Note: The report from Dan Carpenter has not been addressed.
On Wed, Feb 8, 2023 at 10:27 PM Sakari Ailus
<sakari.ailus@xxxxxxxxxxxxxxx> wrote:
>
> Parse newly added ACPI _CRS CSI-2 descriptor for CSI-2 and camera
> configuration. For now, only figure out where the descriptor is present in
> order to allow adding information from it to related devices.
This should contain (a) pointer(s) to the relevant specification material.
> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> ---
> drivers/acpi/Makefile | 2 +-
> drivers/acpi/internal.h | 7 +
> drivers/acpi/mipi.c | 358 ++++++++++++++++++++++++++++++++++++++++
> drivers/acpi/scan.c | 16 +-
> include/acpi/acpi_bus.h | 11 ++
> 5 files changed, 389 insertions(+), 5 deletions(-)
> create mode 100644 drivers/acpi/mipi.c
>
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index a5b649e71ab1b..a98fa1bc15548 100644
> --- a/drivers/acpi/Makefile
> +++ b/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.o
> acpi-y += resource.o
> acpi-y += acpi_processor.o
> acpi-y += processor_core.o
> diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
> index ec584442fb298..1ec4aa92bf17a 100644
> --- a/drivers/acpi/internal.h
> +++ b/drivers/acpi/internal.h
> @@ -282,4 +282,11 @@ void acpi_init_lpit(void);
> static inline void acpi_init_lpit(void) { }
> #endif
>
> +/*--------------------------------------------------------------------------
> + ACPI and MIPI DisCo for Imaging conversion
> + -------------------------------------------------------------------------- */
> +
> +void acpi_crs_csi2_swnodes_del_free(void);
> +void acpi_bus_scan_crs_csi2(acpi_handle handle);
> +
> #endif /* _ACPI_INTERNAL_H_ */
> diff --git a/drivers/acpi/mipi.c b/drivers/acpi/mipi.c
> new file mode 100644
> index 0000000000000..33d50df831933
> --- /dev/null
> +++ b/drivers/acpi/mipi.c
> @@ -0,0 +1,358 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * MIPI DisCo for Imaging support.
I do realize that the last patch in the series contains the
description of this code, but it would be really helpful to put at
least some of it here and update it in the following patches as the
code gets modified.
> + *
> + * Copyright (C) 2023 Intel Corporation
> + */
> +
> +#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"
> +
> +/* Temporary ACPI device handle to software node data structure mapping */
> +struct crs_csi2_swnodes {
> + struct list_head list;
> + acpi_handle handle;
> + struct acpi_device_software_nodes *ads;
> +};
> +
> +static LIST_HEAD(crs_csi2_swnodes);
> +
> +static void crs_csi2_swnode_del_free(struct crs_csi2_swnodes *swnodes)
> +{
> + list_del(&swnodes->list);
> + kfree(swnodes);
> +}
> +
> +void acpi_crs_csi2_swnodes_del_free(void)
> +{
> + struct crs_csi2_swnodes *swnodes, *swnodes_tmp;
> +
> + list_for_each_entry_safe(swnodes, swnodes_tmp, &crs_csi2_swnodes, list)
> + crs_csi2_swnode_del_free(swnodes);
> +}
> +
> +/*
> + * Description of a _CRS CSI2 resource descriptor before software node creation
> + */
> +struct crs_csi2_instance {
> + struct list_head list;
> + struct acpi_resource_csi2_serialbus csi2;
> + acpi_handle remote_handle;
> + char remote_name[];
> +};
> +
> +/* Temporary list of ACPI device nodes with _CRS CSI2 resource descriptors */
> +struct crs_csi2 {
> + struct list_head list;
> + acpi_handle handle;
> + struct list_head buses;
> +};
> +
> +/*
> + * Context for collecting _CRS CSI2 resource descriptors during ACPI namespace
> + * walk
> + */
> +struct scan_check_crs_csi2_context {
> + struct list_head res_head;
> + acpi_handle handle;
> + size_t handle_count;
> +};
> +
> +/* Context for scanning ACPI device nodes for _CRS CSI2 resource descriptors */
> +struct crs_csi2_all {
> + struct list_head crs_csi2_head;
> + size_t handle_count;
> +};
> +
> +/* Scan a single CSI2 resource descriptor in _CRS. */
> +static acpi_status scan_check_crs_csi2_instance(struct acpi_resource *res,
> + void *context)
> +{
> + struct scan_check_crs_csi2_context *inst_context = context;
> + struct acpi_resource_csi2_serialbus *csi2;
> + struct crs_csi2_instance *inst;
> + acpi_handle remote_handle;
> +
> + if (res->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
> + return AE_OK;
> +
> + csi2 = &res->data.csi2_serial_bus;
> +
> + if (csi2->type != ACPI_RESOURCE_SERIAL_TYPE_CSI2)
> + return AE_OK;
> +
> + if (!csi2->resource_source.string_length) {
> + acpi_handle_debug(inst_context->handle,
> + "invalid resource source string length\n");
> + return AE_OK;
> + }
> +
> + if (ACPI_FAILURE(acpi_get_handle(NULL, csi2->resource_source.string_ptr,
> + &remote_handle))) {
> + acpi_handle_warn(inst_context->handle,
> + "cannot get handle for %s\n",
> + csi2->resource_source.string_ptr);
> + return AE_OK;
> + }
> +
> + /*
> + * Allocate space to store the _CRS CSI2 entry and its data and add it
> + * to the list.
> + */
> + inst = kmalloc(struct_size(inst, remote_name, csi2->resource_source.string_length),
> + GFP_KERNEL);
> + if (!inst)
> + return AE_OK;
> +
> + inst->csi2 = *csi2;
> + strscpy(inst->remote_name, csi2->resource_source.string_ptr,
> + csi2->resource_source.string_length);
> + inst->csi2.resource_source.string_ptr = inst->remote_name;
> + inst->remote_handle = remote_handle;
> +
> + list_add(&inst->list, &inst_context->res_head);
> +
> + inst_context->handle_count++;
> +
> + return AE_OK;
> +}
> +
> +/*
> + * Find all devices with _CRS CSI2 resource descriptors and collect them
> + * into a list for later use.
> + */
> +static acpi_status scan_check_crs_csi2(acpi_handle handle, u32 nesting_level,
> + void *context, void **ret)
> +{
> + struct scan_check_crs_csi2_context inst_context = {
> + .handle = handle,
> + .res_head = LIST_HEAD_INIT(inst_context.res_head),
> + };
> + struct crs_csi2_all *csi2_all = context;
> + struct crs_csi2 *csi2;
> +
> + acpi_walk_resources(handle, METHOD_NAME__CRS,
> + scan_check_crs_csi2_instance, &inst_context);
> +
> + if (list_empty(&inst_context.res_head))
> + return AE_OK;
> +
> + /*
> + * Found entry, so allocate memory for it, fill it and add it to the
> + * list.
> + */
> + csi2 = kmalloc(sizeof(*csi2), GFP_KERNEL);
> + if (!csi2)
> + return AE_OK;
> +
> + csi2->handle = handle;
> + list_replace(&inst_context.res_head, &csi2->buses);
> + list_add(&csi2->list, &csi2_all->crs_csi2_head);
> +
> + /* This handle plus remote handles in _CRS CSI2 resource descriptors */
> + csi2_all->handle_count += 1 + inst_context.handle_count;
> +
> + return AE_OK;
> +}
> +
> +struct acpi_handle_ref {
> + acpi_handle handle;
> + unsigned int count;
> +};
> +
> +#define NO_CSI2_PORT (UINT_MAX - 1)
> +
> +static int crs_handle_cmp(const void *__a, const void *__b)
> +{
> + const struct acpi_handle_ref *a = __a, *b = __b;
> +
> + return a->handle < b->handle ? -1 : a->handle > b->handle;
> +}
> +
> +/*
> + * Release entries in temporary storage of ACPI device nodes with _CRS CSI2
> + * resource descriptors.
> + */
> +static void crs_csi2_release(struct list_head *crs_csi2_handles)
> +{
> + struct crs_csi2 *csi2, *csi2_tmp;
> +
> + list_for_each_entry_safe(csi2, csi2_tmp, crs_csi2_handles, list) {
> + struct crs_csi2_instance *inst, *inst_tmp;
> +
> + list_for_each_entry_safe(inst, inst_tmp, &csi2->buses, list) {
> + list_del(&inst->list);
> + kfree(inst);
> + }
> +
> + list_del(&csi2->list);
> + kfree(csi2);
> + }
> +}
> +
> +/*
> + * Allocate memory and set up software nodes for an ACPI device with given
> + * number of CSI-2 ports.
> + */
> +void acpi_crs_csi2_alloc_fill_swnodes(size_t ports_count, acpi_handle handle)
> +{
> + struct acpi_device_software_nodes *ads;
> + struct crs_csi2_swnodes *swnodes;
> + size_t alloc_size;
> + unsigned int i;
> + bool overflow;
> + void *end;
> +
> + /*
> + * Allocate memory for ports, node pointers (number of nodes +
> + * 1 (guardian), nodes (root + number of ports * 2 (for for
> + * every port there is an endpoint)).
> + */
> + overflow = check_mul_overflow(sizeof(*ads->ports) +
> + sizeof(*ads->nodes) * 2 +
> + sizeof(*ads->nodeptrs) * 2,
> + ports_count, &alloc_size);
> + overflow = overflow ||
> + check_add_overflow(sizeof(*ads) + sizeof(*ads->nodes) +
> + sizeof(*ads->nodeptrs) * 2,
> + alloc_size, &alloc_size);
> + if (overflow) {
> + acpi_handle_warn(handle,
> + "too many _CRS CSI2 resource handles (%zu)",
> + ports_count);
> + return;
> + }
> +
> + swnodes = kzalloc(sizeof(*swnodes), GFP_KERNEL);
> + ads = kzalloc(alloc_size, GFP_KERNEL);
> + ads->ports = (void *)(ads + 1);
> + ads->nodes = (void *)(ads->ports + ports_count);
> + ads->nodeptrs = (void *)(ads->nodes + ports_count * 2 + 1);
> + end = ads->nodeptrs + ports_count * 2 + 2;
> + if (!swnodes || !ads || WARN_ON((void *)ads + alloc_size != end)) {
> + kfree(swnodes);
> + kfree(ads);
> + acpi_handle_debug(handle,
> + "cannot allocate for %zu software nodes\n",
> + ports_count);
> + return;
> + }
> +
> + ads->num_ports = ports_count;
> + for (i = 0; i < ports_count * 2 + 1; i++)
> + ads->nodeptrs[i] = &ads->nodes[i];
> + ads->nodeptrs[i] = NULL;
> + for (i = 0; i < ports_count; i++)
> + ads->ports[i].port_nr = NO_CSI2_PORT;
> + swnodes->handle = handle;
> + swnodes->ads = ads;
> + list_add(&swnodes->list, &crs_csi2_swnodes);
> +}
> +
> +/**
> + * acpi_bus_scan_crs_csi2 - Scan a device and its child devices for _CRS CSI-2
> + *
> + * @handle: Root of the ACPI Namespace branch to scan
> + *
> + * This function does a number of things:
> + *
> + * 1. Iteratively scan all ACPI device nodes starting from a handle for _CRS
> + * CSI-2 instances. The instances are stored for later use.
> + *
> + * 2. Count how many references to other devices _CRS CSI-2 instances have in
> + * total.
> + *
> + * 3. Count the number of references to other devices for each _CRS CSI-2
> + * instance.
> + *
> + * 4. Allocate memory for swnodes each ACPI device requires later on, and
> + * generate a list of such allocations.
> + *
> + * Note that struct acpi_device isn't available yet at this time.
> + *
> + * acpi_scan_lock in scan.c must be held when calling this function.
> + */
> +void acpi_bus_scan_crs_csi2(acpi_handle handle)
> +{
> + struct acpi_handle_ref *handle_refs;
> + struct acpi_handle_ref *this = NULL;
> + struct crs_csi2_all csi2_all = {
> + .crs_csi2_head = LIST_HEAD_INIT(csi2_all.crs_csi2_head),
> + };
> + size_t this_count;
> + unsigned int curr = 0;
> + struct crs_csi2 *csi2;
> +
> + /*
> + * Collect the devices that have a _CRS CSI-2 resource. Each CSI-2 TX
> + * port has one.
> + */
> + acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, ACPI_UINT32_MAX,
> + scan_check_crs_csi2, NULL, &csi2_all, NULL);
I still don't like this walk and I still think that it is avoidable.
At least I don't see why it isn't avoidable ATM.
> +
> + /* No handles? Bail out here. */
> + if (!csi2_all.handle_count)
> + return;
> +
> + handle_refs = kcalloc(csi2_all.handle_count + 1, sizeof(*handle_refs),
> + GFP_KERNEL);
> + if (!handle_refs) {
> + acpi_handle_debug(handle, "no memory for %zu handle refs\n",
> + csi2_all.handle_count + 1);
> + return;
> + }
> +
> + /* Associate handles to the number of references. */
> + list_for_each_entry(csi2, &csi2_all.crs_csi2_head, list) {
> + struct crs_csi2_instance *inst;
> + struct acpi_handle_ref *handle_ref;
> +
> + handle_ref = &handle_refs[curr++];
> + handle_ref->handle = csi2->handle;
> +
> + list_for_each_entry(inst, &csi2->buses, list) {
> + handle_refs[curr].handle = inst->remote_handle;
> + handle_refs[curr].count = 1;
> + handle_ref->count++;
> + curr++;
> + }
> + }
> +
> + handle_refs[curr].handle = NULL;
> +
> + /* Sort the handles by remote so duplicates canbe easily found. */
> + sort(handle_refs, csi2_all.handle_count, sizeof(*handle_refs), crs_handle_cmp, NULL);
> +
> + /*
> + * Finally count references in each handle, allocate space for device
> + * specific ports, properties and fill the _CRS CSI2 descriptor
> + * originated data.
> + */
> + this = handle_refs;
> + this_count = this->count;
> + for (curr = 1; curr < csi2_all.handle_count + 1; curr++) {
> + /* Weed out duplicate receiver devices. */
> + if (this->handle == handle_refs[curr].handle) {
> + this_count += handle_refs[curr].count;
> + continue;
> + }
> +
> + acpi_crs_csi2_alloc_fill_swnodes(this_count, this->handle);
> +
> + this = &handle_refs[curr];
> + this_count = this->count;
> + }
> +
> + kfree(handle_refs);
> +
> + crs_csi2_release(&csi2_all.crs_csi2_head);
> +}
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 0c6f06abe3f47..50de874b8f208 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -2423,9 +2423,12 @@ EXPORT_SYMBOL_GPL(acpi_dev_get_next_consumer_dev);
> int acpi_bus_scan(acpi_handle handle)
> {
> struct acpi_device *device = NULL;
> + int ret = 0;
>
> acpi_bus_scan_second_pass = false;
>
> + acpi_bus_scan_crs_csi2(handle);
> +
> /* Pass 1: Avoid enumerating devices with missing dependencies. */
>
> if (ACPI_SUCCESS(acpi_bus_check_add(handle, true, &device)))
> @@ -2433,13 +2436,15 @@ int acpi_bus_scan(acpi_handle handle)
> acpi_bus_check_add_1, NULL, NULL,
> (void **)&device);
>
> - if (!device)
> - return -ENODEV;
> + if (!device) {
> + ret = -ENODEV;
> + goto out_release;
> + }
>
> acpi_bus_attach(device, (void *)true);
>
> if (!acpi_bus_scan_second_pass)
> - return 0;
> + goto out_release;
>
> /* Pass 2: Enumerate all of the remaining devices. */
>
> @@ -2452,7 +2457,10 @@ int acpi_bus_scan(acpi_handle handle)
>
> acpi_bus_attach(device, NULL);
>
> - return 0;
> +out_release:
> + acpi_crs_csi2_swnodes_del_free();
> +
> + return ret;
> }
> EXPORT_SYMBOL(acpi_bus_scan);
>
> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index e44be31115a67..a05fe22c1175c 100644
> --- a/include/acpi/acpi_bus.h
> +++ b/include/acpi/acpi_bus.h
> @@ -360,6 +360,17 @@ struct acpi_device_data {
>
> struct acpi_gpio_mapping;
>
> +struct acpi_device_software_node_port {
> + unsigned int port_nr;
> +};
> +
> +struct acpi_device_software_nodes {
> + struct acpi_device_software_node_port *ports;
> + struct software_node *nodes;
> + const struct software_node **nodeptrs;
> + unsigned int num_ports;
> +};
> +
> /* Device */
> struct acpi_device {
> u32 pld_crc;
> --
> 2.30.2
>
