Merge tag 'v4.1-rockchip-socfixes1' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6-block.git] / lib / iommu-common.c
index fac4f35250c994d7465ace3f2bb1d4f0d91c85ad..df30632f0bef9ec1c36a48d83a6eb87cd18ee405 100644 (file)
@@ -9,37 +9,72 @@
 #include <linux/iommu-helper.h>
 #include <linux/iommu-common.h>
 #include <linux/dma-mapping.h>
+#include <linux/hash.h>
 
 #ifndef        DMA_ERROR_CODE
 #define        DMA_ERROR_CODE (~(dma_addr_t)0x0)
 #endif
 
-#define IOMMU_LARGE_ALLOC      15
+static unsigned long iommu_large_alloc = 15;
+
+static DEFINE_PER_CPU(unsigned int, iommu_hash_common);
+
+static inline bool need_flush(struct iommu_map_table *iommu)
+{
+       return (iommu->lazy_flush != NULL &&
+               (iommu->flags & IOMMU_NEED_FLUSH) != 0);
+}
+
+static inline void set_flush(struct iommu_map_table *iommu)
+{
+       iommu->flags |= IOMMU_NEED_FLUSH;
+}
+
+static inline void clear_flush(struct iommu_map_table *iommu)
+{
+       iommu->flags &= ~IOMMU_NEED_FLUSH;
+}
+
+static void setup_iommu_pool_hash(void)
+{
+       unsigned int i;
+       static bool do_once;
+
+       if (do_once)
+               return;
+       do_once = true;
+       for_each_possible_cpu(i)
+               per_cpu(iommu_hash_common, i) = hash_32(i, IOMMU_POOL_HASHBITS);
+}
 
 /*
- * Initialize iommu_pool entries for the iommu_table. `num_entries'
+ * Initialize iommu_pool entries for the iommu_map_table. `num_entries'
  * is the number of table entries. If `large_pool' is set to true,
  * the top 1/4 of the table will be set aside for pool allocations
- * of more than IOMMU_LARGE_ALLOC pages.
+ * of more than iommu_large_alloc pages.
  */
-extern void iommu_tbl_pool_init(struct iommu_table *iommu,
-                               unsigned long num_entries,
-                               u32 page_table_shift,
-                               const struct iommu_tbl_ops *iommu_tbl_ops,
-                               bool large_pool, u32 npools)
+void iommu_tbl_pool_init(struct iommu_map_table *iommu,
+                        unsigned long num_entries,
+                        u32 table_shift,
+                        void (*lazy_flush)(struct iommu_map_table *),
+                        bool large_pool, u32 npools,
+                        bool skip_span_boundary_check)
 {
        unsigned int start, i;
        struct iommu_pool *p = &(iommu->large_pool);
 
+       setup_iommu_pool_hash();
        if (npools == 0)
                iommu->nr_pools = IOMMU_NR_POOLS;
        else
                iommu->nr_pools = npools;
        BUG_ON(npools > IOMMU_NR_POOLS);
 
-       iommu->page_table_shift = page_table_shift;
-       iommu->iommu_tbl_ops = iommu_tbl_ops;
+       iommu->table_shift = table_shift;
+       iommu->lazy_flush = lazy_flush;
        start = 0;
+       if (skip_span_boundary_check)
+               iommu->flags |= IOMMU_NO_SPAN_BOUND;
        if (large_pool)
                iommu->flags |= IOMMU_HAS_LARGE_POOL;
 
@@ -48,11 +83,11 @@ extern void iommu_tbl_pool_init(struct iommu_table *iommu,
        else
                iommu->poolsize = (num_entries * 3 / 4)/iommu->nr_pools;
        for (i = 0; i < iommu->nr_pools; i++) {
-               spin_lock_init(&(iommu->arena_pool[i].lock));
-               iommu->arena_pool[i].start = start;
-               iommu->arena_pool[i].hint = start;
+               spin_lock_init(&(iommu->pools[i].lock));
+               iommu->pools[i].start = start;
+               iommu->pools[i].hint = start;
                start += iommu->poolsize; /* start for next pool */
-               iommu->arena_pool[i].end = start - 1;
+               iommu->pools[i].end = start - 1;
        }
        if (!large_pool)
                return;
@@ -65,121 +100,136 @@ extern void iommu_tbl_pool_init(struct iommu_table *iommu,
 EXPORT_SYMBOL(iommu_tbl_pool_init);
 
 unsigned long iommu_tbl_range_alloc(struct device *dev,
-                               struct iommu_table *iommu,
+                               struct iommu_map_table *iommu,
                                unsigned long npages,
                                unsigned long *handle,
-                               unsigned int pool_hash)
+                               unsigned long mask,
+                               unsigned int align_order)
 {
+       unsigned int pool_hash = __this_cpu_read(iommu_hash_common);
        unsigned long n, end, start, limit, boundary_size;
-       struct iommu_pool *arena;
+       struct iommu_pool *pool;
        int pass = 0;
        unsigned int pool_nr;
        unsigned int npools = iommu->nr_pools;
        unsigned long flags;
        bool large_pool = ((iommu->flags & IOMMU_HAS_LARGE_POOL) != 0);
-       bool largealloc = (large_pool && npages > IOMMU_LARGE_ALLOC);
+       bool largealloc = (large_pool && npages > iommu_large_alloc);
        unsigned long shift;
+       unsigned long align_mask = 0;
+
+       if (align_order > 0)
+               align_mask = 0xffffffffffffffffl >> (64 - align_order);
 
        /* Sanity check */
        if (unlikely(npages == 0)) {
-               printk_ratelimited("npages == 0\n");
+               WARN_ON_ONCE(1);
                return DMA_ERROR_CODE;
        }
 
        if (largealloc) {
-               arena = &(iommu->large_pool);
-               spin_lock_irqsave(&arena->lock, flags);
+               pool = &(iommu->large_pool);
                pool_nr = 0; /* to keep compiler happy */
        } else {
                /* pick out pool_nr */
                pool_nr =  pool_hash & (npools - 1);
-               arena = &(iommu->arena_pool[pool_nr]);
-
-               /* find first available unlocked pool */
-               while (!spin_trylock_irqsave(&(arena->lock), flags)) {
-                       pool_nr = (pool_nr + 1) & (iommu->nr_pools - 1);
-                       arena = &(iommu->arena_pool[pool_nr]);
-               }
+               pool = &(iommu->pools[pool_nr]);
        }
+       spin_lock_irqsave(&pool->lock, flags);
 
  again:
        if (pass == 0 && handle && *handle &&
-           (*handle >= arena->start) && (*handle < arena->end))
+           (*handle >= pool->start) && (*handle < pool->end))
                start = *handle;
        else
-               start = arena->hint;
+               start = pool->hint;
 
-       limit = arena->end;
+       limit = pool->end;
 
        /* The case below can happen if we have a small segment appended
         * to a large, or when the previous alloc was at the very end of
-        * the available space. If so, go back to the beginning and flush.
+        * the available space. If so, go back to the beginning. If a
+        * flush is needed, it will get done based on the return value
+        * from iommu_area_alloc() below.
         */
-       if (start >= limit) {
-               start = arena->start;
-               if (iommu->iommu_tbl_ops->reset != NULL)
-                       iommu->iommu_tbl_ops->reset(iommu);
+       if (start >= limit)
+               start = pool->start;
+       shift = iommu->table_map_base >> iommu->table_shift;
+       if (limit + shift > mask) {
+               limit = mask - shift + 1;
+               /* If we're constrained on address range, first try
+                * at the masked hint to avoid O(n) search complexity,
+                * but on second pass, start at 0 in pool 0.
+                */
+               if ((start & mask) >= limit || pass > 0) {
+                       spin_unlock(&(pool->lock));
+                       pool = &(iommu->pools[0]);
+                       spin_lock(&(pool->lock));
+                       start = pool->start;
+               } else {
+                       start &= mask;
+               }
        }
 
        if (dev)
                boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
-                                     1 << iommu->page_table_shift);
+                                     1 << iommu->table_shift);
        else
-               boundary_size = ALIGN(1ULL << 32, 1 << iommu->page_table_shift);
+               boundary_size = ALIGN(1ULL << 32, 1 << iommu->table_shift);
 
-       shift = iommu->page_table_map_base >> iommu->page_table_shift;
-       boundary_size = boundary_size >> iommu->page_table_shift;
+       boundary_size = boundary_size >> iommu->table_shift;
        /*
-        * if the iommu has a non-trivial cookie <-> index mapping, we set
+        * if the skip_span_boundary_check had been set during init, we set
         * things up so that iommu_is_span_boundary() merely checks if the
         * (index + npages) < num_tsb_entries
         */
-       if (iommu->iommu_tbl_ops->cookie_to_index != NULL) {
+       if ((iommu->flags & IOMMU_NO_SPAN_BOUND) != 0) {
                shift = 0;
                boundary_size = iommu->poolsize * iommu->nr_pools;
        }
        n = iommu_area_alloc(iommu->map, limit, start, npages, shift,
-                            boundary_size, 0);
+                            boundary_size, align_mask);
        if (n == -1) {
                if (likely(pass == 0)) {
                        /* First failure, rescan from the beginning.  */
-                       arena->hint = arena->start;
-                       if (iommu->iommu_tbl_ops->reset != NULL)
-                               iommu->iommu_tbl_ops->reset(iommu);
+                       pool->hint = pool->start;
+                       set_flush(iommu);
                        pass++;
                        goto again;
                } else if (!largealloc && pass <= iommu->nr_pools) {
-                       spin_unlock(&(arena->lock));
+                       spin_unlock(&(pool->lock));
                        pool_nr = (pool_nr + 1) & (iommu->nr_pools - 1);
-                       arena = &(iommu->arena_pool[pool_nr]);
-                       while (!spin_trylock(&(arena->lock))) {
-                               pool_nr = (pool_nr + 1) & (iommu->nr_pools - 1);
-                               arena = &(iommu->arena_pool[pool_nr]);
-                       }
-                       arena->hint = arena->start;
+                       pool = &(iommu->pools[pool_nr]);
+                       spin_lock(&(pool->lock));
+                       pool->hint = pool->start;
+                       set_flush(iommu);
                        pass++;
                        goto again;
                } else {
                        /* give up */
-                       spin_unlock_irqrestore(&(arena->lock), flags);
-                       return DMA_ERROR_CODE;
+                       n = DMA_ERROR_CODE;
+                       goto bail;
                }
        }
+       if (n < pool->hint || need_flush(iommu)) {
+               clear_flush(iommu);
+               iommu->lazy_flush(iommu);
+       }
 
        end = n + npages;
-
-       arena->hint = end;
+       pool->hint = end;
 
        /* Update handle for SG allocations */
        if (handle)
                *handle = end;
-       spin_unlock_irqrestore(&(arena->lock), flags);
+bail:
+       spin_unlock_irqrestore(&(pool->lock), flags);
 
        return n;
 }
 EXPORT_SYMBOL(iommu_tbl_range_alloc);
 
-static struct iommu_pool *get_pool(struct iommu_table *tbl,
+static struct iommu_pool *get_pool(struct iommu_map_table *tbl,
                                   unsigned long entry)
 {
        struct iommu_pool *p;
@@ -193,31 +243,27 @@ static struct iommu_pool *get_pool(struct iommu_table *tbl,
                unsigned int pool_nr = entry / tbl->poolsize;
 
                BUG_ON(pool_nr >= tbl->nr_pools);
-               p = &tbl->arena_pool[pool_nr];
+               p = &tbl->pools[pool_nr];
        }
        return p;
 }
 
-void iommu_tbl_range_free(struct iommu_table *iommu, u64 dma_addr,
-                         unsigned long npages, bool do_demap, void *demap_arg)
+/* Caller supplies the index of the entry into the iommu map table
+ * itself when the mapping from dma_addr to the entry is not the
+ * default addr->entry mapping below.
+ */
+void iommu_tbl_range_free(struct iommu_map_table *iommu, u64 dma_addr,
+                         unsigned long npages, unsigned long entry)
 {
-       unsigned long entry;
        struct iommu_pool *pool;
        unsigned long flags;
-       unsigned long shift = iommu->page_table_shift;
+       unsigned long shift = iommu->table_shift;
 
-       if (iommu->iommu_tbl_ops->cookie_to_index != NULL) {
-               entry = (*iommu->iommu_tbl_ops->cookie_to_index)(dma_addr,
-                                                                demap_arg);
-       } else {
-               entry = (dma_addr - iommu->page_table_map_base) >> shift;
-       }
+       if (entry == DMA_ERROR_CODE) /* use default addr->entry mapping */
+               entry = (dma_addr - iommu->table_map_base) >> shift;
        pool = get_pool(iommu, entry);
 
        spin_lock_irqsave(&(pool->lock), flags);
-       if (do_demap && iommu->iommu_tbl_ops->demap != NULL)
-               (*iommu->iommu_tbl_ops->demap)(demap_arg, entry, npages);
-
        bitmap_clear(iommu->map, entry, npages);
        spin_unlock_irqrestore(&(pool->lock), flags);
 }