ps3/block: Replace mtd/ps3vram by block/ps3vram

Convert the PS3 Video RAM Storage Driver from an MTD driver to a plain block
device driver.

The ps3vram driver 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.

The new driver is ca. 50% faster for reading, and ca. 10% for writing.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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 FB_PS3=y && BLOCK && m
+	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

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-$(CONFIG_PS3_VRAM)		+= ps3vram.o
 obj-$(CONFIG_ATARI_FLOPPY)	+= ataflop.o
 obj-$(CONFIG_AMIGA_Z2RAM)	+= z2ram.o
 obj-$(CONFIG_BLK_DEV_RAM)	+= brd.o

drivers/mtd/devices/Kconfig

@@ -120,13 +120,6 @@ config MTD_PHRAM
 	  doesn't have access to, memory beyond the mem=xxx limit, nvram,
 	  memory on the video card, etc...
 
-config MTD_PS3VRAM
-	tristate "PS3 video RAM"
-	depends on FB_PS3
-	help
-	  This driver allows you to use excess PS3 video RAM as volatile
-	  storage or system swap.
-
 config MTD_LART
 	tristate "28F160xx flash driver for LART"
 	depends on SA1100_LART

drivers/mtd/devices/Makefile

@@ -16,4 +16,3 @@ obj-$(CONFIG_MTD_LART)		+= lart.o
 obj-$(CONFIG_MTD_BLOCK2MTD)	+= block2mtd.o
 obj-$(CONFIG_MTD_DATAFLASH)	+= mtd_dataflash.o
 obj-$(CONFIG_MTD_M25P80)	+= m25p80.o
-obj-$(CONFIG_MTD_PS3VRAM)	+= ps3vram.o