+++ /dev/null
-/*
- * IOMMU mmap management and range allocation functions.
- * Based almost entirely upon the powerpc iommu allocator.
- */
-
-#include <linux/export.h>
-#include <linux/bitmap.h>
-#include <linux/bug.h>
-#include <linux/iommu-helper.h>
-#include <linux/iommu-common.h>
-#include <linux/dma-mapping.h>
-
-#ifndef DMA_ERROR_CODE
-#define DMA_ERROR_CODE (~(dma_addr_t)0x0)
-#endif
-
-#define IOMMU_LARGE_ALLOC 15
-
-/*
- * Initialize iommu_pool entries for the iommu_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.
- */
-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)
-{
- unsigned int start, i;
- struct iommu_pool *p = &(iommu->large_pool);
-
- 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;
- start = 0;
- if (large_pool)
- iommu->flags |= IOMMU_HAS_LARGE_POOL;
-
- if (!large_pool)
- iommu->poolsize = num_entries/iommu->nr_pools;
- 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;
- start += iommu->poolsize; /* start for next pool */
- iommu->arena_pool[i].end = start - 1;
- }
- if (!large_pool)
- return;
- /* initialize large_pool */
- spin_lock_init(&(p->lock));
- p->start = start;
- p->hint = p->start;
- p->end = num_entries;
-}
-EXPORT_SYMBOL(iommu_tbl_pool_init);
-
-unsigned long iommu_tbl_range_alloc(struct device *dev,
- struct iommu_table *iommu,
- unsigned long npages,
- unsigned long *handle,
- unsigned int pool_hash)
-{
- unsigned long n, end, start, limit, boundary_size;
- struct iommu_pool *arena;
- 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);
- unsigned long shift;
-
- /* Sanity check */
- if (unlikely(npages == 0)) {
- printk_ratelimited("npages == 0\n");
- return DMA_ERROR_CODE;
- }
-
- if (largealloc) {
- arena = &(iommu->large_pool);
- spin_lock_irqsave(&arena->lock, flags);
- 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]);
- }
- }
-
- again:
- if (pass == 0 && handle && *handle &&
- (*handle >= arena->start) && (*handle < arena->end))
- start = *handle;
- else
- start = arena->hint;
-
- limit = arena->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.
- */
- if (start >= limit) {
- start = arena->start;
- if (iommu->iommu_tbl_ops->reset != NULL)
- iommu->iommu_tbl_ops->reset(iommu);
- }
-
- if (dev)
- boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
- 1 << iommu->page_table_shift);
- else
- boundary_size = ALIGN(1ULL << 32, 1 << iommu->page_table_shift);
-
- shift = iommu->page_table_map_base >> iommu->page_table_shift;
- boundary_size = boundary_size >> iommu->page_table_shift;
- /*
- * if the iommu has a non-trivial cookie <-> index mapping, 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) {
- shift = 0;
- boundary_size = iommu->poolsize * iommu->nr_pools;
- }
- n = iommu_area_alloc(iommu->map, limit, start, npages, shift,
- boundary_size, 0);
- 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);
- pass++;
- goto again;
- } else if (!largealloc && pass <= iommu->nr_pools) {
- spin_unlock(&(arena->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;
- pass++;
- goto again;
- } else {
- /* give up */
- spin_unlock_irqrestore(&(arena->lock), flags);
- return DMA_ERROR_CODE;
- }
- }
-
- end = n + npages;
-
- arena->hint = end;
-
- /* Update handle for SG allocations */
- if (handle)
- *handle = end;
- spin_unlock_irqrestore(&(arena->lock), flags);
-
- return n;
-}
-EXPORT_SYMBOL(iommu_tbl_range_alloc);
-
-static struct iommu_pool *get_pool(struct iommu_table *tbl,
- unsigned long entry)
-{
- struct iommu_pool *p;
- unsigned long largepool_start = tbl->large_pool.start;
- bool large_pool = ((tbl->flags & IOMMU_HAS_LARGE_POOL) != 0);
-
- /* The large pool is the last pool at the top of the table */
- if (large_pool && entry >= largepool_start) {
- p = &tbl->large_pool;
- } else {
- unsigned int pool_nr = entry / tbl->poolsize;
-
- BUG_ON(pool_nr >= tbl->nr_pools);
- p = &tbl->arena_pool[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)
-{
- unsigned long entry;
- struct iommu_pool *pool;
- unsigned long flags;
- unsigned long shift = iommu->page_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;
- }
- 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);
-}
-EXPORT_SYMBOL(iommu_tbl_range_free);
projects / cascardo / linux.git / blobdiff