IB/mlx5: Device memory support in mlx5_ib

This patch adds the mlx5_ib driver implementation for the device
memory allocation API.
It implements the ib_device callbacks for allocation and deallocation
operations as well as a new mmap command support which allows mapping
an allocated device memory to a VMA.

The change also adds reporting of device memory maximum size and
alignment parameters reported in device capabilities.

The allocation/deallocation operations are using new firmware
commands to allocate MEMIC memory on the device.

Signed-off-by: Ariel Levkovich <lariel@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/cmd.c

@@ -66,3 +66,109 @@ int mlx5_cmd_modify_cong_params(struct mlx5_core_dev *dev,
 
 	return mlx5_cmd_exec(dev, in, in_size, out, sizeof(out));
 }
+
+int mlx5_cmd_alloc_memic(struct mlx5_memic *memic, phys_addr_t *addr,
+			  u64 length, u32 alignment)
+{
+	struct mlx5_core_dev *dev = memic->dev;
+	u64 num_memic_hw_pages = MLX5_CAP_DEV_MEM(dev, memic_bar_size)
+					>> PAGE_SHIFT;
+	u64 hw_start_addr = MLX5_CAP64_DEV_MEM(dev, memic_bar_start_addr);
+	u32 max_alignment = MLX5_CAP_DEV_MEM(dev, log_max_memic_addr_alignment);
+	u32 num_pages = DIV_ROUND_UP(length, PAGE_SIZE);
+	u32 out[MLX5_ST_SZ_DW(alloc_memic_out)] = {};
+	u32 in[MLX5_ST_SZ_DW(alloc_memic_in)] = {};
+	u32 mlx5_alignment;
+	u64 page_idx = 0;
+	int ret = 0;
+
+	if (!length || (length & MLX5_MEMIC_ALLOC_SIZE_MASK))
+		return -EINVAL;
+
+	/* mlx5 device sets alignment as 64*2^driver_value
+	 * so normalizing is needed.
+	 */
+	mlx5_alignment = (alignment < MLX5_MEMIC_BASE_ALIGN) ? 0 :
+			 alignment - MLX5_MEMIC_BASE_ALIGN;
+	if (mlx5_alignment > max_alignment)
+		return -EINVAL;
+
+	MLX5_SET(alloc_memic_in, in, opcode, MLX5_CMD_OP_ALLOC_MEMIC);
+	MLX5_SET(alloc_memic_in, in, range_size, num_pages * PAGE_SIZE);
+	MLX5_SET(alloc_memic_in, in, memic_size, length);
+	MLX5_SET(alloc_memic_in, in, log_memic_addr_alignment,
+		 mlx5_alignment);
+
+	do {
+		spin_lock(&memic->memic_lock);
+		page_idx = bitmap_find_next_zero_area(memic->memic_alloc_pages,
+						      num_memic_hw_pages,
+						      page_idx,
+						      num_pages, 0);
+
+		if (page_idx + num_pages <= num_memic_hw_pages)
+			bitmap_set(memic->memic_alloc_pages,
+				   page_idx, num_pages);
+		else
+			ret = -ENOMEM;
+
+		spin_unlock(&memic->memic_lock);
+
+		if (ret)
+			return ret;
+
+		MLX5_SET64(alloc_memic_in, in, range_start_addr,
+			   hw_start_addr + (page_idx * PAGE_SIZE));
+
+		ret = mlx5_cmd_exec(dev, in, sizeof(in), out, sizeof(out));
+		if (ret) {
+			spin_lock(&memic->memic_lock);
+			bitmap_clear(memic->memic_alloc_pages,
+				     page_idx, num_pages);
+			spin_unlock(&memic->memic_lock);
+
+			if (ret == -EAGAIN) {
+				page_idx++;
+				continue;
+			}
+
+			return ret;
+		}
+
+		*addr = pci_resource_start(dev->pdev, 0) +
+			MLX5_GET64(alloc_memic_out, out, memic_start_addr);
+
+		return ret;
+	} while (page_idx < num_memic_hw_pages);
+
+	return ret;
+}
+
+int mlx5_cmd_dealloc_memic(struct mlx5_memic *memic, u64 addr, u64 length)
+{
+	struct mlx5_core_dev *dev = memic->dev;
+	u64 hw_start_addr = MLX5_CAP64_DEV_MEM(dev, memic_bar_start_addr);
+	u32 num_pages = DIV_ROUND_UP(length, PAGE_SIZE);
+	u32 out[MLX5_ST_SZ_DW(dealloc_memic_out)] = {0};
+	u32 in[MLX5_ST_SZ_DW(dealloc_memic_in)] = {0};
+	u64 start_page_idx;
+	int err;
+
+	addr -= pci_resource_start(dev->pdev, 0);
+	start_page_idx = (addr - hw_start_addr) >> PAGE_SHIFT;
+
+	MLX5_SET(dealloc_memic_in, in, opcode, MLX5_CMD_OP_DEALLOC_MEMIC);
+	MLX5_SET64(dealloc_memic_in, in, memic_start_addr, addr);
+	MLX5_SET(dealloc_memic_in, in, memic_size, length);
+
+	err =  mlx5_cmd_exec(dev, in, sizeof(in), out, sizeof(out));
+
+	if (!err) {
+		spin_lock(&memic->memic_lock);
+		bitmap_clear(memic->memic_alloc_pages,
+			     start_page_idx, num_pages);
+		spin_unlock(&memic->memic_lock);
+	}
+
+	return err;
+}

drivers/infiniband/hw/mlx5/cmd.h

@@ -33,6 +33,7 @@
 #ifndef MLX5_IB_CMD_H
 #define MLX5_IB_CMD_H
 
+#include "mlx5_ib.h"
 #include <linux/kernel.h>
 #include <linux/mlx5/driver.h>
 
@@ -41,4 +42,7 @@ int mlx5_cmd_query_cong_params(struct mlx5_core_dev *dev, int cong_point,
 			       void *out, int out_size);
 int mlx5_cmd_modify_cong_params(struct mlx5_core_dev *mdev,
 				void *in, int in_size);
+int mlx5_cmd_alloc_memic(struct mlx5_memic *memic, phys_addr_t *addr,
+			 u64 length, u32 alignment);
+int mlx5_cmd_dealloc_memic(struct mlx5_memic *memic, u64 addr, u64 length);
 #endif /* MLX5_IB_CMD_H */

drivers/infiniband/hw/mlx5/main.c

@@ -38,6 +38,7 @@
 #include <linux/pci.h>
 #include <linux/dma-mapping.h>
 #include <linux/slab.h>
+#include <linux/bitmap.h>
 #if defined(CONFIG_X86)
 #include <asm/pat.h>
 #endif
@@ -891,6 +892,11 @@ static int mlx5_ib_query_device(struct ib_device *ibdev,
 		props->raw_packet_caps |= IB_RAW_PACKET_CAP_SCATTER_FCS;
 	}
 
+	if (MLX5_CAP_DEV_MEM(mdev, memic)) {
+		props->max_dm_size =
+			MLX5_CAP_DEV_MEM(mdev, max_memic_size);
+	}
+
 	if (mlx5_get_flow_namespace(dev->mdev, MLX5_FLOW_NAMESPACE_BYPASS))
 		props->device_cap_flags |= IB_DEVICE_MANAGED_FLOW_STEERING;
 
@@ -2014,6 +2020,8 @@ static inline char *mmap_cmd2str(enum mlx5_ib_mmap_cmd cmd)
 		return "best effort WC";
 	case MLX5_IB_MMAP_NC_PAGE:
 		return "NC";
+	case MLX5_IB_MMAP_DEVICE_MEM:
+		return "Device Memory";
 	default:
 		return NULL;
 	}
@@ -2172,6 +2180,34 @@ free_bfreg:
 	return err;
 }
 
+static int dm_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)
+{
+	struct mlx5_ib_ucontext *mctx = to_mucontext(context);
+	struct mlx5_ib_dev *dev = to_mdev(context->device);
+	u16 page_idx = get_extended_index(vma->vm_pgoff);
+	size_t map_size = vma->vm_end - vma->vm_start;
+	u32 npages = map_size >> PAGE_SHIFT;
+	phys_addr_t pfn;
+	pgprot_t prot;
+
+	if (find_next_zero_bit(mctx->dm_pages, page_idx + npages, page_idx) !=
+	    page_idx + npages)
+		return -EINVAL;
+
+	pfn = ((pci_resource_start(dev->mdev->pdev, 0) +
+	      MLX5_CAP64_DEV_MEM(dev->mdev, memic_bar_start_addr)) >>
+	      PAGE_SHIFT) +
+	      page_idx;
+	prot = pgprot_writecombine(vma->vm_page_prot);
+	vma->vm_page_prot = prot;
+
+	if (io_remap_pfn_range(vma, vma->vm_start, pfn, map_size,
+			       vma->vm_page_prot))
+		return -EAGAIN;
+
+	return mlx5_ib_set_vma_data(vma, mctx);
+}
+
 static int mlx5_ib_mmap(struct ib_ucontext *ibcontext, struct vm_area_struct *vma)
 {
 	struct mlx5_ib_ucontext *context = to_mucontext(ibcontext);
@@ -2216,6 +2252,9 @@ static int mlx5_ib_mmap(struct ib_ucontext *ibcontext, struct vm_area_struct *vm
 	case MLX5_IB_MMAP_CLOCK_INFO:
 		return mlx5_ib_mmap_clock_info_page(dev, vma, context);
 
+	case MLX5_IB_MMAP_DEVICE_MEM:
+		return dm_mmap(ibcontext, vma);
+
 	default:
 		return -EINVAL;
 	}
@@ -2223,6 +2262,87 @@ static int mlx5_ib_mmap(struct ib_ucontext *ibcontext, struct vm_area_struct *vm
 	return 0;
 }
 
+struct ib_dm *mlx5_ib_alloc_dm(struct ib_device *ibdev,
+			       struct ib_ucontext *context,
+			       struct ib_dm_alloc_attr *attr,
+			       struct uverbs_attr_bundle *attrs)
+{
+	u64 act_size = roundup(attr->length, MLX5_MEMIC_BASE_SIZE);
+	struct mlx5_memic *memic = &to_mdev(ibdev)->memic;
+	phys_addr_t memic_addr;
+	struct mlx5_ib_dm *dm;
+	u64 start_offset;
+	u32 page_idx;
+	int err;
+
+	dm = kzalloc(sizeof(*dm), GFP_KERNEL);
+	if (!dm)
+		return ERR_PTR(-ENOMEM);
+
+	mlx5_ib_dbg(to_mdev(ibdev), "alloc_memic req: user_length=0x%llx act_length=0x%llx log_alignment=%d\n",
+		    attr->length, act_size, attr->alignment);
+
+	err = mlx5_cmd_alloc_memic(memic, &memic_addr,
+				   act_size, attr->alignment);
+	if (err)
+		goto err_free;
+
+	start_offset = memic_addr & ~PAGE_MASK;
+	page_idx = (memic_addr - pci_resource_start(memic->dev->pdev, 0) -
+		    MLX5_CAP64_DEV_MEM(memic->dev, memic_bar_start_addr)) >>
+		    PAGE_SHIFT;
+
+	err = uverbs_copy_to(attrs,
+			     MLX5_IB_ATTR_ALLOC_DM_RESP_START_OFFSET,
+			     &start_offset, sizeof(start_offset));
+	if (err)
+		goto err_dealloc;
+
+	err = uverbs_copy_to(attrs,
+			     MLX5_IB_ATTR_ALLOC_DM_RESP_PAGE_INDEX,
+			     &page_idx, sizeof(page_idx));
+	if (err)
+		goto err_dealloc;
+
+	bitmap_set(to_mucontext(context)->dm_pages, page_idx,
+		   DIV_ROUND_UP(act_size, PAGE_SIZE));
+
+	dm->dev_addr = memic_addr;
+
+	return &dm->ibdm;
+
+err_dealloc:
+	mlx5_cmd_dealloc_memic(memic, memic_addr,
+			       act_size);
+err_free:
+	kfree(dm);
+	return ERR_PTR(err);
+}
+
+int mlx5_ib_dealloc_dm(struct ib_dm *ibdm)
+{
+	struct mlx5_memic *memic = &to_mdev(ibdm->device)->memic;
+	struct mlx5_ib_dm *dm = to_mdm(ibdm);
+	u64 act_size = roundup(dm->ibdm.length, MLX5_MEMIC_BASE_SIZE);
+	u32 page_idx;
+	int ret;
+
+	ret = mlx5_cmd_dealloc_memic(memic, dm->dev_addr, act_size);
+	if (ret)
+		return ret;
+
+	page_idx = (dm->dev_addr - pci_resource_start(memic->dev->pdev, 0) -
+		    MLX5_CAP64_DEV_MEM(memic->dev, memic_bar_start_addr)) >>
+		    PAGE_SHIFT;
+	bitmap_clear(to_mucontext(ibdm->uobject->context)->dm_pages,
+		     page_idx,
+		     DIV_ROUND_UP(act_size, PAGE_SIZE));
+
+	kfree(dm);
+
+	return 0;
+}
+
 static struct ib_pd *mlx5_ib_alloc_pd(struct ib_device *ibdev,
 				      struct ib_ucontext *context,
 				      struct ib_udata *udata)
@@ -4834,13 +4954,22 @@ static void mlx5_ib_cleanup_multiport_master(struct mlx5_ib_dev *dev)
 	mlx5_nic_vport_disable_roce(dev->mdev);
 }
 
+ADD_UVERBS_ATTRIBUTES_SIMPLE(mlx5_ib_dm, UVERBS_OBJECT_DM,
+			     UVERBS_METHOD_DM_ALLOC,
+			     &UVERBS_ATTR_PTR_OUT(MLX5_IB_ATTR_ALLOC_DM_RESP_START_OFFSET,
+						  UVERBS_ATTR_TYPE(u64),
+						  UA_FLAGS(UVERBS_ATTR_SPEC_F_MANDATORY)),
+			     &UVERBS_ATTR_PTR_OUT(MLX5_IB_ATTR_ALLOC_DM_RESP_PAGE_INDEX,
+						  UVERBS_ATTR_TYPE(u16),
+						  UA_FLAGS(UVERBS_ATTR_SPEC_F_MANDATORY)));
+
 ADD_UVERBS_ATTRIBUTES_SIMPLE(mlx5_ib_flow_action, UVERBS_OBJECT_FLOW_ACTION,
 			     UVERBS_METHOD_FLOW_ACTION_ESP_CREATE,
 			     &UVERBS_ATTR_PTR_IN(MLX5_IB_ATTR_CREATE_FLOW_ACTION_FLAGS,
 						 UVERBS_ATTR_TYPE(u64),
 						 UA_FLAGS(UVERBS_ATTR_SPEC_F_MANDATORY)));
 
-#define NUM_TREES	1
+#define NUM_TREES	2
 static int populate_specs_root(struct mlx5_ib_dev *dev)
 {
 	const struct uverbs_object_tree_def *default_root[NUM_TREES + 1] = {
@@ -4851,6 +4980,10 @@ static int populate_specs_root(struct mlx5_ib_dev *dev)
 	    !WARN_ON(num_trees >= ARRAY_SIZE(default_root)))
 		default_root[num_trees++] = &mlx5_ib_flow_action;
 
+	if (MLX5_CAP_DEV_MEM(dev->mdev, memic) &&
+	    !WARN_ON(num_trees >= ARRAY_SIZE(default_root)))
+		default_root[num_trees++] = &mlx5_ib_dm;
+
 	dev->ib_dev.specs_root =
 		uverbs_alloc_spec_tree(num_trees, default_root);
 
@@ -4925,6 +5058,9 @@ int mlx5_ib_stage_init_init(struct mlx5_ib_dev *dev)
 	INIT_LIST_HEAD(&dev->qp_list);
 	spin_lock_init(&dev->reset_flow_resource_lock);
 
+	spin_lock_init(&dev->memic.memic_lock);
+	dev->memic.dev = mdev;
+
 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
 	err = init_srcu_struct(&dev->mr_srcu);
 	if (err)
@@ -5087,6 +5223,11 @@ int mlx5_ib_stage_caps_init(struct mlx5_ib_dev *dev)
 			(1ull << IB_USER_VERBS_CMD_CLOSE_XRCD);
 	}
 
+	if (MLX5_CAP_DEV_MEM(mdev, memic)) {
+		dev->ib_dev.alloc_dm = mlx5_ib_alloc_dm;
+		dev->ib_dev.dealloc_dm = mlx5_ib_dealloc_dm;
+	}
+
 	dev->ib_dev.create_flow	= mlx5_ib_create_flow;
 	dev->ib_dev.destroy_flow = mlx5_ib_destroy_flow;
 	dev->ib_dev.uverbs_ex_cmd_mask |=

drivers/infiniband/hw/mlx5/mlx5_ib.h

@@ -45,6 +45,7 @@
 #include <linux/mlx5/transobj.h>
 #include <rdma/ib_user_verbs.h>
 #include <rdma/mlx5-abi.h>
+#include <rdma/uverbs_ioctl.h>
 
 #define mlx5_ib_dbg(dev, format, arg...)				\
 pr_debug("%s:%s:%d:(pid %d): " format, (dev)->ib_dev.name, __func__,	\
@@ -108,6 +109,16 @@ enum {
 	MLX5_IB_INVALID_BFREG		= BIT(31),
 };
 
+enum {
+	MLX5_MAX_MEMIC_PAGES = 0x100,
+	MLX5_MEMIC_ALLOC_SIZE_MASK = 0x3f,
+};
+
+enum {
+	MLX5_MEMIC_BASE_ALIGN	= 6,
+	MLX5_MEMIC_BASE_SIZE	= 1 << MLX5_MEMIC_BASE_ALIGN,
+};
+
 struct mlx5_ib_vma_private_data {
 	struct list_head list;
 	struct vm_area_struct *vma;
@@ -131,6 +142,7 @@ struct mlx5_ib_ucontext {
 	struct mutex		vma_private_list_mutex;
 
 	u64			lib_caps;
+	DECLARE_BITMAP(dm_pages, MLX5_MAX_MEMIC_PAGES);
 };
 
 static inline struct mlx5_ib_ucontext *to_mucontext(struct ib_ucontext *ibucontext)
@@ -521,6 +533,11 @@ enum mlx5_ib_mtt_access_flags {
 	MLX5_IB_MTT_WRITE = (1 << 1),
 };
 
+struct mlx5_ib_dm {
+	struct ib_dm		ibdm;
+	phys_addr_t		dev_addr;
+};
+
 #define MLX5_IB_MTT_PRESENT (MLX5_IB_MTT_READ | MLX5_IB_MTT_WRITE)
 
 struct mlx5_ib_mr {
@@ -784,6 +801,12 @@ struct mlx5_ib_flow_action {
 	};
 };
 
+struct mlx5_memic {
+	struct mlx5_core_dev *dev;
+	spinlock_t		memic_lock;
+	DECLARE_BITMAP(memic_alloc_pages, MLX5_MAX_MEMIC_PAGES);
+};
+
 struct mlx5_ib_dev {
 	struct ib_device		ib_dev;
 	struct mlx5_core_dev		*mdev;
@@ -830,6 +853,7 @@ struct mlx5_ib_dev {
 	u8			umr_fence;
 	struct list_head	ib_dev_list;
 	u64			sys_image_guid;
+	struct mlx5_memic	memic;
 };
 
 static inline struct mlx5_ib_cq *to_mibcq(struct mlx5_core_cq *mcq)
@@ -897,6 +921,11 @@ static inline struct mlx5_ib_srq *to_mibsrq(struct mlx5_core_srq *msrq)
 	return container_of(msrq, struct mlx5_ib_srq, msrq);
 }
 
+static inline struct mlx5_ib_dm *to_mdm(struct ib_dm *ibdm)
+{
+	return container_of(ibdm, struct mlx5_ib_dm, ibdm);
+}
+
 static inline struct mlx5_ib_mr *to_mmr(struct ib_mr *ibmr)
 {
 	return container_of(ibmr, struct mlx5_ib_mr, ibmr);
@@ -1041,7 +1070,11 @@ struct ib_rwq_ind_table *mlx5_ib_create_rwq_ind_table(struct ib_device *device,
 						      struct ib_udata *udata);
 int mlx5_ib_destroy_rwq_ind_table(struct ib_rwq_ind_table *wq_ind_table);
 bool mlx5_ib_dc_atomic_is_supported(struct mlx5_ib_dev *dev);
-
+struct ib_dm *mlx5_ib_alloc_dm(struct ib_device *ibdev,
+			       struct ib_ucontext *context,
+			       struct ib_dm_alloc_attr *attr,
+			       struct uverbs_attr_bundle *attrs);
+int mlx5_ib_dealloc_dm(struct ib_dm *ibdm);
 
 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
 void mlx5_ib_internal_fill_odp_caps(struct mlx5_ib_dev *dev);

include/linux/mlx5/mlx5_ifc.h

@@ -92,6 +92,8 @@ enum {
 	MLX5_CMD_OP_DESTROY_MKEY                  = 0x202,
 	MLX5_CMD_OP_QUERY_SPECIAL_CONTEXTS        = 0x203,
 	MLX5_CMD_OP_PAGE_FAULT_RESUME             = 0x204,
+	MLX5_CMD_OP_ALLOC_MEMIC                   = 0x205,
+	MLX5_CMD_OP_DEALLOC_MEMIC                 = 0x206,
 	MLX5_CMD_OP_CREATE_EQ                     = 0x301,
 	MLX5_CMD_OP_DESTROY_EQ                    = 0x302,
 	MLX5_CMD_OP_QUERY_EQ                      = 0x303,
@@ -8886,4 +8888,57 @@ struct mlx5_ifc_destroy_vport_lag_in_bits {
 	u8         reserved_at_40[0x40];
 };
 
+struct mlx5_ifc_alloc_memic_in_bits {
+	u8         opcode[0x10];
+	u8         reserved_at_10[0x10];
+
+	u8         reserved_at_20[0x10];
+	u8         op_mod[0x10];
+
+	u8         reserved_at_30[0x20];
+
+	u8	   reserved_at_40[0x18];
+	u8	   log_memic_addr_alignment[0x8];
+
+	u8         range_start_addr[0x40];
+
+	u8         range_size[0x20];
+
+	u8         memic_size[0x20];
+};
+
+struct mlx5_ifc_alloc_memic_out_bits {
+	u8         status[0x8];
+	u8         reserved_at_8[0x18];
+
+	u8         syndrome[0x20];
+
+	u8         memic_start_addr[0x40];
+};
+
+struct mlx5_ifc_dealloc_memic_in_bits {
+	u8         opcode[0x10];
+	u8         reserved_at_10[0x10];
+
+	u8         reserved_at_20[0x10];
+	u8         op_mod[0x10];
+
+	u8         reserved_at_40[0x40];
+
+	u8         memic_start_addr[0x40];
+
+	u8         memic_size[0x20];
+
+	u8         reserved_at_e0[0x20];
+};
+
+struct mlx5_ifc_dealloc_memic_out_bits {
+	u8         status[0x8];
+	u8         reserved_at_8[0x18];
+
+	u8         syndrome[0x20];
+
+	u8         reserved_at_40[0x40];
+};
+
 #endif /* MLX5_IFC_H */

include/uapi/rdma/mlx5-abi.h

@@ -430,6 +430,7 @@ enum mlx5_ib_mmap_cmd {
 	MLX5_IB_MMAP_CORE_CLOCK                 = 5,
 	MLX5_IB_MMAP_ALLOC_WC                   = 6,
 	MLX5_IB_MMAP_CLOCK_INFO                 = 7,
+	MLX5_IB_MMAP_DEVICE_MEM                 = 8,
 };
 
 enum {

include/uapi/rdma/mlx5_user_ioctl_cmds.h

@@ -40,5 +40,9 @@ enum mlx5_ib_create_flow_action_attrs {
 	MLX5_IB_ATTR_CREATE_FLOW_ACTION_FLAGS = (1U << UVERBS_ID_NS_SHIFT),
 };
 
-#endif
+enum mlx5_ib_alloc_dm_attrs {
+	MLX5_IB_ATTR_ALLOC_DM_RESP_START_OFFSET = (1U << UVERBS_ID_NS_SHIFT),
+	MLX5_IB_ATTR_ALLOC_DM_RESP_PAGE_INDEX,
+};
 
+#endif