr_map0 = soff_hi;
+	}
+
+	*virt = priv->start + soff_lo;
+	*retlen = len;
+	return 0;
+}
+
+static int pmc551_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
+{
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_unpoint()\n");
+#endif
+	return 0;
+}
+
+static int pmc551_read(struct mtd_info *mtd, loff_t from, size_t len,
+			size_t * retlen, u_char * buf)
+{
+	struct mypriv *priv = mtd->priv;
+	u32 soff_hi;		/* start address offset hi */
+	u32 eoff_hi, eoff_lo;	/* end address offset hi/lo */
+	unsigned long end;
+	u_char *ptr;
+	u_char *copyto = buf;
+
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_read(pos:%ld, len:%ld) asize: %ld\n",
+		(long)from, (long)len, (long)priv->asize);
+#endif
+
+	end = from + len - 1;
+	soff_hi = from & ~(priv->asize - 1);
+	eoff_hi = end & ~(priv->asize - 1);
+	eoff_lo = end & (priv->asize - 1);
+
+	pmc551_point(mtd, from, len, retlen, (void **)&ptr, NULL);
+
+	if (soff_hi == eoff_hi) {
+		/* The whole thing fits within one access, so just one shot
+		   will do it. */
+		memcpy(copyto, ptr, len);
+		copyto += len;
+	} else {
+		/* We have to do multiple writes to get all the data
+		   written. */
+		while (soff_hi != eoff_hi) {
+#ifdef CONFIG_MTD_PMC551_DEBUG
+			printk(KERN_DEBUG "pmc551_read() soff_hi: %ld, "
+				"eoff_hi: %ld\n", (long)soff_hi, (long)eoff_hi);
+#endif
+			memcpy(copyto, ptr, priv->asize);
+			copyto += priv->asize;
+			if (soff_hi + priv->asize >= mtd->size) {
+				goto out;
+			}
+			soff_hi += priv->asize;
+			pmc551_point(mtd, soff_hi, priv->asize, retlen,
+				     (void **)&ptr, NULL);
+		}
+		memcpy(copyto, ptr, eoff_lo);
+		copyto += eoff_lo;
+	}
+
+      out:
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_read() done\n");
+#endif
+	*retlen = copyto - buf;
+	return 0;
+}
+
+static int pmc551_write(struct mtd_info *mtd, loff_t to, size_t len,
+			size_t * retlen, const u_char * buf)
+{
+	struct mypriv *priv = mtd->priv;
+	u32 soff_hi;		/* start address offset hi */
+	u32 eoff_hi, eoff_lo;	/* end address offset hi/lo */
+	unsigned long end;
+	u_char *ptr;
+	const u_char *copyfrom = buf;
+
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_write(pos:%ld, len:%ld) asize:%ld\n",
+		(long)to, (long)len, (long)priv->asize);
+#endif
+
+	end = to + len - 1;
+	soff_hi = to & ~(priv->asize - 1);
+	eoff_hi = end & ~(priv->asize - 1);
+	eoff_lo = end & (priv->asize - 1);
+
+	pmc551_point(mtd, to, len, retlen, (void **)&ptr, NULL);
+
+	if (soff_hi == eoff_hi) {
+		/* The whole thing fits within one access, so just one shot
+		   will do it. */
+		memcpy(ptr, copyfrom, len);
+		copyfrom += len;
+	} else {
+		/* We have to do multiple writes to get all the data
+		   written. */
+		while (soff_hi != eoff_hi) {
+#ifdef CONFIG_MTD_PMC551_DEBUG
+			printk(KERN_DEBUG "pmc551_write() soff_hi: %ld, "
+				"eoff_hi: %ld\n", (long)soff_hi, (long)eoff_hi);
+#endif
+			memcpy(ptr, copyfrom, priv->asize);
+			copyfrom += priv->asize;
+			if (soff_hi >= mtd->size) {
+				goto out;
+			}
+			soff_hi += priv->asize;
+			pmc551_point(mtd, soff_hi, priv->asize, retlen,
+				     (void **)&ptr, NULL);
+		}
+		memcpy(ptr, copyfrom, eoff_lo);
+		copyfrom += eoff_lo;
+	}
+
+      out:
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_write() done\n");
+#endif
+	*retlen = copyfrom - buf;
+	return 0;
+}
+
+/*
+ * Fixup routines for the V370PDC
+ * PCI device ID 0x020011b0
+ *
+ * This function basically kick starts the DRAM oboard the card and gets it
+ * ready to be used.  Before this is done the device reads VERY erratic, so
+ * much that it can crash the Linux 2.2.x series kernels when a user cat's
+ * /proc/pci .. though that is mainly a kernel bug in handling the PCI DEVSEL
+ * register.  FIXME: stop spinning on registers .. must implement a timeout
+ * mechanism
+ * returns the size of the memory region found.
+ */
+static int __init fixup_pmc551(struct pci_dev *dev)
+{
+#ifdef CONFIG_MTD_PMC551_BUGFIX
+	u32 dram_data;
+#endif
+	u32 size, dcmd, cfg, dtmp;
+	u16 cmd, tmp, i;
+	u8 bcmd, counter;
+
+	/* Sanity Check */
+	if (!dev) {
+		return -ENODEV;
+	}
+
+	/*
+	 * Attempt to reset the card
+	 * FIXME: Stop Spinning registers
+	 */
+	counter = 0;
+	/* unlock registers */
+	pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, 0xA5);
+	/* read in old data */
+	pci_read_config_byte(dev, PMC551_SYS_CTRL_REG, &bcmd);
+	/* bang the reset line up and down for a few */
+	for (i = 0; i < 10; i++) {
+		counter = 0;
+		bcmd &= ~0x80;
+		while (counter++ < 100) {
+			pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, bcmd);
+		}
+		counter = 0;
+		bcmd |= 0x80;
+		while (counter++ < 100) {
+			pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, bcmd);
+		}
+	}
+	bcmd |= (0x40 | 0x20);
+	pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, bcmd);
+
+	/*
+	 * Take care and turn off the memory on the device while we
+	 * tweak the configurations
+	 */
+	pci_read_config_word(dev, PCI_COMMAND, &cmd);
+	tmp = cmd & ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
+	pci_write_config_word(dev, PCI_COMMAND, tmp);
+
+	/*
+	 * Disable existing aperture before probing memory size
+	 */
+	pci_read_config_dword(dev, PMC551_PCI_MEM_MAP0, &dcmd);
+	dtmp = (dcmd | PMC551_PCI_MEM_MAP_ENABLE | PMC551_PCI_MEM_MAP_REG_EN);
+	pci_write_config_dword(dev, PMC551_PCI_MEM_MAP0, dtmp);
+	/*
+	 * Grab old BAR0 config so that we can figure out memory size
+	 * This is another bit of kludge going on.  The reason for the
+	 * redundancy is I am hoping to retain the original configuration
+	 * previously assigned to the card by the BIOS or some previous
+	 * fixup routine in the kernel.  So we read the old config into cfg,
+	 * then write all 1's to the memory space, read back the result into
+	 * "size", and then write back all the old config.
+	 */
+	pci_read_config_dword(dev, PCI_BASE_ADDRESS_0, &cfg);
+#ifndef CONFIG_MTD_PMC551_BUGFIX
+	pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, ~0);
+	pci_read_config_dword(dev, PCI_BASE_ADDRESS_0, &size);
+	size = (size & PCI_BASE_ADDRESS_MEM_MASK);
+	size &= ~(size - 1);
+	pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, cfg);
+#else
+	/*
+	 * Get the size of the memory by reading all the DRAM size values
+	 * and adding them up.
+	 *
+	 * KLUDGE ALERT: the boards we are using have invalid column and
+	 * row mux values.  We fix them here, but this will break other
+	 * memory configurations.
+	 */
+	pci_read_config_dword(dev, PMC551_DRAM_BLK0, &dram_data);
+	size = PMC551_DRAM_BLK_GET_SIZE(dram_data);
+	dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
+	dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
+	pci_write_config_dword(dev, PMC551_DRAM_BLK0, dram_data);
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK1, &dram_data);
+	size += PMC551_DRAM_BLK_GET_SIZE(dram_data);
+	dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
+	dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
+	pci_write_config_dword(dev, PMC551_DRAM_BLK1, dram_data);
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK2, &dram_data);
+	size += PMC551_DRAM_BLK_GET_SIZE(dram_data);
+	dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
+	dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
+	pci_write_config_dword(dev, PMC551_DRAM_BLK2, dram_data);
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK3, &dram_data);
+	size += PMC551_DRAM_BLK_GET_SIZE(dram_data);
+	dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
+	dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
+	pci_write_config_dword(dev, PMC551_DRAM_BLK3, dram_data);
+
+	/*
+	 * Oops .. something went wrong
+	 */
+	if ((size &= PCI_BASE_ADDRESS_MEM_MASK) == 0) {
+		return -ENODEV;
+	}
+#endif				/* CONFIG_MTD_PMC551_BUGFIX */
+
+	if ((cfg & PCI_BASE_ADDRESS_SPACE) != PCI_BASE_ADDRESS_SPACE_MEMORY) {
+		return -ENODEV;
+	}
+
+	/*
+	 * Precharge Dram
+	 */
+	pci_write_config_word(dev, PMC551_SDRAM_MA, 0x0400);
+	pci_write_config_word(dev, PMC551_SDRAM_CMD, 0x00bf);
+
+	/*
+	 * Wait until command has gone through
+	 * FIXME: register spinning issue
+	 */
+	do {
+		pci_read_config_word(dev, PMC551_SDRAM_CMD, &cmd);
+		if (counter++ > 100)
+			break;
+	} while ((PCI_COMMAND_IO) & cmd);
+
+	/*
+	 * Turn on auto refresh
+	 * The loop is taken directly from Ramix's example code.  I assume that
+	 * this must be held high for some duration of time, but I can find no
+	 * documentation refrencing the reasons why.
+	 */
+	for (i = 1; i <= 8; i++) {
+		pci_write_config_word(dev, PMC551_SDRAM_CMD, 0x0df);
+
+		/*
+		 * Make certain command has gone through
+		 * FIXME: register spinning issue
+		 */
+		counter = 0;
+		do {
+			pci_read_config_word(dev, PMC551_SDRAM_CMD, &cmd);
+			if (counter++ > 100)
+				break;
+		} while ((PCI_COMMAND_IO) & cmd);
+	}
+
+	pci_write_config_word(dev, PMC551_SDRAM_MA, 0x0020);
+	pci_write_config_word(dev, PMC551_SDRAM_CMD, 0x0ff);
+
+	/*
+	 * Wait until command completes
+	 * FIXME: register spinning issue
+	 */
+	counter = 0;
+	do {
+		pci_read_config_word(dev, PMC551_SDRAM_CMD, &cmd);
+		if (counter++ > 100)
+			break;
+	} while ((PCI_COMMAND_IO) & cmd);
+
+	pci_read_config_dword(dev, PMC551_DRAM_CFG, &dcmd);
+	dcmd |= 0x02000000;
+	pci_write_config_dword(dev, PMC551_DRAM_CFG, dcmd);
+
+	/*
+	 * Check to make certain fast back-to-back, if not
+	 * then set it so
+	 */
+	pci_read_config_word(dev, PCI_STATUS, &cmd);
+	if ((cmd & PCI_COMMAND_FAST_BACK) == 0) {
+		cmd |= PCI_COMMAND_FAST_BACK;
+		pci_write_config_word(dev, PCI_STATUS, cmd);
+	}
+
+	/*
+	 * Check to make certain the DEVSEL is set correctly, this device
+	 * has a tendency to assert DEVSEL and TRDY when a write is performed
+	 * to the memory when memory is read-only
+	 */
+	if ((cmd & PCI_STATUS_DEVSEL_MASK) != 0x0) {
+		cmd &= ~PCI_STATUS_DEVSEL_MASK;
+		pci_write_config_word(dev, PCI_STATUS, cmd);
+	}
+	/*
+	 * Set to be prefetchable and put everything back based on old cfg.
+	 * it's possible that the reset of the V370PDC nuked the original
+	 * setup
+	 */
+	/*
+	   cfg |= PCI_BASE_ADDRESS_MEM_PREFETCH;
+	   pci_write_config_dword( dev, PCI_BASE_ADDRESS_0, cfg );
+	 */
+
+	/*
+	 * Turn PCI memory and I/O bus access back on
+	 */
+	pci_write_config_word(dev, PCI_COMMAND,
+			      PCI_COMMAND_MEMORY | PCI_COMMAND_IO);
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	/*
+	 * Some screen fun
+	 */
+	printk(KERN_DEBUG "pmc551: %d%sB (0x%x) of %sprefetchable memory at "
+		"0x%llx\n", (size < 1024) ? size : (size < 1048576) ?
+		size >> 10 : size >> 20,
+		(size < 1024) ? "" : (size < 1048576) ? "Ki" : "Mi", size,
+		((dcmd & (0x1 << 3)) == 0) ? "non-" : "",
+		(unsigned long long)pci_resource_start(dev, 0));
+
+	/*
+	 * Check to see the state of the memory
+	 */
+	pci_read_config_dword(dev, PMC551_DRAM_BLK0, &dcmd);
+	printk(KERN_DEBUG "pmc551: DRAM_BLK0 Flags: %s,%s\n"
+		"pmc551: DRAM_BLK0 Size: %d at %d\n"
+		"pmc551: DRAM_BLK0 Row MUX: %d, Col MUX: %d\n",
+		(((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
+		(((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
+		PMC551_DRAM_BLK_GET_SIZE(dcmd),
+		((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
+		((dcmd >> 9) & 0xF));
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK1, &dcmd);
+	printk(KERN_DEBUG "pmc551: DRAM_BLK1 Flags: %s,%s\n"
+		"pmc551: DRAM_BLK1 Size: %d at %d\n"
+		"pmc551: DRAM_BLK1 Row MUX: %d, Col MUX: %d\n",
+		(((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
+		(((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
+		PMC551_DRAM_BLK_GET_SIZE(dcmd),
+		((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
+		((dcmd >> 9) & 0xF));
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK2, &dcmd);
+	printk(KERN_DEBUG "pmc551: DRAM_BLK2 Flags: %s,%s\n"
+		"pmc551: DRAM_BLK2 Size: %d at %d\n"
+		"pmc551: DRAM_BLK2 Row MUX: %d, Col MUX: %d\n",
+		(((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
+		(((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
+		PMC551_DRAM_BLK_GET_SIZE(dcmd),
+		((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
+		((dcmd >> 9) & 0xF));
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK3, &dcmd);
+	printk(KERN_DEBUG "pmc551: DRAM_BLK3 Flags: %s,%s\n"
+		"pmc551: DRAM_BLK3 Size: %d at %d\n"
+		"pmc551: DRAM_BLK3 Row MUX: %d, Col MUX: %d\n",
+		(((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
+		(((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
+		PMC551_DRAM_BLK_GET_SIZE(dcmd),
+		((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
+		((dcmd >> 9) & 0xF));
+
+	pci_read_config_word(dev, PCI_COMMAND, &cmd);
+	printk(KERN_DEBUG "pmc551: Memory Access %s\n",
+		(((0x1 << 1) & cmd) == 0) ? "off" : "on");
+	printk(KERN_DEBUG "pmc551: I/O Access %s\n",
+		(((0x1 << 0) & cmd) == 0) ? "off" : "on");
+
+	pci_read_config_word(dev, PCI_STATUS, &cmd);
+	printk(KERN_DEBUG "pmc551: Devsel %s\n",
+		((PCI_STATUS_DEVSEL_MASK & cmd) == 0x000) ? "Fast" :
+		((PCI_STATUS_DEVSEL_MASK & cmd) == 0x200) ? "Medium" :
+		((PCI_STATUS_DEVSEL_MASK & cmd) == 0x400) ? "Slow" : "Invalid");
+
+	printk(KERN_DEBUG "pmc551: %sFast Back-to-Back\n",
+		((PCI_COMMAND_FAST_BACK & cmd) == 0) ? "Not " : "");
+
+	pci_read_config_byte(dev, PMC551_SYS_CTRL_REG, &bcmd);
+	printk(KERN_DEBUG "pmc551: EEPROM is under %s control\n"
+		"pmc551: System Control Register is %slocked to PCI access\n"
+		"pmc551: System Control Register is %slocked to EEPROM access\n",
+		(bcmd & 0x1) ? "software" : "hardware",
+		(bcmd & 0x20) ? "" : "un", (bcmd & 0x40) ? "" : "un");
+#endif
+	return size;
+}
+
+/*
+ * Kernel version specific module stuffages
+ */
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mark Ferrell <mferrell@mvista.com>");
+MODULE_DESCRIPTION(PMC551_VERSION);
+
+/*
+ * Stuff these outside the ifdef so as to not bust compiled in driver support
+ */
+static int msize = 0;
+static int asize = 0;
+
+module_param(msize, int, 0);
+MODULE_PARM_DESC(msize, "memory size in MiB [1 - 1024]");
+module_param(asize, int, 0);
+MODULE_PARM_DESC(asize, "aperture size, must be <= memsize [1-1024]");
+
+/*
+ * PMC551 Card Initialization
+ */
+static int __init init_pmc551(void)
+{
+	struct pci_dev *PCI_Device = NULL;
+	struct mypriv *priv;
+	int found = 0;
+	struct mtd_info *mtd;
+	int length = 0;
+
+	if (msize) {
+		msize = (1 << (ffs(msize) - 1)) << 20;
+		if (msize > (1 << 30)) {
+			printk(KERN_NOTICE "pmc551: Invalid memory size [%d]\n",
+				msize);
+			return -EINVAL;
+		}
+	}
+
+	if (asize) {
+		asize = (1 << (ffs(asize) - 1)) << 20;
+		if (asize > (1 << 30)) {
+			printk(KERN_NOTICE "pmc551: Invalid aperture size "
+				"[%d]\n", asize);
+			return -EINVAL;
+		}
+	}
+
+	printk(KERN_INFO PMC551_VERSION);
+
+	/*
+	 * PCU-bus chipset probe.
+	 */
+	for (;;) {
+
+		if ((PCI_Device = pci_get_device(PCI_VENDOR_ID_V3_SEMI,
+						  PCI_DEVICE_ID_V3_SEMI_V370PDC,
+						  PCI_Device)) == NULL) {
+			break;
+		}
+
+		printk(KERN_NOTICE "pmc551: Found PCI V370PDC at 0x%llx\n",
+			(unsigned long long)pci_resource_start(PCI_Device, 0));
+
+		/*
+		 * The PMC551 device acts VERY weird if you don't init it
+		 * first.  i.e. it will not correctly report devsel.  If for
+		 * some reason the sdram is in a wrote-protected state the
+		 * device will DEVSEL when it is written to causing problems
+		 * with the oldproc.c driver in
+		 * some kernels (2.2.*)
+		 */
+		if ((length = fixup_pmc551(PCI_Device)) <= 0) {
+			printk(KERN_NOTICE "pmc551: Cannot init SDRAM\n");
+			break;
+		}
+
+		/*
+		 * This is needed until the driver is capable of reading the
+		 * onboard I2C SROM to discover the "real" memory size.
+		 */
+		if (msize) {
+			length = msize;
+			printk(KERN_NOTICE "pmc551: Using specified memory "
+				"size 0x%x\n", length);
+		} else {
+			msize = length;
+		}
+
+		mtd = kzalloc_obj(struct mtd_info);
+		if (!mtd)
+			break;
+
+		priv = kzalloc_obj(struct mypriv);
+		if (!priv) {
+			kfree(mtd);
+			break;
+		}
+		mtd->priv = priv;
+		priv->dev = PCI_Device;
+
+		if (asize > length) {
+			printk(KERN_NOTICE "pmc551: reducing aperture size to "
+				"fit %dM\n", length >> 20);
+			priv->asize = asize = length;
+		} else if (asize == 0 || asize == length) {
+			printk(KERN_NOTICE "pmc551: Using existing aperture "
+				"size %dM\n", length >> 20);
+			priv->asize = asize = length;
+		} else {
+			printk(KERN_NOTICE "pmc551: Using specified aperture "
+				"size %dM\n", asize >> 20);
+			priv->asize = asize;
+		}
+		priv->start = pci_iomap(PCI_Device, 0, priv->asize);
+
+		if (!priv->start) {
+			printk(KERN_NOTICE "pmc551: Unable to map IO space\n");
+			kfree(mtd->priv);
+			kfree(mtd);
+			break;
+		}
+#ifdef CONFIG_MTD_PMC551_DEBUG
+		printk(KERN_DEBUG "pmc551: setting aperture to %d\n",
+			ffs(priv->asize >> 20) - 1);
+#endif
+
+		priv->base_map0 = (PMC551_PCI_MEM_MAP_REG_EN
+				   | PMC551_PCI_MEM_MAP_ENABLE
+				   | (ffs(priv->asize >> 20) - 1) << 4);
+		priv->curr_map0 = priv->base_map0;
+		pci_write_config_dword(priv->dev, PMC551_PCI_MEM_MAP0,
+					priv->curr_map0);
+
+#ifdef CONFIG_MTD_PMC551_DEBUG
+		printk(KERN_DEBUG "pmc551: aperture set to %d\n",
+			(priv->base_map0 & 0xF0) >> 4);
+#endif
+
+		mtd->size = msize;
+		mtd->flags = MTD_CAP_RAM;
+		mtd->_erase = pmc551_erase;
+		mtd->_read = pmc551_read;
+		mtd->_write = pmc551_write;
+		mtd->_point = pmc551_point;
+		mtd->_unpoint = pmc551_unpoint;
+		mtd->type = MTD_RAM;
+		mtd->name = "PMC551 RAM board";
+		mtd->erasesize = 0x10000;
+		mtd->writesize = 1;
+		mtd->owner = THIS_MODULE;
+
+		if (mtd_device_register(mtd, NULL, 0)) {
+			printk(KERN_NOTICE "pmc551: Failed to register new device\n");
+			pci_iounmap(PCI_Device, priv->start);
+			kfree(mtd->priv);
+			kfree(mtd);
+			break;
+		}
+
+		/* Keep a reference as the mtd_device_register worked */
+		pci_dev_get(PCI_Device);
+
+		printk(KERN_NOTICE "Registered pmc551 memory device.\n");
+		printk(KERN_NOTICE "Mapped %dMiB of memory from 0x%p to 0x%p\n",
+			priv->asize >> 20,
+			priv->start, priv->start + priv->asize);
+		printk(KERN_NOTICE "Total memory is %d%sB\n",
+			(length < 1024) ? length :
+			(length < 1048576) ? length >> 10 : length >> 20,
+			(length < 1024) ? "" : (length < 1048576) ? "Ki" : "Mi");
+		priv->nextpmc551 = pmc551list;
+		pmc551list = mtd;
+		found++;
+	}
+
+	/* Exited early, reference left over */
+	pci_dev_put(PCI_Device);
+
+	if (!pmc551list) {
+		printk(KERN_NOTICE "pmc551: not detected\n");
+		return -ENODEV;
+	} else {
+		printk(KERN_NOTICE "pmc551: %d pmc551 devices loaded\n", found);
+		return 0;
+	}
+}
+
+/*
+ * PMC551 Card Cleanup
+ */
+static void __exit cleanup_pmc551(void)
+{
+	int found = 0;
+	struct mtd_info *mtd;
+	struct mypriv *priv;
+
+	while ((mtd = pmc551list)) {
+		priv = mtd->priv;
+		pmc551list = priv->nextpmc551;
+
+		if (priv->start) {
+			printk(KERN_DEBUG "pmc551: unmapping %dMiB starting at "
+				"0x%p\n", priv->asize >> 20, priv->start);
+			pci_iounmap(priv->dev, priv->start);
+		}
+		pci_dev_put(priv->dev);
+
+		kfree(mtd->priv);
+		mtd_device_unregister(mtd);
+		kfree(mtd);
+		found++;
+	}
+
+	printk(KERN_NOTICE "pmc551: %d pmc551 devices unloaded\n", found);
+}
+
+module_init(init_pmc551);
+module_exit(cleanup_pmc551);