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7ea7e98fd8
The existing implementation of pci_block_user_cfg_access() was recently criticised for providing out of date information and for returning errors on write, which applications won't be expecting. This reimplementation uses a global wait queue and a bit per device. I've open-coded prepare_to_wait() / finish_wait() as I could optimise it significantly by knowing that the pci_lock protected us at all points. It looked a bit funny to be doing a spin_unlock_irqsave(); schedule(), so I used spin_lock_irq() for the _user versions of pci_read_config and pci_write_config. Not carrying a flags pointer around made the code much less nasty. Attempts to block an already blocked device hit a BUG() and attempts to unblock an already unblocked device hit a WARN(). If we need to block access to a device from userspace, it's because it's unsafe for even another bit of the kernel to access the device. An attempt to block a device for a second time means we're about to access the device to perform some other operation, which could provoke undefined behaviour from the device. Signed-off-by: Matthew Wilcox <matthew@wil.cx> Acked-by: Adam Belay <abelay@novell.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
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| .. | ||
| acorn | ||
| acpi | ||
| amba | ||
| ata | ||
| atm | ||
| base | ||
| block | ||
| bluetooth | ||
| cdrom | ||
| char | ||
| clocksource | ||
| connector | ||
| cpufreq | ||
| crypto | ||
| dio | ||
| dma | ||
| edac | ||
| eisa | ||
| fc4 | ||
| firmware | ||
| hwmon | ||
| i2c | ||
| ide | ||
| ieee1394 | ||
| infiniband | ||
| input | ||
| isdn | ||
| leds | ||
| macintosh | ||
| mca | ||
| md | ||
| media | ||
| message | ||
| mfd | ||
| misc | ||
| mmc | ||
| mtd | ||
| net | ||
| nubus | ||
| oprofile | ||
| parisc | ||
| parport | ||
| pci | ||
| pcmcia | ||
| pnp | ||
| rapidio | ||
| rtc | ||
| s390 | ||
| sbus | ||
| scsi | ||
| serial | ||
| sh | ||
| sn | ||
| spi | ||
| tc | ||
| telephony | ||
| usb | ||
| video | ||
| w1 | ||
| zorro | ||
| Kconfig | ||
| Makefile | ||