gpu: nvgpu: Refactor VM init/cleanup

Refactor the API for initializing and cleaning up VMs.

This also involved moving a bunch of GMMU code out into the
gmmu code since part of initializing a VM involves initializing
the page tables for the VM.

JIRA NVGPU-12
JIRA NVGPU-30

Change-Id: I4710f08c26a6e39806f0762a35f6db5c94b64c50
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: http://git-master/r/1477746
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 339 insertions, 5 deletions

diff --git a/drivers/gpu/nvgpu/common/mm/vm.c b/drivers/gpu/nvgpu/common/mm/vm.c
index 3b3b7a10..e42c7c5a 100644
--- a/drivers/gpu/nvgpu/common/mm/vm.c
+++ b/drivers/gpu/nvgpu/common/mm/vm.c
@@ -14,6 +14,8 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <nvgpu/log.h>
+#include <nvgpu/dma.h>
 #include <nvgpu/vm.h>
 #include <nvgpu/vm_area.h>
 #include <nvgpu/lock.h>
@@ -23,6 +25,7 @@
 
 #include "gk20a/gk20a.h"
 #include "gk20a/mm_gk20a.h"
+#include "gk20a/platform_gk20a.h"
 
 int vm_aspace_id(struct vm_gk20a *vm)
 {
@@ -104,6 +107,341 @@ void nvgpu_vm_mapping_batch_finish(struct vm_gk20a *vm,
         nvgpu_mutex_release(&vm->update_gmmu_lock);
 }
 
+static int nvgpu_vm_init_page_tables(struct vm_gk20a *vm)
+{
+        u32 pde_lo, pde_hi;
+        int err;
+
+        pde_range_from_vaddr_range(vm,
+                                   0, vm->va_limit-1,
+                                   &pde_lo, &pde_hi);
+        vm->pdb.entries = nvgpu_vzalloc(vm->mm->g,
+                                        sizeof(struct gk20a_mm_entry) *
+                                        (pde_hi + 1));
+        vm->pdb.num_entries = pde_hi + 1;
+
+        if (!vm->pdb.entries)
+                return -ENOMEM;
+
+        err = nvgpu_zalloc_gmmu_page_table(vm, 0, &vm->mmu_levels[0],
+                                           &vm->pdb, NULL);
+        if (err) {
+                nvgpu_vfree(vm->mm->g, vm->pdb.entries);
+                return err;
+        }
+
+        return 0;
+}
+
+/*
+ * Determine if the passed address space can support big pages or not.
+ */
+int nvgpu_big_pages_possible(struct vm_gk20a *vm, u64 base, u64 size)
+{
+        u64 mask = ((u64)vm->big_page_size << 10) - 1;
+
+        if (base & mask || size & mask)
+                return 0;
+        return 1;
+}
+
+/*
+ * Initialize a semaphore pool. Just return successfully if we do not need
+ * semaphores (i.e when sync-pts are active).
+ */
+static int nvgpu_init_sema_pool(struct vm_gk20a *vm)
+{
+        struct nvgpu_semaphore_sea *sema_sea;
+        struct mm_gk20a *mm = vm->mm;
+        struct gk20a *g = mm->g;
+        int err;
+
+        /*
+         * Don't waste the memory on semaphores if we don't need them.
+         */
+        if (g->gpu_characteristics.flags & NVGPU_GPU_FLAGS_HAS_SYNCPOINTS)
+                return 0;
+
+        if (vm->sema_pool)
+                return 0;
+
+        sema_sea = nvgpu_semaphore_sea_create(g);
+        if (!sema_sea)
+                return -ENOMEM;
+
+        vm->sema_pool = nvgpu_semaphore_pool_alloc(sema_sea);
+        if (!vm->sema_pool)
+                return -ENOMEM;
+
+        /*
+         * Allocate a chunk of GPU VA space for mapping the semaphores. We will
+         * do a fixed alloc in the kernel VM so that all channels have the same
+         * RO address range for the semaphores.
+         *
+         * !!! TODO: cleanup.
+         */
+        sema_sea->gpu_va = nvgpu_alloc_fixed(&vm->kernel,
+                                             vm->va_limit -
+                                             mm->channel.kernel_size,
+                                             512 * PAGE_SIZE,
+                                             SZ_4K);
+        if (!sema_sea->gpu_va) {
+                nvgpu_free(&vm->kernel, sema_sea->gpu_va);
+                nvgpu_vm_put(vm);
+                return -ENOMEM;
+        }
+
+        err = nvgpu_semaphore_pool_map(vm->sema_pool, vm);
+        if (err) {
+                nvgpu_semaphore_pool_unmap(vm->sema_pool, vm);
+                nvgpu_free(vm->vma[gmmu_page_size_small],
+                           vm->sema_pool->gpu_va);
+                return err;
+        }
+
+        return 0;
+}
+
+/**
+ * nvgpu_init_vm() - Initialize an address space.
+ *
+ * @mm - Parent MM.
+ * @vm - The VM to init.
+ * @big_page_size - Size of big pages associated with this VM.
+ * @low_hole - The size of the low hole (unaddressable memory at the bottom of
+ *             the address space.
+ * @kernel_reserved - Space reserved for kernel only allocations.
+ * @aperture_size - Total size of the aperture.
+ * @big_pages - Ignored. Will be set based on other passed params.
+ * @name - Name of the address space.
+ *
+ * This function initializes an address space according to the following map:
+ *
+ *     +--+ 0x0
+ *     |  |
+ *     +--+ @low_hole
+ *     |  |
+ *     ~  ~   This is the "user" section.
+ *     |  |
+ *     +--+ @aperture_size - @kernel_reserved
+ *     |  |
+ *     ~  ~   This is the "kernel" section.
+ *     |  |
+ *     +--+ @aperture_size
+ *
+ * The user section is therefor what ever is left over after the @low_hole and
+ * @kernel_reserved memory have been portioned out. The @kernel_reserved is
+ * always persent at the top of the memory space and the @low_hole is always at
+ * the bottom.
+ *
+ * For certain address spaces a "user" section makes no sense (bar1, etc) so in
+ * such cases the @kernel_reserved and @low_hole should sum to exactly
+ * @aperture_size.
+ */
+int nvgpu_init_vm(struct mm_gk20a *mm,
+                  struct vm_gk20a *vm,
+                  u32 big_page_size,
+                  u64 low_hole,
+                  u64 kernel_reserved,
+                  u64 aperture_size,
+                  bool big_pages,
+                  bool userspace_managed,
+                  char *name)
+{
+        int err;
+        char alloc_name[32];
+        u64 kernel_vma_flags;
+        u64 user_vma_start, user_vma_limit;
+        u64 user_lp_vma_start, user_lp_vma_limit;
+        u64 kernel_vma_start, kernel_vma_limit;
+        struct gk20a *g = mm->g;
+        struct gk20a_platform *p = gk20a_get_platform(g->dev);
+
+        if (WARN_ON(kernel_reserved + low_hole > aperture_size))
+                return -ENOMEM;
+
+        nvgpu_log_info(g, "Init space for %s: valimit=0x%llx, "
+                       "LP size=0x%x lowhole=0x%llx",
+                       name, aperture_size,
+                       (unsigned int)big_page_size, low_hole);
+
+        vm->mm = mm;
+
+        vm->gmmu_page_sizes[gmmu_page_size_small]  = SZ_4K;
+        vm->gmmu_page_sizes[gmmu_page_size_big]    = big_page_size;
+        vm->gmmu_page_sizes[gmmu_page_size_kernel] = SZ_4K;
+
+        /* Set up vma pointers. */
+        vm->vma[gmmu_page_size_small]  = &vm->user;
+        vm->vma[gmmu_page_size_big]    = &vm->user;
+        vm->vma[gmmu_page_size_kernel] = &vm->kernel;
+        if (!p->unify_address_spaces)
+                vm->vma[gmmu_page_size_big] = &vm->user_lp;
+
+        vm->va_start  = low_hole;
+        vm->va_limit  = aperture_size;
+        vm->big_pages = big_pages;
+
+        vm->big_page_size     = vm->gmmu_page_sizes[gmmu_page_size_big];
+        vm->userspace_managed = userspace_managed;
+        vm->mmu_levels        = g->ops.mm.get_mmu_levels(g, vm->big_page_size);
+
+        /* Initialize the page table data structures. */
+        err = nvgpu_vm_init_page_tables(vm);
+        if (err)
+                return err;
+
+        /* Setup vma limits. */
+        if (kernel_reserved + low_hole < aperture_size) {
+                if (p->unify_address_spaces) {
+                        user_vma_start = low_hole;
+                        user_vma_limit = vm->va_limit - kernel_reserved;
+                        user_lp_vma_start = user_vma_limit;
+                        user_lp_vma_limit = user_vma_limit;
+                } else {
+                        user_vma_start = low_hole;
+                        user_vma_limit = __nv_gmmu_va_small_page_limit();
+                        user_lp_vma_start = __nv_gmmu_va_small_page_limit();
+                        user_lp_vma_limit = vm->va_limit - kernel_reserved;
+                }
+        } else {
+                user_vma_start = 0;
+                user_vma_limit = 0;
+                user_lp_vma_start = 0;
+                user_lp_vma_limit = 0;
+        }
+        kernel_vma_start = vm->va_limit - kernel_reserved;
+        kernel_vma_limit = vm->va_limit;
+
+        nvgpu_log_info(g, "user_vma     [0x%llx,0x%llx)",
+                       user_vma_start, user_vma_limit);
+        nvgpu_log_info(g, "user_lp_vma  [0x%llx,0x%llx)",
+                       user_lp_vma_start, user_lp_vma_limit);
+        nvgpu_log_info(g, "kernel_vma   [0x%llx,0x%llx)",
+                       kernel_vma_start, kernel_vma_limit);
+
+        if (WARN_ON(user_vma_start > user_vma_limit) ||
+            WARN_ON(user_lp_vma_start > user_lp_vma_limit) ||
+            WARN_ON(kernel_vma_start >= kernel_vma_limit)) {
+                err = -EINVAL;
+                goto clean_up_page_tables;
+        }
+
+        kernel_vma_flags = (kernel_reserved + low_hole) == aperture_size ?
+                0 : GPU_ALLOC_GVA_SPACE;
+
+        /*
+         * A "user" area only makes sense for the GVA spaces. For VMs where
+         * there is no "user" area user_vma_start will be equal to
+         * user_vma_limit (i.e a 0 sized space). In such a situation the kernel
+         * area must be non-zero in length.
+         */
+        if (user_vma_start >= user_vma_limit &&
+            kernel_vma_start >= kernel_vma_limit) {
+                err = -EINVAL;
+                goto clean_up_page_tables;
+        }
+
+        /*
+         * Determine if big pages are possible in this VM. If a split address
+         * space is used then check the user_lp vma instead of the user vma.
+         */
+        if (p->unify_address_spaces)
+                vm->big_pages = nvgpu_big_pages_possible(vm, user_vma_start,
+                                         user_vma_limit - user_vma_start);
+        else
+                vm->big_pages = nvgpu_big_pages_possible(vm, user_lp_vma_start,
+                                         user_lp_vma_limit - user_lp_vma_start);
+
+        /*
+         * User VMA.
+         */
+        if (user_vma_start < user_vma_limit) {
+                snprintf(alloc_name, sizeof(alloc_name), "gk20a_%s", name);
+                err = __nvgpu_buddy_allocator_init(g, &vm->user,
+                                                   vm, alloc_name,
+                                                   user_vma_start,
+                                                   user_vma_limit -
+                                                   user_vma_start,
+                                                   SZ_4K,
+                                                   GPU_BALLOC_MAX_ORDER,
+                                                   GPU_ALLOC_GVA_SPACE);
+                if (err)
+                        goto clean_up_page_tables;
+        } else {
+                /*
+                 * Make these allocator pointers point to the kernel allocator
+                 * since we still use the legacy notion of page size to choose
+                 * the allocator.
+                 */
+                vm->vma[0] = &vm->kernel;
+                vm->vma[1] = &vm->kernel;
+        }
+
+        /*
+         * User VMA for large pages when a split address range is used.
+         */
+        if (user_lp_vma_start < user_lp_vma_limit) {
+                snprintf(alloc_name, sizeof(alloc_name), "gk20a_%s_lp", name);
+                err = __nvgpu_buddy_allocator_init(g, &vm->user_lp,
+                                                   vm, alloc_name,
+                                                   user_lp_vma_start,
+                                                   user_lp_vma_limit -
+                                                   user_lp_vma_start,
+                                                   vm->big_page_size,
+                                                   GPU_BALLOC_MAX_ORDER,
+                                                   GPU_ALLOC_GVA_SPACE);
+                if (err)
+                        goto clean_up_allocators;
+        }
+
+        /*
+         * Kernel VMA. Must always exist for an address space.
+         */
+        snprintf(alloc_name, sizeof(alloc_name), "gk20a_%s-sys", name);
+        err = __nvgpu_buddy_allocator_init(g, &vm->kernel,
+                                           vm, alloc_name,
+                                           kernel_vma_start,
+                                           kernel_vma_limit - kernel_vma_start,
+                                           SZ_4K,
+                                           GPU_BALLOC_MAX_ORDER,
+                                           kernel_vma_flags);
+        if (err)
+                goto clean_up_allocators;
+
+        vm->mapped_buffers = NULL;
+
+        nvgpu_mutex_init(&vm->update_gmmu_lock);
+        kref_init(&vm->ref);
+        nvgpu_init_list_node(&vm->vm_area_list);
+
+        /*
+         * This is only necessary for channel address spaces. The best way to
+         * distinguish channel address spaces from other address spaces is by
+         * size - if the address space is 4GB or less, it's not a channel.
+         */
+        if (vm->va_limit > SZ_4G) {
+                err = nvgpu_init_sema_pool(vm);
+                if (err)
+                        goto clean_up_allocators;
+        }
+
+        return 0;
+
+clean_up_allocators:
+        if (nvgpu_alloc_initialized(&vm->kernel))
+                nvgpu_alloc_destroy(&vm->kernel);
+        if (nvgpu_alloc_initialized(&vm->user))
+                nvgpu_alloc_destroy(&vm->user);
+        if (nvgpu_alloc_initialized(&vm->user_lp))
+                nvgpu_alloc_destroy(&vm->user_lp);
+clean_up_page_tables:
+        /* Cleans up nvgpu_vm_init_page_tables() */
+        nvgpu_vfree(g, vm->pdb.entries);
+        free_gmmu_pages(vm, &vm->pdb);
+        return err;
+}
+
 void nvgpu_vm_remove_support_nofree(struct vm_gk20a *vm)
 {
         struct nvgpu_mapped_buf *mapped_buffer;
@@ -111,8 +449,6 @@ void nvgpu_vm_remove_support_nofree(struct vm_gk20a *vm)
         struct nvgpu_rbtree_node *node = NULL;
         struct gk20a *g = vm->mm->g;
 
-        gk20a_dbg_fn("");
-
         /*
          * Do this outside of the update_gmmu_lock since unmapping the semaphore
          * pool involves unmapping a GMMU mapping which means aquiring the
@@ -172,12 +508,10 @@ void nvgpu_vm_put(struct vm_gk20a *vm)
         kref_put(&vm->ref, nvgpu_vm_remove_support_kref);
 }
 
-void nvgpu_remove_vm(struct vm_gk20a *vm, struct nvgpu_mem *inst_block)
+void nvgpu_vm_remove(struct vm_gk20a *vm, struct nvgpu_mem *inst_block)
 {
         struct gk20a *g = vm->mm->g;
 
-        gk20a_dbg_fn("");
-
         gk20a_free_inst_block(g, inst_block);
         nvgpu_vm_remove_support_nofree(vm);
 }