Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 697 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/irdma/hmc.c b/drivers/infiniband/hw/irdma/hmc.c
new file mode 100644
index 000000000..49307ce8c
--- /dev/null
+++ b/drivers/infiniband/hw/irdma/hmc.c
@@ -0,0 +1,697 @@
+// SPDX-License-Identifier: GPL-2.0 or Linux-OpenIB
+/* Copyright (c) 2015 - 2021 Intel Corporation */
+#include "osdep.h"
+#include "hmc.h"
+#include "defs.h"
+#include "type.h"
+#include "protos.h"
+
+/**
+ * irdma_find_sd_index_limit - finds segment descriptor index limit
+ * @hmc_info: pointer to the HMC configuration information structure
+ * @type: type of HMC resources we're searching
+ * @idx: starting index for the object
+ * @cnt: number of objects we're trying to create
+ * @sd_idx: pointer to return index of the segment descriptor in question
+ * @sd_limit: pointer to return the maximum number of segment descriptors
+ *
+ * This function calculates the segment descriptor index and index limit
+ * for the resource defined by irdma_hmc_rsrc_type.
+ */
+
+static void irdma_find_sd_index_limit(struct irdma_hmc_info *hmc_info, u32 type,
+				      u32 idx, u32 cnt, u32 *sd_idx,
+				      u32 *sd_limit)
+{
+	u64 fpm_addr, fpm_limit;
+
+	fpm_addr = hmc_info->hmc_obj[(type)].base +
+		   hmc_info->hmc_obj[type].size * idx;
+	fpm_limit = fpm_addr + hmc_info->hmc_obj[type].size * cnt;
+	*sd_idx = (u32)(fpm_addr / IRDMA_HMC_DIRECT_BP_SIZE);
+	*sd_limit = (u32)((fpm_limit - 1) / IRDMA_HMC_DIRECT_BP_SIZE);
+	*sd_limit += 1;
+}
+
+/**
+ * irdma_find_pd_index_limit - finds page descriptor index limit
+ * @hmc_info: pointer to the HMC configuration information struct
+ * @type: HMC resource type we're examining
+ * @idx: starting index for the object
+ * @cnt: number of objects we're trying to create
+ * @pd_idx: pointer to return page descriptor index
+ * @pd_limit: pointer to return page descriptor index limit
+ *
+ * Calculates the page descriptor index and index limit for the resource
+ * defined by irdma_hmc_rsrc_type.
+ */
+
+static void irdma_find_pd_index_limit(struct irdma_hmc_info *hmc_info, u32 type,
+				      u32 idx, u32 cnt, u32 *pd_idx,
+				      u32 *pd_limit)
+{
+	u64 fpm_adr, fpm_limit;
+
+	fpm_adr = hmc_info->hmc_obj[type].base +
+		  hmc_info->hmc_obj[type].size * idx;
+	fpm_limit = fpm_adr + (hmc_info)->hmc_obj[(type)].size * (cnt);
+	*pd_idx = (u32)(fpm_adr / IRDMA_HMC_PAGED_BP_SIZE);
+	*pd_limit = (u32)((fpm_limit - 1) / IRDMA_HMC_PAGED_BP_SIZE);
+	*pd_limit += 1;
+}
+
+/**
+ * irdma_set_sd_entry - setup entry for sd programming
+ * @pa: physical addr
+ * @idx: sd index
+ * @type: paged or direct sd
+ * @entry: sd entry ptr
+ */
+static void irdma_set_sd_entry(u64 pa, u32 idx, enum irdma_sd_entry_type type,
+			       struct irdma_update_sd_entry *entry)
+{
+	entry->data = pa |
+		      FIELD_PREP(IRDMA_PFHMC_SDDATALOW_PMSDBPCOUNT, IRDMA_HMC_MAX_BP_COUNT) |
+		      FIELD_PREP(IRDMA_PFHMC_SDDATALOW_PMSDTYPE,
+				 type == IRDMA_SD_TYPE_PAGED ? 0 : 1) |
+		      FIELD_PREP(IRDMA_PFHMC_SDDATALOW_PMSDVALID, 1);
+
+	entry->cmd = idx | FIELD_PREP(IRDMA_PFHMC_SDCMD_PMSDWR, 1) | BIT(15);
+}
+
+/**
+ * irdma_clr_sd_entry - setup entry for sd clear
+ * @idx: sd index
+ * @type: paged or direct sd
+ * @entry: sd entry ptr
+ */
+static void irdma_clr_sd_entry(u32 idx, enum irdma_sd_entry_type type,
+			       struct irdma_update_sd_entry *entry)
+{
+	entry->data = FIELD_PREP(IRDMA_PFHMC_SDDATALOW_PMSDBPCOUNT, IRDMA_HMC_MAX_BP_COUNT) |
+		      FIELD_PREP(IRDMA_PFHMC_SDDATALOW_PMSDTYPE,
+				 type == IRDMA_SD_TYPE_PAGED ? 0 : 1);
+
+	entry->cmd = idx | FIELD_PREP(IRDMA_PFHMC_SDCMD_PMSDWR, 1) | BIT(15);
+}
+
+/**
+ * irdma_invalidate_pf_hmc_pd - Invalidates the pd cache in the hardware for PF
+ * @dev: pointer to our device struct
+ * @sd_idx: segment descriptor index
+ * @pd_idx: page descriptor index
+ */
+static inline void irdma_invalidate_pf_hmc_pd(struct irdma_sc_dev *dev, u32 sd_idx,
+					      u32 pd_idx)
+{
+	u32 val = FIELD_PREP(IRDMA_PFHMC_PDINV_PMSDIDX, sd_idx) |
+		  FIELD_PREP(IRDMA_PFHMC_PDINV_PMSDPARTSEL, 1) |
+		  FIELD_PREP(IRDMA_PFHMC_PDINV_PMPDIDX, pd_idx);
+
+	writel(val, dev->hw_regs[IRDMA_PFHMC_PDINV]);
+}
+
+/**
+ * irdma_hmc_sd_one - setup 1 sd entry for cqp
+ * @dev: pointer to the device structure
+ * @hmc_fn_id: hmc's function id
+ * @pa: physical addr
+ * @sd_idx: sd index
+ * @type: paged or direct sd
+ * @setsd: flag to set or clear sd
+ */
+int irdma_hmc_sd_one(struct irdma_sc_dev *dev, u8 hmc_fn_id, u64 pa, u32 sd_idx,
+		     enum irdma_sd_entry_type type, bool setsd)
+{
+	struct irdma_update_sds_info sdinfo;
+
+	sdinfo.cnt = 1;
+	sdinfo.hmc_fn_id = hmc_fn_id;
+	if (setsd)
+		irdma_set_sd_entry(pa, sd_idx, type, sdinfo.entry);
+	else
+		irdma_clr_sd_entry(sd_idx, type, sdinfo.entry);
+	return dev->cqp->process_cqp_sds(dev, &sdinfo);
+}
+
+/**
+ * irdma_hmc_sd_grp - setup group of sd entries for cqp
+ * @dev: pointer to the device structure
+ * @hmc_info: pointer to the HMC configuration information struct
+ * @sd_index: sd index
+ * @sd_cnt: number of sd entries
+ * @setsd: flag to set or clear sd
+ */
+static int irdma_hmc_sd_grp(struct irdma_sc_dev *dev,
+			    struct irdma_hmc_info *hmc_info, u32 sd_index,
+			    u32 sd_cnt, bool setsd)
+{
+	struct irdma_hmc_sd_entry *sd_entry;
+	struct irdma_update_sds_info sdinfo = {};
+	u64 pa;
+	u32 i;
+	int ret_code = 0;
+
+	sdinfo.hmc_fn_id = hmc_info->hmc_fn_id;
+	for (i = sd_index; i < sd_index + sd_cnt; i++) {
+		sd_entry = &hmc_info->sd_table.sd_entry[i];
+		if (!sd_entry || (!sd_entry->valid && setsd) ||
+		    (sd_entry->valid && !setsd))
+			continue;
+		if (setsd) {
+			pa = (sd_entry->entry_type == IRDMA_SD_TYPE_PAGED) ?
+				     sd_entry->u.pd_table.pd_page_addr.pa :
+				     sd_entry->u.bp.addr.pa;
+			irdma_set_sd_entry(pa, i, sd_entry->entry_type,
+					   &sdinfo.entry[sdinfo.cnt]);
+		} else {
+			irdma_clr_sd_entry(i, sd_entry->entry_type,
+					   &sdinfo.entry[sdinfo.cnt]);
+		}
+		sdinfo.cnt++;
+		if (sdinfo.cnt == IRDMA_MAX_SD_ENTRIES) {
+			ret_code = dev->cqp->process_cqp_sds(dev, &sdinfo);
+			if (ret_code) {
+				ibdev_dbg(to_ibdev(dev),
+					  "HMC: sd_programming failed err=%d\n",
+					  ret_code);
+				return ret_code;
+			}
+
+			sdinfo.cnt = 0;
+		}
+	}
+	if (sdinfo.cnt)
+		ret_code = dev->cqp->process_cqp_sds(dev, &sdinfo);
+
+	return ret_code;
+}
+
+/**
+ * irdma_hmc_finish_add_sd_reg - program sd entries for objects
+ * @dev: pointer to the device structure
+ * @info: create obj info
+ */
+static int irdma_hmc_finish_add_sd_reg(struct irdma_sc_dev *dev,
+				       struct irdma_hmc_create_obj_info *info)
+{
+	if (info->start_idx >= info->hmc_info->hmc_obj[info->rsrc_type].cnt)
+		return -EINVAL;
+
+	if ((info->start_idx + info->count) >
+	    info->hmc_info->hmc_obj[info->rsrc_type].cnt)
+		return -EINVAL;
+
+	if (!info->add_sd_cnt)
+		return 0;
+	return irdma_hmc_sd_grp(dev, info->hmc_info,
+				info->hmc_info->sd_indexes[0], info->add_sd_cnt,
+				true);
+}
+
+/**
+ * irdma_sc_create_hmc_obj - allocate backing store for hmc objects
+ * @dev: pointer to the device structure
+ * @info: pointer to irdma_hmc_create_obj_info struct
+ *
+ * This will allocate memory for PDs and backing pages and populate
+ * the sd and pd entries.
+ */
+int irdma_sc_create_hmc_obj(struct irdma_sc_dev *dev,
+			    struct irdma_hmc_create_obj_info *info)
+{
+	struct irdma_hmc_sd_entry *sd_entry;
+	u32 sd_idx, sd_lmt;
+	u32 pd_idx = 0, pd_lmt = 0;
+	u32 pd_idx1 = 0, pd_lmt1 = 0;
+	u32 i, j;
+	bool pd_error = false;
+	int ret_code = 0;
+
+	if (info->start_idx >= info->hmc_info->hmc_obj[info->rsrc_type].cnt)
+		return -EINVAL;
+
+	if ((info->start_idx + info->count) >
+	    info->hmc_info->hmc_obj[info->rsrc_type].cnt) {
+		ibdev_dbg(to_ibdev(dev),
+			  "HMC: error type %u, start = %u, req cnt %u, cnt = %u\n",
+			  info->rsrc_type, info->start_idx, info->count,
+			  info->hmc_info->hmc_obj[info->rsrc_type].cnt);
+		return -EINVAL;
+	}
+
+	irdma_find_sd_index_limit(info->hmc_info, info->rsrc_type,
+				  info->start_idx, info->count, &sd_idx,
+				  &sd_lmt);
+	if (sd_idx >= info->hmc_info->sd_table.sd_cnt ||
+	    sd_lmt > info->hmc_info->sd_table.sd_cnt) {
+		return -EINVAL;
+	}
+
+	irdma_find_pd_index_limit(info->hmc_info, info->rsrc_type,
+				  info->start_idx, info->count, &pd_idx,
+				  &pd_lmt);
+
+	for (j = sd_idx; j < sd_lmt; j++) {
+		ret_code = irdma_add_sd_table_entry(dev->hw, info->hmc_info, j,
+						    info->entry_type,
+						    IRDMA_HMC_DIRECT_BP_SIZE);
+		if (ret_code)
+			goto exit_sd_error;
+
+		sd_entry = &info->hmc_info->sd_table.sd_entry[j];
+		if (sd_entry->entry_type == IRDMA_SD_TYPE_PAGED &&
+		    (dev->hmc_info == info->hmc_info &&
+		     info->rsrc_type != IRDMA_HMC_IW_PBLE)) {
+			pd_idx1 = max(pd_idx, (j * IRDMA_HMC_MAX_BP_COUNT));
+			pd_lmt1 = min(pd_lmt, (j + 1) * IRDMA_HMC_MAX_BP_COUNT);
+			for (i = pd_idx1; i < pd_lmt1; i++) {
+				/* update the pd table entry */
+				ret_code = irdma_add_pd_table_entry(dev,
+								    info->hmc_info,
+								    i, NULL);
+				if (ret_code) {
+					pd_error = true;
+					break;
+				}
+			}
+			if (pd_error) {
+				while (i && (i > pd_idx1)) {
+					irdma_remove_pd_bp(dev, info->hmc_info,
+							   i - 1);
+					i--;
+				}
+			}
+		}
+		if (sd_entry->valid)
+			continue;
+
+		info->hmc_info->sd_indexes[info->add_sd_cnt] = (u16)j;
+		info->add_sd_cnt++;
+		sd_entry->valid = true;
+	}
+	return irdma_hmc_finish_add_sd_reg(dev, info);
+
+exit_sd_error:
+	while (j && (j > sd_idx)) {
+		sd_entry = &info->hmc_info->sd_table.sd_entry[j - 1];
+		switch (sd_entry->entry_type) {
+		case IRDMA_SD_TYPE_PAGED:
+			pd_idx1 = max(pd_idx, (j - 1) * IRDMA_HMC_MAX_BP_COUNT);
+			pd_lmt1 = min(pd_lmt, (j * IRDMA_HMC_MAX_BP_COUNT));
+			for (i = pd_idx1; i < pd_lmt1; i++)
+				irdma_prep_remove_pd_page(info->hmc_info, i);
+			break;
+		case IRDMA_SD_TYPE_DIRECT:
+			irdma_prep_remove_pd_page(info->hmc_info, (j - 1));
+			break;
+		default:
+			ret_code = -EINVAL;
+			break;
+		}
+		j--;
+	}
+
+	return ret_code;
+}
+
+/**
+ * irdma_finish_del_sd_reg - delete sd entries for objects
+ * @dev: pointer to the device structure
+ * @info: dele obj info
+ * @reset: true if called before reset
+ */
+static int irdma_finish_del_sd_reg(struct irdma_sc_dev *dev,
+				   struct irdma_hmc_del_obj_info *info,
+				   bool reset)
+{
+	struct irdma_hmc_sd_entry *sd_entry;
+	int ret_code = 0;
+	u32 i, sd_idx;
+	struct irdma_dma_mem *mem;
+
+	if (!reset)
+		ret_code = irdma_hmc_sd_grp(dev, info->hmc_info,
+					    info->hmc_info->sd_indexes[0],
+					    info->del_sd_cnt, false);
+
+	if (ret_code)
+		ibdev_dbg(to_ibdev(dev), "HMC: error cqp sd sd_grp\n");
+	for (i = 0; i < info->del_sd_cnt; i++) {
+		sd_idx = info->hmc_info->sd_indexes[i];
+		sd_entry = &info->hmc_info->sd_table.sd_entry[sd_idx];
+		mem = (sd_entry->entry_type == IRDMA_SD_TYPE_PAGED) ?
+			      &sd_entry->u.pd_table.pd_page_addr :
+			      &sd_entry->u.bp.addr;
+
+		if (!mem || !mem->va) {
+			ibdev_dbg(to_ibdev(dev), "HMC: error cqp sd mem\n");
+		} else {
+			dma_free_coherent(dev->hw->device, mem->size, mem->va,
+					  mem->pa);
+			mem->va = NULL;
+		}
+	}
+
+	return ret_code;
+}
+
+/**
+ * irdma_sc_del_hmc_obj - remove pe hmc objects
+ * @dev: pointer to the device structure
+ * @info: pointer to irdma_hmc_del_obj_info struct
+ * @reset: true if called before reset
+ *
+ * This will de-populate the SDs and PDs.  It frees
+ * the memory for PDS and backing storage.  After this function is returned,
+ * caller should deallocate memory allocated previously for
+ * book-keeping information about PDs and backing storage.
+ */
+int irdma_sc_del_hmc_obj(struct irdma_sc_dev *dev,
+			 struct irdma_hmc_del_obj_info *info, bool reset)
+{
+	struct irdma_hmc_pd_table *pd_table;
+	u32 sd_idx, sd_lmt;
+	u32 pd_idx, pd_lmt, rel_pd_idx;
+	u32 i, j;
+	int ret_code = 0;
+
+	if (info->start_idx >= info->hmc_info->hmc_obj[info->rsrc_type].cnt) {
+		ibdev_dbg(to_ibdev(dev),
+			  "HMC: error start_idx[%04d]  >= [type %04d].cnt[%04d]\n",
+			  info->start_idx, info->rsrc_type,
+			  info->hmc_info->hmc_obj[info->rsrc_type].cnt);
+		return -EINVAL;
+	}
+
+	if ((info->start_idx + info->count) >
+	    info->hmc_info->hmc_obj[info->rsrc_type].cnt) {
+		ibdev_dbg(to_ibdev(dev),
+			  "HMC: error start_idx[%04d] + count %04d  >= [type %04d].cnt[%04d]\n",
+			  info->start_idx, info->count, info->rsrc_type,
+			  info->hmc_info->hmc_obj[info->rsrc_type].cnt);
+		return -EINVAL;
+	}
+
+	irdma_find_pd_index_limit(info->hmc_info, info->rsrc_type,
+				  info->start_idx, info->count, &pd_idx,
+				  &pd_lmt);
+
+	for (j = pd_idx; j < pd_lmt; j++) {
+		sd_idx = j / IRDMA_HMC_PD_CNT_IN_SD;
+
+		if (!info->hmc_info->sd_table.sd_entry[sd_idx].valid)
+			continue;
+
+		if (info->hmc_info->sd_table.sd_entry[sd_idx].entry_type !=
+		    IRDMA_SD_TYPE_PAGED)
+			continue;
+
+		rel_pd_idx = j % IRDMA_HMC_PD_CNT_IN_SD;
+		pd_table = &info->hmc_info->sd_table.sd_entry[sd_idx].u.pd_table;
+		if (pd_table->pd_entry &&
+		    pd_table->pd_entry[rel_pd_idx].valid) {
+			ret_code = irdma_remove_pd_bp(dev, info->hmc_info, j);
+			if (ret_code) {
+				ibdev_dbg(to_ibdev(dev),
+					  "HMC: remove_pd_bp error\n");
+				return ret_code;
+			}
+		}
+	}
+
+	irdma_find_sd_index_limit(info->hmc_info, info->rsrc_type,
+				  info->start_idx, info->count, &sd_idx,
+				  &sd_lmt);
+	if (sd_idx >= info->hmc_info->sd_table.sd_cnt ||
+	    sd_lmt > info->hmc_info->sd_table.sd_cnt) {
+		ibdev_dbg(to_ibdev(dev), "HMC: invalid sd_idx\n");
+		return -EINVAL;
+	}
+
+	for (i = sd_idx; i < sd_lmt; i++) {
+		pd_table = &info->hmc_info->sd_table.sd_entry[i].u.pd_table;
+		if (!info->hmc_info->sd_table.sd_entry[i].valid)
+			continue;
+		switch (info->hmc_info->sd_table.sd_entry[i].entry_type) {
+		case IRDMA_SD_TYPE_DIRECT:
+			ret_code = irdma_prep_remove_sd_bp(info->hmc_info, i);
+			if (!ret_code) {
+				info->hmc_info->sd_indexes[info->del_sd_cnt] =
+					(u16)i;
+				info->del_sd_cnt++;
+			}
+			break;
+		case IRDMA_SD_TYPE_PAGED:
+			ret_code = irdma_prep_remove_pd_page(info->hmc_info, i);
+			if (ret_code)
+				break;
+			if (dev->hmc_info != info->hmc_info &&
+			    info->rsrc_type == IRDMA_HMC_IW_PBLE &&
+			    pd_table->pd_entry) {
+				kfree(pd_table->pd_entry_virt_mem.va);
+				pd_table->pd_entry = NULL;
+			}
+			info->hmc_info->sd_indexes[info->del_sd_cnt] = (u16)i;
+			info->del_sd_cnt++;
+			break;
+		default:
+			break;
+		}
+	}
+	return irdma_finish_del_sd_reg(dev, info, reset);
+}
+
+/**
+ * irdma_add_sd_table_entry - Adds a segment descriptor to the table
+ * @hw: pointer to our hw struct
+ * @hmc_info: pointer to the HMC configuration information struct
+ * @sd_index: segment descriptor index to manipulate
+ * @type: what type of segment descriptor we're manipulating
+ * @direct_mode_sz: size to alloc in direct mode
+ */
+int irdma_add_sd_table_entry(struct irdma_hw *hw,
+			     struct irdma_hmc_info *hmc_info, u32 sd_index,
+			     enum irdma_sd_entry_type type, u64 direct_mode_sz)
+{
+	struct irdma_hmc_sd_entry *sd_entry;
+	struct irdma_dma_mem dma_mem;
+	u64 alloc_len;
+
+	sd_entry = &hmc_info->sd_table.sd_entry[sd_index];
+	if (!sd_entry->valid) {
+		if (type == IRDMA_SD_TYPE_PAGED)
+			alloc_len = IRDMA_HMC_PAGED_BP_SIZE;
+		else
+			alloc_len = direct_mode_sz;
+
+		/* allocate a 4K pd page or 2M backing page */
+		dma_mem.size = ALIGN(alloc_len, IRDMA_HMC_PD_BP_BUF_ALIGNMENT);
+		dma_mem.va = dma_alloc_coherent(hw->device, dma_mem.size,
+						&dma_mem.pa, GFP_KERNEL);
+		if (!dma_mem.va)
+			return -ENOMEM;
+		if (type == IRDMA_SD_TYPE_PAGED) {
+			struct irdma_virt_mem *vmem =
+				&sd_entry->u.pd_table.pd_entry_virt_mem;
+
+			vmem->size = sizeof(struct irdma_hmc_pd_entry) * 512;
+			vmem->va = kzalloc(vmem->size, GFP_KERNEL);
+			if (!vmem->va) {
+				dma_free_coherent(hw->device, dma_mem.size,
+						  dma_mem.va, dma_mem.pa);
+				dma_mem.va = NULL;
+				return -ENOMEM;
+			}
+			sd_entry->u.pd_table.pd_entry = vmem->va;
+
+			memcpy(&sd_entry->u.pd_table.pd_page_addr, &dma_mem,
+			       sizeof(sd_entry->u.pd_table.pd_page_addr));
+		} else {
+			memcpy(&sd_entry->u.bp.addr, &dma_mem,
+			       sizeof(sd_entry->u.bp.addr));
+
+			sd_entry->u.bp.sd_pd_index = sd_index;
+		}
+
+		hmc_info->sd_table.sd_entry[sd_index].entry_type = type;
+		hmc_info->sd_table.use_cnt++;
+	}
+	if (sd_entry->entry_type == IRDMA_SD_TYPE_DIRECT)
+		sd_entry->u.bp.use_cnt++;
+
+	return 0;
+}
+
+/**
+ * irdma_add_pd_table_entry - Adds page descriptor to the specified table
+ * @dev: pointer to our device structure
+ * @hmc_info: pointer to the HMC configuration information structure
+ * @pd_index: which page descriptor index to manipulate
+ * @rsrc_pg: if not NULL, use preallocated page instead of allocating new one.
+ *
+ * This function:
+ *	1. Initializes the pd entry
+ *	2. Adds pd_entry in the pd_table
+ *	3. Mark the entry valid in irdma_hmc_pd_entry structure
+ *	4. Initializes the pd_entry's ref count to 1
+ * assumptions:
+ *	1. The memory for pd should be pinned down, physically contiguous and
+ *	   aligned on 4K boundary and zeroed memory.
+ *	2. It should be 4K in size.
+ */
+int irdma_add_pd_table_entry(struct irdma_sc_dev *dev,
+			     struct irdma_hmc_info *hmc_info, u32 pd_index,
+			     struct irdma_dma_mem *rsrc_pg)
+{
+	struct irdma_hmc_pd_table *pd_table;
+	struct irdma_hmc_pd_entry *pd_entry;
+	struct irdma_dma_mem mem;
+	struct irdma_dma_mem *page = &mem;
+	u32 sd_idx, rel_pd_idx;
+	u64 *pd_addr;
+	u64 page_desc;
+
+	if (pd_index / IRDMA_HMC_PD_CNT_IN_SD >= hmc_info->sd_table.sd_cnt)
+		return -EINVAL;
+
+	sd_idx = (pd_index / IRDMA_HMC_PD_CNT_IN_SD);
+	if (hmc_info->sd_table.sd_entry[sd_idx].entry_type !=
+	    IRDMA_SD_TYPE_PAGED)
+		return 0;
+
+	rel_pd_idx = (pd_index % IRDMA_HMC_PD_CNT_IN_SD);
+	pd_table = &hmc_info->sd_table.sd_entry[sd_idx].u.pd_table;
+	pd_entry = &pd_table->pd_entry[rel_pd_idx];
+	if (!pd_entry->valid) {
+		if (rsrc_pg) {
+			pd_entry->rsrc_pg = true;
+			page = rsrc_pg;
+		} else {
+			page->size = ALIGN(IRDMA_HMC_PAGED_BP_SIZE,
+					   IRDMA_HMC_PD_BP_BUF_ALIGNMENT);
+			page->va = dma_alloc_coherent(dev->hw->device,
+						      page->size, &page->pa,
+						      GFP_KERNEL);
+			if (!page->va)
+				return -ENOMEM;
+
+			pd_entry->rsrc_pg = false;
+		}
+
+		memcpy(&pd_entry->bp.addr, page, sizeof(pd_entry->bp.addr));
+		pd_entry->bp.sd_pd_index = pd_index;
+		pd_entry->bp.entry_type = IRDMA_SD_TYPE_PAGED;
+		page_desc = page->pa | 0x1;
+		pd_addr = pd_table->pd_page_addr.va;
+		pd_addr += rel_pd_idx;
+		memcpy(pd_addr, &page_desc, sizeof(*pd_addr));
+		pd_entry->sd_index = sd_idx;
+		pd_entry->valid = true;
+		pd_table->use_cnt++;
+		irdma_invalidate_pf_hmc_pd(dev, sd_idx, rel_pd_idx);
+	}
+	pd_entry->bp.use_cnt++;
+
+	return 0;
+}
+
+/**
+ * irdma_remove_pd_bp - remove a backing page from a page descriptor
+ * @dev: pointer to our HW structure
+ * @hmc_info: pointer to the HMC configuration information structure
+ * @idx: the page index
+ *
+ * This function:
+ *	1. Marks the entry in pd table (for paged address mode) or in sd table
+ *	   (for direct address mode) invalid.
+ *	2. Write to register PMPDINV to invalidate the backing page in FV cache
+ *	3. Decrement the ref count for the pd _entry
+ * assumptions:
+ *	1. Caller can deallocate the memory used by backing storage after this
+ *	   function returns.
+ */
+int irdma_remove_pd_bp(struct irdma_sc_dev *dev,
+		       struct irdma_hmc_info *hmc_info, u32 idx)
+{
+	struct irdma_hmc_pd_entry *pd_entry;
+	struct irdma_hmc_pd_table *pd_table;
+	struct irdma_hmc_sd_entry *sd_entry;
+	u32 sd_idx, rel_pd_idx;
+	struct irdma_dma_mem *mem;
+	u64 *pd_addr;
+
+	sd_idx = idx / IRDMA_HMC_PD_CNT_IN_SD;
+	rel_pd_idx = idx % IRDMA_HMC_PD_CNT_IN_SD;
+	if (sd_idx >= hmc_info->sd_table.sd_cnt)
+		return -EINVAL;
+
+	sd_entry = &hmc_info->sd_table.sd_entry[sd_idx];
+	if (sd_entry->entry_type != IRDMA_SD_TYPE_PAGED)
+		return -EINVAL;
+
+	pd_table = &hmc_info->sd_table.sd_entry[sd_idx].u.pd_table;
+	pd_entry = &pd_table->pd_entry[rel_pd_idx];
+	if (--pd_entry->bp.use_cnt)
+		return 0;
+
+	pd_entry->valid = false;
+	pd_table->use_cnt--;
+	pd_addr = pd_table->pd_page_addr.va;
+	pd_addr += rel_pd_idx;
+	memset(pd_addr, 0, sizeof(u64));
+	irdma_invalidate_pf_hmc_pd(dev, sd_idx, idx);
+
+	if (!pd_entry->rsrc_pg) {
+		mem = &pd_entry->bp.addr;
+		if (!mem || !mem->va)
+			return -EINVAL;
+
+		dma_free_coherent(dev->hw->device, mem->size, mem->va,
+				  mem->pa);
+		mem->va = NULL;
+	}
+	if (!pd_table->use_cnt)
+		kfree(pd_table->pd_entry_virt_mem.va);
+
+	return 0;
+}
+
+/**
+ * irdma_prep_remove_sd_bp - Prepares to remove a backing page from a sd entry
+ * @hmc_info: pointer to the HMC configuration information structure
+ * @idx: the page index
+ */
+int irdma_prep_remove_sd_bp(struct irdma_hmc_info *hmc_info, u32 idx)
+{
+	struct irdma_hmc_sd_entry *sd_entry;
+
+	sd_entry = &hmc_info->sd_table.sd_entry[idx];
+	if (--sd_entry->u.bp.use_cnt)
+		return -EBUSY;
+
+	hmc_info->sd_table.use_cnt--;
+	sd_entry->valid = false;
+
+	return 0;
+}
+
+/**
+ * irdma_prep_remove_pd_page - Prepares to remove a PD page from sd entry.
+ * @hmc_info: pointer to the HMC configuration information structure
+ * @idx: segment descriptor index to find the relevant page descriptor
+ */
+int irdma_prep_remove_pd_page(struct irdma_hmc_info *hmc_info, u32 idx)
+{
+	struct irdma_hmc_sd_entry *sd_entry;
+
+	sd_entry = &hmc_info->sd_table.sd_entry[idx];
+
+	if (sd_entry->u.pd_table.use_cnt)
+		return -EBUSY;
+
+	sd_entry->valid = false;
+	hmc_info->sd_table.use_cnt--;
+
+	return 0;
+}