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>

1 files changed, 13 insertions, 11 deletions

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;
         }
 }