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2012-02-22dma-helpers: add accounting wrappersPaolo Bonzini
The length of the transfer is already in the sglist, the wrapper simply fetches it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-02-22dma-helpers: add dma_buf_read and dma_buf_writePaolo Bonzini
These helpers do a full transfer from an in-memory buffer to target memory, with support for scatter/gather lists. It will be used to store the reply of an emulated command into a QEMUSGList provided by the adapter. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-15dma: the passed io_func does not return NULLPaolo Bonzini
Initially found with the following semantic patch: @ type @ BlockDriverAIOCB *x; expression E; @@ x = E; - if (x == NULL) { ... } @ acb1 @ expression E, E1; @@ E1->acb = E; - if (E1->acb == NULL) { ... } @ aiocb1 @ expression E, E1; @@ E1->aiocb = E; - if (E1->aiocb == NULL) { ... } @ acb @ expression E, E1; @@ E1.acb = E; - if (E1.acb == NULL) { ... } @ aiocb @ expression E, E1; @@ E1.aiocb = E; - if (E1.aiocb == NULL) { ... } but changed manually to include an assert. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05dma-helpers: Add trace eventsKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-11-01Use dma_addr_t type for scatter/gather codeDavid Gibson
This patch uses the newly created dma_addr_t type throughout the scatter/gather handling code in dma-helpers.c whenever we need to represent a dma bus address. This makes a better distinction as to what is a bus address and what is a cpu physical address. Since we don't support IOMMUs yet, they can't be very different for now, but that will change in future, and this preliminary helps clarify what's going on. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-09-20dma-helpers: rewrite completion/cancellationPaolo Bonzini
This fixes various problems with completion/cancellation: * if the io_func fails to get an AIOCB, the callback wasn't called * If DMA encounters a bounce buffer conflict, and the DMA operation is canceled before the bottom half fires, bad things happen. * memory is not unmapped after cancellation, again causing problems when doing DMA to I/O areas * cancellation could leak the iovec * the callback was missed if the I/O operation failed without returning an AIOCB and probably more that I've missed. The patch fixes them by sharing the cleanup code between completion and cancellation. The dma_bdrv_cb now returns a boolean completed/not completed flag, and the wrapper dma_continue takes care of tasks to do upon completion. Most of these are basically impossible in practice, but it is better to be tidy... Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-19dma-helpers: rename is_write to to_devPaolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-20Use glib memory allocation and free functionsAnthony Liguori
qemu_malloc/qemu_free no longer exist after this commit. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-06-15make dma_bdrv_io available to driversChristoph Hellwig
Make dma_bdrv_io available for drivers, and pass an explicit I/O function instead of hardcoding bdrv_aio_readv/bdrv_aio_writev. This is required to implement non-READ/WRITE dma commands in the ide driver, e.g. the upcoming TRIM support. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2009-10-01Revert "Get rid of _t suffix"Anthony Liguori
In the very least, a change like this requires discussion on the list. The naming convention is goofy and it causes a massive merge problem. Something like this _must_ be presented on the list first so people can provide input and cope with it. This reverts commit 99a0949b720a0936da2052cb9a46db04ffc6db29. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-01Get rid of _t suffixmalc
Some not so obvious bits, slirp and Xen were left alone for the time being. Signed-off-by: malc <av1474@comtv.ru>
2009-05-27fully split aio_pool from BlockDriverChristoph Hellwig
Now that we have a separate aio pool structure we can remove those aio pool details from BlockDriver. Every driver supporting AIO now needs to declare a static AIOPool with the aiocb size and the cancellation method. This cleans up the current code considerably and will make it cleaner and more obvious to support two different aio implementations behind a single BlockDriver. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-04-07Fix a few Sparse warningsblueswir1
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7016 c046a42c-6fe2-441c-8c8c-71466251a162
2009-03-28Fix DMA API when handling an immediate error from block layer (Avi Kivity)aliguori
The block layer may signal an immediate error on an asynchronous request by returning NULL. The DMA API did not handle this correctly, returning an AIO request which would never complete (and which would crash if cancelled). Fix by detecting the failure and propagating it. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6893 c046a42c-6fe2-441c-8c8c-71466251a162
2009-03-20Move block dma helpers aiocb to store dma state (Avi Kivity)aliguori
Use the dedicated dma aiocb to store intermediate state for dma block transactions. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6874 c046a42c-6fe2-441c-8c8c-71466251a162
2009-03-20Implement cancellation method for dma async I/O (Avi Kivity)aliguori
Move the dma helpers to a private aio pool, and implement a cancellation method for them. Should prevent issues when cancelling I/O while dma is in progress. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6872 c046a42c-6fe2-441c-8c8c-71466251a162
2009-02-05Introduce block dma helpers (Avi Kivity)aliguori
These helpers perform read/write requests on entire scatter/gather lists, relieving the device emulation code from mapping and unmapping physical memory, and from looping when map resources are exhausted. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6524 c046a42c-6fe2-441c-8c8c-71466251a162
2009-02-05Add a scatter-gather list type and accessors (Avi Kivity)aliguori
Scatter-gather lists are used extensively in dma-capable devices; a single data structure allows more code reuse later on. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6522 c046a42c-6fe2-441c-8c8c-71466251a162