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 --- sound/firewire/cmp.c | 3 +-- sound/firewire/iso-resources.c | 12 +++--------- sound/firewire/iso-resources.h | 1 - 3 files changed, 4 insertions(+), 12 deletions(-) (limited to 'sound/firewire') diff --git a/sound/firewire/cmp.c b/sound/firewire/cmp.c index 4a37f3a6fab9..14cacbc655dd 100644 --- a/sound/firewire/cmp.c +++ b/sound/firewire/cmp.c @@ -49,10 +49,9 @@ static int pcr_modify(struct cmp_connection *c, enum bus_reset_handling bus_reset_handling) { struct fw_device *device = fw_parent_device(c->resources.unit); - __be32 *buffer = c->resources.buffer; int generation = c->resources.generation; int rcode, errors = 0; - __be32 old_arg; + __be32 old_arg, buffer[2]; int err; buffer[0] = c->last_pcr_value; diff --git a/sound/firewire/iso-resources.c b/sound/firewire/iso-resources.c index 775dbd5f3445..bb9c0c1fb529 100644 --- a/sound/firewire/iso-resources.c +++ b/sound/firewire/iso-resources.c @@ -11,7 +11,6 @@ #include #include #include -#include #include #include "iso-resources.h" @@ -25,10 +24,6 @@ */ int fw_iso_resources_init(struct fw_iso_resources *r, struct fw_unit *unit) { - r->buffer = kmalloc(2 * 4, GFP_KERNEL); - if (!r->buffer) - return -ENOMEM; - r->channels_mask = ~0uLL; r->unit = fw_unit_get(unit); mutex_init(&r->mutex); @@ -44,7 +39,6 @@ int fw_iso_resources_init(struct fw_iso_resources *r, struct fw_unit *unit) void fw_iso_resources_destroy(struct fw_iso_resources *r) { WARN_ON(r->allocated); - kfree(r->buffer); mutex_destroy(&r->mutex); fw_unit_put(r->unit); } @@ -131,7 +125,7 @@ retry_after_bus_reset: bandwidth = r->bandwidth + r->bandwidth_overhead; fw_iso_resource_manage(card, r->generation, r->channels_mask, - &channel, &bandwidth, true, r->buffer); + &channel, &bandwidth, true); if (channel == -EAGAIN) { mutex_unlock(&r->mutex); goto retry_after_bus_reset; @@ -184,7 +178,7 @@ int fw_iso_resources_update(struct fw_iso_resources *r) bandwidth = r->bandwidth + r->bandwidth_overhead; fw_iso_resource_manage(card, r->generation, 1uLL << r->channel, - &channel, &bandwidth, true, r->buffer); + &channel, &bandwidth, true); /* * When another bus reset happens, pretend that the allocation * succeeded; we will try again for the new generation later. @@ -220,7 +214,7 @@ void fw_iso_resources_free(struct fw_iso_resources *r) if (r->allocated) { bandwidth = r->bandwidth + r->bandwidth_overhead; fw_iso_resource_manage(card, r->generation, 1uLL << r->channel, - &channel, &bandwidth, false, r->buffer); + &channel, &bandwidth, false); if (channel < 0) dev_err(&r->unit->device, "isochronous resource deallocation failed\n"); diff --git a/sound/firewire/iso-resources.h b/sound/firewire/iso-resources.h index 3f0730e4d841..5a9af7c61657 100644 --- a/sound/firewire/iso-resources.h +++ b/sound/firewire/iso-resources.h @@ -24,7 +24,6 @@ struct fw_iso_resources { unsigned int bandwidth_overhead; int generation; /* in which allocation is valid */ bool allocated; - __be32 *buffer; }; int fw_iso_resources_init(struct fw_iso_resources *r, -- cgit v1.2.3