On Wednesday, March 29, 2023 12:09:44 PM CEST Sakari Ailus wrote: > Parse newly added ACPI _CRS CSI-2 descriptor for CSI-2 and camera > configuration, associate it with appropriate devices and allocate memory for > software nodes needed to create a DT-like data structure for drivers. It occurred to me, that there would be so many things I would like to change in this patch, so it would be better to create my own version of it, which is appended. It is based on https://patchwork.kernel.org/project/linux-acpi/patch/2694293.mvXUDI8C0e@kreacher/ that has just been posted. IIUC, the idea is to extract the ACPI handle for each resource source in every _CRS CSI-2 resource descriptor and count how many times each handle appears in a CSI-2 context, either because it is referenced from a _CRS CSI-2 resource descriptor (as a "resource source"), or because its device object has CSI-2 resource descriptors in _CRS. This allows a set of software nodes to be allocated for each of these handles. If I got that totally wrong, please let me know. Otherwise, I will rework the remaining patches in the series to match this one. Thanks! --- From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Subject: [PATCH] ACPI: scan: Parse _CRS CSI-2 descriptors for all devices Parse ACPI _CRS CSI-2 resource descriptors defined since ACPI 6.4 (for CSI-2 and camera configuration) for all device objects in the ACPI namespace, find the corresponding "remote" device objects for them and allocate memory for software nodes needed to create a DT-like data structure for drivers (that will be taken care of by subsequent patches). Co-developed-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> --- drivers/acpi/Makefile | 2 drivers/acpi/internal.h | 7 drivers/acpi/mipi-disco-imaging.c | 313 ++++++++++++++++++++++++++++++++++++++ drivers/acpi/scan.c | 49 ++++- include/acpi/acpi_bus.h | 11 + 5 files changed, 372 insertions(+), 10 deletions(-) create mode 100644 drivers/acpi/mipi-disco-imaging.c Index: linux-pm/drivers/acpi/Makefile =================================================================== --- linux-pm.orig/drivers/acpi/Makefile +++ linux-pm/drivers/acpi/Makefile @@ -37,7 +37,7 @@ acpi-$(CONFIG_ACPI_SLEEP) += proc.o # ACPI Bus and Device Drivers # acpi-y += bus.o glue.o -acpi-y += scan.o +acpi-y += scan.o mipi-disco-imaging.o acpi-y += resource.o acpi-y += acpi_processor.o acpi-y += processor_core.o Index: linux-pm/drivers/acpi/internal.h =================================================================== --- linux-pm.orig/drivers/acpi/internal.h +++ linux-pm/drivers/acpi/internal.h @@ -282,4 +282,11 @@ void acpi_init_lpit(void); static inline void acpi_init_lpit(void) { } #endif +/*-------------------------------------------------------------------------- + ACPI _CRS CSI-2 and MIPI DisCo for Imaging + -------------------------------------------------------------------------- */ + +void acpi_mipi_check_crs_csi2(acpi_handle handle); +void acpi_mipi_scan_crs_csi2(void); + #endif /* _ACPI_INTERNAL_H_ */ Index: linux-pm/drivers/acpi/mipi-disco-imaging.c =================================================================== --- /dev/null +++ linux-pm/drivers/acpi/mipi-disco-imaging.c @@ -0,0 +1,313 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * MIPI DisCo for Imaging support. + * + * Copyright (C) 2023 Intel Corporation + * + * Support MIPI DisCo for Imaging by parsing ACPI _CRS CSI-2 records defined in + * Section 6.4.3.8.2.4 "Camera Serial Interface (CSI-2) Connection Resource + * Descriptor" of ACPI 6.5. + * + * The implementation looks for the information in the ACPI namespace (CSI-2 + * resource descriptors in _CRS) and constructs software nodes that are + * compatible with Documentation/firmware-guide/acpi/dsd/graph.rst. + */ + +#include <linux/acpi.h> +#include <linux/limits.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/overflow.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/sort.h> +#include <linux/string.h> + +#include "internal.h" + +static LIST_HEAD(acpi_mipi_crs_csi2_list); + +/* + * List entry for the list of devices with software nodes allocated in + * accordance with the information from _CRS CSI-2 device desciptiors. + */ +struct crs_csi2_dev_swnodes { + struct list_head entry; + acpi_handle handle; + struct acpi_device_software_nodes *swnodes; +}; + +static LIST_HEAD(crs_csi2_swnodes); + +static void acpi_mipi_data_tag(acpi_handle handle, void *context) +{ +} + +/* Connection data extracted from one _CRS CSI-2 resource descriptor. */ +struct crs_csi2_connection { + struct list_head entry; + struct acpi_resource_csi2_serialbus csi2_data; + acpi_handle remote_handle; + char remote_name[]; +}; + +/* Data extracted from _CRS CSI-2 resource descriptors for one device. */ +struct crs_csi2 { + struct list_head entry; + acpi_handle handle; + struct list_head connections; + u32 port_count; +}; + +static acpi_status csi2_resource_extract(struct acpi_resource *res, void *context) +{ + struct crs_csi2 *csi2 = context; + struct acpi_resource_csi2_serialbus *csi2_res; + struct acpi_resource_source *csi2_res_src; + u16 csi2_res_src_length; + struct crs_csi2_connection *conn; + acpi_handle remote_handle; + + if (res->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) + return AE_OK; + + csi2_res = &res->data.csi2_serial_bus; + + if (csi2_res->type != ACPI_RESOURCE_SERIAL_TYPE_CSI2) + return AE_OK; + + csi2_res_src = &csi2_res->resource_source; + if (ACPI_FAILURE(acpi_get_handle(NULL, csi2_res_src->string_ptr, + &remote_handle))) { + acpi_handle_debug(csi2->handle, + "unable to find resource source\n"); + return AE_OK; + } + csi2_res_src_length = csi2_res_src->string_length; + if (!csi2_res_src_length) { + acpi_handle_debug(csi2->handle, + "invalid resource source string length\n"); + return AE_OK; + } + + conn = kmalloc(struct_size(conn, remote_name, csi2_res_src_length + 1), + GFP_KERNEL); + if (!conn) + return AE_OK; + + conn->csi2_data = *csi2_res; + strscpy(conn->remote_name, csi2_res_src->string_ptr, csi2_res_src_length); + conn->csi2_data.resource_source.string_ptr = conn->remote_name; + conn->remote_handle = remote_handle; + + list_add(&conn->entry, &csi2->connections); + + return AE_OK; +} + +static struct crs_csi2 *create_crs_csi2_entry(acpi_handle handle) +{ + struct crs_csi2 *csi2_entry; + + csi2_entry = kzalloc(sizeof(*csi2_entry), GFP_KERNEL); + if (!csi2_entry) + return NULL; + + csi2_entry->handle = handle; + INIT_LIST_HEAD(&csi2_entry->connections); + csi2_entry->port_count = 1; + + if (ACPI_FAILURE(acpi_attach_data(handle, acpi_mipi_data_tag, csi2_entry))) { + kfree(csi2_entry); + return NULL; + } + + return csi2_entry; +} + +/** + * acpi_mipi_check_crs_csi2 - Look for devices with _CRS CSI-2 resources + * @handle: ACPI namespace walk starting point. + * + * Find all devices with _CRS CSI-2 resource descriptors in the ACPI namespace + * branch starting at @handle and collect them into a list. + */ +void acpi_mipi_check_crs_csi2(acpi_handle handle) +{ + struct crs_csi2 csi2 = { + .handle = handle, + .connections = LIST_HEAD_INIT(csi2.connections), + }; + struct crs_csi2 *csi2_entry; + + /* + * Avoid creating _CRS CSI-2 list entries for devices without any CSI-2 + * resource descriptions in _CRS to reduce overhead. + */ + acpi_walk_resources(handle, METHOD_NAME__CRS, csi2_resource_extract, &csi2); + if (list_empty(&csi2.connections)) + return; + + /* + * Create a _CRS CSI-2 entry to store the extracted connection + * information and add it to the global list. + */ + csi2_entry = create_crs_csi2_entry(handle); + if (!csi2_entry) + return; /* There's nothing we really can do about this. */ + + list_replace(&csi2.connections, &csi2_entry->connections); + list_add(&csi2_entry->entry, &acpi_mipi_crs_csi2_list); +} + +#define NO_CSI2_PORT (UINT_MAX - 1) + +static void alloc_fill_crs_csi2_swnodes(acpi_handle handle, size_t port_count) +{ + struct acpi_device_software_nodes *swnodes; + struct crs_csi2_dev_swnodes *swnodes_entry; + size_t alloc_size; + unsigned int i; + bool overflow; + + /* + * Allocate memory for ports, node pointers (number of nodes + + * 1 (guardian), nodes (root + number of ports * 2 (because for + * every port there is an endpoint)). + */ + overflow = check_mul_overflow(sizeof(*swnodes->ports) + + sizeof(*swnodes->nodes) * 2 + + sizeof(*swnodes->nodeptrs) * 2, + port_count, &alloc_size); + overflow = overflow || + check_add_overflow(sizeof(*swnodes) + + sizeof(*swnodes->nodes) + + sizeof(*swnodes->nodeptrs) * 2, + alloc_size, &alloc_size); + if (overflow) { + acpi_handle_warn(handle, + "too many _CRS CSI-2 resource handles (%zu)", + port_count); + return; + } + + swnodes_entry = kzalloc(sizeof(*swnodes_entry), GFP_KERNEL); + swnodes = kmalloc(alloc_size, GFP_KERNEL); + if (!swnodes_entry || !swnodes) + goto out_free; + + swnodes->ports = (struct acpi_device_software_node_port *)(swnodes + 1); + swnodes->nodes = (struct software_node *)(swnodes->ports + port_count); + swnodes->nodeptrs = (const struct software_node **)(swnodes->nodes + 1 + + 2 * port_count); + swnodes->num_ports = port_count; + + for (i = 0; i < 2 * port_count + 1; i++) + swnodes->nodeptrs[i] = &swnodes->nodes[i]; + + swnodes->nodeptrs[i] = NULL; + + for (i = 0; i < port_count; i++) + swnodes->ports[i].port_nr = NO_CSI2_PORT; + + swnodes_entry->handle = handle; + swnodes_entry->swnodes = swnodes; + + list_add(&swnodes_entry->entry, &crs_csi2_swnodes); + + return; + +out_free: + kfree(swnodes_entry); + kfree(swnodes); + acpi_handle_debug(handle, "unable to allocate for %zu software nodes\n", + port_count); +} + +static void acpi_mipi_crs_csi2_release(void) +{ + struct crs_csi2 *csi2, *csi2_tmp; + + list_for_each_entry_safe(csi2, csi2_tmp, &acpi_mipi_crs_csi2_list, entry) { + struct crs_csi2_connection *conn, *conn_tmp; + + list_for_each_entry_safe(conn, conn_tmp, &csi2->connections, + entry) { + list_del(&conn->entry); + kfree(conn); + } + + list_del(&csi2->entry); + acpi_detach_data(csi2->handle, acpi_mipi_data_tag); + kfree(csi2); + } +} + +/** + * acpi_mipi_scan_crs_csi2 - Allocate ACPI _CRS CSI-2 software nodes + * + * Note that this function must be called before any struct acpi_device objects + * are bound to any ACPI drivers or scan handlers, so it cannot assume the + * existence of struct acpi_device objects for every device present in the ACPI + * namespace. + * + * acpi_scan_lock in scan.c must be held when calling this function. + */ +void acpi_mipi_scan_crs_csi2(void) +{ + struct crs_csi2 *csi2; + LIST_HEAD(aux_list); + + /* Count references to each ACPI handle in the CSI-2 connection graph. */ + list_for_each_entry(csi2, &acpi_mipi_crs_csi2_list, entry) { + struct crs_csi2_connection *conn; + + list_for_each_entry(conn, &csi2->connections, entry) { + struct crs_csi2 *remote_csi2; + acpi_status status; + + status = acpi_get_data_full(conn->remote_handle, + acpi_mipi_data_tag, + (void **)&remote_csi2, + NULL); + if (ACPI_SUCCESS(status) && remote_csi2) { + remote_csi2->port_count++; + continue; + } + + /* + * The "remote" device has no _CRS CSI-2 list entry yet, + * so create one for it and add it to the list. + */ + remote_csi2 = create_crs_csi2_entry(conn->remote_handle); + if (!remote_csi2) + continue; + + list_add(&remote_csi2->entry, &aux_list); + } + } + list_splice(&aux_list, &acpi_mipi_crs_csi2_list); + + /* Allocate softwware nodes for representing the CSI-2 information. */ + list_for_each_entry(csi2, &acpi_mipi_crs_csi2_list, entry) + alloc_fill_crs_csi2_swnodes(csi2->handle, csi2->port_count); + + acpi_mipi_crs_csi2_release(); +} + +static void crs_csi2_swnode_del_free(struct crs_csi2_dev_swnodes *swnodes) +{ + list_del(&swnodes->entry); + kfree(swnodes); +} + +/** + * acpi_mipi_swnodes_release - Free the list of devices with _CRS CSI-2 swnodes + */ +void acpi_mipi_swnodes_release(void) +{ + struct crs_csi2_dev_swnodes *sn, *sn_tmp; + + list_for_each_entry_safe(sn, sn_tmp, &crs_csi2_swnodes, entry) + crs_csi2_swnode_del_free(sn); +} Index: linux-pm/include/acpi/acpi_bus.h =================================================================== --- linux-pm.orig/include/acpi/acpi_bus.h +++ linux-pm/include/acpi/acpi_bus.h @@ -363,6 +363,17 @@ struct acpi_device_data { struct acpi_gpio_mapping; +struct acpi_device_software_node_port { + unsigned int port_nr; +}; + +struct acpi_device_software_nodes { + struct software_node *nodes; + const struct software_node **nodeptrs; + struct acpi_device_software_node_port *ports; + unsigned int num_ports; +}; + /* Device */ struct acpi_device { u32 pld_crc; Index: linux-pm/drivers/acpi/scan.c =================================================================== --- linux-pm.orig/drivers/acpi/scan.c +++ linux-pm/drivers/acpi/scan.c @@ -1970,7 +1970,7 @@ static void acpi_scan_init_hotplug(struc } } -static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep) +static u32 acpi_scan_check_dep(acpi_handle handle) { struct acpi_handle_list dep_devices; acpi_status status; @@ -1983,8 +1983,7 @@ static u32 acpi_scan_check_dep(acpi_hand * 2. ACPI nodes describing USB ports. * Still, checking for _HID catches more then just these cases ... */ - if (!check_dep || !acpi_has_method(handle, "_DEP") || - !acpi_has_method(handle, "_HID")) + if (!acpi_has_method(handle, "_DEP") || !acpi_has_method(handle, "_HID")) return 0; status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices); @@ -2029,7 +2028,16 @@ static u32 acpi_scan_check_dep(acpi_hand return count; } -static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep, +static acpi_status acpi_scan_check_crs_csi2_cb(acpi_handle handle, + u32 lvl_not_used, + void *not_used, + void **ret_p_not_used) +{ + acpi_mipi_check_crs_csi2(handle); + return AE_OK; +} + +static acpi_status acpi_bus_check_add(acpi_handle handle, bool first_pass, struct acpi_device **adev_p) { struct acpi_device *device = acpi_fetch_acpi_dev(handle); @@ -2047,9 +2055,25 @@ static acpi_status acpi_bus_check_add(ac if (acpi_device_should_be_hidden(handle)) return AE_OK; - /* Bail out if there are dependencies. */ - if (acpi_scan_check_dep(handle, check_dep) > 0) - return AE_CTRL_DEPTH; + if (first_pass) { + acpi_mipi_check_crs_csi2(handle); + + /* Bail out if there are dependencies. */ + if (acpi_scan_check_dep(handle) > 0) { + /* + * The entire CSI-2 connection graph needs to be + * extracted before any drivers or scan handlers + * are bound to struct device objects, so scan + * _CRS CSI-2 resource descriptors for all + * devices below the current handle. + */ + acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, + ACPI_UINT32_MAX, + acpi_scan_check_crs_csi2_cb, + NULL, NULL, NULL); + return AE_CTRL_DEPTH; + } + } fallthrough; case ACPI_TYPE_ANY: /* for ACPI_ROOT_OBJECT */ @@ -2072,10 +2096,10 @@ static acpi_status acpi_bus_check_add(ac } /* - * If check_dep is true at this point, the device has no dependencies, + * If first_pass is true at this point, the device has no dependencies, * or the creation of the device object would have been postponed above. */ - acpi_add_single_object(&device, handle, type, !check_dep); + acpi_add_single_object(&device, handle, type, !first_pass); if (!device) return AE_CTRL_DEPTH; @@ -2487,6 +2511,13 @@ int acpi_bus_scan(acpi_handle handle) if (!device) return -ENODEV; + /* + * Allocate ACPI _CRS CSI-2 software nodes using information extracted + * from the _CRS CSI-2 resource descriptors during the ACPI namespace + * walk above. + */ + acpi_mipi_scan_crs_csi2(); + acpi_bus_attach(device, (void *)true); /* Pass 2: Enumerate all of the remaining devices. */
