firewire: Split the iso buffer out from fw_iso_context and avoid vmalloc.
authorKristian Høgsberg <krh@redhat.com>
Fri, 16 Feb 2007 22:34:38 +0000 (17:34 -0500)
committerStefan Richter <stefanr@s5r6.in-berlin.de>
Fri, 9 Mar 2007 21:02:57 +0000 (22:02 +0100)
This patch splits out the iso buffer so we can initialize it at mmap
time with the size provided in the mmap call.  Furthermore, allocate
the backing pages using alloc_page to avoid setting up kernel side
virtual memory mappings for the pages.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
drivers/firewire/fw-device-cdev.c
drivers/firewire/fw-device-cdev.h
drivers/firewire/fw-iso.c
drivers/firewire/fw-ohci.c
drivers/firewire/fw-transaction.h

index 1b9e5f7c012982c38e028f4489d180627b3fea53..6284375c639073f6aba6b9e760e403e7521c9c89 100644 (file)
@@ -71,8 +71,10 @@ struct client {
        struct list_head event_list;
        struct semaphore event_list_sem;
        wait_queue_head_t wait;
-       unsigned long vm_start;
+
        struct fw_iso_context *iso_context;
+       struct fw_iso_buffer buffer;
+       unsigned long vm_start;
 };
 
 static inline void __user *
@@ -406,7 +408,6 @@ static int ioctl_create_iso_context(struct client *client, void __user *arg)
 
        client->iso_context = fw_iso_context_create(client->device->card,
                                                    FW_ISO_CONTEXT_TRANSMIT,
-                                                   request.buffer_size,
                                                    iso_callback, client);
        if (IS_ERR(client->iso_context))
                return PTR_ERR(client->iso_context);
@@ -418,8 +419,7 @@ static int ioctl_queue_iso(struct client *client, void __user *arg)
 {
        struct fw_cdev_queue_iso request;
        struct fw_cdev_iso_packet __user *p, *end, *next;
-       void *payload, *payload_end;
-       unsigned long index;
+       unsigned long payload, payload_end;
        int count;
        struct {
                struct fw_iso_packet packet;
@@ -434,20 +434,17 @@ static int ioctl_queue_iso(struct client *client, void __user *arg)
        /* If the user passes a non-NULL data pointer, has mmap()'ed
         * the iso buffer, and the pointer points inside the buffer,
         * we setup the payload pointers accordingly.  Otherwise we
-        * set them both to NULL, which will still let packets with
+        * set them both to 0, which will still let packets with
         * payload_length == 0 through.  In other words, if no packets
         * use the indirect payload, the iso buffer need not be mapped
         * and the request.data pointer is ignored.*/
 
-       index = (unsigned long)request.data - client->vm_start;
-       if (request.data != 0 && client->vm_start != 0 &&
-           index <= client->iso_context->buffer_size) {
-               payload = client->iso_context->buffer + index;
-               payload_end = client->iso_context->buffer +
-                       client->iso_context->buffer_size;
-       } else {
-               payload = NULL;
-               payload_end = NULL;
+       payload = (unsigned long)request.data - client->vm_start;
+       payload_end = payload + (client->buffer.page_count << PAGE_SHIFT);
+       if (request.data == 0 || client->buffer.pages == NULL ||
+           payload >= payload_end) {
+               payload = 0;
+               payload_end = 0;
        }
 
        if (!access_ok(VERIFY_READ, request.packets, request.size))
@@ -473,7 +470,7 @@ static int ioctl_queue_iso(struct client *client, void __user *arg)
                        return -EINVAL;
 
                if (fw_iso_context_queue(client->iso_context,
-                                        &u.packet, payload))
+                                        &u.packet, &client->buffer, payload))
                        break;
 
                p = next;
@@ -483,8 +480,7 @@ static int ioctl_queue_iso(struct client *client, void __user *arg)
 
        request.size    -= uptr_to_u64(p) - request.packets;
        request.packets  = uptr_to_u64(p);
-       request.data     =
-               client->vm_start + (payload - client->iso_context->buffer);
+       request.data     = client->vm_start + payload;
 
        if (copy_to_user(arg, &request, sizeof request))
                return -EFAULT;
@@ -549,13 +545,41 @@ fw_device_op_compat_ioctl(struct file *file,
 static int fw_device_op_mmap(struct file *file, struct vm_area_struct *vma)
 {
        struct client *client = file->private_data;
+       enum dma_data_direction direction;
+       unsigned long size;
+       int page_count, retval;
+
+       /* FIXME: We could support multiple buffers, but we don't. */
+       if (client->buffer.pages != NULL)
+               return -EBUSY;
+
+       if (!(vma->vm_flags & VM_SHARED))
+               return -EINVAL;
 
-       if (client->iso_context->buffer == NULL)
+       if (vma->vm_start & ~PAGE_MASK)
                return -EINVAL;
 
        client->vm_start = vma->vm_start;
+       size = vma->vm_end - vma->vm_start;
+       page_count = size >> PAGE_SHIFT;
+       if (size & ~PAGE_MASK)
+               return -EINVAL;
+
+       if (vma->vm_flags & VM_WRITE)
+               direction = DMA_TO_DEVICE;
+       else
+               direction = DMA_FROM_DEVICE;
+
+       retval = fw_iso_buffer_init(&client->buffer, client->device->card,
+                                   page_count, direction);
+       if (retval < 0)
+               return retval;
 
-       return remap_vmalloc_range(vma, client->iso_context->buffer, 0);
+       retval = fw_iso_buffer_map(&client->buffer, vma);
+       if (retval < 0)
+               fw_iso_buffer_destroy(&client->buffer, client->device->card);
+
+       return retval;
 }
 
 static int fw_device_op_release(struct inode *inode, struct file *file)
@@ -564,6 +588,9 @@ static int fw_device_op_release(struct inode *inode, struct file *file)
        struct address_handler *h, *next;
        struct request *r, *next_r;
 
+       if (client->buffer.pages)
+               fw_iso_buffer_destroy(&client->buffer, client->device->card);
+
        if (client->iso_context)
                fw_iso_context_destroy(client->iso_context);
 
index ddbae43ca1a4a9f4ebd09adc2c7908fcb8602762..003cc669551bed555423d3c6d8b40cd59b4580f0 100644 (file)
@@ -126,7 +126,7 @@ struct fw_cdev_allocate {
 };
 
 struct fw_cdev_create_iso_context {
-       __u32 buffer_size;
+       __u32 handle;
 };
 
 struct fw_cdev_iso_packet {
index 6481e3df2c93197c362660c1e812bab028477345..4e7ba8672929c67b6ad4d68854bc962cb25fdf6b 100644 (file)
 #include "fw-topology.h"
 #include "fw-device.h"
 
-static int
-setup_iso_buffer(struct fw_iso_context *ctx, size_t size,
-                enum dma_data_direction direction)
+int
+fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card,
+                  int page_count, enum dma_data_direction direction)
 {
-       struct page *page;
-       int i, j;
-       void *p;
-
-       ctx->buffer_size = PAGE_ALIGN(size);
-       if (size == 0)
-               return 0;
-
-       ctx->buffer = vmalloc_32_user(ctx->buffer_size);
-       if (ctx->buffer == NULL)
-               goto fail_buffer_alloc;
-
-       ctx->page_count = ctx->buffer_size >> PAGE_SHIFT;
-       ctx->pages =
-           kzalloc(ctx->page_count * sizeof(ctx->pages[0]), GFP_KERNEL);
-       if (ctx->pages == NULL)
-               goto fail_pages_alloc;
-
-       p = ctx->buffer;
-       for (i = 0; i < ctx->page_count; i++, p += PAGE_SIZE) {
-               page = vmalloc_to_page(p);
-               ctx->pages[i] = dma_map_page(ctx->card->device,
-                                            page, 0, PAGE_SIZE, direction);
-               if (dma_mapping_error(ctx->pages[i]))
-                       goto fail_mapping;
+       int i, j, retval = -ENOMEM;
+       dma_addr_t address;
+
+       buffer->page_count = page_count;
+       buffer->direction = direction;
+
+       buffer->pages = kmalloc(page_count * sizeof(buffer->pages[0]),
+                               GFP_KERNEL);
+       if (buffer->pages == NULL)
+               goto out;
+
+       for (i = 0; i < buffer->page_count; i++) {
+               buffer->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32);
+               if (buffer->pages[i] == NULL)
+                       goto out_pages;
+               
+               address = dma_map_page(card->device, buffer->pages[i],
+                                      0, PAGE_SIZE, direction);
+               if (dma_mapping_error(address)) {
+                       __free_page(buffer->pages[i]);
+                       goto out_pages;
+               }
+               set_page_private(buffer->pages[i], address);
        }
 
        return 0;
 
- fail_mapping:
-       for (j = 0; j < i; j++)
-               dma_unmap_page(ctx->card->device, ctx->pages[j],
+ out_pages:
+       for (j = 0; j < i; j++) {
+               address = page_private(buffer->pages[j]);
+               dma_unmap_page(card->device, address,
                               PAGE_SIZE, DMA_TO_DEVICE);
- fail_pages_alloc:
-       vfree(ctx->buffer);
- fail_buffer_alloc:
-       return -ENOMEM;
+               __free_page(buffer->pages[j]);
+       }
+       kfree(buffer->pages);
+ out:
+       buffer->pages = NULL;
+       return retval;
+}
+
+int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma)
+{
+       unsigned long uaddr;
+       int i, retval;
+
+       uaddr = vma->vm_start;
+       for (i = 0; i < buffer->page_count; i++) {
+               retval = vm_insert_page(vma, uaddr, buffer->pages[i]);
+               if (retval)
+                       return retval;
+               uaddr += PAGE_SIZE;
+       }
+
+       return 0;
 }
 
-static void destroy_iso_buffer(struct fw_iso_context *ctx)
+void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer,
+                          struct fw_card *card)
 {
        int i;
+       dma_addr_t address;
 
-       for (i = 0; i < ctx->page_count; i++)
-               dma_unmap_page(ctx->card->device, ctx->pages[i],
+       for (i = 0; i < buffer->page_count; i++) {
+               address = page_private(buffer->pages[i]);
+               dma_unmap_page(card->device, address,
                               PAGE_SIZE, DMA_TO_DEVICE);
+               __free_page(buffer->pages[i]);
+       }
 
-       kfree(ctx->pages);
-       vfree(ctx->buffer);
+       kfree(buffer->pages);
+       buffer->pages = NULL;
 }
 
 struct fw_iso_context *fw_iso_context_create(struct fw_card *card, int type,
-                                            size_t buffer_size,
                                             fw_iso_callback_t callback,
                                             void *callback_data)
 {
        struct fw_iso_context *ctx;
-       int retval;
 
        ctx = card->driver->allocate_iso_context(card, type);
        if (IS_ERR(ctx))
@@ -100,12 +120,6 @@ struct fw_iso_context *fw_iso_context_create(struct fw_card *card, int type,
        ctx->callback = callback;
        ctx->callback_data = callback_data;
 
-       retval = setup_iso_buffer(ctx, buffer_size, DMA_TO_DEVICE);
-       if (retval < 0) {
-               card->driver->free_iso_context(ctx);
-               return ERR_PTR(retval);
-       }
-
        return ctx;
 }
 EXPORT_SYMBOL(fw_iso_context_create);
@@ -114,8 +128,6 @@ void fw_iso_context_destroy(struct fw_iso_context *ctx)
 {
        struct fw_card *card = ctx->card;
 
-       destroy_iso_buffer(ctx);
-
        card->driver->free_iso_context(ctx);
 }
 EXPORT_SYMBOL(fw_iso_context_destroy);
@@ -133,10 +145,12 @@ EXPORT_SYMBOL(fw_iso_context_send);
 
 int
 fw_iso_context_queue(struct fw_iso_context *ctx,
-                    struct fw_iso_packet *packet, void *payload)
+                    struct fw_iso_packet *packet,
+                    struct fw_iso_buffer *buffer,
+                    unsigned long payload)
 {
        struct fw_card *card = ctx->card;
 
-       return card->driver->queue_iso(ctx, packet, payload);
+       return card->driver->queue_iso(ctx, packet, buffer, payload);
 }
 EXPORT_SYMBOL(fw_iso_context_queue);
index 72f80361fc431507d2a31db44314e6c30b3975ad..8499d70bf9ee447c6ab57244eb45d7dac0a0a3bd 100644 (file)
@@ -1251,14 +1251,16 @@ static void ohci_free_iso_context(struct fw_iso_context *base)
 
 static int
 ohci_queue_iso(struct fw_iso_context *base,
-              struct fw_iso_packet *packet, void *payload)
+              struct fw_iso_packet *packet,
+              struct fw_iso_buffer *buffer,
+              unsigned long payload)
 {
        struct iso_context *ctx = (struct iso_context *)base;
        struct fw_ohci *ohci = fw_ohci(ctx->base.card);
        struct descriptor *d, *end, *last, *tail, *pd;
        struct fw_iso_packet *p;
        __le32 *header;
-       dma_addr_t d_bus;
+       dma_addr_t d_bus, page_bus;
        u32 z, header_z, payload_z, irq;
        u32 payload_index, payload_end_index, next_page_index;
        int index, page, end_page, i, length, offset;
@@ -1267,7 +1269,7 @@ ohci_queue_iso(struct fw_iso_context *base,
         * packet, retransmit or terminate.. */
 
        p = packet;
-       payload_index = payload - ctx->base.buffer;
+       payload_index = payload;
        d = ctx->head_descriptor;
        tail = ctx->tail_descriptor;
        end = ctx->buffer + ISO_BUFFER_SIZE / sizeof(struct descriptor);
@@ -1337,7 +1339,9 @@ ohci_queue_iso(struct fw_iso_context *base,
                length             =
                        min(next_page_index, payload_end_index) - payload_index;
                pd[i].req_count    = cpu_to_le16(length);
-               pd[i].data_address = cpu_to_le32(ctx->base.pages[page] + offset);
+
+               page_bus = page_private(buffer->pages[page]);
+               pd[i].data_address = cpu_to_le32(page_bus + offset);
 
                payload_index += length;
        }
index 8f0283cf1a7a191f169aec7edb88ad24ec90f05b..89c6dda279365923a82be7ef54466d0dbb8581af 100644 (file)
@@ -27,6 +27,7 @@
 #include <linux/interrupt.h>
 #include <linux/list.h>
 #include <linux/fs.h>
+#include <linux/dma-mapping.h>
 
 #define TCODE_WRITE_QUADLET_REQUEST    0
 #define TCODE_WRITE_BLOCK_REQUEST      1
@@ -336,6 +337,18 @@ struct fw_iso_context;
 typedef void (*fw_iso_callback_t) (struct fw_iso_context *context,
                                   int status, u32 cycle, void *data);
 
+/* An iso buffer is just a set of pages mapped for DMA in the
+ * specified direction.  Since the pages are to be used for DMA, they
+ * are not mapped into the kernel virtual address space.  We store the
+ * DMA address in the page private. The helper function
+ * fw_iso_buffer_map() will map the pages into a given vma. */
+
+struct fw_iso_buffer {
+       enum dma_data_direction direction;
+       struct page **pages;
+       int page_count;
+};
+
 struct fw_iso_context {
        struct fw_card *card;
        int type;
@@ -343,19 +356,24 @@ struct fw_iso_context {
        int speed;
        fw_iso_callback_t callback;
        void *callback_data;
-
-       void *buffer;
-       size_t buffer_size;
-       dma_addr_t *pages;
-       int page_count;
 };
 
+int
+fw_iso_buffer_init(struct fw_iso_buffer *buffer,
+                  struct fw_card *card,
+                  int page_count,
+                  enum dma_data_direction direction);
+int
+fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma);
+void
+fw_iso_buffer_destroy(struct fw_iso_buffer *buffer, struct fw_card *card);
+
 struct fw_iso_context *
 fw_iso_context_create(struct fw_card *card, int type,
-                     size_t buffer_size,
                      fw_iso_callback_t callback,
                      void *callback_data);
 
+
 void
 fw_iso_context_destroy(struct fw_iso_context *ctx);
 
@@ -365,7 +383,9 @@ fw_iso_context_start(struct fw_iso_context *ctx,
 
 int
 fw_iso_context_queue(struct fw_iso_context *ctx,
-                    struct fw_iso_packet *packet, void *payload);
+                    struct fw_iso_packet *packet,
+                    struct fw_iso_buffer *buffer,
+                    unsigned long payload);
 
 int
 fw_iso_context_send(struct fw_iso_context *ctx,
@@ -410,7 +430,9 @@ struct fw_card_driver {
        int (*send_iso)(struct fw_iso_context *ctx, s32 cycle);
 
        int (*queue_iso)(struct fw_iso_context *ctx,
-                        struct fw_iso_packet *packet, void *payload);
+                        struct fw_iso_packet *packet,
+                        struct fw_iso_buffer *buffer,
+                        unsigned long payload);
 };
 
 int