K 10 svn:author V 3 ken K 8 svn:date V 27 2018-02-06T15:58:22.654544Z K 7 svn:log V 2968 Diagnostic buffer fixes for the mps(4) and mpr(4) drivers. In mp{r,s}_diag_register(), which is used to register diagnostic buffers with the mp{r,s}(4) firmware, we allocate DMAable memory. There were several issues here: o No checking of the bus_dmamap_load() return value. If the load failed or got deferred, mp{r,s}_diag_register() continued on as if nothing had happened. We now check the return value and bail out if it fails. o No waiting for a deferred load callback. bus_dmamap_load() calls a supplied callback when the mapping is done. This is generally done immediately, but it can be deferred. mp{r,s}_diag_register() did not check to see whether the callback was already done before proceeding on. We now sleep until the callback is done if it is deferred. o No call to bus_dmamap_sync(... BUS_DMASYNC_PREREAD) after the memory is allocated and loaded. This is necessary on some platforms to synchronize host memory that is going to be updated by a device. Both drivers would also panic if the firmware was reinitialized while a diagnostic buffer operation was in progress. This fixes that problem as well. (The driver will reinitialize the firmware in various circumstances, but the problem I ran into was that the firmware would generate an IOC Fault due to a PCIe error.) mp{r,s}var.h: Add a new structure, struct mpr_busdma_context, that is used for deferred busdma load callbacks. Add a prototype for mp{r,s}_memaddr_wait_cb(). mp{r,s}.c: Add a new busdma callback function, mp{r,s}_memaddr_wait_cb(). This provides synchronization for callers that want to wait on a deferred bus_dmamap_load() callback. mp{r,s}_user.c: In bus_dmamap_register(), add a call to bus_dmamap_sync() with the BUS_DMASYNC_PREREAD flag set after an allocation is loaded. Also, check the return value of bus_dmamap_load(). If it fails, bail out. If it is EINPROGRESS, wait for the callback to happen. We use an interruptible sleep (msleep with PCATCH) and let the callback clean things up if we get interrupted. In mpr_diag_read_buffer() and mps_diag_read_buffer(), call bus_dmamap_sync(..., BUS_DMASYNC_POSTREAD) before copying the data out to make sure the data is in stable storage. In mp{r,s}_post_fw_diag_buffer() and mp{r,s}_release_fw_diag_buffer(), check the reply to see whether it is NULL. It can be NULL (and the command non-NULL) if the controller gets reinitialized while we're waiting for the command to complete but the driver structures aren't reallocated. The driver structures generally won't be reallocated unless there is a firmware upgrade that changes one of the IOCFacts. When freeing diagnostic buffers in mp{r,s}_diag_register() and mp{r,s}_diag_unregister(), zero/NULL out the buffer after freeing it. This will prevent a duplicate free in some situations. Sponsored by: Spectra Logic Reviewed by: mav, scottl MFC after: 1 week Differential Revision: D13453 END