Russell King 2be23c475a ARM: Ensure PTE modifications via dma_alloc_coherent are visible ... Dave Hylands reports: | We've observed a problem with dma_alloc_writecombine when the system | is under heavy load (heavy bus traffic). We've managed to reduce the | problem to the following snippet, which is run from a kthread in a | continuous loop: | | void *virtAddr; | dma_addr_t physAddr; | unsigned int numBytes = 256; | | for (;;) { | virtAddr = dma_alloc_writecombine(NULL, | numBytes, &physAddr, GFP_KERNEL); | if (virtAddr == NULL) { | printk(KERN_ERR "Running out of memory\n"); | break; | } | | /* access DMA memory allocated */ | tmp = virtAddr; | *tmp = 0x77; | | /* free DMA memory */ | dma_free_writecombine(NULL, | numBytes, virtAddr, physAddr); | | ...sleep here... | } | | By itself, the code will run forever with no issues. However, as we | increase our bus traffic (typically using DMA) then the *tmp = 0x77 | line will eventually cause a page fault. If we add a small delay (a | few microseconds) before the *tmp = 0x77, then we don't see a page | fault, even under heavy load. A dsb() is required after modifying the PTE entries to ensure that they will always be visible. Add this dsb(). Reported-by: Dave Hylands <dhylands@gmail.com> Tested-by: Dave Hylands <dhylands@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>		2010-09-08 16:27:56 +01:00
..
boot	Merge branches 'master' and 'devel' into for-linus	2010-08-10 23:17:52 +01:00
common	Revert "[ARM] pxa: remove now unnecessary dma_needs_bounce()"	2010-09-08 12:28:39 +01:00
configs	omap: Fix omap_4430sdp_defconfig for make oldconfig	2010-08-16 09:22:04 +03:00
include/asm	Revert "[ARM] pxa: remove now unnecessary dma_needs_bounce()"	2010-09-08 12:28:39 +01:00
kernel	ARM: 6352/1: perf: fix event validation	2010-09-02 16:36:42 +01:00
lib
mach-aaec2000
mach-at91	ARM: 6323/1: cam60: don't use __init for cam60_spi_{flash_platform_data,partitions}	2010-08-10 22:46:56 +01:00
mach-bcmring
mach-clps711x	ARM: 6283/1: Remove useless PCIO_BASE definitions	2010-08-05 10:35:49 +01:00
mach-cns3xxx
mach-davinci	Merge branch 'davinci-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-davinci	2010-08-08 10:00:55 -07:00
mach-dove
mach-ebsa110
mach-ep93xx	ARM: 6359/1: ep93xx: move clock initialization earlier	2010-09-08 12:28:39 +01:00
mach-footbridge
mach-gemini
mach-h720x	ARM: 6283/1: Remove useless PCIO_BASE definitions	2010-08-05 10:35:49 +01:00
mach-imx	ARM: imx: fix build failure concerning otg/ulpi	2010-08-23 20:50:17 -07:00
mach-integrator	ARM: 6283/1: Remove useless PCIO_BASE definitions	2010-08-05 10:35:49 +01:00
mach-iop13xx
mach-iop32x
mach-iop33x
mach-ixp4xx	Merge git://git.infradead.org/mtd-2.6	2010-08-15 17:32:47 -07:00
mach-ixp23xx	ARM: 6283/1: Remove useless PCIO_BASE definitions	2010-08-05 10:35:49 +01:00
mach-ixp2000
mach-kirkwood	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6	2010-08-07 17:07:31 -07:00
mach-ks8695
mach-lh7a40x
mach-loki
mach-lpc32xx
mach-mmp
mach-msm	Merge branch 'msm-core' of git://codeaurora.org/quic/kernel/dwalker/linux-msm	2010-08-12 10:07:32 -07:00
mach-mv78xx0
mach-mx3	Merge branch 'imx-for-2.6.36' of git://git.pengutronix.de/git/imx/linux-2.6	2010-09-01 10:08:50 +01:00
mach-mx5	mx5/clock: fix clear bit fields issue in _clk_ccgr_disable function	2010-08-21 12:22:43 +02:00
mach-mx25	Merge branch 'imx-for-2.6.36' of git://git.pengutronix.de/git/imx/linux-2.6	2010-09-01 10:08:50 +01:00
mach-mxc91231
mach-netx
mach-nomadik
mach-ns9xxx
mach-nuc93x
mach-omap1
mach-omap2	OMAP3: PM: ensure IO wakeups are properly disabled	2010-08-16 09:22:05 +03:00
mach-orion5x	ARM: Fix gen_nand probe structures contents	2010-08-12 02:21:18 +01:00
mach-pnx4008
mach-pxa	ARM: pxa: fix CI_HSYNC and CI_VSYNC MFP defines for pxa300	2010-08-30 09:59:43 +08:00
mach-realview
mach-rpc
mach-s3c24a0/include/mach
mach-s3c64xx	ARM: SAMSUNG: Fix on build warning regarding VMALLOC_END type	2010-08-27 15:28:38 +09:00
mach-s3c2400
mach-s3c2410	ARM: SAMSUNG: Fix on build warning regarding VMALLOC_END type	2010-08-27 15:28:38 +09:00
mach-s3c2412
mach-s3c2416	s3c-fb: add device name initialization	2010-08-11 08:59:10 -07:00
mach-s3c2440	panic: keep blinking in spite of long spin timer mode	2010-08-11 08:59:22 -07:00
mach-s3c2443	s3c-fb: add device name initialization	2010-08-11 08:59:10 -07:00
mach-s5p6440	ARM: SAMSUNG: Fix on build warning regarding VMALLOC_END type	2010-08-27 15:28:38 +09:00
mach-s5p6442	ARM: SAMSUNG: Fix on build warning regarding VMALLOC_END type	2010-08-27 15:28:38 +09:00
mach-s5pc100	Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm	2010-08-11 09:13:19 -07:00
mach-s5pv210	ARM: S5P: VMALLOC_END should be unsigned long	2010-08-23 10:50:36 +09:00
mach-s5pv310	ARM: S5PV310: Fix on Secondary CPU startup	2010-08-27 18:29:58 +09:00
mach-sa1100	Merge branch 'devel' of git://git.kernel.org/pub/scm/linux/kernel/git/ycmiao/pxa-linux-2.6 into devel-stable	2010-08-06 18:10:25 +01:00
mach-shark
mach-shmobile	ARM: mach-shmobile: ap4evb: fix write protect for SDHI1	2010-08-20 20:41:23 +09:00
mach-spear3xx
mach-spear6xx
mach-stmp37xx
mach-stmp378x
mach-tegra	arm: tegra: VMALLOC_END should be unsigned long	2010-08-22 12:54:23 -07:00
mach-u300	ARM: 6297/1: move U300 timer to dynamic clock lookup	2010-08-10 22:10:56 +01:00
mach-ux500	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx	2010-08-09 21:00:07 -07:00
mach-versatile	ARM: 6282/1: Remove useless definitions from versatile hardware.h	2010-08-05 10:35:49 +01:00
mach-vexpress
mach-w90x900	i2c/nuc900: add i2c driver support for nuc900	2010-08-11 00:34:38 +01:00
mm	ARM: Ensure PTE modifications via dma_alloc_coherent are visible	2010-09-08 16:27:56 +01:00
nwfpe
oprofile
plat-iop
plat-mxc	ARM: imx: set cache line size to 64 bytes for i.MX5	2010-08-21 12:22:43 +02:00
plat-nomadik	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx	2010-08-09 21:00:07 -07:00
plat-omap	omap: Fix sev instruction usage for multi-omap	2010-08-16 09:22:04 +03:00
plat-orion	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6	2010-08-07 17:07:31 -07:00
plat-pxa	ARM: pxa: Make id const in pwm_probe()	2010-08-30 09:59:44 +08:00
plat-s3c24xx
plat-s5p	ARM: S5PV310: Fix on Secondary CPU startup	2010-08-27 18:29:58 +09:00
plat-samsung	s5pc110: SDHCI-s3c can override host capabilities	2010-08-20 09:34:55 -07:00
plat-spear
plat-stmp3xxx
plat-versatile
tools
vfp
Kconfig	ARM: S5PV310: Fix on default ZRELADDR of ARCH_S5PV310	2010-08-27 15:29:11 +09:00
Kconfig-nommu
Kconfig.debug
Makefile	ARM: 6328/1: Build with -fno-dwarf2-cfi-asm	2010-08-14 23:58:43 +01:00