mem-buf: Add infrastructure for requesting specific IPA address

gh_rm_mem_accept allows a VM to request memory to be mapped to a specific
IPA address. Modify function parameters to allow for future use of this
feature.

Change-Id: I6ad586886563e769549e4966369da48c27ca0a5c
Signed-off-by: Patrick Daly <quic_pdaly@quicinc.com>

drivers/soc/qcom/mem_buf/mem-buf-dev-gh.c

@@ -131,6 +131,24 @@ struct sg_table *dup_gh_sgl_desc_to_sgt(struct gh_sgl_desc *sgl_desc)
 }
 EXPORT_SYMBOL(dup_gh_sgl_desc_to_sgt);
 
+struct gh_sgl_desc *dup_gh_sgl_desc(struct gh_sgl_desc *sgl_desc)
+{
+	size_t size;
+	struct gh_sgl_desc *copy;
+
+	if (!sgl_desc)
+		return NULL;
+
+	size = offsetof(struct gh_sgl_desc, sgl_entries[sgl_desc->n_sgl_entries]);
+	copy = kvmalloc(size, GFP_KERNEL);
+	if (!copy)
+		return ERR_PTR(-ENOMEM);
+
+	memcpy(copy, sgl_desc, size);
+	return copy;
+}
+EXPORT_SYMBOL(dup_gh_sgl_desc);
+
 size_t mem_buf_get_sgl_buf_size(struct gh_sgl_desc *sgl_desc)
 {
 	size_t size = 0;
@@ -176,13 +194,17 @@ static int mem_buf_hyp_assign_table_gh(struct gh_sgl_desc *sgl_desc, int src_vmi
 /*
  * @memparcel_hdl:
  *	GH_RM_TRANS_TYPE_DONATE - memparcel_hdl will be set to MEM_BUF_MEMPARCEL_INVALID
-	on success, and (possibly) set to a different valid memparcel on error. This is
-	because accepting a donated memparcel handle destroys that handle.
-	GH_RM_TRANS_TYPE_LEND - unmodified.
-	GH_RM_TRANS_TYPE_SHARE - unmodified.
+ *	on success, and (possibly) set to a different valid memparcel on error. This is
+ *	because accepting a donated memparcel handle destroys that handle.
+ *	GH_RM_TRANS_TYPE_LEND - unmodified.
+ *	GH_RM_TRANS_TYPE_SHARE - unmodified.
+ * @sgl_desc:
+ *	If *sgl_desc is not NULL, request specific IPA address(es). Otherwise, hypervisor
+ *	will choose the IPA address, and return it here.
  */
-struct gh_sgl_desc *mem_buf_map_mem_s2(u32 op, gh_memparcel_handle_t *__memparcel_hdl,
-					struct gh_acl_desc *acl_desc, int src_vmid)
+int mem_buf_map_mem_s2(u32 op, gh_memparcel_handle_t *__memparcel_hdl,
+			struct gh_acl_desc *acl_desc, struct gh_sgl_desc **__sgl_desc,
+			int src_vmid)
 {
 	int ret, ret2;
 	struct gh_sgl_desc *sgl_desc;
@@ -190,24 +212,24 @@ struct gh_sgl_desc *mem_buf_map_mem_s2(u32 op, gh_memparcel_handle_t *__memparce
 		   GH_RM_MEM_ACCEPT_DONE;
 	gh_memparcel_handle_t memparcel_hdl = *__memparcel_hdl;
 
-	if (!acl_desc)
-		return ERR_PTR(-EINVAL);
+	if (!acl_desc || !__sgl_desc)
+		return -EINVAL;
 
 	/*
 	 * memory returns to its original IPA address when accepted by HLOS. For example,
 	 * scattered memory returns to being scattered memory.
 	 */
-	if (current_vmid != VMID_HLOS)
+	if (current_vmid != VMID_HLOS || (*__sgl_desc && (*__sgl_desc)->n_sgl_entries == 1))
 		flags |= GH_RM_MEM_ACCEPT_MAP_IPA_CONTIGUOUS;
 
 	pr_debug("%s: adding CPU MMU stage 2 mappings\n", __func__);
 	sgl_desc = gh_rm_mem_accept(memparcel_hdl, GH_RM_MEM_TYPE_NORMAL, op,
-				    flags, 0, acl_desc, NULL,
+				    flags, 0, acl_desc, *__sgl_desc,
 				    NULL, 0);
 	if (IS_ERR(sgl_desc)) {
 		pr_err("%s failed to map memory in stage 2 rc: %d\n", __func__,
 		       PTR_ERR(sgl_desc));
-		return sgl_desc;
+		return PTR_ERR(sgl_desc);
 	}
 
 	if (op == GH_RM_TRANS_TYPE_DONATE)
@@ -218,7 +240,8 @@ struct gh_sgl_desc *mem_buf_map_mem_s2(u32 op, gh_memparcel_handle_t *__memparce
 		goto err_relinquish;
 
 	trace_map_mem_s2(memparcel_hdl, sgl_desc);
-	return sgl_desc;
+	*__sgl_desc = sgl_desc;
+	return 0;
 
 err_relinquish:
 	if (op == GH_RM_TRANS_TYPE_DONATE)
@@ -226,12 +249,18 @@ struct gh_sgl_desc *mem_buf_map_mem_s2(u32 op, gh_memparcel_handle_t *__memparce
 					__memparcel_hdl);
 	else
 		ret2 = mem_buf_unmap_mem_s2(memparcel_hdl);
-	kvfree(sgl_desc);
+
+	/*
+	 * Only free sgl_desc if caller passed NULL in *__sgl_desc to request
+	 * gh_rm_mem_accept to allocate new IPA/sgl_desc.
+	 */
+	if (sgl_desc != *__sgl_desc)
+		kvfree(sgl_desc);
 	if (ret2) {
 		pr_err("%s failed to recover\n", __func__);
-		return ERR_PTR(-EADDRNOTAVAIL);
+		return -EADDRNOTAVAIL;
 	}
-	return ERR_PTR(ret);
+	return ret;
 }
 EXPORT_SYMBOL(mem_buf_map_mem_s2);
 

drivers/soc/qcom/mem_buf/mem-buf-dev.h

@@ -50,13 +50,15 @@ static inline int mem_buf_unmap_mem_s1(struct gh_sgl_desc *sgl_desc)
 struct gh_acl_desc *mem_buf_vmid_perm_list_to_gh_acl(int *vmids, int *perms,
 						     unsigned int nr_acl_entries);
 struct gh_sgl_desc *mem_buf_sgt_to_gh_sgl_desc(struct sg_table *sgt);
-struct gh_sgl_desc *mem_buf_map_mem_s2(u32 op, gh_memparcel_handle_t *__memparcel_hdl,
-				       struct gh_acl_desc *acl_desc, int src_vmid);
+int mem_buf_map_mem_s2(u32 op, gh_memparcel_handle_t *__memparcel_hdl,
+			struct gh_acl_desc *acl_desc, struct gh_sgl_desc **sgl_desc,
+			int src_vmid);
 int mem_buf_unmap_mem_s2(gh_memparcel_handle_t memparcel_hdl);
 int mem_buf_gh_acl_desc_to_vmid_perm_list(struct gh_acl_desc *acl_desc,
 					  int **vmids, int **perms);
 size_t mem_buf_get_sgl_buf_size(struct gh_sgl_desc *sgl_desc);
 struct sg_table *dup_gh_sgl_desc_to_sgt(struct gh_sgl_desc *sgl_desc);
+struct gh_sgl_desc *dup_gh_sgl_desc(struct gh_sgl_desc *sgl_desc);
 int mem_buf_assign_mem_gunyah(u32 op, struct sg_table *sgt,
 			      struct mem_buf_lend_kernel_arg *arg);
 int mem_buf_unassign_mem_gunyah(gh_memparcel_handle_t memparcel_hdl);
@@ -82,10 +84,11 @@ static inline struct gh_sgl_desc *mem_buf_sgt_to_gh_sgl_desc(struct sg_table *sg
 	return ERR_PTR(-EINVAL);
 }
 
-static inline struct gh_sgl_desc *mem_buf_map_mem_s2(u32 op, gh_memparcel_handle_t *__memparcel_hdl,
-					struct gh_acl_desc *acl_desc, int src_vmid)
+static inline int mem_buf_map_mem_s2(u32 op, gh_memparcel_handle_t *__memparcel_hdl,
+				     struct gh_acl_desc *acl_desc, struct gh_sgl_desc **__sgl_desc,
+				     int src_vmid)
 {
-	return ERR_PTR(-EINVAL);
+	return -EINVAL;
 }
 
 static inline int mem_buf_unmap_mem_s2(gh_memparcel_handle_t memparcel_hdl)
@@ -109,6 +112,11 @@ static inline struct sg_table *dup_gh_sgl_desc_to_sgt(struct gh_sgl_desc *sgl_de
 	return ERR_PTR(-EINVAL);
 }
 
+static inline struct gh_sgl_desc *dup_gh_sgl_desc(struct gh_sgl_desc *sgl_desc)
+{
+	return ERR_PTR(-EINVAL);
+}
+
 static inline int mem_buf_assign_mem_gunyah(u32 op, struct sg_table *sgt,
 					    struct mem_buf_lend_kernel_arg *arg)
 {

drivers/soc/qcom/mem_buf/mem-buf-gh.c

@@ -396,7 +396,7 @@ static void mem_buf_cleanup_alloc_req(struct mem_buf_xfer_mem *xfer_mem,
 			if (ret < 0)
 				return;
 		} else {
-			struct gh_sgl_desc *sgl_desc;
+			struct gh_sgl_desc *sgl_desc = NULL;
 			struct gh_acl_desc *acl_desc;
 			size_t size;
 
@@ -409,9 +409,9 @@ static void mem_buf_cleanup_alloc_req(struct mem_buf_xfer_mem *xfer_mem,
 			acl_desc->acl_entries[0].vmid = VMID_HLOS;
 			acl_desc->acl_entries[0].perms = GH_RM_ACL_X | GH_RM_ACL_W | GH_RM_ACL_R;
 
-			sgl_desc = mem_buf_map_mem_s2(GH_RM_TRANS_TYPE_DONATE, &memparcel_hdl,
-						      acl_desc, VMID_TUIVM);
-			if (IS_ERR(sgl_desc)) {
+			ret = mem_buf_map_mem_s2(GH_RM_TRANS_TYPE_DONATE, &memparcel_hdl,
+						      acl_desc, &sgl_desc, VMID_TUIVM);
+			if (ret) {
 				kfree(acl_desc);
 				return;
 			}
@@ -879,7 +879,6 @@ static void *mem_buf_alloc(struct mem_buf_allocation_data *alloc_data)
 	int ret;
 	struct file *filp;
 	struct mem_buf_desc *membuf;
-	struct gh_sgl_desc *sgl_desc;
 	int perms = PERM_READ | PERM_WRITE | PERM_EXEC;
 
 	if (!(mem_buf_capability & MEM_BUF_CAP_CONSUMER))
@@ -897,6 +896,8 @@ static void *mem_buf_alloc(struct mem_buf_allocation_data *alloc_data)
 
 	pr_debug("%s: mem buf alloc begin\n", __func__);
 	membuf->size = ALIGN(alloc_data->size, MEM_BUF_MHP_ALIGNMENT);
+
+	/* Create copies of data structures from alloc_data as they may be on-stack */
 	membuf->acl_desc = mem_buf_vmid_perm_list_to_gh_acl(
 				alloc_data->vmids, &perms,
 				alloc_data->nr_acl_entries);
@@ -904,6 +905,15 @@ static void *mem_buf_alloc(struct mem_buf_allocation_data *alloc_data)
 		ret = PTR_ERR(membuf->acl_desc);
 		goto err_alloc_acl_list;
 	}
+
+	if (alloc_data->sgl_desc) {
+		membuf->sgl_desc = dup_gh_sgl_desc(alloc_data->sgl_desc);
+		if (IS_ERR(membuf->sgl_desc)) {
+			ret = PTR_ERR(membuf->sgl_desc);
+			goto err_alloc_sgl_desc;
+		}
+	}
+
 	membuf->trans_type = alloc_data->trans_type;
 	membuf->src_mem_type = alloc_data->src_mem_type;
 	membuf->dst_mem_type = alloc_data->dst_mem_type;
@@ -936,11 +946,10 @@ static void *mem_buf_alloc(struct mem_buf_allocation_data *alloc_data)
 	if (ret)
 		goto err_mem_req;
 
-	sgl_desc = mem_buf_map_mem_s2(membuf->trans_type, &membuf->memparcel_hdl,
-				      membuf->acl_desc, VMID_HLOS);
-	if (IS_ERR(sgl_desc))
+	ret = mem_buf_map_mem_s2(membuf->trans_type, &membuf->memparcel_hdl,
+				 membuf->acl_desc, &membuf->sgl_desc, VMID_HLOS);
+	if (ret)
 		goto err_map_mem_s2;
-	membuf->sgl_desc = sgl_desc;
 
 	ret = mem_buf_map_mem_s1(membuf->sgl_desc);
 	if (ret)
@@ -975,7 +984,6 @@ static void *mem_buf_alloc(struct mem_buf_allocation_data *alloc_data)
 err_map_mem_s1:
 err_map_mem_s2:
 	mem_buf_relinquish_mem(membuf);
-	kvfree(membuf->sgl_desc);
 err_mem_req:
 	mem_buf_destroy_txn(mem_buf_msgq_hdl, membuf->txn);
 err_init_txn:
@@ -983,6 +991,9 @@ static void *mem_buf_alloc(struct mem_buf_allocation_data *alloc_data)
 err_alloc_dst_data:
 	mem_buf_free_mem_type_data(membuf->src_mem_type, membuf->src_data);
 err_alloc_src_data:
+	if (membuf->sgl_desc)
+		kvfree(membuf->sgl_desc);
+err_alloc_sgl_desc:
 	kfree(membuf->acl_desc);
 err_alloc_acl_list:
 	kfree(membuf);
@@ -1077,7 +1088,8 @@ struct dma_buf *mem_buf_retrieve(struct mem_buf_retrieve_kernel_arg *arg)
 	int ret, op;
 	struct qcom_sg_buffer *buffer;
 	struct gh_acl_desc *acl_desc;
-	struct gh_sgl_desc *sgl_desc;
+	/* Hypervisor picks the IPA address */
+	struct gh_sgl_desc *sgl_desc = NULL;
 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 	struct dma_buf *dmabuf;
 	struct sg_table *sgt;
@@ -1100,11 +1112,10 @@ struct dma_buf *mem_buf_retrieve(struct mem_buf_retrieve_kernel_arg *arg)
 	}
 
 	op = mem_buf_get_mem_xfer_type_gh(acl_desc, arg->sender_vmid);
-	sgl_desc = mem_buf_map_mem_s2(op, &arg->memparcel_hdl, acl_desc, arg->sender_vmid);
-	if (IS_ERR(sgl_desc)) {
-		ret = PTR_ERR(sgl_desc);
+	ret = mem_buf_map_mem_s2(op, &arg->memparcel_hdl, acl_desc, &sgl_desc,
+					arg->sender_vmid);
+	if (ret)
 		goto err_map_s2;
-	}
 
 	ret = mem_buf_map_mem_s1(sgl_desc);
 	if (ret < 0)
@@ -1173,6 +1184,7 @@ static int mem_buf_prep_alloc_data(struct mem_buf_allocation_data *alloc_data,
 		goto err_acl;
 
 	/* alloc_data->trans_type set later according to src&dest_mem_type */
+	alloc_data->sgl_desc = NULL;
 	alloc_data->src_mem_type = allocation_args->src_mem_type;
 	alloc_data->dst_mem_type = allocation_args->dst_mem_type;
 

include/linux/mem-buf.h

@@ -40,6 +40,7 @@ int mem_buf_dma_buf_set_destructor(struct dma_buf *dmabuf,
  * @acl_list: A list of VMID and permission pairs that describe what VMIDs will
  * have access to the memory, and with what permissions
  * @trans_type: One of GH_RM_TRANS_TYPE_DONATE/LEND/SHARE
+ * @sgl_desc: Optional. Requests a specific set of IPA addresses.
  * @src_mem_type: The type of memory that the remote VM should allocate
  * (e.g. ION memory)
  * @src_data: A pointer to memory type specific data that the remote VM may need
@@ -55,6 +56,7 @@ struct mem_buf_allocation_data {
 	int *vmids;
 	int *perms;
 	u32 trans_type;
+	struct gh_sgl_desc *sgl_desc;
 	enum mem_buf_mem_type src_mem_type;
 	void *src_data;
 	enum mem_buf_mem_type dst_mem_type;