firewire: core: do not DMA-map stack addresses

The DMA mapping API cannot map on-stack addresses, as explained in
Documentation/DMA-mapping.txt.  Convert the two cases of on-stack packet
payload buffers in firewire-core (payload of lock requests in the bus
manager work and in iso resource management) to slab-allocated memory.

There are a number on-stack buffers for quadlet write or quadlet read
requests in firewire-core and firewire-sbp2.  These are harmless; they
are copied to/ from card driver internal DMA buffers since quadlet
payloads are inlined with packet headers.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

4 files changed, 25 insertions, 20 deletions

diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c
index 543fccac81bb..f74edae5cb4c 100644
--- a/drivers/firewire/core-card.c
+++ b/drivers/firewire/core-card.c
@@ -196,8 +196,8 @@ static void allocate_broadcast_channel(struct fw_card *card, int generation)
 {
         int channel, bandwidth = 0;
 
-        fw_iso_resource_manage(card, generation, 1ULL << 31,
-                               &channel, &bandwidth, true);
+        fw_iso_resource_manage(card, generation, 1ULL << 31, &channel,
+                               &bandwidth, true, card->bm_transaction_data);
         if (channel == 31) {
                 card->broadcast_channel_allocated = true;
                 device_for_each_child(card->device, (void *)(long)generation,
@@ -230,7 +230,6 @@ static void fw_card_bm_work(struct work_struct *work)
         bool do_reset = false;
         bool root_device_is_running;
         bool root_device_is_cmc;
-        __be32 lock_data[2];
 
         spin_lock_irqsave(&card->lock, flags);
 
@@ -273,22 +272,23 @@ static void fw_card_bm_work(struct work_struct *work)
                         goto pick_me;
                 }
 
-                lock_data[0] = cpu_to_be32(0x3f);
-                lock_data[1] = cpu_to_be32(local_id);
+                card->bm_transaction_data[0] = cpu_to_be32(0x3f);
+                card->bm_transaction_data[1] = cpu_to_be32(local_id);
 
                 spin_unlock_irqrestore(&card->lock, flags);
 
                 rcode = fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
                                 irm_id, generation, SCODE_100,
                                 CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID,
-                                lock_data, sizeof(lock_data));
+                                card->bm_transaction_data,
+                                sizeof(card->bm_transaction_data));
 
                 if (rcode == RCODE_GENERATION)
                         /* Another bus reset, BM work has been rescheduled. */
                         goto out;
 
                 if (rcode == RCODE_COMPLETE &&
-                    lock_data[0] != cpu_to_be32(0x3f)) {
+                    card->bm_transaction_data[0] != cpu_to_be32(0x3f)) {
 
                         /* Somebody else is BM.  Only act as IRM. */
                         if (local_id == irm_id)
diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index d1d30c615b0f..ced186d7e9a9 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -125,6 +125,7 @@ struct iso_resource {
         int generation;
         u64 channels;
         s32 bandwidth;
+        __be32 transaction_data[2];
         struct iso_resource_event *e_alloc, *e_dealloc;
 };
 
@@ -1049,7 +1050,8 @@ static void iso_resource_work(struct work_struct *work)
                         r->channels, &channel, &bandwidth,
                         todo == ISO_RES_ALLOC ||
                         todo == ISO_RES_REALLOC ||
-                        todo == ISO_RES_ALLOC_ONCE);
+                        todo == ISO_RES_ALLOC_ONCE,
+                        r->transaction_data);
         /*
          * Is this generation outdated already?  As long as this resource sticks
          * in the idr, it will be scheduled again for a newer generation or at
diff --git a/drivers/firewire/core-iso.c b/drivers/firewire/core-iso.c
index 166f19c6d38d..110e731f5574 100644
--- a/drivers/firewire/core-iso.c
+++ b/drivers/firewire/core-iso.c
@@ -177,9 +177,8 @@ EXPORT_SYMBOL(fw_iso_context_stop);
  */
 
 static int manage_bandwidth(struct fw_card *card, int irm_id, int generation,
-                            int bandwidth, bool allocate)
+                            int bandwidth, bool allocate, __be32 data[2])
 {
-        __be32 data[2];
         int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0;
 
         /*
@@ -215,9 +214,9 @@ static int manage_bandwidth(struct fw_card *card, int irm_id, int generation,
 }
 
 static int manage_channel(struct fw_card *card, int irm_id, int generation,
-                          u32 channels_mask, u64 offset, bool allocate)
+                u32 channels_mask, u64 offset, bool allocate, __be32 data[2])
 {
-        __be32 data[2], c, all, old;
+        __be32 c, all, old;
         int i, retry = 5;
 
         old = all = allocate ? cpu_to_be32(~0) : 0;
@@ -260,7 +259,7 @@ static int manage_channel(struct fw_card *card, int irm_id, int generation,
 }
 
 static void deallocate_channel(struct fw_card *card, int irm_id,
-                               int generation, int channel)
+                               int generation, int channel, __be32 buffer[2])
 {
         u32 mask;
         u64 offset;
@@ -269,7 +268,7 @@ static void deallocate_channel(struct fw_card *card, int irm_id,
         offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI :
                                 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO;
 
-        manage_channel(card, irm_id, generation, mask, offset, false);
+        manage_channel(card, irm_id, generation, mask, offset, false, buffer);
 }
 
 /**
@@ -298,7 +297,7 @@ static void deallocate_channel(struct fw_card *card, int irm_id,
  */
 void fw_iso_resource_manage(struct fw_card *card, int generation,
                             u64 channels_mask, int *channel, int *bandwidth,
-                            bool allocate)
+                            bool allocate, __be32 buffer[2])
 {
         u32 channels_hi = channels_mask;        /* channels 31...0 */
         u32 channels_lo = channels_mask >> 32;  /* channels 63...32 */
@@ -310,10 +309,12 @@ void fw_iso_resource_manage(struct fw_card *card, int generation,
 
         if (channels_hi)
                 c = manage_channel(card, irm_id, generation, channels_hi,
-                    CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI, allocate);
+                                CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI,
+                                allocate, buffer);
         if (channels_lo && c < 0) {
                 c = manage_channel(card, irm_id, generation, channels_lo,
-                    CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO, allocate);
+                                CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO,
+                                allocate, buffer);
                 if (c >= 0)
                         c += 32;
         }
@@ -325,12 +326,13 @@ void fw_iso_resource_manage(struct fw_card *card, int generation,
         if (*bandwidth == 0)
                 return;
 
-        ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate);
+        ret = manage_bandwidth(card, irm_id, generation, *bandwidth,
+                               allocate, buffer);
         if (ret < 0)
                 *bandwidth = 0;
 
         if (allocate && ret < 0 && c >= 0) {
-                deallocate_channel(card, irm_id, generation, c);
+                deallocate_channel(card, irm_id, generation, c, buffer);
                 *channel = ret;
         }
 }
diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h
index c3cfc647e5e3..6052816be353 100644
--- a/drivers/firewire/core.h
+++ b/drivers/firewire/core.h
@@ -120,7 +120,8 @@ void fw_node_event(struct fw_card *card, struct fw_node *node, int event);
 
 int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma);
 void fw_iso_resource_manage(struct fw_card *card, int generation,
-                u64 channels_mask, int *channel, int *bandwidth, bool allocate);
+                            u64 channels_mask, int *channel, int *bandwidth,
+                            bool allocate, __be32 buffer[2]);
 
 
 /* -topology */