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>

diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c
index 543fcca..f74edae 100644 (file)
--- 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 d1d30c6..ced186d 100644 (file)
--- 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 166f19c..110e731 100644 (file)
--- 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 c3cfc64..6052816 100644 (file)
--- 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 */

diff --git a/include/linux/firewire.h b/include/linux/firewire.h
index 9823946..192d1e4 100644 (file)
--- a/include/linux/firewire.h
+++ b/include/linux/firewire.h
@@ -127,6 +127,7 @@ struct fw_card {
        struct delayed_work work;
        int bm_retries;
        int bm_generation;
+       __be32 bm_transaction_data[2];
 
        bool broadcast_channel_allocated;
        u32 broadcast_channel;