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path: root/drivers/dma
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2006-10-05IRQ: Maintain regs pointer globally rather than passing to IRQ handlersDavid Howells
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-07-21[I/OAT]: Remove pci_module_init() from Intel I/OAT DMA engineHenrik Kretzschmar
Changes pci_module_init() to pci_register_driver(). Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-03[IOAT]: fix kernel-doc in source filesRandy Dunlap
Fix kernel-doc warnings in drivers/dma/: - use correct function & parameter names - add descriptions where omitted Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-03[IOAT]: Fix a warning in ioatdmaBenoit Boissinot
drivers/dma/ioatdma.c: In function 'ioat_init_module': drivers/dma/ioatdma.c:830: warning: control reaches end of non-void function Signed-off-by: Benoit Boissinot <benoit.boissinot@ens-lyon.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-03[IOAT]: drivers/dma/iovlock.c: make num_pages_spanned() staticAdrian Bunk
This patch makes the needlessly global num_pages_spanned() static. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-03[IOAT]: fix sparse ulong warningRandy Dunlap
Fix sparse warning: drivers/dma/ioatdma.c:444:32: warning: constant 0xFFFFFFFFFFFFFFC0 is so big it is unsigned long Also needs a MAINTAINERS entry. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-02[PATCH] irq-flags: misc drivers: Use the new IRQF_ constantsThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[IOAT]: Do not dereference THIS_MODULE directly to set unsafe.David S. Miller
Use the __unsafe() macro instead. Noticed by Miles Lane. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17[I/OAT]: Do not use for_each_cpu().Andrew Morton
for_each_cpu() is going away (and is gone in -mm). Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Chris Leech <christopher.leech@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17[I/OAT]: Utility functions for offloading sk_buff to iovec copiesChris Leech
Provides for pinning user space pages in memory, copying to iovecs, and copying from sk_buffs including fragmented and chained sk_buffs. Signed-off-by: Chris Leech <christopher.leech@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17[I/OAT]: Setup the networking subsystem as a DMA clientChris Leech
Attempts to allocate per-CPU DMA channels Signed-off-by: Chris Leech <christopher.leech@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17[I/OAT]: Move PCI_DEVICE_ID_INTEL_IOAT to linux/pci_ids.hDavid S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17[I/OAT]: ioatdma.c needs linux/dma-mapping.hDavid S. Miller
For DMA_*_MASK defines. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17[I/OAT]: Driver for the Intel(R) I/OAT DMA engineChris Leech
Adds a new ioatdma driver Signed-off-by: Chris Leech <christopher.leech@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17[I/OAT]: DMA memcpy subsystemChris Leech
Provides an API for offloading memory copies to DMA devices Signed-off-by: Chris Leech <christopher.leech@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>