Subject: Re: [PATCH/RFC] ps3/block: Add ps3vram-ng driver for accessing video RAM as block device

From: Benjamin Herrenschmidt <[email-masked]>
Date: Thu, 05 Mar 2009 10:27:35 +1100

On Wed, 2009-03-04 at 14:57 +0100, Geert Uytterhoeven wrote:
> 	Hi,
> 
> Below is the rewrite of the PS3 Video RAM Storage Driver as a plain block
> device, as requested by Arnd Bergmann.
> 
> The MTD-based PS3 Video RAM Storage Driver was integrated into the mainline
> kernel in 2.6.29-rc1.
> 
> Ideally, we think it would be best if the existing MTD-based ps3vram driver
> would be replaced by the new block-based ps3vram driver before 2.6.29 is
> released. This would relieve the burden of supporting two different swap space
> schemes on PS3 (swap on /dev/mtdblock0 vs. /dev/ps3vram) from the distro
> maintainer's shoulders, as in that case there would never have been a stable
> kernel version containing the MTD-based ps3vram driver.

This is very very very late ... we are at rc7, probably one rc before
final... as much as I like integrating drivers later, I'll ask Linus
opinion on this one.

Linus ? What do you reckon ? Maybe a better option is just to remove
ps3nvram from .29 and merge the new one in .30 ?

Cheers,
Ben.

> What do you think? If this is accepted, I'll submit a patch to remove the MTD
> ps3vram and add the new driver as ps3vram (instead of ps3vram-ng).
> 
> Thanks for your (review and other) comments!
> 
> ---
> >From e19ce619675bc150cd82701e7b272f7018c36527 Mon Sep 17 00:00:00 2001
> From: Geert Uytterhoeven <[email-masked]>
> Date: Wed, 25 Feb 2009 18:32:10 +0100
> Subject: [PATCH] ps3/block: Add ps3vram-ng driver for accessing video RAM as block device
> 
> Add ps3vram-ng driver, which exposes unused video RAM on the PS3 as a block
> device suitable for storage or swap.  Fast data transfer is achieved
> using a local cache in system RAM and DMA transfers via the GPU.
> 
> Notes:
>   - As both the existing MTD ps3vram and ps3vram-ng bind to the same PS3 system
>     bus device, the driver which is loaded first by udev wins. However, you can
>     unload ps3vram, and load ps3vram-ng later.
>   - ps3vram-ng is faster than ps3vram:
>       o 1 MiB blocks: +50% (read), +5% (write)
>       o 4 KiB blocks: +50% (read), +5% (write)
>       o 512 B blocks: +10% (read), +10% (write)
> 
> Signed-off-by: Geert Uytterhoeven <[email-masked]>
> Cc: Jim Paris <[email-masked]>
> Cc: Vivien Chappelier <[email-masked]>
> ---
>  arch/powerpc/platforms/ps3/Kconfig |    7 +
>  drivers/block/Makefile             |    1 +
>  drivers/block/ps3vram_ng.c         |  916 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 924 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/block/ps3vram_ng.c
> 
> diff --git a/arch/powerpc/platforms/ps3/Kconfig b/arch/powerpc/platforms/ps3/Kconfig
> index 920cf7a..b3b7a20 100644
> --- a/arch/powerpc/platforms/ps3/Kconfig
> +++ b/arch/powerpc/platforms/ps3/Kconfig
> @@ -128,6 +128,13 @@ config PS3_FLASH
>  	  be disabled on the kernel command line using "ps3flash=off", to
>  	  not allocate this fixed buffer.
>  
> +config PS3_VRAM
> +	tristate "PS3 Video RAM Storage Driver"
> +	depends on PPC_PS3 && BLOCK
> +	help
> +	  This driver allows you to use excess PS3 video RAM as volatile
> +	  storage or system swap.
> +
>  config PS3_LPM
>  	tristate "PS3 Logical Performance Monitor support"
>  	depends on PPC_PS3
> diff --git a/drivers/block/Makefile b/drivers/block/Makefile
> index 204332b..ad3e45e 100644
> --- a/drivers/block/Makefile
> +++ b/drivers/block/Makefile
> @@ -9,6 +9,7 @@ obj-$(CONFIG_MAC_FLOPPY)	+= swim3.o
>  obj-$(CONFIG_BLK_DEV_FD)	+= floppy.o
>  obj-$(CONFIG_AMIGA_FLOPPY)	+= amiflop.o
>  obj-$(CONFIG_PS3_DISK)		+= ps3disk.o
> +obj-$(CONFIG_PS3_VRAM)		+= ps3vram_ng.o
>  obj-$(CONFIG_ATARI_FLOPPY)	+= ataflop.o
>  obj-$(CONFIG_AMIGA_Z2RAM)	+= z2ram.o
>  obj-$(CONFIG_BLK_DEV_RAM)	+= brd.o
> diff --git a/drivers/block/ps3vram_ng.c b/drivers/block/ps3vram_ng.c
> new file mode 100644
> index 0000000..fa24a17
> --- /dev/null
> +++ b/drivers/block/ps3vram_ng.c
> @@ -0,0 +1,916 @@
> +/*
> + * ps3vram - Use extra PS3 video ram as MTD block device.
> + *
> + * Copyright 2009 Sony Corporation
> + *
> + * Based on the MTD ps3vram driver, which is
> + * Copyright (c) 2007-2008 Jim Paris <[email-masked]>
> + * Added support RSX DMA Vivien Chappelier <[email-masked]>
> + */
> +
> +#include <linux/blkdev.h>
> +#include <linux/delay.h>
> +#include <linux/kthread.h>
> +#include <linux/proc_fs.h>
> +#include <linux/seq_file.h>
> +
> +#include <asm/firmware.h>
> +#include <asm/lv1call.h>
> +#include <asm/ps3.h>
> +
> +
> +#define DEVICE_NAME		"ps3vram"
> +
> +
> +#define XDR_BUF_SIZE (2 * 1024 * 1024) /* XDR buffer (must be 1MiB aligned) */
> +#define XDR_IOIF 0x0c000000
> +
> +#define FIFO_BASE XDR_IOIF
> +#define FIFO_SIZE (64 * 1024)
> +
> +#define DMA_PAGE_SIZE (4 * 1024)
> +
> +#define CACHE_PAGE_SIZE (256 * 1024)
> +#define CACHE_PAGE_COUNT ((XDR_BUF_SIZE - FIFO_SIZE) / CACHE_PAGE_SIZE)
> +
> +#define CACHE_OFFSET CACHE_PAGE_SIZE
> +#define FIFO_OFFSET 0
> +
> +#define CTRL_PUT 0x10
> +#define CTRL_GET 0x11
> +#define CTRL_TOP 0x15
> +
> +#define UPLOAD_SUBCH	1
> +#define DOWNLOAD_SUBCH	2
> +
> +#define NV_MEMORY_TO_MEMORY_FORMAT_OFFSET_IN	0x0000030c
> +#define NV_MEMORY_TO_MEMORY_FORMAT_NOTIFY	0x00000104
> +
> +#define L1GPU_CONTEXT_ATTRIBUTE_FB_BLIT 0x601
> +
> +#define CACHE_PAGE_PRESENT 1
> +#define CACHE_PAGE_DIRTY   2
> +
> +struct ps3vram_tag {
> +	unsigned int address;
> +	unsigned int flags;
> +};
> +
> +struct ps3vram_cache {
> +	unsigned int page_count;
> +	unsigned int page_size;
> +	struct ps3vram_tag *tags;
> +	unsigned int hit;
> +	unsigned int miss;
> +};
> +
> +struct ps3vram_priv {
> +	spinlock_t lock;		/* Request queue spinlock */
> +	struct task_struct *thread;
> +	struct request_queue *queue;
> +	struct gendisk *gendisk;
> +
> +	u64 size;
> +
> +	u64 memory_handle;
> +	u64 context_handle;
> +	u32 *ctrl;
> +	u32 *reports;
> +	u8 __iomem *ddr_base;
> +	u8 *xdr_buf;
> +
> +	u32 *fifo_base;
> +	u32 *fifo_ptr;
> +
> +	struct ps3vram_cache cache;
> +};
> +
> +
> +static int ps3vram_major;
> +
> +
> +static struct block_device_operations ps3vram_fops = {
> +	.owner		= THIS_MODULE,
> +};
> +
> +
> +#define DMA_NOTIFIER_HANDLE_BASE 0x66604200 /* first DMA notifier handle */
> +#define DMA_NOTIFIER_OFFSET_BASE 0x1000     /* first DMA notifier offset */
> +#define DMA_NOTIFIER_SIZE        0x40
> +#define NOTIFIER 7	/* notifier used for completion report */
> +
> +/* A trailing '-' means to subtract off ps3fb_videomemory.size */
> +static char *size = "256M-";
> +module_param(size, charp, 0);
> +MODULE_PARM_DESC(size, "memory size");
> +
> +static u32 *ps3vram_get_notifier(u32 *reports, int notifier)
> +{
> +	return (void *)reports + DMA_NOTIFIER_OFFSET_BASE +
> +	       DMA_NOTIFIER_SIZE * notifier;
> +}
> +
> +static void ps3vram_notifier_reset(struct ps3_system_bus_device *dev)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +	u32 *notify = ps3vram_get_notifier(priv->reports, NOTIFIER);
> +	int i;
> +
> +	for (i = 0; i < 4; i++)
> +		notify[i] = 0xffffffff;
> +}
> +
> +static int ps3vram_notifier_wait(struct ps3_system_bus_device *dev,
> +				 unsigned int timeout_ms)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +	u32 *notify = ps3vram_get_notifier(priv->reports, NOTIFIER);
> +	unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);
> +
> +	do {
> +		if (!notify[3])
> +			return 0;
> +		msleep(1);
> +	} while (time_before(jiffies, timeout));
> +
> +	return -ETIMEDOUT;
> +}
> +
> +static void ps3vram_init_ring(struct ps3_system_bus_device *dev)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +
> +	priv->ctrl[CTRL_PUT] = FIFO_BASE + FIFO_OFFSET;
> +	priv->ctrl[CTRL_GET] = FIFO_BASE + FIFO_OFFSET;
> +}
> +
> +static int ps3vram_wait_ring(struct ps3_system_bus_device *dev,
> +			     unsigned int timeout_ms)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +	unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);
> +
> +	do {
> +		if (priv->ctrl[CTRL_PUT] == priv->ctrl[CTRL_GET])
> +			return 0;
> +		msleep(1);
> +	} while (time_before(jiffies, timeout));
> +
> +	dev_dbg(&dev->core, "FIFO timeout (%08x/%08x/%08x)\n",
> +		priv->ctrl[CTRL_PUT], priv->ctrl[CTRL_GET],
> +		priv->ctrl[CTRL_TOP]);
> +
> +	return -ETIMEDOUT;
> +}
> +
> +static void ps3vram_out_ring(struct ps3vram_priv *priv, u32 data)
> +{
> +	*(priv->fifo_ptr)++ = data;
> +}
> +
> +static void ps3vram_begin_ring(struct ps3vram_priv *priv, u32 chan, u32 tag,
> +			       u32 size)
> +{
> +	ps3vram_out_ring(priv, (size << 18) | (chan << 13) | tag);
> +}
> +
> +static void ps3vram_rewind_ring(struct ps3_system_bus_device *dev)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +	u64 status;
> +
> +	ps3vram_out_ring(priv, 0x20000000 | (FIFO_BASE + FIFO_OFFSET));
> +
> +	priv->ctrl[CTRL_PUT] = FIFO_BASE + FIFO_OFFSET;
> +
> +	/* asking the HV for a blit will kick the FIFO */
> +	status = lv1_gpu_context_attribute(priv->context_handle,
> +					   L1GPU_CONTEXT_ATTRIBUTE_FB_BLIT, 0,
> +					   0, 0, 0);
> +	if (status)
> +		dev_err(&dev->core,
> +			"%s: lv1_gpu_context_attribute failed %llu\n",
> +			__func__, status);
> +
> +	priv->fifo_ptr = priv->fifo_base;
> +}
> +
> +static void ps3vram_fire_ring(struct ps3_system_bus_device *dev)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +	u64 status;
> +
> +	mutex_lock(&ps3_gpu_mutex);
> +
> +	priv->ctrl[CTRL_PUT] = FIFO_BASE + FIFO_OFFSET +
> +			       (priv->fifo_ptr - priv->fifo_base) * sizeof(u32);
> +
> +	/* asking the HV for a blit will kick the FIFO */
> +	status = lv1_gpu_context_attribute(priv->context_handle,
> +					   L1GPU_CONTEXT_ATTRIBUTE_FB_BLIT, 0,
> +					   0, 0, 0);
> +	if (status)
> +		dev_err(&dev->core,
> +			"%s: lv1_gpu_context_attribute failed %llu\n",
> +			__func__, status);
> +
> +	if ((priv->fifo_ptr - priv->fifo_base) * sizeof(u32) >
> +	    FIFO_SIZE - 1024) {
> +		dev_dbg(&dev->core, "FIFO full, rewinding\n");
> +		ps3vram_wait_ring(dev, 200);
> +		ps3vram_rewind_ring(dev);
> +	}
> +
> +	mutex_unlock(&ps3_gpu_mutex);
> +}
> +
> +static void ps3vram_bind(struct ps3_system_bus_device *dev)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +
> +	ps3vram_begin_ring(priv, UPLOAD_SUBCH, 0, 1);
> +	ps3vram_out_ring(priv, 0x31337303);
> +	ps3vram_begin_ring(priv, UPLOAD_SUBCH, 0x180, 3);
> +	ps3vram_out_ring(priv, DMA_NOTIFIER_HANDLE_BASE + NOTIFIER);
> +	ps3vram_out_ring(priv, 0xfeed0001);	/* DMA system RAM instance */
> +	ps3vram_out_ring(priv, 0xfeed0000);     /* DMA video RAM instance */
> +
> +	ps3vram_begin_ring(priv, DOWNLOAD_SUBCH, 0, 1);
> +	ps3vram_out_ring(priv, 0x3137c0de);
> +	ps3vram_begin_ring(priv, DOWNLOAD_SUBCH, 0x180, 3);
> +	ps3vram_out_ring(priv, DMA_NOTIFIER_HANDLE_BASE + NOTIFIER);
> +	ps3vram_out_ring(priv, 0xfeed0000);	/* DMA video RAM instance */
> +	ps3vram_out_ring(priv, 0xfeed0001);	/* DMA system RAM instance */
> +
> +	ps3vram_fire_ring(dev);
> +}
> +
> +static int ps3vram_upload(struct ps3_system_bus_device *dev,
> +			  unsigned int src_offset, unsigned int dst_offset,
> +			  int len, int count)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +
> +	ps3vram_begin_ring(priv, UPLOAD_SUBCH,
> +			   NV_MEMORY_TO_MEMORY_FORMAT_OFFSET_IN, 8);
> +	ps3vram_out_ring(priv, XDR_IOIF + src_offset);
> +	ps3vram_out_ring(priv, dst_offset);
> +	ps3vram_out_ring(priv, len);
> +	ps3vram_out_ring(priv, len);
> +	ps3vram_out_ring(priv, len);
> +	ps3vram_out_ring(priv, count);
> +	ps3vram_out_ring(priv, (1 << 8) | 1);
> +	ps3vram_out_ring(priv, 0);
> +
> +	ps3vram_notifier_reset(dev);
> +	ps3vram_begin_ring(priv, UPLOAD_SUBCH,
> +			   NV_MEMORY_TO_MEMORY_FORMAT_NOTIFY, 1);
> +	ps3vram_out_ring(priv, 0);
> +	ps3vram_begin_ring(priv, UPLOAD_SUBCH, 0x100, 1);
> +	ps3vram_out_ring(priv, 0);
> +	ps3vram_fire_ring(dev);
> +	if (ps3vram_notifier_wait(dev, 200) < 0) {
> +		dev_dbg(&dev->core, "%s: Notifier timeout\n", __func__);
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ps3vram_download(struct ps3_system_bus_device *dev,
> +			    unsigned int src_offset, unsigned int dst_offset,
> +			    int len, int count)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +
> +	ps3vram_begin_ring(priv, DOWNLOAD_SUBCH,
> +			   NV_MEMORY_TO_MEMORY_FORMAT_OFFSET_IN, 8);
> +	ps3vram_out_ring(priv, src_offset);
> +	ps3vram_out_ring(priv, XDR_IOIF + dst_offset);
> +	ps3vram_out_ring(priv, len);
> +	ps3vram_out_ring(priv, len);
> +	ps3vram_out_ring(priv, len);
> +	ps3vram_out_ring(priv, count);
> +	ps3vram_out_ring(priv, (1 << 8) | 1);
> +	ps3vram_out_ring(priv, 0);
> +
> +	ps3vram_notifier_reset(dev);
> +	ps3vram_begin_ring(priv, DOWNLOAD_SUBCH,
> +			   NV_MEMORY_TO_MEMORY_FORMAT_NOTIFY, 1);
> +	ps3vram_out_ring(priv, 0);
> +	ps3vram_begin_ring(priv, DOWNLOAD_SUBCH, 0x100, 1);
> +	ps3vram_out_ring(priv, 0);
> +	ps3vram_fire_ring(dev);
> +	if (ps3vram_notifier_wait(dev, 200) < 0) {
> +		dev_dbg(&dev->core, "%s: Notifier timeout\n", __func__);
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
> +static void ps3vram_cache_evict(struct ps3_system_bus_device *dev, int entry)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +	struct ps3vram_cache *cache = &priv->cache;
> +
> +	if (!(cache->tags[entry].flags & CACHE_PAGE_DIRTY))
> +		return;
> +
> +	dev_dbg(&dev->core, "Flushing %d: 0x%08x\n", entry,
> +		cache->tags[entry].address);
> +	if (ps3vram_upload(dev, CACHE_OFFSET + entry * cache->page_size,
> +			   cache->tags[entry].address, DMA_PAGE_SIZE,
> +			   cache->page_size / DMA_PAGE_SIZE) < 0) {
> +		dev_err(&dev->core,
> +			"Failed to upload from 0x%x to " "0x%x size 0x%x\n",
> +			entry * cache->page_size, cache->tags[entry].address,
> +			cache->page_size);
> +	}
> +	cache->tags[entry].flags &= ~CACHE_PAGE_DIRTY;
> +}
> +
> +static void ps3vram_cache_load(struct ps3_system_bus_device *dev, int entry,
> +			       unsigned int address)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +	struct ps3vram_cache *cache = &priv->cache;
> +
> +	dev_dbg(&dev->core, "Fetching %d: 0x%08x\n", entry, address);
> +	if (ps3vram_download(dev, address,
> +			     CACHE_OFFSET + entry * cache->page_size,
> +			     DMA_PAGE_SIZE,
> +			     cache->page_size / DMA_PAGE_SIZE) < 0) {
> +		dev_err(&dev->core,
> +			"Failed to download from 0x%x to 0x%x size 0x%x\n",
> +			address, entry * cache->page_size, cache->page_size);
> +	}
> +
> +	cache->tags[entry].address = address;
> +	cache->tags[entry].flags |= CACHE_PAGE_PRESENT;
> +}
> +
> +
> +static void ps3vram_cache_flush(struct ps3_system_bus_device *dev)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +	struct ps3vram_cache *cache = &priv->cache;
> +	int i;
> +
> +	dev_dbg(&dev->core, "FLUSH\n");
> +	for (i = 0; i < cache->page_count; i++) {
> +		ps3vram_cache_evict(dev, i);
> +		cache->tags[i].flags = 0;
> +	}
> +}
> +
> +static unsigned int ps3vram_cache_match(struct ps3_system_bus_device *dev,
> +					loff_t address)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +	struct ps3vram_cache *cache = &priv->cache;
> +	unsigned int base;
> +	unsigned int offset;
> +	int i;
> +	static int counter;
> +
> +	offset = (unsigned int) (address & (cache->page_size - 1));
> +	base = (unsigned int) (address - offset);
> +
> +	/* fully associative check */
> +	for (i = 0; i < cache->page_count; i++) {
> +		if ((cache->tags[i].flags & CACHE_PAGE_PRESENT) &&
> +		    cache->tags[i].address == base) {
> +			cache->hit++;
> +			dev_dbg(&dev->core, "Found entry %d: 0x%08x\n", i,
> +				cache->tags[i].address);
> +			return i;
> +		}
> +	}
> +
> +	/* choose a random entry */
> +	i = (jiffies + (counter++)) % cache->page_count;
> +	dev_dbg(&dev->core, "Using entry %d\n", i);
> +
> +	ps3vram_cache_evict(dev, i);
> +	ps3vram_cache_load(dev, i, base);
> +
> +	cache->miss++;
> +	return i;
> +}
> +
> +static int ps3vram_cache_init(struct ps3_system_bus_device *dev)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +
> +	priv->cache.page_count = CACHE_PAGE_COUNT;
> +	priv->cache.page_size = CACHE_PAGE_SIZE;
> +	priv->cache.tags = kzalloc(sizeof(struct ps3vram_tag) *
> +				   CACHE_PAGE_COUNT, GFP_KERNEL);
> +	if (priv->cache.tags == NULL) {
> +		dev_err(&dev->core, "Could not allocate cache tags\n");
> +		return -ENOMEM;
> +	}
> +
> +	dev_info(&dev->core, "Created ram cache: %d entries, %d KiB each\n",
> +		CACHE_PAGE_COUNT, CACHE_PAGE_SIZE / 1024);
> +
> +	return 0;
> +}
> +
> +static void ps3vram_cache_cleanup(struct ps3_system_bus_device *dev)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +
> +	ps3vram_cache_flush(dev);
> +	kfree(priv->cache.tags);
> +}
> +
> +static int ps3vram_read(struct ps3_system_bus_device *dev, loff_t from,
> +			size_t len, size_t *retlen, u_char *buf)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +	unsigned int cached, count;
> +
> +	dev_dbg(&dev->core, "%s: from=0x%08x len=0x%zx\n", __func__,
> +		(unsigned int)from, len);
> +
> +	if (from >= priv->size)
> +		return -EINVAL;
> +
> +	if (len > priv->size - from)
> +		len = priv->size - from;
> +
> +	/* Copy from vram to buf */
> +	count = len;
> +	while (count) {
> +		unsigned int offset, avail;
> +		unsigned int entry;
> +
> +		offset = (unsigned int) (from & (priv->cache.page_size - 1));
> +		avail  = priv->cache.page_size - offset;
> +
> +		entry = ps3vram_cache_match(dev, from);
> +		cached = CACHE_OFFSET + entry * priv->cache.page_size + offset;
> +
> +		dev_dbg(&dev->core, "%s: from=%08x cached=%08x offset=%08x "
> +			"avail=%08x count=%08x\n", __func__,
> +			(unsigned int)from, cached, offset, avail, count);
> +
> +		if (avail > count)
> +			avail = count;
> +		memcpy(buf, priv->xdr_buf + cached, avail);
> +
> +		buf += avail;
> +		count -= avail;
> +		from += avail;
> +	}
> +
> +	*retlen = len;
> +	return 0;
> +}
> +
> +static int ps3vram_write(struct ps3_system_bus_device *dev, loff_t to,
> +			 size_t len, size_t *retlen, const u_char *buf)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +	unsigned int cached, count;
> +
> +	if (to >= priv->size)
> +		return -EINVAL;
> +
> +	if (len > priv->size - to)
> +		len = priv->size - to;
> +
> +	/* Copy from buf to vram */
> +	count = len;
> +	while (count) {
> +		unsigned int offset, avail;
> +		unsigned int entry;
> +
> +		offset = (unsigned int) (to & (priv->cache.page_size - 1));
> +		avail  = priv->cache.page_size - offset;
> +
> +		entry = ps3vram_cache_match(dev, to);
> +		cached = CACHE_OFFSET + entry * priv->cache.page_size + offset;
> +
> +		dev_dbg(&dev->core, "%s: to=%08x cached=%08x offset=%08x "
> +			"avail=%08x count=%08x\n", __func__, (unsigned int)to,
> +			cached, offset, avail, count);
> +
> +		if (avail > count)
> +			avail = count;
> +		memcpy(priv->xdr_buf + cached, buf, avail);
> +
> +		priv->cache.tags[entry].flags |= CACHE_PAGE_DIRTY;
> +
> +		buf += avail;
> +		count -= avail;
> +		to += avail;
> +	}
> +
> +	*retlen = len;
> +	return 0;
> +}
> +
> +static int ps3vram_proc_show(struct seq_file *m, void *v)
> +{
> +	struct ps3vram_priv *priv = m->private;
> +
> +	seq_printf(m, "hit:%u\nmiss:%u\n", priv->cache.hit, priv->cache.miss);
> +	return 0;
> +}
> +
> +static int ps3vram_proc_open(struct inode *inode, struct file *file)
> +{
> +	return single_open(file, ps3vram_proc_show, PDE(inode)->data);
> +}
> +
> +static const struct file_operations ps3vram_proc_fops = {
> +	.owner		= THIS_MODULE,
> +	.open		= ps3vram_proc_open,
> +	.read		= seq_read,
> +	.llseek		= seq_lseek,
> +	.release	= single_release,
> +};
> +
> +static void __devinit ps3vram_proc_init(struct ps3_system_bus_device *dev)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +	struct proc_dir_entry *pde;
> +
> +	pde = proc_create(DEVICE_NAME, 0444, NULL, &ps3vram_proc_fops);
> +	if (!pde) {
> +		dev_warn(&dev->core, "failed to create /proc entry\n");
> +		return;
> +	}
> +
> +	pde->owner = THIS_MODULE;
> +	pde->data = priv;
> +}
> +
> +static void ps3vram_do_request(struct ps3_system_bus_device *dev,
> +			       struct request *req)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +	int write, res, uptodate = 0;
> +	const char *op;
> +	sector_t start_sector;
> +	unsigned int sectors;
> +	loff_t offset;
> +	size_t len, retlen;
> +
> +	write = rq_data_dir(req);
> +	op = write ? "write" : "read";
> +
> +	start_sector = req->sector;
> +	sectors = req->current_nr_sectors;
> +	dev_dbg(&dev->core, "%s %u sectors starting at %lu\n", op, sectors,
> +		start_sector);
> +
> +	offset = start_sector << 9;
> +	len = sectors << 9;
> +
> +	if (write)
> +		res = ps3vram_write(dev, offset, len, &retlen, req->buffer);
> +	else
> +		res = ps3vram_read(dev, offset, len, &retlen, req->buffer);
> +
> +	if (res) {
> +		dev_err(&dev->core, "%s failed\n", op);
> +		goto out;
> +	}
> +
> +	if (retlen != len) {
> +		dev_err(&dev->core, "Short %s\n", op);
> +		goto out;
> +	}
> +
> +	dev_dbg(&dev->core, "%s completed\n", op);
> +
> +	uptodate = 1;
> +
> +out:
> +	spin_lock_irq(&priv->lock);
> +	end_request(req, uptodate);
> +	spin_unlock_irq(&priv->lock);
> +}
> +
> +static int ps3vram_thread(void *data)
> +{
> +	struct ps3_system_bus_device *dev = data;
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +	struct request_queue *q = priv->queue;
> +	struct request *req;
> +
> +	dev_dbg(&dev->core, "%s init\n", __func__);
> +
> +	current->flags |= PF_NOFREEZE;
> +
> +	while (!kthread_should_stop()) {
> +		spin_lock_irq(&priv->lock);
> +		set_current_state(TASK_INTERRUPTIBLE);
> +		req = elv_next_request(q);
> +		if (!req) {
> +			spin_unlock_irq(&priv->lock);
> +			schedule();
> +			continue;
> +		}
> +		if (!blk_fs_request(req)) {
> +			blk_dump_rq_flags(req, DEVICE_NAME " bad request");
> +			end_request(req, 0);
> +			spin_unlock_irq(&priv->lock);
> +			continue;
> +		}
> +		spin_unlock_irq(&priv->lock);
> +		ps3vram_do_request(dev, req);
> +	}
> +
> +	dev_dbg(&dev->core, "%s exit\n", __func__);
> +	return 0;
> +}
> +
> +static void ps3vram_request(struct request_queue *q)
> +{
> +	struct ps3_system_bus_device *dev = q->queuedata;
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +
> +	dev_dbg(&dev->core, "Waking up thread\n");
> +	wake_up_process(priv->thread);
> +}
> +
> +
> +static int __devinit ps3vram_probe(struct ps3_system_bus_device *dev)
> +{
> +	struct ps3vram_priv *priv;
> +	int error, status;
> +	struct request_queue *queue;
> +	struct gendisk *gendisk;
> +	u64 ddr_lpar, ctrl_lpar, info_lpar, reports_lpar, ddr_size,
> +	    reports_size;
> +	char *rest;
> +	struct task_struct *task;
> +
> +	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> +	if (!priv) {
> +		error = -ENOMEM;
> +		goto fail;
> +	}
> +
> +	dev->core.driver_data = priv;
> +	spin_lock_init(&priv->lock);
> +
> +	priv = dev->core.driver_data;
> +
> +	/* Allocate XDR buffer (1MiB aligned) */
> +	priv->xdr_buf = (void *)__get_free_pages(GFP_KERNEL,
> +		get_order(XDR_BUF_SIZE));
> +	if (priv->xdr_buf == NULL) {
> +		dev_dbg(&dev->core, "Could not allocate XDR buffer\n");
> +		error = -ENOMEM;
> +		goto fail_free_priv;
> +	}
> +
> +	/* Put FIFO at begginning of XDR buffer */
> +	priv->fifo_base = (u32 *) (priv->xdr_buf + FIFO_OFFSET);
> +	priv->fifo_ptr = priv->fifo_base;
> +
> +	/* XXX: Need to open GPU, in case ps3fb or snd_ps3 aren't loaded */
> +	if (ps3_open_hv_device(dev)) {
> +		dev_err(&dev->core, "ps3_open_hv_device failed\n");
> +		error = -EAGAIN;
> +		goto out_close_gpu;
> +	}
> +
> +	/* Request memory */
> +	status = -1;
> +	ddr_size = memparse(size, &rest);
> +	if (*rest == '-')
> +		ddr_size -= ps3fb_videomemory.size;
> +	ddr_size = ALIGN(ddr_size, 1024*1024);
> +	if (ddr_size <= 0) {
> +		dev_err(&dev->core, "Specified size is too small\n");
> +		error = -EINVAL;
> +		goto out_close_gpu;
> +	}
> +
> +	while (ddr_size > 0) {
> +		status = lv1_gpu_memory_allocate(ddr_size, 0, 0, 0, 0,
> +						 &priv->memory_handle,
> +						 &ddr_lpar);
> +		if (!status)
> +			break;
> +		ddr_size -= 1024*1024;
> +	}
> +	if (status || ddr_size <= 0) {
> +		dev_err(&dev->core, "lv1_gpu_memory_allocate failed %d\n",
> +			status);
> +		error = -ENOMEM;
> +		goto out_free_xdr_buf;
> +	}
> +
> +	/* Request context */
> +	status = lv1_gpu_context_allocate(priv->memory_handle, 0,
> +					  &priv->context_handle, &ctrl_lpar,
> +					  &info_lpar, &reports_lpar,
> +					  &reports_size);
> +	if (status) {
> +		dev_err(&dev->core, "lv1_gpu_context_allocate failed %d\n",
> +			status);
> +		error = -ENOMEM;
> +		goto out_free_memory;
> +	}
> +
> +	/* Map XDR buffer to RSX */
> +	status = lv1_gpu_context_iomap(priv->context_handle, XDR_IOIF,
> +				       ps3_mm_phys_to_lpar(__pa(priv->xdr_buf)),
> +				       XDR_BUF_SIZE, 0);
> +	if (status) {
> +		dev_err(&dev->core, "lv1_gpu_context_iomap failed %d\n",
> +			status);
> +		error = -ENOMEM;
> +		goto out_free_context;
> +	}
> +
> +	priv->ddr_base = ioremap_flags(ddr_lpar, ddr_size, _PAGE_NO_CACHE);
> +
> +	if (!priv->ddr_base) {
> +		dev_err(&dev->core, "ioremap DDR failed\n");
> +		error = -ENOMEM;
> +		goto out_free_context;
> +	}
> +
> +	priv->ctrl = ioremap(ctrl_lpar, 64 * 1024);
> +	if (!priv->ctrl) {
> +		dev_err(&dev->core, "ioremap CTRL failed\n");
> +		error = -ENOMEM;
> +		goto out_unmap_vram;
> +	}
> +
> +	priv->reports = ioremap(reports_lpar, reports_size);
> +	if (!priv->reports) {
> +		dev_err(&dev->core, "ioremap REPORTS failed\n");
> +		error = -ENOMEM;
> +		goto out_unmap_ctrl;
> +	}
> +
> +	mutex_lock(&ps3_gpu_mutex);
> +	ps3vram_init_ring(dev);
> +	mutex_unlock(&ps3_gpu_mutex);
> +
> +	priv->size = ddr_size;
> +
> +	ps3vram_bind(dev);
> +
> +	mutex_lock(&ps3_gpu_mutex);
> +	error = ps3vram_wait_ring(dev, 100);
> +	mutex_unlock(&ps3_gpu_mutex);
> +	if (error < 0) {
> +		dev_err(&dev->core, "Failed to initialize channels\n");
> +		error = -ETIMEDOUT;
> +		goto out_unmap_reports;
> +	}
> +
> +	ps3vram_cache_init(dev);
> +	ps3vram_proc_init(dev);
> +
> +	queue = blk_init_queue(ps3vram_request, &priv->lock);
> +	if (!queue) {
> +		dev_err(&dev->core, "blk_init_queue failed\n");
> +		error = -ENOMEM;
> +		goto out_cache_cleanup;
> +	}
> +
> +	priv->queue = queue;
> +	queue->queuedata = dev;
> +
> +	gendisk = alloc_disk(1);
> +	if (!gendisk) {
> +		dev_err(&dev->core, "alloc_disk failed\n");
> +		error = -ENOMEM;
> +		goto fail_cleanup_queue;
> +	}
> +
> +	priv->gendisk = gendisk;
> +	gendisk->major = ps3vram_major;
> +	gendisk->first_minor = 0;
> +	gendisk->fops = &ps3vram_fops;
> +	gendisk->queue = queue;
> +	gendisk->private_data = dev;
> +	gendisk->driverfs_dev = &dev->core;
> +	strlcpy(gendisk->disk_name, DEVICE_NAME, sizeof(gendisk->disk_name));
> +	set_capacity(gendisk, priv->size >> 9);
> +
> +	task = kthread_run(ps3vram_thread, dev, DEVICE_NAME);
> +	if (IS_ERR(task)) {
> +		error = PTR_ERR(task);
> +		goto fail_free_disk;
> +	}
> +	priv->thread = task;
> +
> +	dev_info(&dev->core, "%s: Using %lu MiB of GPU memory\n",
> +		 gendisk->disk_name, get_capacity(gendisk) >> 11);
> +
> +	add_disk(gendisk);
> +	return 0;
> +
> +fail_free_disk:
> +	put_disk(priv->gendisk);
> +fail_cleanup_queue:
> +	blk_cleanup_queue(queue);
> +out_cache_cleanup:
> +	remove_proc_entry(DEVICE_NAME, NULL);
> +	ps3vram_cache_cleanup(dev);
> +out_unmap_reports:
> +	iounmap(priv->reports);
> +out_unmap_ctrl:
> +	iounmap(priv->ctrl);
> +out_unmap_vram:
> +	iounmap(priv->ddr_base);
> +out_free_context:
> +	lv1_gpu_context_free(priv->context_handle);
> +out_free_memory:
> +	lv1_gpu_memory_free(priv->memory_handle);
> +out_close_gpu:
> +	ps3_close_hv_device(dev);
> +out_free_xdr_buf:
> +	free_pages((unsigned long) priv->xdr_buf, get_order(XDR_BUF_SIZE));
> +fail_free_priv:
> +	kfree(priv);
> +	dev->core.driver_data = NULL;
> +fail:
> +	return error;
> +}
> +
> +static int ps3vram_remove(struct ps3_system_bus_device *dev)
> +{
> +	struct ps3vram_priv *priv = dev->core.driver_data;
> +
> +	BUG_ON(!elv_queue_empty(priv->queue));
> +
> +	kthread_stop(priv->thread);
> +	del_gendisk(priv->gendisk);
> +	blk_cleanup_queue(priv->queue);
> +	put_disk(priv->gendisk);
> +	remove_proc_entry(DEVICE_NAME, NULL);
> +	ps3vram_cache_cleanup(dev);
> +	iounmap(priv->reports);
> +	iounmap(priv->ctrl);
> +	iounmap(priv->ddr_base);
> +	lv1_gpu_context_free(priv->context_handle);
> +	lv1_gpu_memory_free(priv->memory_handle);
> +	ps3_close_hv_device(dev);
> +	free_pages((unsigned long) priv->xdr_buf, get_order(XDR_BUF_SIZE));
> +	kfree(priv);
> +	dev->core.driver_data = NULL;
> +	return 0;
> +}
> +
> +static struct ps3_system_bus_driver ps3vram = {
> +	.match_id	= PS3_MATCH_ID_GPU,
> +	.match_sub_id	= PS3_MATCH_SUB_ID_GPU_RAMDISK,
> +	.core.name	= DEVICE_NAME,
> +	.core.owner	= THIS_MODULE,
> +	.probe		= ps3vram_probe,
> +	.remove		= ps3vram_remove,
> +	.shutdown	= ps3vram_remove,
> +};
> +
> +
> +static int __init ps3vram_init(void)
> +{
> +	int error;
> +
> +	if (!firmware_has_feature(FW_FEATURE_PS3_LV1))
> +		return -ENODEV;
> +
> +	error = register_blkdev(0, DEVICE_NAME);
> +	if (error <= 0) {
> +		pr_err("%s: register_blkdev failed %d\n", DEVICE_NAME, error);
> +		return error;
> +	}
> +	ps3vram_major = error;
> +
> +	pr_info("%s: registered block device major %d\n", DEVICE_NAME,
> +		ps3vram_major);
> +
> +	error = ps3_system_bus_driver_register(&ps3vram);
> +	if (error)
> +		unregister_blkdev(ps3vram_major, DEVICE_NAME);
> +
> +	return error;
> +}
> +
> +static void __exit ps3vram_exit(void)
> +{
> +	ps3_system_bus_driver_unregister(&ps3vram);
> +	unregister_blkdev(ps3vram_major, DEVICE_NAME);
> +}
> +
> +module_init(ps3vram_init);
> +module_exit(ps3vram_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("PS3 Video RAM Storage Driver");
> +MODULE_AUTHOR("Sony Corporation");
> +MODULE_ALIAS(PS3_MODULE_ALIAS_GPU_RAMDISK);