1 files changed, 426 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/common/mm/pd_cache.c b/drivers/gpu/nvgpu/common/mm/pd_cache.c
new file mode 100644
index 00000000..4f312eff
--- /dev/null
+++ b/drivers/gpu/nvgpu/common/mm/pd_cache.c
@@ -0,0 +1,426 @@
+/*
+ * Copyright (c) 2017, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <nvgpu/log.h>
+#include <nvgpu/dma.h>
+#include <nvgpu/gmmu.h>
+#include <nvgpu/nvgpu_mem.h>
+#include <nvgpu/list.h>
+#include <nvgpu/log2.h>
+
+#include "gk20a/gk20a.h"
+#include "gk20a/mm_gk20a.h"
+
+#define pd_dbg(g, fmt, args...) nvgpu_log(g, gpu_dbg_pd_cache, fmt, ##args)
+
+/**
+ * DOC: PD cache
+ *
+ * In the name of saving memory with the many sub-page sized PD levels in Pascal
+ * and beyond a way of packing PD tables together is necessary. This code here
+ * does just that. If a PD table only requires 1024 bytes, then it is possible
+ * to have 4 of these PDs in one page. This is even more pronounced for 256 byte
+ * PD tables.
+ *
+ * The pd cache is basially just a slab allocator. Each instance of the nvgpu
+ * driver makes one of these structs:
+ *
+ *   struct nvgpu_pd_cache {
+ *      struct nvgpu_list_node           full[NVGPU_PD_CACHE_COUNT];
+ *      struct nvgpu_list_node           partial[NVGPU_PD_CACHE_COUNT];
+ *
+ *      struct nvgpu_rbtree_node        *mem_tree;
+ *   };
+ *
+ * There are two sets of lists, the full and the partial. The full lists contain
+ * pages of memory for which all the memory in that page is in use. The partial
+ * lists contain partially full pages of memory which can be used for more PD
+ * allocations. There a couple of assumptions here:
+ *
+ *   1. PDs greater than or equal to the page size bypass the pd cache.
+ *   2. PDs are always power of 2 and greater than %NVGPU_PD_CACHE_MIN bytes.
+ *
+ * There are NVGPU_PD_CACHE_COUNT full lists and the same number of partial
+ * lists. For a 4Kb page NVGPU_PD_CACHE_COUNT is 4. This is enough space for
+ * 256, 512, 1024, and 2048 byte PDs.
+ *
+ * __nvgpu_pd_alloc() will allocate a PD for the GMMU. It will check if the PD
+ * size is page size or larger and choose the correct allocation scheme - either
+ * from the PD cache or directly. Similarly __nvgpu_pd_free() will free a PD
+ * allocated by __nvgpu_pd_alloc().
+ *
+ * Since the top level PD (the PDB) is a page aligned pointer but less than a
+ * page size the direct functions must be used for allocating PDBs. Otherwise
+ * there would be alignment issues for the PDBs when they get packed.
+ */
+
+static u32 nvgpu_pd_cache_nr(u32 bytes)
+{
+        return ilog2(bytes >> (NVGPU_PD_CACHE_MIN_SHIFT - 1));
+}
+
+static u32 nvgpu_pd_cache_get_mask(struct nvgpu_pd_mem_entry *pentry)
+{
+        u32 mask_offset = 1 << (PAGE_SIZE / pentry->pd_size);
+
+        return mask_offset - 1;
+}
+
+int nvgpu_pd_cache_init(struct gk20a *g)
+{
+        struct nvgpu_pd_cache *cache;
+        int i;
+
+        /*
+         * This gets called from finalize_poweron() so we need to make sure we
+         * don't reinit the pd_cache over and over.
+         */
+        if (g->mm.pd_cache)
+                return 0;
+
+        cache = nvgpu_kzalloc(g, sizeof(*cache));
+        if (!cache) {
+                nvgpu_err(g, "Failed to alloc pd_cache!");
+                return -ENOMEM;
+        }
+
+        for (i = 0; i < NVGPU_PD_CACHE_COUNT; i++) {
+                nvgpu_init_list_node(&cache->full[i]);
+                nvgpu_init_list_node(&cache->partial[i]);
+        }
+
+        cache->mem_tree = NULL;
+        g->mm.pd_cache = cache;
+        nvgpu_mutex_init(&cache->lock);
+
+        pd_dbg(g, "PD cache initialized!");
+
+        return 0;
+}
+
+void nvgpu_pd_cache_fini(struct gk20a *g)
+{
+        int i;
+        struct nvgpu_pd_cache *cache = g->mm.pd_cache;
+
+        if (!cache)
+                return;
+
+        for (i = 0; i < NVGPU_PD_CACHE_COUNT; i++) {
+                WARN_ON(!nvgpu_list_empty(&cache->full[i]));
+                WARN_ON(!nvgpu_list_empty(&cache->partial[i]));
+        }
+
+        nvgpu_kfree(g, g->mm.pd_cache);
+}
+
+/*
+ * This is the simple pass-through for greater than page or page sized PDs.
+ *
+ * Note: this does not need the cache lock since it does not modify any of the
+ * PD cache data structures.
+ */
+int __nvgpu_pd_cache_alloc_direct(struct gk20a *g,
+                                  struct nvgpu_gmmu_pd *pd, u32 bytes)
+{
+        int err;
+
+        pd_dbg(g, "PD-Alloc [D] %u bytes", bytes);
+
+        pd->mem = nvgpu_kzalloc(g, sizeof(*pd->mem));
+        if (!pd->mem) {
+                pd_dbg(g, "OOM allocating nvgpu_mem struct!");
+                return -ENOMEM;
+        }
+
+        err = nvgpu_dma_alloc_flags(g, NVGPU_DMA_FORCE_CONTIGUOUS,
+                                    bytes, pd->mem);
+        if (err) {
+                pd_dbg(g, "OOM allocating page directory!");
+                nvgpu_kfree(g, pd->mem);
+                return -ENOMEM;
+        }
+
+        pd->cached = false;
+        pd->mem_offs = 0;
+
+        return 0;
+}
+
+/*
+ * Make a new nvgpu_pd_cache_entry and allocate a PD from it. Update the passed
+ * pd to reflect this allocation.
+ */
+static int nvgpu_pd_cache_alloc_new(struct gk20a *g,
+                                    struct nvgpu_pd_cache *cache,
+                                    struct nvgpu_gmmu_pd *pd,
+                                    u32 bytes)
+{
+        struct nvgpu_pd_mem_entry *pentry;
+
+        pd_dbg(g, "PD-Alloc [C]   New: offs=0");
+
+        pentry = nvgpu_kzalloc(g, sizeof(*pentry));
+        if (!pentry) {
+                pd_dbg(g, "OOM allocating pentry!");
+                return -ENOMEM;
+        }
+
+        if (nvgpu_dma_alloc_flags(g, NVGPU_DMA_FORCE_CONTIGUOUS,
+                                  PAGE_SIZE, &pentry->mem)) {
+                nvgpu_kfree(g, pentry);
+                pd_dbg(g, "Unable to DMA alloc!");
+                return -ENOMEM;
+        }
+
+        pentry->pd_size = bytes;
+        nvgpu_list_add(&pentry->list_entry,
+                       &cache->partial[nvgpu_pd_cache_nr(bytes)]);
+
+        /*
+         * This allocates the very first PD table in the set of tables in this
+         * nvgpu_pd_mem_entry.
+         */
+        pentry->alloc_map = 1;
+
+        /*
+         * Now update the nvgpu_gmmu_pd to reflect this allocation.
+         */
+        pd->mem = &pentry->mem;
+        pd->mem_offs = 0;
+        pd->cached = true;
+
+        pentry->tree_entry.key_start = (u64)(uintptr_t)&pentry->mem;
+        nvgpu_rbtree_insert(&pentry->tree_entry, &cache->mem_tree);
+
+        return 0;
+}
+
+static int nvgpu_pd_cache_alloc_from_partial(struct gk20a *g,
+                                             struct nvgpu_pd_cache *cache,
+                                             struct nvgpu_pd_mem_entry *pentry,
+                                             struct nvgpu_gmmu_pd *pd)
+{
+        unsigned long bit_offs;
+        u32 mem_offs;
+        u32 pentry_mask = nvgpu_pd_cache_get_mask(pentry);
+
+        /*
+         * Find and allocate an open PD.
+         */
+        bit_offs = ffz(pentry->alloc_map);
+        mem_offs = bit_offs * pentry->pd_size;
+
+        /* Bit map full. Somethings wrong. */
+        if (WARN_ON(bit_offs >= ffz(pentry_mask)))
+                return -ENOMEM;
+
+        pentry->alloc_map |= 1 << bit_offs;
+
+        pd_dbg(g, "PD-Alloc [C]   Partial: offs=%lu", bit_offs);
+
+        /*
+         * First update the pd.
+         */
+        pd->mem = &pentry->mem;
+        pd->mem_offs = mem_offs;
+        pd->cached = true;
+
+        /*
+         * Now make sure the pentry is in the correct list (full vs partial).
+         */
+        if ((pentry->alloc_map & pentry_mask) == pentry_mask) {
+                pd_dbg(g, "Adding pentry to full list!");
+                nvgpu_list_del(&pentry->list_entry);
+                nvgpu_list_add(&pentry->list_entry,
+                        &cache->full[nvgpu_pd_cache_nr(pentry->pd_size)]);
+        }
+
+        return 0;
+}
+
+/*
+ * Get a partially full nvgpu_pd_mem_entry. Returns NULL if there is no partial
+ * nvgpu_pd_mem_entry's.
+ */
+static struct nvgpu_pd_mem_entry *nvgpu_pd_cache_get_partial(
+        struct nvgpu_pd_cache *cache, u32 bytes)
+{
+        struct nvgpu_list_node *list =
+                &cache->partial[nvgpu_pd_cache_nr(bytes)];
+
+        if (nvgpu_list_empty(list))
+                return NULL;
+
+        return nvgpu_list_first_entry(list,
+                                      nvgpu_pd_mem_entry,
+                                      list_entry);
+}
+
+/*
+ * Allocate memory from an nvgpu_mem for the page directory.
+ */
+static int nvgpu_pd_cache_alloc(struct gk20a *g, struct nvgpu_pd_cache *cache,
+                                struct nvgpu_gmmu_pd *pd, u32 bytes)
+{
+        struct nvgpu_pd_mem_entry *pentry;
+        int err;
+
+        pd_dbg(g, "PD-Alloc [C] %u bytes", bytes);
+
+        if (bytes & (bytes - 1) ||
+            (bytes >= PAGE_SIZE ||
+             bytes < NVGPU_PD_CACHE_MIN)) {
+                pd_dbg(g, "PD-Alloc [C]   Invalid (bytes=%u)!", bytes);
+                return -EINVAL;
+        }
+
+        pentry = nvgpu_pd_cache_get_partial(cache, bytes);
+        if (!pentry)
+                err = nvgpu_pd_cache_alloc_new(g, cache, pd, bytes);
+        else
+                err = nvgpu_pd_cache_alloc_from_partial(g, cache, pentry, pd);
+
+        if (err)
+                pd_dbg(g, "PD-Alloc [C] Failed!");
+
+        return err;
+}
+
+/*
+ * Allocate the DMA memory for a page directory. This handles the necessary PD
+ * cache logistics. Since on Parker and later GPUs some of the page  directories
+ * are smaller than a page packing these PDs together saves a lot of memory.
+ */
+int __nvgpu_pd_alloc(struct vm_gk20a *vm, struct nvgpu_gmmu_pd *pd, u32 bytes)
+{
+        struct gk20a *g = gk20a_from_vm(vm);
+        int err;
+
+        /*
+         * Simple case: PD is bigger than a page so just do a regular DMA
+         * alloc.
+         */
+        if (bytes >= PAGE_SIZE) {
+                err = __nvgpu_pd_cache_alloc_direct(g, pd, bytes);
+                if (err)
+                        return err;
+
+                return 0;
+        }
+
+        if (WARN_ON(!g->mm.pd_cache))
+                return -ENOMEM;
+
+        nvgpu_mutex_acquire(&g->mm.pd_cache->lock);
+        err = nvgpu_pd_cache_alloc(g, g->mm.pd_cache, pd, bytes);
+        nvgpu_mutex_release(&g->mm.pd_cache->lock);
+
+        return err;
+}
+
+void __nvgpu_pd_cache_free_direct(struct gk20a *g, struct nvgpu_gmmu_pd *pd)
+{
+        pd_dbg(g, "PD-Free  [D] 0x%p", pd->mem);
+
+        if (!pd->mem)
+                return;
+
+        nvgpu_dma_free(g, pd->mem);
+        nvgpu_kfree(g, pd->mem);
+        pd->mem = NULL;
+}
+
+static void nvgpu_pd_cache_free_mem_entry(struct gk20a *g,
+                                          struct nvgpu_pd_cache *cache,
+                                          struct nvgpu_pd_mem_entry *pentry)
+{
+        nvgpu_dma_free(g, &pentry->mem);
+        nvgpu_list_del(&pentry->list_entry);
+        nvgpu_rbtree_unlink(&pentry->tree_entry, &cache->mem_tree);
+        nvgpu_kfree(g, pentry);
+}
+
+static void nvgpu_pd_cache_do_free(struct gk20a *g,
+                                   struct nvgpu_pd_cache *cache,
+                                   struct nvgpu_pd_mem_entry *pentry,
+                                   struct nvgpu_gmmu_pd *pd)
+{
+        u32 index = pd->mem_offs / pentry->pd_size;
+        u32 bit = 1 << index;
+
+        /* Mark entry as free. */
+        pentry->alloc_map &= ~bit;
+
+        if (pentry->alloc_map & nvgpu_pd_cache_get_mask(pentry)) {
+                /*
+                 * Partially full still. If it was already on the partial list
+                 * this just re-adds it.
+                 */
+                nvgpu_list_del(&pentry->list_entry);
+                nvgpu_list_add(&pentry->list_entry,
+                        &cache->partial[nvgpu_pd_cache_nr(pentry->pd_size)]);
+        } else {
+                /* Empty now so free it. */
+                nvgpu_pd_cache_free_mem_entry(g, cache, pentry);
+        }
+}
+
+static struct nvgpu_pd_mem_entry *nvgpu_pd_cache_look_up(
+        struct gk20a *g,
+        struct nvgpu_pd_cache *cache,
+        struct nvgpu_gmmu_pd *pd)
+{
+        struct nvgpu_rbtree_node *node;
+
+        nvgpu_rbtree_search((u64)(uintptr_t)pd->mem, &node,
+                            cache->mem_tree);
+        if (!node)
+                return NULL;
+
+        return nvgpu_pd_mem_entry_from_tree_entry(node);
+}
+
+static void nvgpu_pd_cache_free(struct gk20a *g, struct nvgpu_pd_cache *cache,
+                                struct nvgpu_gmmu_pd *pd)
+{
+        struct nvgpu_pd_mem_entry *pentry;
+
+        pd_dbg(g, "PD-Free  [C] 0x%p", pd->mem);
+
+        pentry = nvgpu_pd_cache_look_up(g, cache, pd);
+        if (!pentry) {
+                WARN(1, "Attempting to free non-existent pd");
+                return;
+        }
+
+        nvgpu_pd_cache_do_free(g, cache, pentry, pd);
+}
+
+void __nvgpu_pd_free(struct vm_gk20a *vm, struct nvgpu_gmmu_pd *pd)
+{
+        struct gk20a *g = gk20a_from_vm(vm);
+
+        /*
+         * Simple case: just DMA free.
+         */
+        if (!pd->cached)
+                return __nvgpu_pd_cache_free_direct(g, pd);
+
+        nvgpu_mutex_acquire(&g->mm.pd_cache->lock);
+        nvgpu_pd_cache_free(g, g->mm.pd_cache, pd);
+        nvgpu_mutex_release(&g->mm.pd_cache->lock);
+}