mm: slab: reduce the kmalloc() minimum alignment if DMA bouncing possible

[linux-2.6-microblaze.git] / mm / slab_common.c

diff --git a/mm/slab_common.c b/mm/slab_common.c
index 7f06915..43c0081 100644 (file)
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -17,6 +17,8 @@
 #include <linux/cpu.h>
 #include <linux/uaccess.h>
 #include <linux/seq_file.h>
+#include <linux/dma-mapping.h>
+#include <linux/swiotlb.h>
 #include <linux/proc_fs.h>
 #include <linux/debugfs.h>
 #include <linux/kasan.h>
@@ -862,9 +864,22 @@ void __init setup_kmalloc_cache_index_table(void)
        }
 }
 
+static unsigned int __kmalloc_minalign(void)
+{
+#ifdef CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC
+       if (io_tlb_default_mem.nslabs)
+               return ARCH_KMALLOC_MINALIGN;
+#endif
+       return dma_get_cache_alignment();
+}
+
 void __init
 new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
 {
+       unsigned int minalign = __kmalloc_minalign();
+       unsigned int aligned_size = kmalloc_info[idx].size;
+       int aligned_idx = idx;
+
        if ((KMALLOC_RECLAIM != KMALLOC_NORMAL) && (type == KMALLOC_RECLAIM)) {
                flags |= SLAB_RECLAIM_ACCOUNT;
        } else if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_CGROUP)) {
@@ -877,9 +892,17 @@ new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
                flags |= SLAB_CACHE_DMA;
        }
 
-       kmalloc_caches[type][idx] = create_kmalloc_cache(
-                                       kmalloc_info[idx].name[type],
-                                       kmalloc_info[idx].size, flags);
+       if (minalign > ARCH_KMALLOC_MINALIGN) {
+               aligned_size = ALIGN(aligned_size, minalign);
+               aligned_idx = __kmalloc_index(aligned_size, false);
+       }
+
+       if (!kmalloc_caches[type][aligned_idx])
+               kmalloc_caches[type][aligned_idx] = create_kmalloc_cache(
+                                       kmalloc_info[aligned_idx].name[type],
+                                       aligned_size, flags);
+       if (idx != aligned_idx)
+               kmalloc_caches[type][idx] = kmalloc_caches[type][aligned_idx];
 
        /*
         * If CONFIG_MEMCG_KMEM is enabled, disable cache merging for