block: Move queue limits to an embedded struct

To accommodate stacking drivers that do not have an associated request
queue we're moving the limits to a separate, embedded structure.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2 files changed, 60 insertions, 39 deletions

diff --git a/block/blk-settings.c b/block/blk-settings.c
index 0b32f984eed2..b0f547cecfb8 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -179,16 +179,16 @@ void blk_queue_bounce_limit(struct request_queue *q, u64 dma_mask)
          */
         if (b_pfn < (min_t(u64, 0xffffffffUL, BLK_BOUNCE_HIGH) >> PAGE_SHIFT))
                 dma = 1;
-        q->bounce_pfn = max_low_pfn;
+        q->limits.bounce_pfn = max_low_pfn;
 #else
         if (b_pfn < blk_max_low_pfn)
                 dma = 1;
-        q->bounce_pfn = b_pfn;
+        q->limits.bounce_pfn = b_pfn;
 #endif
         if (dma) {
                 init_emergency_isa_pool();
                 q->bounce_gfp = GFP_NOIO | GFP_DMA;
-                q->bounce_pfn = b_pfn;
+                q->limits.bounce_pfn = b_pfn;
         }
 }
 EXPORT_SYMBOL(blk_queue_bounce_limit);
@@ -211,10 +211,10 @@ void blk_queue_max_sectors(struct request_queue *q, unsigned int max_sectors)
         }
 
         if (BLK_DEF_MAX_SECTORS > max_sectors)
-                q->max_hw_sectors = q->max_sectors = max_sectors;
+                q->limits.max_hw_sectors = q->limits.max_sectors = max_sectors;
         else {
-                q->max_sectors = BLK_DEF_MAX_SECTORS;
-                q->max_hw_sectors = max_sectors;
+                q->limits.max_sectors = BLK_DEF_MAX_SECTORS;
+                q->limits.max_hw_sectors = max_sectors;
         }
 }
 EXPORT_SYMBOL(blk_queue_max_sectors);
@@ -222,9 +222,9 @@ EXPORT_SYMBOL(blk_queue_max_sectors);
 void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_sectors)
 {
         if (BLK_DEF_MAX_SECTORS > max_sectors)
-                q->max_hw_sectors = BLK_DEF_MAX_SECTORS;
+                q->limits.max_hw_sectors = BLK_DEF_MAX_SECTORS;
         else
-                q->max_hw_sectors = max_sectors;
+                q->limits.max_hw_sectors = max_sectors;
 }
 EXPORT_SYMBOL(blk_queue_max_hw_sectors);
 
@@ -247,7 +247,7 @@ void blk_queue_max_phys_segments(struct request_queue *q,
                        __func__, max_segments);
         }
 
-        q->max_phys_segments = max_segments;
+        q->limits.max_phys_segments = max_segments;
 }
 EXPORT_SYMBOL(blk_queue_max_phys_segments);
 
@@ -271,7 +271,7 @@ void blk_queue_max_hw_segments(struct request_queue *q,
                        __func__, max_segments);
         }
 
-        q->max_hw_segments = max_segments;
+        q->limits.max_hw_segments = max_segments;
 }
 EXPORT_SYMBOL(blk_queue_max_hw_segments);
 
@@ -292,7 +292,7 @@ void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size)
                        __func__, max_size);
         }
 
-        q->max_segment_size = max_size;
+        q->limits.max_segment_size = max_size;
 }
 EXPORT_SYMBOL(blk_queue_max_segment_size);
 
@@ -308,7 +308,7 @@ EXPORT_SYMBOL(blk_queue_max_segment_size);
  **/
 void blk_queue_logical_block_size(struct request_queue *q, unsigned short size)
 {
-        q->logical_block_size = size;
+        q->limits.logical_block_size = size;
 }
 EXPORT_SYMBOL(blk_queue_logical_block_size);
 
@@ -325,14 +325,27 @@ EXPORT_SYMBOL(blk_queue_logical_block_size);
 void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b)
 {
         /* zero is "infinity" */
-        t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
-        t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
-        t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask, b->seg_boundary_mask);
-
-        t->max_phys_segments = min_not_zero(t->max_phys_segments, b->max_phys_segments);
-        t->max_hw_segments = min_not_zero(t->max_hw_segments, b->max_hw_segments);
-        t->max_segment_size = min_not_zero(t->max_segment_size, b->max_segment_size);
-        t->logical_block_size = max(t->logical_block_size, b->logical_block_size);
+        t->limits.max_sectors = min_not_zero(queue_max_sectors(t),
+                                             queue_max_sectors(b));
+
+        t->limits.max_hw_sectors = min_not_zero(queue_max_hw_sectors(t),
+                                                queue_max_hw_sectors(b));
+
+        t->limits.seg_boundary_mask = min_not_zero(queue_segment_boundary(t),
+                                                   queue_segment_boundary(b));
+
+        t->limits.max_phys_segments = min_not_zero(queue_max_phys_segments(t),
+                                                   queue_max_phys_segments(b));
+
+        t->limits.max_hw_segments = min_not_zero(queue_max_hw_segments(t),
+                                                 queue_max_hw_segments(b));
+
+        t->limits.max_segment_size = min_not_zero(queue_max_segment_size(t),
+                                                  queue_max_segment_size(b));
+
+        t->limits.logical_block_size = max(queue_logical_block_size(t),
+                                           queue_logical_block_size(b));
+
         if (!t->queue_lock)
                 WARN_ON_ONCE(1);
         else if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags)) {
@@ -430,7 +443,7 @@ void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask)
                        __func__, mask);
         }
 
-        q->seg_boundary_mask = mask;
+        q->limits.seg_boundary_mask = mask;
 }
 EXPORT_SYMBOL(blk_queue_segment_boundary);
 
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 29b48f7b4ba8..b7bb6fdba12c 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -307,6 +307,21 @@ struct blk_cmd_filter {
         struct kobject kobj;
 };
 
+struct queue_limits {
+        unsigned long           bounce_pfn;
+        unsigned long           seg_boundary_mask;
+
+        unsigned int            max_hw_sectors;
+        unsigned int            max_sectors;
+        unsigned int            max_segment_size;
+
+        unsigned short          logical_block_size;
+        unsigned short          max_hw_segments;
+        unsigned short          max_phys_segments;
+
+        unsigned char           no_cluster;
+};
+
 struct request_queue
 {
         /*
@@ -358,7 +373,6 @@ struct request_queue
         /*
          * queue needs bounce pages for pages above this limit
          */
-        unsigned long           bounce_pfn;
         gfp_t                   bounce_gfp;
 
         /*
@@ -387,14 +401,6 @@ struct request_queue
         unsigned int            nr_congestion_off;
         unsigned int            nr_batching;
 
-        unsigned int            max_sectors;
-        unsigned int            max_hw_sectors;
-        unsigned short          max_phys_segments;
-        unsigned short          max_hw_segments;
-        unsigned short          logical_block_size;
-        unsigned int            max_segment_size;
-
-        unsigned long           seg_boundary_mask;
         void                    *dma_drain_buffer;
         unsigned int            dma_drain_size;
         unsigned int            dma_pad_mask;
@@ -410,6 +416,8 @@ struct request_queue
         struct timer_list       timeout;
         struct list_head        timeout_list;
 
+        struct queue_limits     limits;
+
         /*
          * sg stuff
          */
@@ -991,45 +999,45 @@ extern void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter);
 
 static inline unsigned long queue_bounce_pfn(struct request_queue *q)
 {
-        return q->bounce_pfn;
+        return q->limits.bounce_pfn;
 }
 
 static inline unsigned long queue_segment_boundary(struct request_queue *q)
 {
-        return q->seg_boundary_mask;
+        return q->limits.seg_boundary_mask;
 }
 
 static inline unsigned int queue_max_sectors(struct request_queue *q)
 {
-        return q->max_sectors;
+        return q->limits.max_sectors;
 }
 
 static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
 {
-        return q->max_hw_sectors;
+        return q->limits.max_hw_sectors;
 }
 
 static inline unsigned short queue_max_hw_segments(struct request_queue *q)
 {
-        return q->max_hw_segments;
+        return q->limits.max_hw_segments;
 }
 
 static inline unsigned short queue_max_phys_segments(struct request_queue *q)
 {
-        return q->max_phys_segments;
+        return q->limits.max_phys_segments;
 }
 
 static inline unsigned int queue_max_segment_size(struct request_queue *q)
 {
-        return q->max_segment_size;
+        return q->limits.max_segment_size;
 }
 
 static inline unsigned short queue_logical_block_size(struct request_queue *q)
 {
         int retval = 512;
 
-        if (q && q->logical_block_size)
-                retval = q->logical_block_size;
+        if (q && q->limits.logical_block_size)
+                retval = q->limits.logical_block_size;
 
         return retval;
 }