Revert "staging: tidspbridge - move all iommu related code to a new file"

This reverts commit f94378f9f9a897fc08e9d12733401ae52466e408.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Omar Ramirez Luna <omar.ramirez@ti.com>

7 files changed, 289 insertions, 391 deletions

diff --git a/drivers/staging/tidspbridge/Makefile b/drivers/staging/tidspbridge/Makefile
index 37bd3bcc03a..1a091faac04 100644
--- a/drivers/staging/tidspbridge/Makefile
+++ b/drivers/staging/tidspbridge/Makefile
@@ -2,7 +2,7 @@ obj-$(CONFIG_TIDSPBRIDGE)	+= bridgedriver.o
 
 libgen = gen/gb.o gen/gs.o gen/gh.o gen/uuidutil.o
 libcore = core/chnl_sm.o core/msg_sm.o core/io_sm.o core/tiomap3430.o \
-                core/tiomap3430_pwr.o core/tiomap_io.o core/dsp-mmu.o \
+                core/tiomap3430_pwr.o core/tiomap_io.o \
                 core/ue_deh.o core/wdt.o core/dsp-clock.o core/sync.o
 libpmgr = pmgr/chnl.o pmgr/io.o pmgr/msg.o pmgr/cod.o pmgr/dev.o pmgr/dspapi.o \
                 pmgr/dmm.o pmgr/cmm.o pmgr/dbll.o
diff --git a/drivers/staging/tidspbridge/core/_deh.h b/drivers/staging/tidspbridge/core/_deh.h
index 8ae263387a8..f1254f0aa03 100644
--- a/drivers/staging/tidspbridge/core/_deh.h
+++ b/drivers/staging/tidspbridge/core/_deh.h
@@ -27,6 +27,9 @@
 struct deh_mgr {
         struct bridge_dev_context *hbridge_context;     /* Bridge context. */
         struct ntfy_object *ntfy_obj;   /* NTFY object */
+
+        /* MMU Fault DPC */
+        struct tasklet_struct dpc_tasklet;
 };
 
 int mmu_fault_isr(struct iommu *mmu);
diff --git a/drivers/staging/tidspbridge/core/_tiomap.h b/drivers/staging/tidspbridge/core/_tiomap.h
index e0a801c1cb9..cd7ff8810a0 100644
--- a/drivers/staging/tidspbridge/core/_tiomap.h
+++ b/drivers/staging/tidspbridge/core/_tiomap.h
@@ -23,7 +23,8 @@
 #include <plat/clockdomain.h>
 #include <mach-omap2/prm-regbits-34xx.h>
 #include <mach-omap2/cm-regbits-34xx.h>
-#include <dspbridge/dsp-mmu.h>
+#include <plat/iommu.h>
+#include <plat/iovmm.h>
 #include <dspbridge/devdefs.h>
 #include <dspbridge/dspioctl.h> /* for bridge_ioctl_extproc defn */
 #include <dspbridge/sync.h>
@@ -379,4 +380,28 @@ extern s32 dsp_debug;
  */
 int sm_interrupt_dsp(struct bridge_dev_context *dev_context, u16 mb_val);
 
+/**
+ * user_to_dsp_map() - maps user to dsp virtual address
+ * @mmu:        Pointer to iommu handle.
+ * @uva:                Virtual user space address.
+ * @da          DSP address
+ * @size                Buffer size to map.
+ * @usr_pgs     struct page array pointer where the user pages will be stored
+ *
+ * This function maps a user space buffer into DSP virtual address.
+ *
+ */
+u32 user_to_dsp_map(struct iommu *mmu, u32 uva, u32 da, u32 size,
+                                                struct page **usr_pgs);
+
+/**
+ * user_to_dsp_unmap() - unmaps DSP virtual buffer.
+ * @mmu:        Pointer to iommu handle.
+ * @da          DSP address
+ *
+ * This function unmaps a user space buffer into DSP virtual address.
+ *
+ */
+int user_to_dsp_unmap(struct iommu *mmu, u32 da);
+
 #endif /* _TIOMAP_ */
diff --git a/drivers/staging/tidspbridge/core/dsp-mmu.c b/drivers/staging/tidspbridge/core/dsp-mmu.c
deleted file mode 100644
index 983c95adc8f..00000000000
--- a/drivers/staging/tidspbridge/core/dsp-mmu.c
+++ /dev/null
@@ -1,317 +0,0 @@
-/*
- * dsp-mmu.c
- *
- * DSP-BIOS Bridge driver support functions for TI OMAP processors.
- *
- * DSP iommu.
- *
- * Copyright (C) 2010 Texas Instruments, Inc.
- *
- * This package is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
- * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
- */
-
-#include <dspbridge/host_os.h>
-#include <plat/dmtimer.h>
-#include <dspbridge/dbdefs.h>
-#include <dspbridge/dev.h>
-#include <dspbridge/io_sm.h>
-#include <dspbridge/dspdeh.h>
-#include "_tiomap.h"
-
-#include <dspbridge/dsp-mmu.h>
-
-#define MMU_CNTL_TWL_EN         (1 << 2)
-
-static struct tasklet_struct mmu_tasklet;
-
-#ifdef CONFIG_TIDSPBRIDGE_BACKTRACE
-static void mmu_fault_print_stack(struct bridge_dev_context *dev_context)
-{
-        void *dummy_addr;
-        u32 fa, tmp;
-        struct iotlb_entry e;
-        struct iommu *mmu = dev_context->dsp_mmu;
-        dummy_addr = (void *)__get_free_page(GFP_ATOMIC);
-
-        /*
-         * Before acking the MMU fault, let's make sure MMU can only
-         * access entry #0. Then add a new entry so that the DSP OS
-         * can continue in order to dump the stack.
-         */
-        tmp = iommu_read_reg(mmu, MMU_CNTL);
-        tmp &= ~MMU_CNTL_TWL_EN;
-        iommu_write_reg(mmu, tmp, MMU_CNTL);
-        fa = iommu_read_reg(mmu, MMU_FAULT_AD);
-        e.da = fa & PAGE_MASK;
-        e.pa = virt_to_phys(dummy_addr);
-        e.valid = 1;
-        e.prsvd = 1;
-        e.pgsz = IOVMF_PGSZ_4K & MMU_CAM_PGSZ_MASK;
-        e.endian = MMU_RAM_ENDIAN_LITTLE;
-        e.elsz = MMU_RAM_ELSZ_32;
-        e.mixed = 0;
-
-        load_iotlb_entry(mmu, &e);
-
-        dsp_clk_enable(DSP_CLK_GPT8);
-
-        dsp_gpt_wait_overflow(DSP_CLK_GPT8, 0xfffffffe);
-
-        /* Clear MMU interrupt */
-        tmp = iommu_read_reg(mmu, MMU_IRQSTATUS);
-        iommu_write_reg(mmu, tmp, MMU_IRQSTATUS);
-
-        dump_dsp_stack(dev_context);
-        dsp_clk_disable(DSP_CLK_GPT8);
-
-        iopgtable_clear_entry(mmu, fa);
-        free_page((unsigned long)dummy_addr);
-}
-#endif
-
-
-static void fault_tasklet(unsigned long data)
-{
-        struct iommu *mmu = (struct iommu *)data;
-        struct bridge_dev_context *dev_ctx;
-        struct deh_mgr *dm;
-        u32 fa;
-        dev_get_deh_mgr(dev_get_first(), &dm);
-        dev_get_bridge_context(dev_get_first(), &dev_ctx);
-
-        if (!dm || !dev_ctx)
-                return;
-
-        fa = iommu_read_reg(mmu, MMU_FAULT_AD);
-
-#ifdef CONFIG_TIDSPBRIDGE_BACKTRACE
-        print_dsp_trace_buffer(dev_ctx);
-        dump_dl_modules(dev_ctx);
-        mmu_fault_print_stack(dev_ctx);
-#endif
-
-        bridge_deh_notify(dm, DSP_MMUFAULT, fa);
-}
-
-/*
- *  ======== mmu_fault_isr ========
- *      ISR to be triggered by a DSP MMU fault interrupt.
- */
-static int mmu_fault_callback(struct iommu *mmu)
-{
-        if (!mmu)
-                return -EPERM;
-
-        iommu_write_reg(mmu, 0, MMU_IRQENABLE);
-        tasklet_schedule(&mmu_tasklet);
-        return 0;
-}
-
-/**
- * dsp_mmu_init() - initialize dsp_mmu module and returns a handle
- *
- * This function initialize dsp mmu module and returns a struct iommu
- * handle to use it for dsp maps.
- *
- */
-struct iommu *dsp_mmu_init()
-{
-        struct iommu *mmu;
-
-        mmu = iommu_get("iva2");
-
-        if (!IS_ERR(mmu)) {
-                tasklet_init(&mmu_tasklet, fault_tasklet, (unsigned long)mmu);
-                mmu->isr = mmu_fault_callback;
-        }
-
-        return mmu;
-}
-
-/**
- * dsp_mmu_exit() - destroy dsp mmu module
- * @mmu:        Pointer to iommu handle.
- *
- * This function destroys dsp mmu module.
- *
- */
-void dsp_mmu_exit(struct iommu *mmu)
-{
-        if (mmu)
-                iommu_put(mmu);
-        tasklet_kill(&mmu_tasklet);
-}
-
-/**
- * user_va2_pa() - get physical address from userspace address.
- * @mm:         mm_struct Pointer of the process.
- * @address:    Virtual user space address.
- *
- */
-static u32 user_va2_pa(struct mm_struct *mm, u32 address)
-{
-        pgd_t *pgd;
-        pmd_t *pmd;
-        pte_t *ptep, pte;
-
-        pgd = pgd_offset(mm, address);
-        if (!(pgd_none(*pgd) || pgd_bad(*pgd))) {
-                pmd = pmd_offset(pgd, address);
-                if (!(pmd_none(*pmd) || pmd_bad(*pmd))) {
-                        ptep = pte_offset_map(pmd, address);
-                        if (ptep) {
-                                pte = *ptep;
-                                if (pte_present(pte))
-                                        return pte & PAGE_MASK;
-                        }
-                }
-        }
-
-        return 0;
-}
-
-/**
- * get_io_pages() - pin and get pages of io user's buffer.
- * @mm:         mm_struct Pointer of the process.
- * @uva:                Virtual user space address.
- * @pages       Pages to be pined.
- * @usr_pgs     struct page array pointer where the user pages will be stored
- *
- */
-static int get_io_pages(struct mm_struct *mm, u32 uva, unsigned pages,
-                                                struct page **usr_pgs)
-{
-        u32 pa;
-        int i;
-        struct page *pg;
-
-        for (i = 0; i < pages; i++) {
-                pa = user_va2_pa(mm, uva);
-
-                if (!pfn_valid(__phys_to_pfn(pa)))
-                        break;
-
-                pg = phys_to_page(pa);
-                usr_pgs[i] = pg;
-                get_page(pg);
-        }
-        return i;
-}
-
-/**
- * user_to_dsp_map() - maps user to dsp virtual address
- * @mmu:        Pointer to iommu handle.
- * @uva:                Virtual user space address.
- * @da          DSP address
- * @size                Buffer size to map.
- * @usr_pgs     struct page array pointer where the user pages will be stored
- *
- * This function maps a user space buffer into DSP virtual address.
- *
- */
-u32 user_to_dsp_map(struct iommu *mmu, u32 uva, u32 da, u32 size,
-                                struct page **usr_pgs)
-{
-        int res, w;
-        unsigned pages;
-        int i;
-        struct vm_area_struct *vma;
-        struct mm_struct *mm = current->mm;
-        struct sg_table *sgt;
-        struct scatterlist *sg;
-
-        if (!size || !usr_pgs)
-                return -EINVAL;
-
-        pages = size / PG_SIZE4K;
-
-        down_read(&mm->mmap_sem);
-        vma = find_vma(mm, uva);
-        while (vma && (uva + size > vma->vm_end))
-                vma = find_vma(mm, vma->vm_end + 1);
-
-        if (!vma) {
-                pr_err("%s: Failed to get VMA region for 0x%x (%d)\n",
-                                                __func__, uva, size);
-                up_read(&mm->mmap_sem);
-                return -EINVAL;
-        }
-        if (vma->vm_flags & (VM_WRITE | VM_MAYWRITE))
-                w = 1;
-
-        if (vma->vm_flags & VM_IO)
-                i = get_io_pages(mm, uva, pages, usr_pgs);
-        else
-                i = get_user_pages(current, mm, uva, pages, w, 1,
-                                                        usr_pgs, NULL);
-        up_read(&mm->mmap_sem);
-
-        if (i < 0)
-                return i;
-
-        if (i < pages) {
-                res = -EFAULT;
-                goto err_pages;
-        }
-
-        sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
-        if (!sgt) {
-                res = -ENOMEM;
-                goto err_pages;
-        }
-
-        res = sg_alloc_table(sgt, pages, GFP_KERNEL);
-
-        if (res < 0)
-                goto err_sg;
-
-        for_each_sg(sgt->sgl, sg, sgt->nents, i)
-                sg_set_page(sg, usr_pgs[i], PAGE_SIZE, 0);
-
-        da = iommu_vmap(mmu, da, sgt, IOVMF_ENDIAN_LITTLE | IOVMF_ELSZ_32);
-
-        if (!IS_ERR_VALUE(da))
-                return da;
-        res = (int)da;
-
-        sg_free_table(sgt);
-err_sg:
-        kfree(sgt);
-        i = pages;
-err_pages:
-        while (i--)
-                put_page(usr_pgs[i]);
-        return res;
-}
-
-/**
- * user_to_dsp_unmap() - unmaps DSP virtual buffer.
- * @mmu:        Pointer to iommu handle.
- * @da          DSP address
- *
- * This function unmaps a user space buffer into DSP virtual address.
- *
- */
-int user_to_dsp_unmap(struct iommu *mmu, u32 da)
-{
-        unsigned i;
-        struct sg_table *sgt;
-        struct scatterlist *sg;
-
-        sgt = iommu_vunmap(mmu, da);
-        if (!sgt)
-                return -EFAULT;
-
-        for_each_sg(sgt->sgl, sg, sgt->nents, i)
-                put_page(sg_page(sg));
-        sg_free_table(sgt);
-        kfree(sgt);
-
-        return 0;
-}
diff --git a/drivers/staging/tidspbridge/core/tiomap3430.c b/drivers/staging/tidspbridge/core/tiomap3430.c
index 53b38b2b9ce..984a35a068e 100644
--- a/drivers/staging/tidspbridge/core/tiomap3430.c
+++ b/drivers/staging/tidspbridge/core/tiomap3430.c
@@ -53,6 +53,7 @@
 #include "_tiomap.h"
 #include "_tiomap_pwr.h"
 #include "tiomap_io.h"
+#include "_deh.h"
 
 /* Offset in shared mem to write to in order to synchronize start with DSP */
 #define SHMSYNCOFFSET 4         /* GPP byte offset */
@@ -67,6 +68,7 @@
 #define MMU_SMALL_PAGE_MASK      0xFFFFF000
 #define OMAP3_IVA2_BOOTADDR_MASK 0xFFFFFC00
 #define PAGES_II_LVL_TABLE   512
+#define PHYS_TO_PAGE(phys)      pfn_to_page((phys) >> PAGE_SHIFT)
 
 /*
  * This is a totally ugly layer violation, but needed until
@@ -364,16 +366,17 @@ static int bridge_brd_start(struct bridge_dev_context *dev_ctxt,
                                         OMAP3430_IVA2_MOD, OMAP2_RM_RSTCTRL);
                 mmu = dev_context->dsp_mmu;
                 if (mmu)
-                        dsp_mmu_exit(mmu);
-                mmu = dsp_mmu_init();
+                        iommu_put(mmu);
+                mmu = iommu_get("iva2");
                 if (IS_ERR(mmu)) {
-                        dev_err(bridge, "dsp_mmu_init failed!\n");
+                        dev_err(bridge, "iommu_get failed!\n");
                         dev_context->dsp_mmu = NULL;
                         status = (int)mmu;
                 }
         }
         if (!status) {
                 dev_context->dsp_mmu = mmu;
+                mmu->isr = mmu_fault_isr;
                 sm_sg = &dev_context->sh_s;
                 sg0_da = iommu_kmap(mmu, sm_sg->seg0_da, sm_sg->seg0_pa,
                         sm_sg->seg0_size, IOVMF_ENDIAN_LITTLE | IOVMF_ELSZ_32);
@@ -629,7 +632,7 @@ static int bridge_brd_stop(struct bridge_dev_context *dev_ctxt)
                 }
                 iommu_kunmap(dev_context->dsp_mmu, dev_context->sh_s.seg0_da);
                 iommu_kunmap(dev_context->dsp_mmu, dev_context->sh_s.seg1_da);
-                dsp_mmu_exit(dev_context->dsp_mmu);
+                iommu_put(dev_context->dsp_mmu);
                 dev_context->dsp_mmu = NULL;
         }
         /* Reset IVA IOMMU*/
@@ -944,6 +947,173 @@ static int bridge_brd_mem_write(struct bridge_dev_context *dev_ctxt,
 }
 
 /*
+ *  ======== user_va2_pa ========
+ *  Purpose:
+ *      This function walks through the page tables to convert a userland
+ *      virtual address to physical address
+ */
+static u32 user_va2_pa(struct mm_struct *mm, u32 address)
+{
+        pgd_t *pgd;
+        pmd_t *pmd;
+        pte_t *ptep, pte;
+
+        pgd = pgd_offset(mm, address);
+        if (!(pgd_none(*pgd) || pgd_bad(*pgd))) {
+                pmd = pmd_offset(pgd, address);
+                if (!(pmd_none(*pmd) || pmd_bad(*pmd))) {
+                        ptep = pte_offset_map(pmd, address);
+                        if (ptep) {
+                                pte = *ptep;
+                                if (pte_present(pte))
+                                        return pte & PAGE_MASK;
+                        }
+                }
+        }
+
+        return 0;
+}
+
+/**
+ * get_io_pages() - pin and get pages of io user's buffer.
+ * @mm:         mm_struct Pointer of the process.
+ * @uva:                Virtual user space address.
+ * @pages       Pages to be pined.
+ * @usr_pgs     struct page array pointer where the user pages will be stored
+ *
+ */
+static int get_io_pages(struct mm_struct *mm, u32 uva, unsigned pages,
+                                                struct page **usr_pgs)
+{
+        u32 pa;
+        int i;
+        struct page *pg;
+
+        for (i = 0; i < pages; i++) {
+                pa = user_va2_pa(mm, uva);
+
+                if (!pfn_valid(__phys_to_pfn(pa)))
+                        break;
+
+                pg = PHYS_TO_PAGE(pa);
+                usr_pgs[i] = pg;
+                get_page(pg);
+        }
+        return i;
+}
+
+/**
+ * user_to_dsp_map() - maps user to dsp virtual address
+ * @mmu:        Pointer to iommu handle.
+ * @uva:                Virtual user space address.
+ * @da          DSP address
+ * @size                Buffer size to map.
+ * @usr_pgs     struct page array pointer where the user pages will be stored
+ *
+ * This function maps a user space buffer into DSP virtual address.
+ *
+ */
+u32 user_to_dsp_map(struct iommu *mmu, u32 uva, u32 da, u32 size,
+                                struct page **usr_pgs)
+{
+        int res, w;
+        unsigned pages, i;
+        struct vm_area_struct *vma;
+        struct mm_struct *mm = current->mm;
+        struct sg_table *sgt;
+        struct scatterlist *sg;
+
+        if (!size || !usr_pgs)
+                return -EINVAL;
+
+        pages = size / PG_SIZE4K;
+
+        down_read(&mm->mmap_sem);
+        vma = find_vma(mm, uva);
+        while (vma && (uva + size > vma->vm_end))
+                vma = find_vma(mm, vma->vm_end + 1);
+
+        if (!vma) {
+                pr_err("%s: Failed to get VMA region for 0x%x (%d)\n",
+                                                __func__, uva, size);
+                up_read(&mm->mmap_sem);
+                return -EINVAL;
+        }
+        if (vma->vm_flags & (VM_WRITE | VM_MAYWRITE))
+                w = 1;
+
+        if (vma->vm_flags & VM_IO)
+                i = get_io_pages(mm, uva, pages, usr_pgs);
+        else
+                i = get_user_pages(current, mm, uva, pages, w, 1,
+                                                        usr_pgs, NULL);
+        up_read(&mm->mmap_sem);
+
+        if (i < 0)
+                return i;
+
+        if (i < pages) {
+                res = -EFAULT;
+                goto err_pages;
+        }
+
+        sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+        if (!sgt) {
+                res = -ENOMEM;
+                goto err_pages;
+        }
+
+        res = sg_alloc_table(sgt, pages, GFP_KERNEL);
+
+        if (res < 0)
+                goto err_sg;
+
+        for_each_sg(sgt->sgl, sg, sgt->nents, i)
+                sg_set_page(sg, usr_pgs[i], PAGE_SIZE, 0);
+
+        da = iommu_vmap(mmu, da, sgt, IOVMF_ENDIAN_LITTLE | IOVMF_ELSZ_32);
+
+        if (!IS_ERR_VALUE(da))
+                return da;
+        res = (int)da;
+
+        sg_free_table(sgt);
+err_sg:
+        kfree(sgt);
+        i = pages;
+err_pages:
+        while (i--)
+                put_page(usr_pgs[i]);
+        return res;
+}
+
+/**
+ * user_to_dsp_unmap() - unmaps DSP virtual buffer.
+ * @mmu:        Pointer to iommu handle.
+ * @da          DSP address
+ *
+ * This function unmaps a user space buffer into DSP virtual address.
+ *
+ */
+int user_to_dsp_unmap(struct iommu *mmu, u32 da)
+{
+        unsigned i;
+        struct sg_table *sgt;
+        struct scatterlist *sg;
+
+        sgt = iommu_vunmap(mmu, da);
+        if (!sgt)
+                return -EFAULT;
+
+        for_each_sg(sgt->sgl, sg, sgt->nents, i)
+                put_page(sg_page(sg));
+        sg_free_table(sgt);
+        kfree(sgt);
+
+        return 0;
+}
+
+/*
  *  ======== wait_for_start ========
  *      Wait for the singal from DSP that it has started, or time out.
  */
diff --git a/drivers/staging/tidspbridge/core/ue_deh.c b/drivers/staging/tidspbridge/core/ue_deh.c
index e24ea0c7391..2e1ac89644d 100644
--- a/drivers/staging/tidspbridge/core/ue_deh.c
+++ b/drivers/staging/tidspbridge/core/ue_deh.c
@@ -31,6 +31,32 @@
 #include <dspbridge/drv.h>
 #include <dspbridge/wdt.h>
 
+#define MMU_CNTL_TWL_EN         (1 << 2)
+
+static void mmu_fault_dpc(unsigned long data)
+{
+        struct deh_mgr *deh = (void *)data;
+
+        if (!deh)
+                return;
+
+        bridge_deh_notify(deh, DSP_MMUFAULT, 0);
+}
+
+int mmu_fault_isr(struct iommu *mmu)
+{
+        struct deh_mgr *dm;
+
+        dev_get_deh_mgr(dev_get_first(), &dm);
+
+        if (!dm)
+                return -EPERM;
+
+        iommu_write_reg(mmu, 0, MMU_IRQENABLE);
+        tasklet_schedule(&dm->dpc_tasklet);
+        return 0;
+}
+
 int bridge_deh_create(struct deh_mgr **ret_deh,
                 struct dev_object *hdev_obj)
 {
@@ -58,6 +84,9 @@ int bridge_deh_create(struct deh_mgr **ret_deh,
         }
         ntfy_init(deh->ntfy_obj);
 
+        /* Create a MMUfault DPC */
+        tasklet_init(&deh->dpc_tasklet, mmu_fault_dpc, (u32) deh);
+
         /* Fill in context structure */
         deh->hbridge_context = hbridge_context;
 
@@ -81,6 +110,9 @@ int bridge_deh_destroy(struct deh_mgr *deh)
                 kfree(deh->ntfy_obj);
         }
 
+        /* Free DPC object */
+        tasklet_kill(&deh->dpc_tasklet);
+
         /* Deallocate the DEH manager object */
         kfree(deh);
 
@@ -101,6 +133,51 @@ int bridge_deh_register_notify(struct deh_mgr *deh, u32 event_mask,
                 return ntfy_unregister(deh->ntfy_obj, hnotification);
 }
 
+#ifdef CONFIG_TIDSPBRIDGE_BACKTRACE
+static void mmu_fault_print_stack(struct bridge_dev_context *dev_context)
+{
+        void *dummy_addr;
+        u32 fa, tmp;
+        struct iotlb_entry e;
+        struct iommu *mmu = dev_context->dsp_mmu;
+        dummy_addr = (void *)__get_free_page(GFP_ATOMIC);
+
+        /*
+         * Before acking the MMU fault, let's make sure MMU can only
+         * access entry #0. Then add a new entry so that the DSP OS
+         * can continue in order to dump the stack.
+         */
+        tmp = iommu_read_reg(mmu, MMU_CNTL);
+        tmp &= ~MMU_CNTL_TWL_EN;
+        iommu_write_reg(mmu, tmp, MMU_CNTL);
+        fa = iommu_read_reg(mmu, MMU_FAULT_AD);
+        e.da = fa & PAGE_MASK;
+        e.pa = virt_to_phys(dummy_addr);
+        e.valid = 1;
+        e.prsvd = 1;
+        e.pgsz = IOVMF_PGSZ_4K & MMU_CAM_PGSZ_MASK;
+        e.endian = MMU_RAM_ENDIAN_LITTLE;
+        e.elsz = MMU_RAM_ELSZ_32;
+        e.mixed = 0;
+
+        load_iotlb_entry(dev_context->dsp_mmu, &e);
+
+        dsp_clk_enable(DSP_CLK_GPT8);
+
+        dsp_gpt_wait_overflow(DSP_CLK_GPT8, 0xfffffffe);
+
+        /* Clear MMU interrupt */
+        tmp = iommu_read_reg(mmu, MMU_IRQSTATUS);
+        iommu_write_reg(mmu, tmp, MMU_IRQSTATUS);
+
+        dump_dsp_stack(dev_context);
+        dsp_clk_disable(DSP_CLK_GPT8);
+
+        iopgtable_clear_entry(mmu, fa);
+        free_page((unsigned long)dummy_addr);
+}
+#endif
+
 static inline const char *event_to_string(int event)
 {
         switch (event) {
@@ -116,6 +193,7 @@ void bridge_deh_notify(struct deh_mgr *deh, int event, int info)
 {
         struct bridge_dev_context *dev_context;
         const char *str = event_to_string(event);
+        u32 fa;
 
         if (!deh)
                 return;
@@ -133,7 +211,13 @@ void bridge_deh_notify(struct deh_mgr *deh, int event, int info)
 #endif
                 break;
         case DSP_MMUFAULT:
-                dev_err(bridge, "%s: %s, addr=0x%x", __func__, str, info);
+                fa = iommu_read_reg(dev_context->dsp_mmu, MMU_FAULT_AD);
+                dev_err(bridge, "%s: %s, addr=0x%x", __func__, str, fa);
+#ifdef CONFIG_TIDSPBRIDGE_BACKTRACE
+                print_dsp_trace_buffer(dev_context);
+                dump_dl_modules(dev_context);
+                mmu_fault_print_stack(dev_context);
+#endif
                 break;
         default:
                 dev_err(bridge, "%s: %s", __func__, str);
diff --git a/drivers/staging/tidspbridge/include/dspbridge/dsp-mmu.h b/drivers/staging/tidspbridge/include/dspbridge/dsp-mmu.h
deleted file mode 100644
index cb38d4cc073..00000000000
--- a/drivers/staging/tidspbridge/include/dspbridge/dsp-mmu.h
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- * dsp-mmu.h
- *
- * DSP-BIOS Bridge driver support functions for TI OMAP processors.
- *
- * DSP iommu.
- *
- * Copyright (C) 2005-2010 Texas Instruments, Inc.
- *
- * This package is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
- * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
- */
-
-#ifndef _DSP_MMU_
-#define _DSP_MMU_
-
-#include <plat/iommu.h>
-#include <plat/iovmm.h>
-
-/**
- * dsp_mmu_init() - initialize dsp_mmu module and returns a handle
- *
- * This function initialize dsp mmu module and returns a struct iommu
- * handle to use it for dsp maps.
- *
- */
-struct iommu *dsp_mmu_init(void);
-
-/**
- * dsp_mmu_exit() - destroy dsp mmu module
- * @mmu:        Pointer to iommu handle.
- *
- * This function destroys dsp mmu module.
- *
- */
-void dsp_mmu_exit(struct iommu *mmu);
-
-/**
- * user_to_dsp_map() - maps user to dsp virtual address
- * @mmu:        Pointer to iommu handle.
- * @uva:                Virtual user space address.
- * @da          DSP address
- * @size                Buffer size to map.
- * @usr_pgs     struct page array pointer where the user pages will be stored
- *
- * This function maps a user space buffer into DSP virtual address.
- *
- */
-u32 user_to_dsp_map(struct iommu *mmu, u32 uva, u32 da, u32 size,
-                                                struct page **usr_pgs);
-
-/**
- * user_to_dsp_unmap() - unmaps DSP virtual buffer.
- * @mmu:        Pointer to iommu handle.
- * @da          DSP address
- *
- * This function unmaps a user space buffer into DSP virtual address.
- *
- */
-int user_to_dsp_unmap(struct iommu *mmu, u32 da);
-
-#endif