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authorClemens Ladisch <clemens@ladisch.de>2010-11-30 10:25:17 +0300
committerStefan Richter <stefanr@s5r6.in-berlin.de>2010-12-13 22:39:15 +0300
commitec766a7970126f99665992c0b0b10bd60a4d6208 (patch)
treedc049e0bcb3e1fb33a68efea8760391af62f6681 /drivers/firewire
parent2dd5bed59356e03610bebe1a37c397788df50b9b (diff)
downloadlinux-ec766a7970126f99665992c0b0b10bd60a4d6208.tar.xz
firewire: ohci: use common buffer for self IDs and AR descriptors
The buffers used for the selfIDs packets and the AR request and response descriptors end up using three pages because dma_alloc_coherent() allocates at least one page per call. However, these data structures would all fit into 4 KB, so we can save space by using a common buffer for them. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Diffstat (limited to 'drivers/firewire')
-rw-r--r--drivers/firewire/ohci.c66
1 files changed, 34 insertions, 32 deletions
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 01b3bc9154a6..eb7b591e1c1b 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -193,6 +193,9 @@ struct fw_ohci {
struct mutex phy_reg_mutex;
+ void *misc_buffer;
+ dma_addr_t misc_buffer_bus;
+
struct ar_context ar_request_ctx;
struct ar_context ar_response_ctx;
struct context at_request_ctx;
@@ -623,11 +626,6 @@ static void ar_context_release(struct ar_context *ctx)
{
unsigned int i;
- if (ctx->descriptors)
- dma_free_coherent(ctx->ohci->card.device,
- AR_BUFFERS * sizeof(struct descriptor),
- ctx->descriptors, ctx->descriptors_bus);
-
if (ctx->buffer)
vm_unmap_ram(ctx->buffer, AR_BUFFERS + AR_WRAPAROUND_PAGES);
@@ -925,8 +923,8 @@ error:
ctx->pointer = NULL;
}
-static int ar_context_init(struct ar_context *ctx,
- struct fw_ohci *ohci, u32 regs)
+static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
+ unsigned int descriptors_offset, u32 regs)
{
unsigned int i;
dma_addr_t dma_addr;
@@ -960,13 +958,8 @@ static int ar_context_init(struct ar_context *ctx,
if (!ctx->buffer)
goto out_of_memory;
- ctx->descriptors =
- dma_alloc_coherent(ohci->card.device,
- AR_BUFFERS * sizeof(struct descriptor),
- &ctx->descriptors_bus,
- GFP_KERNEL);
- if (!ctx->descriptors)
- goto out_of_memory;
+ ctx->descriptors = ohci->misc_buffer + descriptors_offset;
+ ctx->descriptors_bus = ohci->misc_buffer_bus + descriptors_offset;
for (i = 0; i < AR_BUFFERS; i++) {
d = &ctx->descriptors[i];
@@ -3108,12 +3101,28 @@ static int __devinit pci_probe(struct pci_dev *dev,
if (param_quirks)
ohci->quirks = param_quirks;
- err = ar_context_init(&ohci->ar_request_ctx, ohci,
+ /*
+ * Because dma_alloc_coherent() allocates at least one page,
+ * we save space by using a common buffer for the AR request/
+ * response descriptors and the self IDs buffer.
+ */
+ BUILD_BUG_ON(AR_BUFFERS * sizeof(struct descriptor) > PAGE_SIZE/4);
+ BUILD_BUG_ON(SELF_ID_BUF_SIZE > PAGE_SIZE/2);
+ ohci->misc_buffer = dma_alloc_coherent(ohci->card.device,
+ PAGE_SIZE,
+ &ohci->misc_buffer_bus,
+ GFP_KERNEL);
+ if (!ohci->misc_buffer) {
+ err = -ENOMEM;
+ goto fail_iounmap;
+ }
+
+ err = ar_context_init(&ohci->ar_request_ctx, ohci, 0,
OHCI1394_AsReqRcvContextControlSet);
if (err < 0)
- goto fail_iounmap;
+ goto fail_misc_buf;
- err = ar_context_init(&ohci->ar_response_ctx, ohci,
+ err = ar_context_init(&ohci->ar_response_ctx, ohci, PAGE_SIZE/4,
OHCI1394_AsRspRcvContextControlSet);
if (err < 0)
goto fail_arreq_ctx;
@@ -3148,15 +3157,8 @@ static int __devinit pci_probe(struct pci_dev *dev,
goto fail_contexts;
}
- /* self-id dma buffer allocation */
- ohci->self_id_cpu = dma_alloc_coherent(ohci->card.device,
- SELF_ID_BUF_SIZE,
- &ohci->self_id_bus,
- GFP_KERNEL);
- if (ohci->self_id_cpu == NULL) {
- err = -ENOMEM;
- goto fail_contexts;
- }
+ ohci->self_id_cpu = ohci->misc_buffer + PAGE_SIZE/2;
+ ohci->self_id_bus = ohci->misc_buffer_bus + PAGE_SIZE/2;
bus_options = reg_read(ohci, OHCI1394_BusOptions);
max_receive = (bus_options >> 12) & 0xf;
@@ -3166,7 +3168,7 @@ static int __devinit pci_probe(struct pci_dev *dev,
err = fw_card_add(&ohci->card, max_receive, link_speed, guid);
if (err)
- goto fail_self_id;
+ goto fail_contexts;
version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
fw_notify("Added fw-ohci device %s, OHCI v%x.%x, "
@@ -3176,9 +3178,6 @@ static int __devinit pci_probe(struct pci_dev *dev,
return 0;
- fail_self_id:
- dma_free_coherent(ohci->card.device, SELF_ID_BUF_SIZE,
- ohci->self_id_cpu, ohci->self_id_bus);
fail_contexts:
kfree(ohci->ir_context_list);
kfree(ohci->it_context_list);
@@ -3189,6 +3188,9 @@ static int __devinit pci_probe(struct pci_dev *dev,
ar_context_release(&ohci->ar_response_ctx);
fail_arreq_ctx:
ar_context_release(&ohci->ar_request_ctx);
+ fail_misc_buf:
+ dma_free_coherent(ohci->card.device, PAGE_SIZE,
+ ohci->misc_buffer, ohci->misc_buffer_bus);
fail_iounmap:
pci_iounmap(dev, ohci->registers);
fail_iomem:
@@ -3228,10 +3230,10 @@ static void pci_remove(struct pci_dev *dev)
if (ohci->config_rom)
dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
ohci->config_rom, ohci->config_rom_bus);
- dma_free_coherent(ohci->card.device, SELF_ID_BUF_SIZE,
- ohci->self_id_cpu, ohci->self_id_bus);
ar_context_release(&ohci->ar_request_ctx);
ar_context_release(&ohci->ar_response_ctx);
+ dma_free_coherent(ohci->card.device, PAGE_SIZE,
+ ohci->misc_buffer, ohci->misc_buffer_bus);
context_release(&ohci->at_request_ctx);
context_release(&ohci->at_response_ctx);
kfree(ohci->it_context_list);