[Feature]add MT2731_MP2_MR2_SVN388 baseline version

Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/bsp/lk/kernel/vm/vmm.c b/src/bsp/lk/kernel/vm/vmm.c
new file mode 100644
index 0000000..978d0f3
--- /dev/null
+++ b/src/bsp/lk/kernel/vm/vmm.c
@@ -0,0 +1,756 @@
+/*
+ * Copyright (c) 2014 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <trace.h>
+#include <assert.h>
+#include <err.h>
+#include <string.h>
+#include <lib/console.h>
+#include <kernel/vm.h>
+#include <kernel/mutex.h>
+#include "vm_priv.h"
+
+#define LOCAL_TRACE 0
+
+static struct list_node aspace_list = LIST_INITIAL_VALUE(aspace_list);
+static mutex_t vmm_lock = MUTEX_INITIAL_VALUE(vmm_lock);
+
+vmm_aspace_t _kernel_aspace;
+
+static void dump_aspace(const vmm_aspace_t *a);
+static void dump_region(const vmm_region_t *r);
+
+void vmm_init(void)
+{
+    /* initialize the kernel address space */
+    strlcpy(_kernel_aspace.name, "kernel", sizeof(_kernel_aspace.name));
+    _kernel_aspace.base = KERNEL_ASPACE_BASE,
+    _kernel_aspace.size = KERNEL_ASPACE_SIZE,
+    _kernel_aspace.flags = VMM_FLAG_ASPACE_KERNEL;
+    list_initialize(&_kernel_aspace.region_list);
+
+    list_add_head(&aspace_list, &_kernel_aspace.node);
+}
+
+static inline bool is_inside_aspace(const vmm_aspace_t *aspace, vaddr_t vaddr)
+{
+    DEBUG_ASSERT(aspace);
+
+    return (vaddr >= aspace->base && vaddr <= aspace->base + aspace->size - 1);
+}
+
+static bool is_region_inside_aspace(const vmm_aspace_t *aspace, vaddr_t vaddr, size_t size)
+{
+    DEBUG_ASSERT(aspace);
+
+    /* is the starting address within the address space*/
+    if (!is_inside_aspace(aspace, vaddr))
+        return false;
+
+    if (size == 0)
+        return true;
+
+    /* see if the size is enough to wrap the integer */
+    if (vaddr + size - 1 < vaddr)
+        return false;
+
+    /* test to see if the end address is within the address space's */
+    if (vaddr + size - 1 > aspace->base + aspace->size - 1)
+        return false;
+
+    return true;
+}
+
+static size_t trim_to_aspace(const vmm_aspace_t *aspace, vaddr_t vaddr, size_t size)
+{
+    DEBUG_ASSERT(aspace);
+    DEBUG_ASSERT(is_inside_aspace(aspace, vaddr));
+
+    if (size == 0)
+        return size;
+
+    size_t offset = vaddr - aspace->base;
+
+    //LTRACEF("vaddr 0x%lx size 0x%zx offset 0x%zx aspace base 0x%lx aspace size 0x%zx\n",
+    //        vaddr, size, offset, aspace->base, aspace->size);
+
+    if (offset + size < offset)
+        size = ULONG_MAX - offset - 1;
+
+    //LTRACEF("size now 0x%zx\n", size);
+
+    if (offset + size >= aspace->size - 1)
+        size = aspace->size - offset;
+
+    //LTRACEF("size now 0x%zx\n", size);
+
+    return size;
+}
+
+static vmm_region_t *alloc_region_struct(const char *name, vaddr_t base, size_t size, uint flags, uint arch_mmu_flags)
+{
+    DEBUG_ASSERT(name);
+
+    vmm_region_t *r = malloc(sizeof(vmm_region_t));
+    if (!r)
+        return NULL;
+
+    strlcpy(r->name, name, sizeof(r->name));
+    r->base = base;
+    r->size = size;
+    r->flags = flags;
+    r->arch_mmu_flags = arch_mmu_flags;
+    list_initialize(&r->page_list);
+
+    return r;
+}
+
+/* add a region to the appropriate spot in the address space list,
+ * testing to see if there's a space */
+static status_t add_region_to_aspace(vmm_aspace_t *aspace, vmm_region_t *r)
+{
+    DEBUG_ASSERT(aspace);
+    DEBUG_ASSERT(r);
+
+    LTRACEF("aspace %p base 0x%lx size 0x%zx r %p base 0x%lx size 0x%zx\n",
+            aspace, aspace->base, aspace->size, r, r->base, r->size);
+
+    /* only try if the region will at least fit in the address space */
+    if (r->size == 0 || !is_region_inside_aspace(aspace, r->base, r->size)) {
+        LTRACEF("region was out of range\n");
+        return ERR_OUT_OF_RANGE;
+    }
+
+    vaddr_t r_end = r->base + r->size - 1;
+
+    /* does it fit in front */
+    vmm_region_t *last;
+    last = list_peek_head_type(&aspace->region_list, vmm_region_t, node);
+    if (!last || r_end < last->base) {
+        /* empty list or not empty and fits before the first element */
+        list_add_head(&aspace->region_list, &r->node);
+        return NO_ERROR;
+    }
+
+    /* walk the list, finding the right spot to put it */
+    list_for_every_entry(&aspace->region_list, last, vmm_region_t, node) {
+        /* does it go after last? */
+        if (r->base > last->base + last->size - 1) {
+            /* get the next element in the list */
+            vmm_region_t *next = list_next_type(&aspace->region_list, &last->node, vmm_region_t, node);
+            if (!next || (r_end < next->base)) {
+                /* end of the list or next exists and it goes between them */
+                list_add_after(&last->node, &r->node);
+                return NO_ERROR;
+            }
+        }
+    }
+
+    LTRACEF("couldn't find spot\n");
+    return ERR_NO_MEMORY;
+}
+
+/*
+ *  Try to pick the spot within specified gap
+ *
+ *  Arch can override this to impose it's own restrictions.
+ */
+__WEAK vaddr_t arch_mmu_pick_spot(vaddr_t base, uint prev_region_arch_mmu_flags,
+                                  vaddr_t end,  uint next_region_arch_mmu_flags,
+                                  vaddr_t align, size_t size, uint arch_mmu_flags)
+{
+    /* just align it by default */
+    return ALIGN(base, align);
+}
+
+/*
+ *  Returns true if the caller has to stop search
+ */
+static inline bool check_gap(vmm_aspace_t *aspace,
+                             vmm_region_t *prev, vmm_region_t *next,
+                             vaddr_t *pva, vaddr_t align, size_t size,
+                             uint arch_mmu_flags)
+{
+    vaddr_t gap_beg; /* first byte of a gap */
+    vaddr_t gap_end; /* last byte of a gap */
+
+    DEBUG_ASSERT(aspace);
+    DEBUG_ASSERT(pva);
+
+    if (prev)
+        gap_beg = prev->base + prev->size;
+    else
+        gap_beg = aspace->base;
+
+    if (next) {
+        if (gap_beg == next->base)
+            goto next_gap;  /* no gap between regions */
+        gap_end = next->base - 1;
+    } else {
+        if (gap_beg == (aspace->base + aspace->size))
+            goto not_found;  /* no gap at the end of address space. Stop search */
+        gap_end = aspace->base + aspace->size - 1;
+    }
+
+    *pva = arch_mmu_pick_spot(gap_beg, prev ? prev->arch_mmu_flags : ARCH_MMU_FLAG_INVALID,
+                              gap_end, next ? next->arch_mmu_flags : ARCH_MMU_FLAG_INVALID,
+                              align, size, arch_mmu_flags);
+    if (*pva < gap_beg)
+        goto not_found; /* address wrapped around */
+
+    if (*pva < gap_end && ((gap_end - *pva + 1) >= size)) {
+        /* we have enough room */
+        return true; /* found spot, stop search */
+    }
+
+next_gap:
+    return false; /* continue search */
+
+not_found:
+    *pva = -1;
+    return true; /* not_found: stop search */
+}
+
+static vaddr_t alloc_spot(vmm_aspace_t *aspace, size_t size, uint8_t align_pow2,
+                          uint arch_mmu_flags, struct list_node **before)
+{
+    DEBUG_ASSERT(aspace);
+    DEBUG_ASSERT(size > 0 && IS_PAGE_ALIGNED(size));
+
+    LTRACEF("aspace %p size 0x%zx align %hhu\n", aspace, size, align_pow2);
+
+    if (align_pow2 < PAGE_SIZE_SHIFT)
+        align_pow2 = PAGE_SIZE_SHIFT;
+    vaddr_t align = 1UL << align_pow2;
+
+    vaddr_t spot;
+    vmm_region_t *r = NULL;
+
+    /* try to pick spot at the beginning of address space */
+    if (check_gap(aspace, NULL,
+                  list_peek_head_type(&aspace->region_list, vmm_region_t, node),
+                  &spot, align, size, arch_mmu_flags))
+        goto done;
+
+    /* search the middle of the list */
+    list_for_every_entry(&aspace->region_list, r, vmm_region_t, node) {
+        if (check_gap(aspace, r,
+                      list_next_type(&aspace->region_list, &r->node, vmm_region_t, node),
+                      &spot, align, size, arch_mmu_flags))
+            goto done;
+    }
+
+    /* couldn't find anything */
+    return -1;
+
+done:
+    if (before)
+        *before = r ? &r->node : &aspace->region_list;
+    return spot;
+}
+
+/* allocate a region structure and stick it in the address space */
+static vmm_region_t *alloc_region(vmm_aspace_t *aspace, const char *name, size_t size,
+        vaddr_t vaddr, uint8_t align_pow2,
+        uint vmm_flags, uint region_flags, uint arch_mmu_flags)
+{
+    /* make a region struct for it and stick it in the list */
+    vmm_region_t *r = alloc_region_struct(name, vaddr, size, region_flags, arch_mmu_flags);
+    if (!r)
+        return NULL;
+
+    /* if they ask us for a specific spot, put it there */
+    if (vmm_flags & VMM_FLAG_VALLOC_SPECIFIC) {
+        /* stick it in the list, checking to see if it fits */
+        if (add_region_to_aspace(aspace, r) < 0) {
+            /* didn't fit */
+            free(r);
+            return NULL;
+        }
+    } else {
+        /* allocate a virtual slot for it */
+        struct list_node *before = NULL;
+
+        vaddr = alloc_spot(aspace, size, align_pow2, arch_mmu_flags, &before);
+        LTRACEF("alloc_spot returns 0x%lx, before %p\n", vaddr, before);
+
+        if (vaddr == (vaddr_t)-1) {
+            LTRACEF("failed to find spot\n");
+            free(r);
+            return NULL;
+        }
+
+        DEBUG_ASSERT(before != NULL);
+
+        r->base = (vaddr_t)vaddr;
+
+        /* add it to the region list */
+        list_add_after(before, &r->node);
+    }
+
+    return r;
+}
+
+status_t vmm_reserve_space(vmm_aspace_t *aspace, const char *name, size_t size, vaddr_t vaddr)
+{
+    LTRACEF("aspace %p name '%s' size 0x%zx vaddr 0x%lx\n", aspace, name, size, vaddr);
+
+    DEBUG_ASSERT(IS_PAGE_ALIGNED(vaddr));
+    DEBUG_ASSERT(IS_PAGE_ALIGNED(size));
+
+    if (!name)
+        name = "";
+
+    if (size == 0)
+        return NO_ERROR;
+    if (!IS_PAGE_ALIGNED(vaddr) || !IS_PAGE_ALIGNED(size))
+        return ERR_INVALID_ARGS;
+
+    if (!is_inside_aspace(aspace, vaddr))
+        return ERR_OUT_OF_RANGE;
+
+    /* trim the size */
+    size = trim_to_aspace(aspace, vaddr, size);
+
+    mutex_acquire(&vmm_lock);
+
+    /* lookup how it's already mapped */
+    uint arch_mmu_flags = 0;
+    arch_mmu_query(vaddr, NULL, &arch_mmu_flags);
+
+    /* build a new region structure */
+    vmm_region_t *r = alloc_region(aspace, name, size, vaddr, 0, VMM_FLAG_VALLOC_SPECIFIC, VMM_REGION_FLAG_RESERVED, arch_mmu_flags);
+
+    mutex_release(&vmm_lock);
+    return r ? NO_ERROR : ERR_NO_MEMORY;
+}
+
+status_t vmm_alloc_physical(vmm_aspace_t *aspace, const char *name, size_t size, void **ptr, uint8_t align_log2, paddr_t paddr, uint vmm_flags, uint arch_mmu_flags)
+{
+    status_t ret;
+
+    LTRACEF("aspace %p name '%s' size 0x%zx ptr %p paddr 0x%lx vmm_flags 0x%x arch_mmu_flags 0x%x\n",
+            aspace, name, size, ptr ? *ptr : 0, paddr, vmm_flags, arch_mmu_flags);
+
+    DEBUG_ASSERT(IS_PAGE_ALIGNED(paddr));
+    DEBUG_ASSERT(IS_PAGE_ALIGNED(size));
+
+    if (!name)
+        name = "";
+
+    if (size == 0)
+        return NO_ERROR;
+    if (!IS_PAGE_ALIGNED(paddr) || !IS_PAGE_ALIGNED(size))
+        return ERR_INVALID_ARGS;
+
+    vaddr_t vaddr = 0;
+
+    /* if they're asking for a specific spot, copy the address */
+    if (vmm_flags & VMM_FLAG_VALLOC_SPECIFIC) {
+        /* can't ask for a specific spot and then not provide one */
+        if (!ptr) {
+            return ERR_INVALID_ARGS;
+        }
+        vaddr = (vaddr_t)*ptr;
+    }
+
+    mutex_acquire(&vmm_lock);
+
+    /* allocate a region and put it in the aspace list */
+    vmm_region_t *r = alloc_region(aspace, name, size, vaddr, align_log2, vmm_flags,
+            VMM_REGION_FLAG_PHYSICAL, arch_mmu_flags);
+    if (!r) {
+        ret = ERR_NO_MEMORY;
+        goto err_alloc_region;
+    }
+
+    /* return the vaddr if requested */
+    if (ptr)
+        *ptr = (void *)r->base;
+
+    /* map all of the pages */
+    int err = arch_mmu_map(r->base, paddr, size / PAGE_SIZE, arch_mmu_flags);
+    LTRACEF("arch_mmu_map returns %d\n", err);
+
+    ret = NO_ERROR;
+
+err_alloc_region:
+    mutex_release(&vmm_lock);
+    return ret;
+}
+
+status_t vmm_alloc_contiguous(vmm_aspace_t *aspace, const char *name, size_t size, void **ptr,
+        uint8_t align_pow2, uint vmm_flags, uint arch_mmu_flags)
+{
+    status_t err = NO_ERROR;
+
+    LTRACEF("aspace %p name '%s' size 0x%zx ptr %p align %hhu vmm_flags 0x%x arch_mmu_flags 0x%x\n",
+            aspace, name, size, ptr ? *ptr : 0, align_pow2, vmm_flags, arch_mmu_flags);
+
+    size = ROUNDUP(size, PAGE_SIZE);
+    if (size == 0)
+        return ERR_INVALID_ARGS;
+
+    if (!name)
+        name = "";
+
+    vaddr_t vaddr = 0;
+
+    /* if they're asking for a specific spot, copy the address */
+    if (vmm_flags & VMM_FLAG_VALLOC_SPECIFIC) {
+        /* can't ask for a specific spot and then not provide one */
+        if (!ptr) {
+            err = ERR_INVALID_ARGS;
+            goto err;
+        }
+        vaddr = (vaddr_t)*ptr;
+    }
+
+    /* allocate physical memory up front, in case it cant be satisfied */
+    struct list_node page_list;
+    list_initialize(&page_list);
+
+    paddr_t pa = 0;
+    /* allocate a run of physical pages */
+    size_t count = pmm_alloc_contiguous(size / PAGE_SIZE, align_pow2, &pa, &page_list);
+    if (count < size / PAGE_SIZE) {
+        DEBUG_ASSERT(count == 0); /* check that the pmm didn't allocate a partial run */
+        err = ERR_NO_MEMORY;
+        goto err;
+    }
+
+    mutex_acquire(&vmm_lock);
+
+    /* allocate a region and put it in the aspace list */
+    vmm_region_t *r = alloc_region(aspace, name, size, vaddr, align_pow2, vmm_flags,
+            VMM_REGION_FLAG_PHYSICAL, arch_mmu_flags);
+    if (!r) {
+        err = ERR_NO_MEMORY;
+        goto err1;
+    }
+
+    /* return the vaddr if requested */
+    if (ptr)
+        *ptr = (void *)r->base;
+
+    /* map all of the pages */
+    arch_mmu_map(r->base, pa, size / PAGE_SIZE, arch_mmu_flags);
+    // XXX deal with error mapping here
+
+    vm_page_t *p;
+    while ((p = list_remove_head_type(&page_list, vm_page_t, node))) {
+        list_add_tail(&r->page_list, &p->node);
+    }
+
+    mutex_release(&vmm_lock);
+    return NO_ERROR;
+
+err1:
+    mutex_release(&vmm_lock);
+    pmm_free(&page_list);
+err:
+    return err;
+}
+
+status_t vmm_alloc(vmm_aspace_t *aspace, const char *name, size_t size, void **ptr,
+        uint8_t align_pow2, uint vmm_flags, uint arch_mmu_flags)
+{
+    status_t err = NO_ERROR;
+
+    LTRACEF("aspace %p name '%s' size 0x%zx ptr %p align %hhu vmm_flags 0x%x arch_mmu_flags 0x%x\n",
+            aspace, name, size, ptr ? *ptr : 0, align_pow2, vmm_flags, arch_mmu_flags);
+
+    size = ROUNDUP(size, PAGE_SIZE);
+    if (size == 0)
+        return ERR_INVALID_ARGS;
+
+    if (!name)
+        name = "";
+
+    vaddr_t vaddr = 0;
+
+    /* if they're asking for a specific spot, copy the address */
+    if (vmm_flags & VMM_FLAG_VALLOC_SPECIFIC) {
+        /* can't ask for a specific spot and then not provide one */
+        if (!ptr) {
+            err = ERR_INVALID_ARGS;
+            goto err;
+        }
+        vaddr = (vaddr_t)*ptr;
+    }
+
+    /* allocate physical memory up front, in case it cant be satisfied */
+
+    /* allocate a random pile of pages */
+    struct list_node page_list;
+    list_initialize(&page_list);
+
+    size_t count = pmm_alloc_pages(size / PAGE_SIZE, &page_list);
+    DEBUG_ASSERT(count <= size);
+    if (count < size / PAGE_SIZE) {
+        LTRACEF("failed to allocate enough pages (asked for %zu, got %zu)\n", size / PAGE_SIZE, count);
+        pmm_free(&page_list);
+        err = ERR_NO_MEMORY;
+        goto err;
+    }
+
+    mutex_acquire(&vmm_lock);
+
+    /* allocate a region and put it in the aspace list */
+    vmm_region_t *r = alloc_region(aspace, name, size, vaddr, align_pow2, vmm_flags,
+            VMM_REGION_FLAG_PHYSICAL, arch_mmu_flags);
+    if (!r) {
+        err = ERR_NO_MEMORY;
+        goto err1;
+    }
+
+    /* return the vaddr if requested */
+    if (ptr)
+        *ptr = (void *)r->base;
+
+    /* map all of the pages */
+    /* XXX use smarter algorithm that tries to build runs */
+    vm_page_t *p;
+    vaddr_t va = r->base;
+    DEBUG_ASSERT(IS_PAGE_ALIGNED(va));
+    while ((p = list_remove_head_type(&page_list, vm_page_t, node))) {
+        DEBUG_ASSERT(va <= r->base + r->size - 1);
+
+        paddr_t pa = page_to_address(p);
+        DEBUG_ASSERT(IS_PAGE_ALIGNED(pa));
+
+        arch_mmu_map(va, pa, 1, arch_mmu_flags);
+        // XXX deal with error mapping here
+
+        list_add_tail(&r->page_list, &p->node);
+
+        va += PAGE_SIZE;
+    }
+
+    mutex_release(&vmm_lock);
+    return NO_ERROR;
+
+err1:
+    mutex_release(&vmm_lock);
+    pmm_free(&page_list);
+err:
+    return err;
+}
+
+static vmm_region_t *vmm_find_region(const vmm_aspace_t *aspace, vaddr_t vaddr)
+{
+    vmm_region_t *r;
+
+    DEBUG_ASSERT(aspace);
+
+    if (!aspace)
+        return NULL;
+
+    /* search the region list */
+    list_for_every_entry(&aspace->region_list, r, vmm_region_t, node) {
+        if ((vaddr >= r->base) && (vaddr <= r->base + r->size - 1))
+            return r;
+    }
+
+    return NULL;
+}
+
+status_t vmm_free_region(vmm_aspace_t *aspace, vaddr_t vaddr)
+{
+    DEBUG_ASSERT(aspace);
+
+    mutex_acquire(&vmm_lock);
+
+    vmm_region_t *r = vmm_find_region (aspace, vaddr);
+    if (!r) {
+        mutex_release(&vmm_lock);
+        return ERR_NOT_FOUND;
+    }
+
+    /* remove it from aspace */
+    list_delete(&r->node);
+
+    /* unmap it */
+    arch_mmu_unmap(r->base, r->size / PAGE_SIZE);
+
+    mutex_release(&vmm_lock);
+
+    /* return physical pages if any */
+    pmm_free(&r->page_list);
+
+    /* free it */
+    free(r);
+
+    return NO_ERROR;
+}
+
+status_t vmm_create_aspace(vmm_aspace_t **_aspace, const char *name, uint flags)
+{
+    DEBUG_ASSERT(_aspace);
+
+    vmm_aspace_t *aspace = malloc(sizeof(vmm_aspace_t));
+    if (!aspace)
+        return ERR_NO_MEMORY;
+
+    if (name)
+        strlcpy(aspace->name, name, sizeof(aspace->name));
+    else
+        strlcpy(aspace->name, "unnamed", sizeof(aspace->name));
+
+    if (flags & VMM_FLAG_ASPACE_KERNEL) {
+        aspace->base = KERNEL_ASPACE_BASE;
+        aspace->size = KERNEL_ASPACE_SIZE;
+    } else {
+        aspace->base = USER_ASPACE_BASE;
+        aspace->size = USER_ASPACE_SIZE;
+    }
+
+    list_clear_node(&aspace->node);
+    list_initialize(&aspace->region_list);
+
+    mutex_acquire(&vmm_lock);
+    list_add_head(&aspace_list, &aspace->node);
+    mutex_release(&vmm_lock);
+
+    *_aspace = aspace;
+
+    return NO_ERROR;
+}
+
+status_t vmm_free_aspace(vmm_aspace_t *aspace)
+{
+    DEBUG_ASSERT(aspace);
+
+    /* pop it out of the global aspace list */
+    mutex_acquire(&vmm_lock);
+    if (!list_in_list(&aspace->node)) {
+        mutex_release(&vmm_lock);
+        return ERR_INVALID_ARGS;
+    }
+    list_delete(&aspace->node);
+
+    /* free all of the regions */
+    struct list_node region_list = LIST_INITIAL_VALUE(region_list);
+
+    vmm_region_t *r;
+    while ((r = list_remove_head_type(&aspace->region_list, vmm_region_t, node))) {
+        /* add it to our tempoary list */
+        list_add_tail(&region_list, &r->node);
+
+        /* unmap it */
+        arch_mmu_unmap(r->base, r->size / PAGE_SIZE);
+    }
+    mutex_release(&vmm_lock);
+
+    /* without the vmm lock held, free all of the pmm pages and the structure */
+    while ((r = list_remove_head_type(&region_list, vmm_region_t, node))) {
+        /* return physical pages if any */
+        pmm_free(&r->page_list);
+
+        /* free it */
+        free(r);
+    }
+
+    /* free the aspace */
+    free(aspace);
+
+    return NO_ERROR;
+}
+
+static void dump_region(const vmm_region_t *r)
+{
+    DEBUG_ASSERT(r);
+
+    printf("\tregion %p: name '%s' range 0x%lx - 0x%lx size 0x%zx flags 0x%x mmu_flags 0x%x\n",
+            r, r->name, r->base, r->base + r->size - 1, r->size, r->flags, r->arch_mmu_flags);
+}
+
+static void dump_aspace(const vmm_aspace_t *a)
+{
+    DEBUG_ASSERT(a);
+
+    printf("aspace %p: name '%s' range 0x%lx - 0x%lx size 0x%zx flags 0x%x\n",
+            a, a->name, a->base, a->base + a->size - 1, a->size, a->flags);
+
+    printf("regions:\n");
+    vmm_region_t *r;
+    list_for_every_entry(&a->region_list, r, vmm_region_t, node) {
+        dump_region(r);
+    }
+}
+
+static int cmd_vmm(int argc, const cmd_args *argv)
+{
+    if (argc < 2) {
+notenoughargs:
+        printf("not enough arguments\n");
+usage:
+        printf("usage:\n");
+        printf("%s aspaces\n", argv[0].str);
+        printf("%s alloc <size> <align_pow2>\n", argv[0].str);
+        printf("%s alloc_physical <paddr> <size> <align_pow2>\n", argv[0].str);
+        printf("%s alloc_contig <size> <align_pow2>\n", argv[0].str);
+        printf("%s create_aspace\n", argv[0].str);
+        return ERR_GENERIC;
+    }
+
+    if (!strcmp(argv[1].str, "aspaces")) {
+        vmm_aspace_t *a;
+        list_for_every_entry(&aspace_list, a, vmm_aspace_t, node) {
+            dump_aspace(a);
+        }
+    } else if (!strcmp(argv[1].str, "alloc")) {
+        if (argc < 4) goto notenoughargs;
+
+        void *ptr = (void *)0x99;
+        status_t err = vmm_alloc(vmm_get_kernel_aspace(), "alloc test", argv[2].u, &ptr, argv[3].u, 0, 0);
+        printf("vmm_alloc returns %d, ptr %p\n", err, ptr);
+    } else if (!strcmp(argv[1].str, "alloc_physical")) {
+        if (argc < 4) goto notenoughargs;
+
+        void *ptr = (void *)0x99;
+        status_t err = vmm_alloc_physical(vmm_get_kernel_aspace(), "physical test", argv[3].u, &ptr, argv[4].u, argv[2].u, 0, ARCH_MMU_FLAG_UNCACHED_DEVICE);
+        printf("vmm_alloc_physical returns %d, ptr %p\n", err, ptr);
+    } else if (!strcmp(argv[1].str, "alloc_contig")) {
+        if (argc < 4) goto notenoughargs;
+
+        void *ptr = (void *)0x99;
+        status_t err = vmm_alloc_contiguous(vmm_get_kernel_aspace(), "contig test", argv[2].u, &ptr, argv[3].u, 0, 0);
+        printf("vmm_alloc_contig returns %d, ptr %p\n", err, ptr);
+    } else if (!strcmp(argv[1].str, "create_aspace")) {
+        vmm_aspace_t *aspace;
+        status_t err = vmm_create_aspace(&aspace, "test", 0);
+        printf("vmm_create_aspace returns %d, aspace %p\n", err, aspace);
+    } else {
+        printf("unknown command\n");
+        goto usage;
+    }
+
+    return NO_ERROR;
+}
+
+STATIC_COMMAND_START
+#if LK_DEBUGLEVEL > 0
+STATIC_COMMAND("vmm", "virtual memory manager", &cmd_vmm)
+#endif
+STATIC_COMMAND_END(vmm);
+