[PATCH] initialize TCE tables

A fairly recent platform requirement states that the OS must clear the
whole TCE table at setup time, in case firmware left any active
mappings in it.  Without this initialization, dynamic bus removes can
fail.  Firmware rejects these requests if active mappings still exist
for a slot that has been deallocated by the OS.

Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/ppc64/kernel/iommu.c b/arch/ppc64/kernel/iommu.c
index 3441646..8316426 100644 (file)
--- a/arch/ppc64/kernel/iommu.c
+++ b/arch/ppc64/kernel/iommu.c
@@ -423,6 +423,9 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl)
        tbl->it_largehint = tbl->it_halfpoint;
        spin_lock_init(&tbl->it_lock);
 
+       /* Clear the hardware table in case firmware left allocations in it */
+       ppc_md.tce_free(tbl, tbl->it_offset, tbl->it_size);
+
        if (!welcomed) {
                printk(KERN_INFO "IOMMU table initialized, virtual merging %s\n",
                       novmerge ? "disabled" : "enabled");