habanalabs: Add an option to map CB to device MMU
authorTomer Tayar <ttayar@habana.ai>
Thu, 9 Jul 2020 13:17:48 +0000 (16:17 +0300)
committerOded Gabbay <oded.gabbay@gmail.com>
Tue, 22 Sep 2020 15:49:54 +0000 (18:49 +0300)
There are cases in which the device should access the host memory of a
CB through the device MMU, and thus this memory should be mapped.
The patch adds a flag to the CB IOCTL, in which a user can ask the
driver to perform the mapping when creating a CB.
The mapping is allowed only if a dedicated VA range was allocated for
the specific ASIC.

Signed-off-by: Tomer Tayar <ttayar@habana.ai>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
drivers/misc/habanalabs/common/command_buffer.c
drivers/misc/habanalabs/common/context.c
drivers/misc/habanalabs/common/habanalabs.h
drivers/misc/habanalabs/gaudi/gaudi.c
drivers/misc/habanalabs/goya/goya.c
include/uapi/misc/habanalabs.h

index 0cb556f..901e213 100644 (file)
 #include <linux/uaccess.h>
 #include <linux/genalloc.h>
 
+static int cb_map_mem(struct hl_ctx *ctx, struct hl_cb *cb)
+{
+       struct hl_device *hdev = ctx->hdev;
+       struct asic_fixed_properties *prop = &hdev->asic_prop;
+       struct hl_vm_va_block *va_block, *tmp;
+       dma_addr_t bus_addr;
+       u64 virt_addr;
+       u32 page_size = prop->pmmu.page_size;
+       s32 offset;
+       int rc;
+
+       if (!hdev->supports_cb_mapping) {
+               dev_err_ratelimited(hdev->dev,
+                               "Cannot map CB because no VA range is allocated for CB mapping\n");
+               return -EINVAL;
+       }
+
+       if (!hdev->mmu_enable) {
+               dev_err_ratelimited(hdev->dev,
+                               "Cannot map CB because MMU is disabled\n");
+               return -EINVAL;
+       }
+
+       INIT_LIST_HEAD(&cb->va_block_list);
+
+       for (bus_addr = cb->bus_address;
+                       bus_addr < cb->bus_address + cb->size;
+                       bus_addr += page_size) {
+
+               virt_addr = (u64) gen_pool_alloc(ctx->cb_va_pool, page_size);
+               if (!virt_addr) {
+                       dev_err(hdev->dev,
+                               "Failed to allocate device virtual address for CB\n");
+                       rc = -ENOMEM;
+                       goto err_va_pool_free;
+               }
+
+               va_block = kzalloc(sizeof(*va_block), GFP_KERNEL);
+               if (!va_block) {
+                       rc = -ENOMEM;
+                       gen_pool_free(ctx->cb_va_pool, virt_addr, page_size);
+                       goto err_va_pool_free;
+               }
+
+               va_block->start = virt_addr;
+               va_block->end = virt_addr + page_size;
+               va_block->size = page_size;
+               list_add_tail(&va_block->node, &cb->va_block_list);
+       }
+
+       mutex_lock(&ctx->mmu_lock);
+
+       bus_addr = cb->bus_address;
+       offset = 0;
+       list_for_each_entry(va_block, &cb->va_block_list, node) {
+               rc = hl_mmu_map(ctx, va_block->start, bus_addr, va_block->size,
+                               list_is_last(&va_block->node,
+                                               &cb->va_block_list));
+               if (rc) {
+                       dev_err(hdev->dev, "Failed to map VA %#llx to CB\n",
+                               va_block->start);
+                       goto err_va_umap;
+               }
+
+               bus_addr += va_block->size;
+               offset += va_block->size;
+       }
+
+       hdev->asic_funcs->mmu_invalidate_cache(hdev, false, VM_TYPE_USERPTR);
+
+       mutex_unlock(&ctx->mmu_lock);
+
+       cb->is_mmu_mapped = true;
+
+       return 0;
+
+err_va_umap:
+       list_for_each_entry(va_block, &cb->va_block_list, node) {
+               if (offset <= 0)
+                       break;
+               hl_mmu_unmap(ctx, va_block->start, va_block->size,
+                               offset <= va_block->size);
+               offset -= va_block->size;
+       }
+
+       hdev->asic_funcs->mmu_invalidate_cache(hdev, true, VM_TYPE_USERPTR);
+
+       mutex_unlock(&ctx->mmu_lock);
+
+err_va_pool_free:
+       list_for_each_entry_safe(va_block, tmp, &cb->va_block_list, node) {
+               gen_pool_free(ctx->cb_va_pool, va_block->start, va_block->size);
+               list_del(&va_block->node);
+               kfree(va_block);
+       }
+
+       return rc;
+}
+
+static void cb_unmap_mem(struct hl_ctx *ctx, struct hl_cb *cb)
+{
+       struct hl_device *hdev = ctx->hdev;
+       struct hl_vm_va_block *va_block, *tmp;
+
+       mutex_lock(&ctx->mmu_lock);
+
+       list_for_each_entry(va_block, &cb->va_block_list, node)
+               if (hl_mmu_unmap(ctx, va_block->start, va_block->size,
+                               list_is_last(&va_block->node,
+                                               &cb->va_block_list)))
+                       dev_warn_ratelimited(hdev->dev,
+                                       "Failed to unmap CB's va 0x%llx\n",
+                                       va_block->start);
+
+       hdev->asic_funcs->mmu_invalidate_cache(hdev, true, VM_TYPE_USERPTR);
+
+       mutex_unlock(&ctx->mmu_lock);
+
+       list_for_each_entry_safe(va_block, tmp, &cb->va_block_list, node) {
+               gen_pool_free(ctx->cb_va_pool, va_block->start, va_block->size);
+               list_del(&va_block->node);
+               kfree(va_block);
+       }
+}
+
 static void cb_fini(struct hl_device *hdev, struct hl_cb *cb)
 {
        if (cb->is_internal)
@@ -47,6 +172,9 @@ static void cb_release(struct kref *ref)
 
        hl_debugfs_remove_cb(cb);
 
+       if (cb->is_mmu_mapped)
+               cb_unmap_mem(cb->ctx, cb);
+
        hl_ctx_put(cb->ctx);
 
        cb_do_release(hdev, cb);
@@ -110,7 +238,7 @@ static struct hl_cb *hl_cb_alloc(struct hl_device *hdev, u32 cb_size,
 
 int hl_cb_create(struct hl_device *hdev, struct hl_cb_mgr *mgr,
                        struct hl_ctx *ctx, u32 cb_size, bool internal_cb,
-                       u64 *handle)
+                       bool map_cb, u64 *handle)
 {
        struct hl_cb *cb;
        bool alloc_new_cb = true;
@@ -169,13 +297,26 @@ int hl_cb_create(struct hl_device *hdev, struct hl_cb_mgr *mgr,
        cb->ctx = ctx;
        hl_ctx_get(hdev, cb->ctx);
 
+       if (map_cb) {
+               if (ctx_id == HL_KERNEL_ASID_ID) {
+                       dev_err(hdev->dev,
+                               "CB mapping is not supported for kernel context\n");
+                       rc = -EINVAL;
+                       goto release_cb;
+               }
+
+               rc = cb_map_mem(ctx, cb);
+               if (rc)
+                       goto release_cb;
+       }
+
        spin_lock(&mgr->cb_lock);
        rc = idr_alloc(&mgr->cb_handles, cb, 1, 0, GFP_ATOMIC);
        spin_unlock(&mgr->cb_lock);
 
        if (rc < 0) {
                dev_err(hdev->dev, "Failed to allocate IDR for a new CB\n");
-               goto release_cb;
+               goto unmap_mem;
        }
 
        cb->id = (u64) rc;
@@ -194,6 +335,9 @@ int hl_cb_create(struct hl_device *hdev, struct hl_cb_mgr *mgr,
 
        return 0;
 
+unmap_mem:
+       if (cb->is_mmu_mapped)
+               cb_unmap_mem(cb->ctx, cb);
 release_cb:
        hl_ctx_put(cb->ctx);
        cb_do_release(hdev, cb);
@@ -256,7 +400,9 @@ int hl_cb_ioctl(struct hl_fpriv *hpriv, void *data)
                        rc = -EINVAL;
                } else {
                        rc = hl_cb_create(hdev, &hpriv->cb_mgr, hpriv->ctx,
-                                       args->in.cb_size, false, &handle);
+                                       args->in.cb_size, false,
+                                       !!(args->in.flags & HL_CB_FLAGS_MAP),
+                                       &handle);
                }
 
                memset(args, 0, sizeof(*args));
@@ -442,7 +588,7 @@ struct hl_cb *hl_cb_kernel_create(struct hl_device *hdev, u32 cb_size,
        int rc;
 
        rc = hl_cb_create(hdev, &hdev->kernel_cb_mgr, hdev->kernel_ctx, cb_size,
-                               internal_cb, &cb_handle);
+                               internal_cb, false, &cb_handle);
        if (rc) {
                dev_err(hdev->dev,
                        "Failed to allocate CB for the kernel driver %d\n", rc);
@@ -498,3 +644,45 @@ int hl_cb_pool_fini(struct hl_device *hdev)
 
        return 0;
 }
+
+int hl_cb_va_pool_init(struct hl_ctx *ctx)
+{
+       struct hl_device *hdev = ctx->hdev;
+       struct asic_fixed_properties *prop = &hdev->asic_prop;
+       int rc;
+
+       if (!hdev->supports_cb_mapping)
+               return 0;
+
+       ctx->cb_va_pool = gen_pool_create(__ffs(prop->pmmu.page_size), -1);
+       if (!ctx->cb_va_pool) {
+               dev_err(hdev->dev,
+                       "Failed to create VA gen pool for CB mapping\n");
+               return -ENOMEM;
+       }
+
+       rc = gen_pool_add(ctx->cb_va_pool, prop->cb_va_start_addr,
+                       prop->cb_va_end_addr - prop->cb_va_start_addr, -1);
+       if (rc) {
+               dev_err(hdev->dev,
+                       "Failed to add memory to VA gen pool for CB mapping\n");
+               goto err_pool_destroy;
+       }
+
+       return 0;
+
+err_pool_destroy:
+       gen_pool_destroy(ctx->cb_va_pool);
+
+       return rc;
+}
+
+void hl_cb_va_pool_fini(struct hl_ctx *ctx)
+{
+       struct hl_device *hdev = ctx->hdev;
+
+       if (!hdev->supports_cb_mapping)
+               return;
+
+       gen_pool_destroy(ctx->cb_va_pool);
+}
index b168a9f..df8171a 100644 (file)
@@ -37,6 +37,7 @@ static void hl_ctx_fini(struct hl_ctx *ctx)
                if ((hdev->in_debug) && (hdev->compute_ctx == ctx))
                        hl_device_set_debug_mode(hdev, false);
 
+               hl_cb_va_pool_fini(ctx);
                hl_vm_ctx_fini(ctx);
                hl_asid_free(hdev, ctx->asid);
        } else {
@@ -155,15 +156,24 @@ int hl_ctx_init(struct hl_device *hdev, struct hl_ctx *ctx, bool is_kernel_ctx)
                        goto err_asid_free;
                }
 
+               rc = hl_cb_va_pool_init(ctx);
+               if (rc) {
+                       dev_err(hdev->dev,
+                               "Failed to init VA pool for mapped CB\n");
+                       goto err_vm_ctx_fini;
+               }
+
                rc = hdev->asic_funcs->ctx_init(ctx);
                if (rc) {
                        dev_err(hdev->dev, "ctx_init failed\n");
-                       goto err_vm_ctx_fini;
+                       goto err_cb_va_pool_fini;
                }
        }
 
        return 0;
 
+err_cb_va_pool_fini:
+       hl_cb_va_pool_fini(ctx);
 err_vm_ctx_fini:
        hl_vm_ctx_fini(ctx);
 err_asid_free:
index 88c68b6..eaa9bf3 100644 (file)
@@ -291,6 +291,10 @@ struct hl_mmu_properties {
  * @pcie_aux_dbi_reg_addr: Address of the PCIE_AUX DBI register.
  * @mmu_pgt_addr: base physical address in DRAM of MMU page tables.
  * @mmu_dram_default_page_addr: DRAM default page physical address.
+ * @cb_va_start_addr: virtual start address of command buffers which are mapped
+ *                    to the device's MMU.
+ * @cb_va_end_addr: virtual end address of command buffers which are mapped to
+ *                  the device's MMU.
  * @mmu_pgt_size: MMU page tables total size.
  * @mmu_pte_size: PTE size in MMU page tables.
  * @mmu_hop_table_size: MMU hop table size.
@@ -339,6 +343,8 @@ struct asic_fixed_properties {
        u64                             pcie_aux_dbi_reg_addr;
        u64                             mmu_pgt_addr;
        u64                             mmu_dram_default_page_addr;
+       u64                             cb_va_start_addr;
+       u64                             cb_va_end_addr;
        u32                             mmu_pgt_size;
        u32                             mmu_pte_size;
        u32                             mmu_hop_table_size;
@@ -421,6 +427,8 @@ struct hl_cb_mgr {
  * @lock: spinlock to protect mmap/cs flows.
  * @debugfs_list: node in debugfs list of command buffers.
  * @pool_list: node in pool list of command buffers.
+ * @va_block_list: list of virtual addresses blocks of the CB if it is mapped to
+ *                 the device's MMU.
  * @id: the CB's ID.
  * @kernel_address: Holds the CB's kernel virtual address.
  * @bus_address: Holds the CB's DMA address.
@@ -430,6 +438,7 @@ struct hl_cb_mgr {
  * @mmap: true if the CB is currently mmaped to user.
  * @is_pool: true if CB was acquired from the pool, false otherwise.
  * @is_internal: internaly allocated
+ * @is_mmu_mapped: true if the CB is mapped to the device's MMU.
  */
 struct hl_cb {
        struct kref             refcount;
@@ -438,6 +447,7 @@ struct hl_cb {
        spinlock_t              lock;
        struct list_head        debugfs_list;
        struct list_head        pool_list;
+       struct list_head        va_block_list;
        u64                     id;
        u64                     kernel_address;
        dma_addr_t              bus_address;
@@ -447,6 +457,7 @@ struct hl_cb {
        u8                      mmap;
        u8                      is_pool;
        u8                      is_internal;
+       u8                      is_mmu_mapped;
 };
 
 
@@ -843,6 +854,8 @@ struct hl_va_range {
  * @mmu_lock: protects the MMU page tables. Any change to the PGT, modifying the
  *            MMU hash or walking the PGT requires talking this lock.
  * @debugfs_list: node in debugfs list of contexts.
+ * @cb_va_pool: device VA pool for command buffers which are mapped to the
+ *              device's MMU.
  * @cs_sequence: sequence number for CS. Value is assigned to a CS and passed
  *                     to user so user could inquire about CS. It is used as
  *                     index to cs_pending array.
@@ -874,6 +887,7 @@ struct hl_ctx {
        struct mutex            mmu_lock;
        struct list_head        debugfs_list;
        struct hl_cs_counters   cs_counters;
+       struct gen_pool         *cb_va_pool;
        u64                     cs_sequence;
        u64                     *dram_default_hops;
        spinlock_t              cs_lock;
@@ -1574,6 +1588,7 @@ struct hl_mmu_funcs {
  * @sync_stream_queue_idx: helper index for sync stream queues initialization.
  * @supports_coresight: is CoreSight supported.
  * @supports_soft_reset: is soft reset supported.
+ * @supports_cb_mapping: is mapping a CB to the device's MMU supported.
  */
 struct hl_device {
        struct pci_dev                  *pdev;
@@ -1673,6 +1688,7 @@ struct hl_device {
        u8                              sync_stream_queue_idx;
        u8                              supports_coresight;
        u8                              supports_soft_reset;
+       u8                              supports_cb_mapping;
 
        /* Parameters for bring-up */
        u8                              mmu_enable;
@@ -1840,7 +1856,7 @@ void hl_hwmon_fini(struct hl_device *hdev);
 
 int hl_cb_create(struct hl_device *hdev, struct hl_cb_mgr *mgr,
                        struct hl_ctx *ctx, u32 cb_size, bool internal_cb,
-                       u64 *handle);
+                       bool map_cb, u64 *handle);
 int hl_cb_destroy(struct hl_device *hdev, struct hl_cb_mgr *mgr, u64 cb_handle);
 int hl_cb_mmap(struct hl_fpriv *hpriv, struct vm_area_struct *vma);
 struct hl_cb *hl_cb_get(struct hl_device *hdev,        struct hl_cb_mgr *mgr,
@@ -1852,6 +1868,8 @@ struct hl_cb *hl_cb_kernel_create(struct hl_device *hdev, u32 cb_size,
                                        bool internal_cb);
 int hl_cb_pool_init(struct hl_device *hdev);
 int hl_cb_pool_fini(struct hl_device *hdev);
+int hl_cb_va_pool_init(struct hl_ctx *ctx);
+void hl_cb_va_pool_fini(struct hl_ctx *ctx);
 
 void hl_cs_rollback_all(struct hl_device *hdev);
 struct hl_cs_job *hl_cs_allocate_job(struct hl_device *hdev,
index b51cc6c..6f7f6ad 100644 (file)
@@ -4115,7 +4115,7 @@ static int gaudi_parse_cb_mmu(struct hl_device *hdev,
                        sizeof(struct packet_msg_prot) * 2;
 
        rc = hl_cb_create(hdev, &hdev->kernel_cb_mgr, hdev->kernel_ctx,
-                               parser->patched_cb_size, false,
+                               parser->patched_cb_size, false, false,
                                &patched_cb_handle);
 
        if (rc) {
@@ -4189,7 +4189,7 @@ static int gaudi_parse_cb_no_mmu(struct hl_device *hdev,
                goto free_userptr;
 
        rc = hl_cb_create(hdev, &hdev->kernel_cb_mgr, hdev->kernel_ctx,
-                               parser->patched_cb_size, false,
+                               parser->patched_cb_size, false, false,
                                &patched_cb_handle);
        if (rc) {
                dev_err(hdev->dev,
index 6c81a4b..5cddd46 100644 (file)
@@ -3811,7 +3811,7 @@ static int goya_parse_cb_mmu(struct hl_device *hdev,
                        sizeof(struct packet_msg_prot) * 2;
 
        rc = hl_cb_create(hdev, &hdev->kernel_cb_mgr, hdev->kernel_ctx,
-                               parser->patched_cb_size, false,
+                               parser->patched_cb_size, false, false,
                                &patched_cb_handle);
 
        if (rc) {
@@ -3885,7 +3885,7 @@ static int goya_parse_cb_no_mmu(struct hl_device *hdev,
                goto free_userptr;
 
        rc = hl_cb_create(hdev, &hdev->kernel_cb_mgr, hdev->kernel_ctx,
-                               parser->patched_cb_size, false,
+                               parser->patched_cb_size, false, false,
                                &patched_cb_handle);
        if (rc) {
                dev_err(hdev->dev,
index d449f8a..9705b8a 100644 (file)
@@ -462,6 +462,9 @@ struct hl_info_args {
 /* 2MB minus 32 bytes for 2xMSG_PROT */
 #define HL_MAX_CB_SIZE         (0x200000 - 32)
 
+/* Indicates whether the command buffer should be mapped to the device's MMU */
+#define HL_CB_FLAGS_MAP                0x1
+
 struct hl_cb_in {
        /* Handle of CB or 0 if we want to create one */
        __u64 cb_handle;
@@ -473,7 +476,8 @@ struct hl_cb_in {
        __u32 cb_size;
        /* Context ID - Currently not in use */
        __u32 ctx_id;
-       __u32 pad;
+       /* HL_CB_FLAGS_* */
+       __u32 flags;
 };
 
 struct hl_cb_out {
@@ -856,6 +860,12 @@ struct hl_debug_args {
  * When creating a new CB, the IOCTL returns a handle of it, and the user-space
  * process needs to use that handle to mmap the buffer so it can access them.
  *
+ * In some instances, the device must access the command buffer through the
+ * device's MMU, and thus its memory should be mapped. In these cases, user can
+ * indicate the driver that such a mapping is required.
+ * The resulting device virtual address will be used internally by the driver,
+ * and won't be returned to user.
+ *
  */
 #define HL_IOCTL_CB            \
                _IOWR('H', 0x02, union hl_cb_args)