fsl_usdpaa: Remove TLB entries when unmapping memory

TLB1 entries must be removed when unmapping a DMA map from a
process so they don't point to the wrong physical memory if
a new map reuses the same virtual address

Signed-off-by: Roy Pledge <Roy.Pledge@freescale.com>

3 files changed, 26 insertions, 0 deletions

diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c
index e52e121..360a0ce 100644
--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -147,6 +147,18 @@ void settlbcam(int index, unsigned long virt, phys_addr_t phys,
 	loadcam_entry(index);
 }
 
+void cleartlbcam(unsigned long virt, unsigned int pid)
+{
+	int i = 0;
+	for (i = 0; i < NUM_TLBCAMS; i++) {
+		if (tlbcam_addrs[i].start == virt) {
+			TLBCAM[i].MAS1 = 0;
+			loadcam_entry(i);
+			return;
+		}
+	}
+}
+
 unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
 			  phys_addr_t phys)
 {
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index dbbba8d..5880a74 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -94,6 +94,8 @@ extern void _tlbia(void);
 void settlbcam(int index, unsigned long virt, phys_addr_t phys,
 	       unsigned long size, unsigned long flags, unsigned int pid);
 
+void cleartlbcam(unsigned long virt, unsigned int pid);
+
 #ifdef CONFIG_PPC32
 
 extern void mapin_ram(void);
diff --git a/drivers/staging/fsl_qbman/fsl_usdpaa.c b/drivers/staging/fsl_qbman/fsl_usdpaa.c
index 55223cd..0c54657 100644
--- a/drivers/staging/fsl_qbman/fsl_usdpaa.c
+++ b/drivers/staging/fsl_qbman/fsl_usdpaa.c
@@ -20,6 +20,7 @@
 #include <linux/memblock.h>
 #include <linux/slab.h>
 #include <linux/mman.h>
+#include <mm/mmu_decl.h>
 
 /* Physical address range of the memory reservation, exported for mm/mem.c */
 static u64 phys_start;
@@ -1117,6 +1118,7 @@ static long ioctl_dma_unmap(struct ctx *ctx, void __user *arg)
 	struct mem_fragment *current_frag;
 	size_t sz;
 	unsigned long base;
+	unsigned long vaddr;
 
 	down_write(&current->mm->mmap_sem);
 	vma = find_vma(current->mm, (unsigned long)arg);
@@ -1150,9 +1152,19 @@ map_match:
 	}
 
 	current_frag = map->root_frag;
+	vaddr = (unsigned long) map->virt_addr;
 	for (i = 0; i < map->frag_count; i++) {
 		DPA_ASSERT(current_frag->refs > 0);
 		--current_frag->refs;
+		/*
+		 * Make sure we invalidate the TLB entry for
+		 * this fragment, otherwise a remap of a different
+		 * page to this vaddr would give acces to an
+		 * incorrect piece of memory
+		 */
+		cleartlbcam(vaddr, mfspr(SPRN_PID));
+
+		vaddr += current_frag->len;
 		current_frag = list_entry(current_frag->list.prev,
 					  struct mem_fragment, list);
 	}