From f30e6d3e419bfb5540fa82ba7eca01d578556e6b Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Fri, 22 Apr 2011 15:13:54 +0200 Subject: firewire: octlet AT payloads can be stack-allocated We do not need slab allocations anymore in order to satisfy streaming DMA mapping constraints, thanks to commit da28947e7e36 "firewire: ohci: avoid separate DMA mapping for small AT payloads". (Besides, the slab-allocated buffers that firewire-core, firewire-sbp2, and firedtv used to provide for 8-byte write and lock requests were still not fully portable since they crossed cacheline boundaries or shared a cacheline with unrelated CPU-accessed data. snd-firewire-lib got this aspect right by using an extra kmalloc/ kfree just for the 8-byte transaction buffer.) This change replaces kmalloc'ed lock transaction scratch buffers in firewire-core, firedtv, and snd-firewire-lib by local stack allocations. Perhaps the most notable result of the change is simpler locking because there is no need to serialize usages of preallocated per-device buffers anymore. Also, allocations and deallocations are simpler. Signed-off-by: Stefan Richter Acked-by: Clemens Ladisch --- include/linux/firewire.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/firewire.h b/include/linux/firewire.h index c64f3680d4f1..de90e1ff8488 100644 --- a/include/linux/firewire.h +++ b/include/linux/firewire.h @@ -125,7 +125,6 @@ struct fw_card { struct delayed_work bm_work; /* bus manager job */ int bm_retries; int bm_generation; - __be32 bm_transaction_data[2]; int bm_node_id; bool bm_abdicate; @@ -447,6 +446,6 @@ int fw_iso_context_stop(struct fw_iso_context *ctx); void fw_iso_context_destroy(struct fw_iso_context *ctx); void fw_iso_resource_manage(struct fw_card *card, int generation, u64 channels_mask, int *channel, int *bandwidth, - bool allocate, __be32 buffer[2]); + bool allocate); #endif /* _LINUX_FIREWIRE_H */ -- cgit v1.2.3 From 13882a82ee1646336c3996c93b4a560a55d2a419 Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Mon, 2 May 2011 09:33:56 +0200 Subject: firewire: optimize iso queueing by setting wake only after the last packet When queueing iso packets, the run time is dominated by the two MMIO accesses that set the DMA context's wake bit. Because most drivers submit packets in batches, we can save much time by removing all but the last wakeup. The internal kernel API is changed to require a call to fw_iso_context_queue_flush() after a batch of queued packets. The user space API does not change, so one call to FW_CDEV_IOC_QUEUE_ISO must specify multiple packets to take advantage of this optimization. In my measurements, this patch reduces the time needed to queue fifty skip packets from userspace to one sixth on a 2.5 GHz CPU, or to one third at 800 MHz. Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter --- include/linux/firewire.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/firewire.h b/include/linux/firewire.h index de90e1ff8488..c0fb405bb435 100644 --- a/include/linux/firewire.h +++ b/include/linux/firewire.h @@ -440,6 +440,7 @@ int fw_iso_context_queue(struct fw_iso_context *ctx, struct fw_iso_packet *packet, struct fw_iso_buffer *buffer, unsigned long payload); +void fw_iso_context_queue_flush(struct fw_iso_context *ctx); int fw_iso_context_start(struct fw_iso_context *ctx, int cycle, int sync, int tags); int fw_iso_context_stop(struct fw_iso_context *ctx); -- cgit v1.2.3 From 105e53f863c04e1d9e5bb34bf753c9fdbce6a60c Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Sun, 1 May 2011 20:50:31 +0200 Subject: firewire: sbp2: parallelize login, reconnect, logout The struct sbp2_logical_unit.work items can all be executed in parallel but are not reentrant. Furthermore, reconnect or re-login work must be executed in a WQ_MEM_RECLAIM workqueue. Hence replace the old single-threaded firewire-sbp2 workqueue by a concurrency-managed but non-reentrant workqueue with rescuer. firewire-core already maintains one, hence use this one. In earlier versions of this change, I observed occasional failures of parallel INQUIRY to an Initio INIC-2430 FireWire 800 to dual IDE bridge. More testing indicates that parallel INQUIRY is not actually a problem, but too quick successions of logout and login + INQUIRY, e.g. a quick sequence of cable plugout and plugin, can result in failed INQUIRY. This does not seem to be something that should or could be addressed by serialization. Another dual-LU device to which I currently have access to, an OXUF924DSB FireWire 800 to dual SATA bridge with firmware from MacPower, has been successfully tested with this too. This change is beneficial to environments with two or more FireWire storage devices, especially if they are located on the same bus. Management tasks that should be performed as soon and as quickly as possible, especially reconnect, are no longer held up by tasks on other devices that may take a long time, especially login with INQUIRY and sd or sr driver probe. Signed-off-by: Stefan Richter --- include/linux/firewire.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/firewire.h b/include/linux/firewire.h index c0fb405bb435..5e6f42789afe 100644 --- a/include/linux/firewire.h +++ b/include/linux/firewire.h @@ -449,4 +449,6 @@ void fw_iso_resource_manage(struct fw_card *card, int generation, u64 channels_mask, int *channel, int *bandwidth, bool allocate); +extern struct workqueue_struct *fw_workqueue; + #endif /* _LINUX_FIREWIRE_H */ -- cgit v1.2.3