[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [XEN][RFC PATCH v3 11/14] xen/arm: Implement device tree node addition functionalities
Update sysctl XEN_SYSCTL_dt_overlay to enable support for dtbo nodes addition using device tree overlay. xl overlay add file.dtbo: Each time overlay nodes are added using .dtbo, a new fdt(memcpy of device_tree_flattened) is created and updated with overlay nodes. This updated fdt is further unflattened to a dt_host_new. Next, it checks if any of the overlay nodes already exists in the dt_host. If overlay nodes doesn't exist then find the overlay nodes in dt_host_new, find the overlay node's parent in dt_host and add the nodes as child under their parent in the dt_host. The node is attached as the last node under target parent. Finally, add IRQs, add device to IOMMUs, set permissions and map MMIO for the overlay node. When a node is added using overlay, a new entry is allocated in the overlay_track to keep the track of memory allocation due to addition of overlay node. This is helpful for freeing the memory allocated when a device tree node is removed. Signed-off-by: Vikram Garhwal <fnu.vikram@xxxxxxxxxx> --- xen/common/dt_overlay.c | 324 ++++++++++++++++++++++++++++++++++++ xen/include/public/sysctl.h | 1 + 2 files changed, 325 insertions(+) diff --git a/xen/common/dt_overlay.c b/xen/common/dt_overlay.c index fcb31de495..01aed62d74 100644 --- a/xen/common/dt_overlay.c +++ b/xen/common/dt_overlay.c @@ -82,6 +82,64 @@ static int dt_overlay_remove_node(struct dt_device_node *device_node) return 0; } +static int dt_overlay_add_node(struct dt_device_node *device_node, + const char *parent_node_path) +{ + struct dt_device_node *parent_node; + struct dt_device_node *np; + struct dt_device_node *next_node; + struct dt_device_node *new_node; + + parent_node = dt_find_node_by_path(parent_node_path); + + new_node = device_node; + + if ( new_node == NULL ) + return -EINVAL; + + if ( parent_node == NULL ) + { + dt_dprintk("Node not found. Partial dtb will not be added"); + return -EINVAL; + } + + /* + * If node is found. We can attach the device_node as a child of the + * parent node. + */ + + /* If parent has no child. */ + if ( parent_node->child == NULL ) + { + next_node = parent_node->allnext; + new_node->parent = parent_node; + parent_node->allnext = new_node; + parent_node->child = new_node; + /* Now plug next_node at the end of device_node. */ + new_node->allnext = next_node; + } else { + /* If parent has at least one child node. */ + + /* + * Iterate to the last child node of parent. + */ + for ( np = parent_node->child; np->sibling != NULL; np = np->sibling ) + { + } + + next_node = np->allnext; + new_node->parent = parent_node; + np->sibling = new_node; + np->allnext = new_node; + /* Now plug next_node at the end of device_node. */ + new_node->sibling = next_node; + new_node->allnext = next_node; + np->sibling->sibling = NULL; + } + + return 0; +} + /* Basic sanity check for the dtbo tool stack provided to Xen. */ static int check_overlay_fdt(const void *overlay_fdt, uint32_t overlay_fdt_size) { @@ -377,6 +435,267 @@ out: return rc; } +/* + * Adds device tree nodes under target node. + * We use dt_host_new to unflatten the updated device_tree_flattened. This is + * done to avoid the removal of device_tree generation, iomem regions mapping to + * hardware domain done by handle_node(). + */ +static long handle_add_overlay_nodes(void *overlay_fdt, + uint32_t overlay_fdt_size) +{ + int rc = 0; + struct dt_device_node *overlay_node; + char **nodes_full_path = NULL; + int **nodes_irq = NULL; + int *node_num_irq = NULL; + void *fdt = NULL; + struct dt_device_node *dt_host_new = NULL; + struct domain *d = hardware_domain; + struct overlay_track *tr = NULL; + unsigned int naddr; + unsigned int num_irq; + unsigned int i, j, k; + unsigned int num_overlay_nodes; + u64 addr, size; + + fdt = xmalloc_bytes(fdt_totalsize(device_tree_flattened)); + if ( fdt == NULL ) + return -ENOMEM; + + num_overlay_nodes = overlay_node_count(overlay_fdt); + if ( num_overlay_nodes == 0 ) + { + xfree(fdt); + return -ENOMEM; + } + + spin_lock(&overlay_lock); + + memcpy(fdt, device_tree_flattened, fdt_totalsize(device_tree_flattened)); + + rc = check_overlay_fdt(overlay_fdt, overlay_fdt_size); + if ( rc ) + { + xfree(fdt); + return rc; + } + + /* + * overlay_get_nodes_info is called to get the node information from dtbo. + * This is done before fdt_overlay_apply() because the overlay apply will + * erase the magic of overlay_fdt. + */ + rc = overlay_get_nodes_info(overlay_fdt, &nodes_full_path, + num_overlay_nodes); + if ( rc ) + { + printk(XENLOG_ERR "Getting nodes information failed with error %d\n", + rc); + goto err; + } + + nodes_irq = xmalloc_bytes(num_overlay_nodes * sizeof(int *)); + + if ( nodes_irq == NULL ) + { + rc = -ENOMEM; + goto err; + } + memset(nodes_irq, 0x0, num_overlay_nodes * sizeof(int *)); + + node_num_irq = xmalloc_bytes(num_overlay_nodes * sizeof(int)); + if ( node_num_irq == NULL ) + { + rc = -ENOMEM; + goto err; + } + memset(node_num_irq, 0x0, num_overlay_nodes * sizeof(int)); + + rc = fdt_overlay_apply(fdt, overlay_fdt); + if ( rc ) + { + printk(XENLOG_ERR "Adding overlay node failed with error %d\n", rc); + goto err; + } + + for ( j = 0; j < num_overlay_nodes; j++ ) + { + /* Check if any of the node already exists in dt_host. */ + overlay_node = dt_find_node_by_path(nodes_full_path[j]); + if ( overlay_node != NULL ) + { + printk(XENLOG_ERR "node %s exists in device tree\n", + nodes_full_path[j]); + rc = -EINVAL; + goto err; + } + } + + /* Unflatten the fdt into a new dt_host. */ + unflatten_device_tree(fdt, &dt_host_new); + + for ( j = 0; j < num_overlay_nodes; j++ ) + { + dt_dprintk("Adding node: %s\n", nodes_full_path[j]); + + /* Find the newly added node in dt_host_new by it's full path. */ + overlay_node = _dt_find_node_by_path(dt_host_new, nodes_full_path[j]); + if ( overlay_node == NULL ) + { + dt_dprintk("%s node not found\n", nodes_full_path[j]); + rc = -EFAULT; + goto remove_node; + } + + /* Add the node to dt_host. */ + rc = dt_overlay_add_node(overlay_node, overlay_node->parent->full_name); + if ( rc ) + { + /* Node not added in dt_host. */ + goto remove_node; + } + + overlay_node = dt_find_node_by_path(overlay_node->full_name); + if ( overlay_node == NULL ) + { + /* Sanity check. But code will never come here. */ + printk(XENLOG_ERR "Cannot find %s node under updated dt_host\n", + overlay_node->name); + goto remove_node; + } + + /* First let's handle the interrupts. */ + rc = handle_device_interrupts(d, overlay_node, false); + if ( rc ) + { + printk(XENLOG_ERR "Interrupt failed\n"); + goto remove_node; + } + + /* Store IRQs for each node. */ + num_irq = dt_number_of_irq(overlay_node); + node_num_irq[j] = num_irq; + nodes_irq[j] = xmalloc_bytes(num_irq * sizeof(int)); + if ( nodes_irq[j] == NULL ) + { + rc = -ENOMEM; + goto remove_node; + } + + for ( k = 0; k < num_irq; k++ ) + { + nodes_irq[j][k] = platform_get_irq(overlay_node, k); + } + + /* Add device to IOMMUs */ + rc = iommu_add_dt_device(overlay_node); + if ( rc < 0 ) + { + printk(XENLOG_ERR "Failed to add %s to the IOMMU\n", + dt_node_full_name(overlay_node)); + goto remove_node; + } + + /* Set permissions. */ + naddr = dt_number_of_address(overlay_node); + + dt_dprintk("%s passthrough = %d naddr = %u\n", + dt_node_full_name(overlay_node), false, naddr); + + /* Give permission for map MMIOs */ + for ( i = 0; i < naddr; i++ ) + { + struct map_range_data mr_data = { .d = d, + .p2mt = p2m_mmio_direct_c, + .skip_mapping = true }; + rc = dt_device_get_address(overlay_node, i, &addr, &size); + if ( rc ) + { + printk(XENLOG_ERR "Unable to retrieve address %u for %s\n", + i, dt_node_full_name(overlay_node)); + goto remove_node; + } + + rc = map_range_to_domain(overlay_node, addr, size, &mr_data); + if ( rc ) + goto remove_node; + } + } + + /* This will happen if everything above goes right. */ + tr = xzalloc(struct overlay_track); + if ( tr == NULL ) + { + rc = -ENOMEM; + goto remove_node; + } + + tr->dt_host_new = dt_host_new; + tr->fdt = fdt; + tr->nodes_fullname = nodes_full_path; + tr->num_nodes = num_overlay_nodes; + tr->nodes_irq = nodes_irq; + tr->node_num_irq = node_num_irq; + + if ( tr->nodes_fullname == NULL ) + { + rc = -ENOMEM; + goto remove_node; + } + + INIT_LIST_HEAD(&tr->entry); + list_add_tail(&tr->entry, &overlay_tracker); + + spin_unlock(&overlay_lock); + return rc; + +/* + * Failure case. We need to remove the nodes, free tracker(if tr exists) and + * dt_host_new. + */ +remove_node: + rc = remove_nodes(nodes_full_path, nodes_irq, node_num_irq, j); + + if ( rc ) + { + printk(XENLOG_ERR "Removing node failed\n"); + spin_unlock(&overlay_lock); + return rc; + } + +err: + spin_unlock(&overlay_lock); + + xfree(dt_host_new); + xfree(fdt); + + if ( nodes_full_path != NULL ) + { + for ( i = 0; i < num_overlay_nodes && nodes_full_path[i] != NULL; i++ ) + { + xfree(nodes_full_path[i]); + } + xfree(nodes_full_path); + } + + if ( nodes_irq != NULL ) + { + for ( i = 0; i < num_overlay_nodes && nodes_irq[i] != NULL; i++ ) + { + xfree(nodes_irq[i]); + } + xfree(nodes_irq); + } + + if ( node_num_irq ) + xfree(node_num_irq); + + xfree(tr); + + return rc; +} + long dt_sysctl(struct xen_sysctl *op) { long ret = 0; @@ -404,6 +723,11 @@ long dt_sysctl(struct xen_sysctl *op) switch ( op->u.dt_overlay.overlay_op ) { + case XEN_SYSCTL_DT_OVERLAY_ADD: + ret = handle_add_overlay_nodes(overlay_fdt, + op->u.dt_overlay.overlay_fdt_size); + break; + case XEN_SYSCTL_DT_OVERLAY_REMOVE: ret = check_overlay_fdt(overlay_fdt, op->u.dt_overlay.overlay_fdt_size); diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h index e256aeb7c6..bb3ef44989 100644 --- a/xen/include/public/sysctl.h +++ b/xen/include/public/sysctl.h @@ -1069,6 +1069,7 @@ typedef struct xen_sysctl_cpu_policy xen_sysctl_cpu_policy_t; DEFINE_XEN_GUEST_HANDLE(xen_sysctl_cpu_policy_t); #endif +#define XEN_SYSCTL_DT_OVERLAY_ADD 1 #define XEN_SYSCTL_DT_OVERLAY_REMOVE 2 /* -- 2.17.1
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