swiotlb: Add swiotlb_free() function

swiotlb_free() function frees all allocated memory for swiotlb.

We need to initialize swiotlb before IOMMU initialization (x86
and powerpc needs to allocate memory from bootmem allocator). If
IOMMU initialization is successful, we need to free swiotlb
resource (don't want to waste 64MB).

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: chrisw@sous-sol.org
Cc: dwmw2@infradead.org
Cc: joerg.roedel@amd.com
Cc: muli@il.ibm.com
LKML-Reference: <1257849980-22640-8-git-send-email-fujita.tomonori@lab.ntt.co.jp>
[ -v2: build fix for the !CONFIG_SWIOTLB case ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 73b1f1cec423e8905db463c32a6fb8d96cf9fa0f..59bafa6902907dbfc570b9ea0ce107fcc2e20163 100644 (file)
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -88,4 +88,10 @@ swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr);
 extern int
 swiotlb_dma_supported(struct device *hwdev, u64 mask);
 
+#ifdef CONFIG_SWIOTLB
+extern void __init swiotlb_free(void);
+#else
+static inline void swiotlb_free(void) { }
+#endif
+
 #endif /* __LINUX_SWIOTLB_H */

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index ac25cd28e8077717263b03a179df2764acd10a50..eee512b63f17f804252dff7bb5d62289ac333062 100644 (file)
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -97,6 +97,8 @@ static phys_addr_t *io_tlb_orig_addr;
  */
 static DEFINE_SPINLOCK(io_tlb_lock);
 
+static int late_alloc;
+
 static int __init
 setup_io_tlb_npages(char *str)
 {
@@ -262,6 +264,8 @@ swiotlb_late_init_with_default_size(size_t default_size)
 
        swiotlb_print_info(bytes);
 
+       late_alloc = 1;
+
        return 0;
 
 cleanup4:
@@ -281,6 +285,32 @@ cleanup1:
        return -ENOMEM;
 }
 
+void __init swiotlb_free(void)
+{
+       if (!io_tlb_overflow_buffer)
+               return;
+
+       if (late_alloc) {
+               free_pages((unsigned long)io_tlb_overflow_buffer,
+                          get_order(io_tlb_overflow));
+               free_pages((unsigned long)io_tlb_orig_addr,
+                          get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
+               free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
+                                                                sizeof(int)));
+               free_pages((unsigned long)io_tlb_start,
+                          get_order(io_tlb_nslabs << IO_TLB_SHIFT));
+       } else {
+               free_bootmem_late(__pa(io_tlb_overflow_buffer),
+                                 io_tlb_overflow);
+               free_bootmem_late(__pa(io_tlb_orig_addr),
+                                 io_tlb_nslabs * sizeof(phys_addr_t));
+               free_bootmem_late(__pa(io_tlb_list),
+                                 io_tlb_nslabs * sizeof(int));
+               free_bootmem_late(__pa(io_tlb_start),
+                                 io_tlb_nslabs << IO_TLB_SHIFT);
+       }
+}
+
 static int is_swiotlb_buffer(phys_addr_t paddr)
 {
        return paddr >= virt_to_phys(io_tlb_start) &&