|
@@ -47,6 +47,8 @@ static int novmerge = 0;
|
|
|
static int novmerge = 1;
|
|
|
#endif
|
|
|
|
|
|
+static int protect4gb = 1;
|
|
|
+
|
|
|
static inline unsigned long iommu_num_pages(unsigned long vaddr,
|
|
|
unsigned long slen)
|
|
|
{
|
|
@@ -58,6 +60,16 @@ static inline unsigned long iommu_num_pages(unsigned long vaddr,
|
|
|
return npages;
|
|
|
}
|
|
|
|
|
|
+static int __init setup_protect4gb(char *str)
|
|
|
+{
|
|
|
+ if (strcmp(str, "on") == 0)
|
|
|
+ protect4gb = 1;
|
|
|
+ else if (strcmp(str, "off") == 0)
|
|
|
+ protect4gb = 0;
|
|
|
+
|
|
|
+ return 1;
|
|
|
+}
|
|
|
+
|
|
|
static int __init setup_iommu(char *str)
|
|
|
{
|
|
|
if (!strcmp(str, "novmerge"))
|
|
@@ -67,6 +79,7 @@ static int __init setup_iommu(char *str)
|
|
|
return 1;
|
|
|
}
|
|
|
|
|
|
+__setup("protect4gb=", setup_protect4gb);
|
|
|
__setup("iommu=", setup_iommu);
|
|
|
|
|
|
static unsigned long iommu_range_alloc(struct iommu_table *tbl,
|
|
@@ -439,6 +452,9 @@ void iommu_unmap_sg(struct iommu_table *tbl, struct scatterlist *sglist,
|
|
|
struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid)
|
|
|
{
|
|
|
unsigned long sz;
|
|
|
+ unsigned long start_index, end_index;
|
|
|
+ unsigned long entries_per_4g;
|
|
|
+ unsigned long index;
|
|
|
static int welcomed = 0;
|
|
|
struct page *page;
|
|
|
|
|
@@ -460,7 +476,7 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid)
|
|
|
|
|
|
#ifdef CONFIG_CRASH_DUMP
|
|
|
if (ppc_md.tce_get) {
|
|
|
- unsigned long index, tceval;
|
|
|
+ unsigned long tceval;
|
|
|
unsigned long tcecount = 0;
|
|
|
|
|
|
/*
|
|
@@ -490,6 +506,23 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid)
|
|
|
ppc_md.tce_free(tbl, tbl->it_offset, tbl->it_size);
|
|
|
#endif
|
|
|
|
|
|
+ /*
|
|
|
+ * DMA cannot cross 4 GB boundary. Mark last entry of each 4
|
|
|
+ * GB chunk as reserved.
|
|
|
+ */
|
|
|
+ if (protect4gb) {
|
|
|
+ entries_per_4g = 0x100000000l >> IOMMU_PAGE_SHIFT;
|
|
|
+
|
|
|
+ /* Mark the last bit before a 4GB boundary as used */
|
|
|
+ start_index = tbl->it_offset | (entries_per_4g - 1);
|
|
|
+ start_index -= tbl->it_offset;
|
|
|
+
|
|
|
+ end_index = tbl->it_size;
|
|
|
+
|
|
|
+ for (index = start_index; index < end_index - 1; index += entries_per_4g)
|
|
|
+ __set_bit(index, tbl->it_map);
|
|
|
+ }
|
|
|
+
|
|
|
if (!welcomed) {
|
|
|
printk(KERN_INFO "IOMMU table initialized, virtual merging %s\n",
|
|
|
novmerge ? "disabled" : "enabled");
|