Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc

Pull sparc fixes from David Miller
 "Unfortunately, I brown paper bagged the generic iommu pool allocator
  by applying the wrong revision of the patch series.

  This reverts the bad one, and puts the right one in"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  iommu-common: Fix PARISC compile-time warnings
  sparc: Make LDC use common iommu poll management functions
  sparc: Make sparc64 use scalable lib/iommu-common.c functions
  Break up monolithic iommu table/lock into finer graularity pools and lock
  sparc: Revert generic IOMMU allocator.

1 files changed, 118 insertions, 72 deletions

diff --git a/lib/iommu-common.c b/lib/iommu-common.c
index fac4f35250c9..a1a517cba7ec 100644
--- a/lib/iommu-common.c
+++ b/lib/iommu-common.c
@@ -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
+unsigned long iommu_large_alloc = 15;
+
+static  DEFINE_PER_CPU(unsigned int, iommu_pool_hash);
+
+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_pool_hash, 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,
+extern void iommu_tbl_pool_init(struct iommu_map_table *iommu,
                                 unsigned long num_entries,
-                                u32 page_table_shift,
-                                const struct iommu_tbl_ops *iommu_tbl_ops,
-                                bool large_pool, u32 npools)
+                                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_pool_hash);
         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);
 }