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authorStefan Richter <stefanr@s5r6.in-berlin.de>2011-04-22 15:13:54 +0200
committerStefan Richter <stefanr@s5r6.in-berlin.de>2011-05-10 22:53:44 +0200
commitf30e6d3e419bfb5540fa82ba7eca01d578556e6b (patch)
treee4d6e7bad161a76b09557bf7513358ae1ce8f7fb /drivers/firewire/core-card.c
parent020abf03cd659388f94cb328e1e1df0656e0d7ff (diff)
downloadop-kernel-dev-f30e6d3e419bfb5540fa82ba7eca01d578556e6b.zip
op-kernel-dev-f30e6d3e419bfb5540fa82ba7eca01d578556e6b.tar.gz
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 <stefanr@s5r6.in-berlin.de> Acked-by: Clemens Ladisch <clemens@ladisch.de>
Diffstat (limited to 'drivers/firewire/core-card.c')
-rw-r--r--drivers/firewire/core-card.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c
index 3c44fbc8..e119f1e 100644
--- a/drivers/firewire/core-card.c
+++ b/drivers/firewire/core-card.c
@@ -258,8 +258,7 @@ static void allocate_broadcast_channel(struct fw_card *card, int generation)
if (!card->broadcast_channel_allocated) {
fw_iso_resource_manage(card, generation, 1ULL << 31,
- &channel, &bandwidth, true,
- card->bm_transaction_data);
+ &channel, &bandwidth, true);
if (channel != 31) {
fw_notify("failed to allocate broadcast channel\n");
return;
@@ -294,6 +293,7 @@ static void bm_work(struct work_struct *work)
bool root_device_is_cmc;
bool irm_is_1394_1995_only;
bool keep_this_irm;
+ __be32 transaction_data[2];
spin_lock_irq(&card->lock);
@@ -355,21 +355,21 @@ static void bm_work(struct work_struct *work)
goto pick_me;
}
- card->bm_transaction_data[0] = cpu_to_be32(0x3f);
- card->bm_transaction_data[1] = cpu_to_be32(local_id);
+ transaction_data[0] = cpu_to_be32(0x3f);
+ transaction_data[1] = cpu_to_be32(local_id);
spin_unlock_irq(&card->lock);
rcode = fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
irm_id, generation, SCODE_100,
CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID,
- card->bm_transaction_data, 8);
+ transaction_data, 8);
if (rcode == RCODE_GENERATION)
/* Another bus reset, BM work has been rescheduled. */
goto out;
- bm_id = be32_to_cpu(card->bm_transaction_data[0]);
+ bm_id = be32_to_cpu(transaction_data[0]);
spin_lock_irq(&card->lock);
if (rcode == RCODE_COMPLETE && generation == card->generation)
@@ -490,11 +490,11 @@ static void bm_work(struct work_struct *work)
/*
* Make sure that the cycle master sends cycle start packets.
*/
- card->bm_transaction_data[0] = cpu_to_be32(CSR_STATE_BIT_CMSTR);
+ transaction_data[0] = cpu_to_be32(CSR_STATE_BIT_CMSTR);
rcode = fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
root_id, generation, SCODE_100,
CSR_REGISTER_BASE + CSR_STATE_SET,
- card->bm_transaction_data, 4);
+ transaction_data, 4);
if (rcode == RCODE_GENERATION)
goto out;
}
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