Staging: poch: Remove circular buffer header

Remove the circular buffer header. Which has been superseded by the
ioctl consume interface.

Signed-off-by: Vijay Kumar B <vijaykumar@bravegnu.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 8 insertions, 108 deletions

diff --git a/drivers/staging/poch/README b/drivers/staging/poch/README
index 842afd46499..600121f7d67 100644
--- a/drivers/staging/poch/README
+++ b/drivers/staging/poch/README
@@ -1,7 +1,6 @@
 TODO:
         - Rx block size is limited to < 2048, hardware bug?
         - Group size is limited to < page size, kernel alloc/mmap API issues
-        - fix/workaround cache issues in circular buffer header
         - test whether Tx is transmitting data from provided buffers
         - handle device unplug case
         - handle temperature above threshold
diff --git a/drivers/staging/poch/poch.c b/drivers/staging/poch/poch.c
index babd881809a..9095158fb1b 100644
--- a/drivers/staging/poch/poch.c
+++ b/drivers/staging/poch/poch.c
@@ -197,9 +197,6 @@ struct channel_info {
 
         /* Contains the header and circular buffer exported to userspace. */
         spinlock_t group_offsets_lock;
-        struct poch_cbuf_header *header;
-        struct page *header_pg;
-        unsigned long header_size;
 
         /* Last group consumed by user space. */
         unsigned int consumed;
@@ -329,14 +326,12 @@ static ssize_t show_mmap_size(struct device *dev,
         int len;
         unsigned long mmap_size;
         unsigned long group_pages;
-        unsigned long header_pages;
         unsigned long total_group_pages;
 
         group_pages = npages(channel->group_size);
-        header_pages = npages(channel->header_size);
         total_group_pages = group_pages * channel->group_count;
 
-        mmap_size = (header_pages + total_group_pages) * PAGE_SIZE;
+        mmap_size = total_group_pages * PAGE_SIZE;
         len = sprintf(buf, "%lu\n", mmap_size);
         return len;
 }
@@ -369,10 +364,8 @@ static int poch_channel_alloc_groups(struct channel_info *channel)
 {
         unsigned long i;
         unsigned long group_pages;
-        unsigned long header_pages;
 
         group_pages = npages(channel->group_size);
-        header_pages = npages(channel->header_size);
 
         for (i = 0; i < channel->group_count; i++) {
                 struct poch_group_info *group;
@@ -402,8 +395,7 @@ static int poch_channel_alloc_groups(struct channel_info *channel)
                  * this?
                  */
                 group->dma_addr = page_to_pfn(group->pg) * PAGE_SIZE;
-                group->user_offset =
-                        (header_pages + (i * group_pages)) * PAGE_SIZE;
+                group->user_offset = (i * group_pages) * PAGE_SIZE;
 
                 printk(KERN_INFO PFX "%ld: user_offset: 0x%lx\n", i,
                        group->user_offset);
@@ -525,56 +517,6 @@ static void channel_dma_init(struct channel_info *channel)
 
 }
 
-static int poch_channel_alloc_header(struct channel_info *channel)
-{
-        struct poch_cbuf_header *header = channel->header;
-        unsigned long group_offset_size;
-        unsigned long tot_group_offsets_size;
-
-        /* Allocate memory to hold header exported userspace */
-        group_offset_size = sizeof(header->group_offsets[0]);
-        tot_group_offsets_size = group_offset_size * channel->group_count;
-        channel->header_size = sizeof(*header) + tot_group_offsets_size;
-        channel->header_pg = alloc_pages(GFP_KERNEL | __GFP_ZERO,
-                                         get_order(channel->header_size));
-        if (!channel->header_pg)
-                return -ENOMEM;
-
-        channel->header = page_address(channel->header_pg);
-
-        return 0;
-}
-
-static void poch_channel_free_header(struct channel_info *channel)
-{
-        unsigned int order;
-
-        order = get_order(channel->header_size);
-        __free_pages(channel->header_pg, order);
-}
-
-static void poch_channel_init_header(struct channel_info *channel)
-{
-        int i;
-        struct poch_group_info *groups;
-        s32 *group_offsets;
-
-        channel->header->group_size_bytes = channel->group_size;
-        channel->header->group_count = channel->group_count;
-
-        spin_lock_init(&channel->group_offsets_lock);
-
-        group_offsets = channel->header->group_offsets;
-        groups = channel->groups;
-
-        for (i = 0; i < channel->group_count; i++) {
-                if (channel->dir == CHANNEL_DIR_RX)
-                        group_offsets[i] = -1;
-                else
-                        group_offsets[i] = groups[i].user_offset;
-        }
-}
-
 static void __poch_channel_clear_counters(struct channel_info *channel)
 {
         channel->counters.pll_unlock = 0;
@@ -617,12 +559,6 @@ static int poch_channel_init(struct channel_info *channel,
                 goto out_free_group_info;
         }
 
-        ret = poch_channel_alloc_header(channel);
-        if (ret) {
-                dev_err(dev, "error allocating user space header\n");
-                goto out_free_groups;
-        }
-
         channel->fpga_iomem = poch_dev->fpga_iomem;
         channel->bridge_iomem = poch_dev->bridge_iomem;
         channel->iomem_lock = &poch_dev->iomem_lock;
@@ -630,14 +566,8 @@ static int poch_channel_init(struct channel_info *channel,
 
         __poch_channel_clear_counters(channel);
 
-        printk(KERN_WARNING "poch_channel_init_header\n");
-
-        poch_channel_init_header(channel);
-
         return 0;
 
- out_free_groups:
-        poch_channel_free_groups(channel);
  out_free_group_info:
         kfree(channel->groups);
  out:
@@ -881,7 +811,6 @@ static int poch_release(struct inode *inode, struct file *filp)
         }
 
         atomic_dec(&channel->inited);
-        poch_channel_free_header(channel);
         poch_channel_free_groups(channel);
         kfree(channel->groups);
         atomic_inc(&channel->free);
@@ -890,7 +819,7 @@ static int poch_release(struct inode *inode, struct file *filp)
 }
 
 /*
- * Map the header and the group buffers, to user space.
+ * Map the the group buffers, to user space.
  */
 static int poch_mmap(struct file *filp, struct vm_area_struct *vma)
 {
@@ -900,7 +829,6 @@ static int poch_mmap(struct file *filp, struct vm_area_struct *vma)
         unsigned long size;
 
         unsigned long group_pages;
-        unsigned long header_pages;
         unsigned long total_group_pages;
 
         int pg_num;
@@ -917,30 +845,16 @@ static int poch_mmap(struct file *filp, struct vm_area_struct *vma)
         }
 
         group_pages = npages(channel->group_size);
-        header_pages = npages(channel->header_size);
         total_group_pages = group_pages * channel->group_count;
 
         size = vma->vm_end - vma->vm_start;
-        if (size != (header_pages + total_group_pages) * PAGE_SIZE) {
+        if (size != total_group_pages * PAGE_SIZE) {
                 printk(KERN_WARNING PFX "required %lu bytes\n", size);
                 return -EINVAL;
         }
 
         start = vma->vm_start;
 
-        /* FIXME: Cleanup required on failure? */
-        pg = channel->header_pg;
-        for (pg_num = 0; pg_num < header_pages; pg_num++, pg++) {
-                printk(KERN_DEBUG PFX "page_count: %d\n", page_count(pg));
-                printk(KERN_DEBUG PFX "%d: header: 0x%lx\n", pg_num, start);
-                ret = vm_insert_page(vma, start, pg);
-                if (ret) {
-                        printk(KERN_DEBUG "vm_insert 1 failed at %lx\n", start);
-                        return ret;
-                }
-                start += PAGE_SIZE;
-        }
-
         for (i = 0; i < channel->group_count; i++) {
                 pg = channel->groups[i].pg;
                 for (pg_num = 0; pg_num < group_pages; pg_num++, pg++) {
@@ -967,20 +881,16 @@ static int poch_mmap(struct file *filp, struct vm_area_struct *vma)
  */
 static int poch_channel_available(struct channel_info *channel)
 {
-        int i;
+        int available = 0;
 
         spin_lock_irq(&channel->group_offsets_lock);
 
-        for (i = 0; i < channel->group_count; i++) {
-                if (channel->header->group_offsets[i] != -1) {
-                        spin_unlock_irq(&channel->group_offsets_lock);
-                        return 1;
-                }
-        }
+        if (channel->consumed != channel->transfer)
+                available = 1;
 
         spin_unlock_irq(&channel->group_offsets_lock);
 
-        return 0;
+        return available;
 }
 
 static unsigned int poch_poll(struct file *filp, poll_table *pt)
@@ -1138,7 +1048,6 @@ static void poch_irq_dma(struct channel_info *channel)
         long groups_done;
         unsigned long i, j;
         struct poch_group_info *groups;
-        s32 *group_offsets;
         u32 curr_group_reg;
 
         if (!atomic_read(&channel->inited))
@@ -1158,14 +1067,12 @@ static void poch_irq_dma(struct channel_info *channel)
         if (groups_done <= 0)
                 groups_done += channel->group_count;
 
-        group_offsets = channel->header->group_offsets;
         groups = channel->groups;
 
         spin_lock(&channel->group_offsets_lock);
 
         for (i = 0; i < groups_done; i++) {
                 j = (prev_transfer + i) % channel->group_count;
-                group_offsets[j] = groups[j].user_offset;
 
                 channel->transfer += 1;
                 channel->transfer %= channel->group_count;
diff --git a/drivers/staging/poch/poch.h b/drivers/staging/poch/poch.h
index ba1490b4252..bf622448ac8 100644
--- a/drivers/staging/poch/poch.h
+++ b/drivers/staging/poch/poch.h
@@ -7,12 +7,6 @@
  * include/linux for final version.
  *
  */
-struct poch_cbuf_header {
-        __s32 group_size_bytes;
-        __s32 group_count;
-        __s32 group_offsets[0];
-};
-
 struct poch_counters {
         __u32 fifo_empty;
         __u32 fifo_overflow;