Hi Mathieu
-----Original Message-----
From: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Date: Tuesday, March 9, 2021 at 8:53 AM
To: Ben Levinsky <BLEVINSK@xxxxxxxxxx>
Cc: "devicetree@xxxxxxxxxxxxxxx" <devicetree@xxxxxxxxxxxxxxx>, "linux-remoteproc@xxxxxxxxxxxxxxx" <linux-remoteproc@xxxxxxxxxxxxxxx>, "linux-kernel@xxxxxxxxxxxxxxx" <linux-kernel@xxxxxxxxxxxxxxx>, "linux-arm-kernel@xxxxxxxxxxxxxxxxxxx" <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>, Michal Simek <michals@xxxxxxxxxx>
Subject: Re: [PATCH v26 5/5] remoteproc: Add initial zynqmp R5 remoteproc driver
[...]
> +
> +/**
> + * zynqmp_r5_probe - Probes ZynqMP R5 processor device node
> + * this is called for each individual R5 core to
> + * set up mailbox, Xilinx platform manager unique ID,
> + * add to rproc core
> + *
> + * @pdev: domain platform device for current R5 core
> + * @node: pointer of the device node for current R5 core
> + * @rpu_mode: mode to configure RPU, split or lockstep
> + *
> + * Return: 0 for success, negative value for failure.
> + */
> +static struct zynqmp_r5_rproc *zynqmp_r5_probe(struct platform_device *pdev,
> + struct device_node *node,
> + enum rpu_oper_mode rpu_mode)
> +{
> + int ret, num_banks;
> + struct device *dev = &pdev->dev;
> + struct rproc *rproc_ptr;
> + struct zynqmp_r5_rproc *z_rproc;
> + struct device_node *r5_node;
> +
> + /* Allocate remoteproc instance */
> + rproc_ptr = devm_rproc_alloc(dev, dev_name(dev), &zynqmp_r5_rproc_ops,
> + NULL, sizeof(struct zynqmp_r5_rproc));
> + if (!rproc_ptr) {
> + ret = -ENOMEM;
> + goto error;
> + }
> +
> + rproc_ptr->auto_boot = false;
> + z_rproc = rproc_ptr->priv;
> + z_rproc->rproc = rproc_ptr;
> + r5_node = z_rproc->rproc->dev.parent->of_node;
> +
> + /* Set up DMA mask */
> + ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
> + if (ret)
> + goto error;
> +
> + /* Get R5 power domain node */
> + ret = of_property_read_u32(node, "power-domain", &z_rproc->pnode_id);
> + if (ret)
> + goto error;
> +
> + ret = r5_set_mode(z_rproc, rpu_mode);
> + if (ret)
> + goto error;
> +
> + if (of_property_read_bool(node, "mboxes")) {
> + ret = zynqmp_r5_setup_mbox(z_rproc, node);
> + if (ret)
> + goto error;
> + }
> +
> + /* go through TCM banks for r5 node */
> + num_banks = of_count_phandle_with_args(r5_node, BANK_LIST_PROP, NULL);
> + if (num_banks <= 0) {
> + dev_err(dev, "need to specify TCM banks\n");
> + ret = -EINVAL;
> + goto error;
> + }
> +
> + if (num_banks > NUM_SRAMS) {
> + dev_err(dev, "max number of srams is %d. given: %d \r\n",
> + NUM_SRAMS, num_banks);
> + ret = -EINVAL;
> + goto error;
> + }
> +
> + /* construct collection of srams used by the current R5 core */
> + for (; num_banks; num_banks--) {
> + struct resource rsc;
> + struct device_node *dt_node;
> + resource_size_t size;
> + int i;
> +
> + dt_node = of_parse_phandle(r5_node, BANK_LIST_PROP, i);
Variable @i is not initialised but it is used as an index to retrieve a handle
to the sram banks. That code _should_ have failed frequently or at least have
yielded abnormal results often enough to be noticed. Why wasn't it the case?
I will stop here for the moment.
[Ben]
Yes this should be initialized. The reason this got through is that as i defaults to 0 and the 0th bank housed the required data. the case where SRAMS that can be written to, 0xFFE20000 in this case of split mode and on R5-0, was not caught.
Instead of i I will use
sram_node = of_parse_phandle(node, BANK_LIST_PROP,
num_banks - 1);
sram_node is the var name given in the function called by probe to collect the SRAM information.
If there is other feedback please let me know
Thanks
Ben
> + if (!dt_node) {
> + ret = -EINVAL;
> + goto error;
> + }
> +
> + ret = of_address_to_resource(dt_node, 0, &rsc);
> + if (ret < 0) {
> + of_node_put(dt_node);
> + goto error;
> + }
> +
> + of_node_put(dt_node);
> + size = resource_size(&rsc);
> +
> + /*
> + * Find corresponding Xilinx platform management ID.
> + * The bank information is used in prepare/unprepare and
> + * parse_fw.
> + */
> + for (i = 0; i < NUM_SRAMS; i++) {
> + if (rsc.start == zynqmp_banks[i].addr) {
> + z_rproc->srams[i].addr = rsc.start;
> + z_rproc->srams[i].size = size;
> + z_rproc->srams[i].id = zynqmp_banks[i].id;
> + break;
> + }
> + }
> +
> + if (i == NUM_SRAMS) {
> + dev_err(dev, "sram %llx is not valid.\n", rsc.start);
> + ret = -EINVAL;
> + goto error;
> + }
> + }
> +
> + /* Add R5 remoteproc */
> + ret = devm_rproc_add(dev, rproc_ptr);
> + if (ret) {
> + zynqmp_r5_cleanup_mbox(z_rproc);
> + goto error;
> + }
> +
> + return z_rproc;
> +error:
> + return ERR_PTR(ret);
> +}
> +
> +/*
> + * zynqmp_r5_remoteproc_probe
> + *
> + * @pdev: domain platform device for R5 cluster
> + *
> + * called when driver is probed, for each R5 core specified in DT,
> + * setup as needed to do remoteproc-related operations
> + *
> + * Return: 0 for success, negative value for failure.
> + */
> +static int zynqmp_r5_remoteproc_probe(struct platform_device *pdev)
> +{
> + int ret, core_count;
> + struct device *dev = &pdev->dev;
> + struct device_node *nc;
> + enum rpu_oper_mode rpu_mode = PM_RPU_MODE_LOCKSTEP;
> + struct list_head *cluster; /* list to track each core's rproc */
> + struct zynqmp_r5_rproc *z_rproc;
> + struct platform_device *child_pdev;
> + struct list_head *pos;
> +
> + ret = of_property_read_u32(dev->of_node, "xlnx,cluster-mode", &rpu_mode);
> + if (ret < 0 || (rpu_mode != PM_RPU_MODE_LOCKSTEP &&
> + rpu_mode != PM_RPU_MODE_SPLIT)) {
> + dev_err(dev, "invalid cluster mode: ret %d mode %x\n",
> + ret, rpu_mode);
> + return ret;
> + }
> +
> + dev_dbg(dev, "RPU configuration: %s\n",
> + rpu_mode == PM_RPU_MODE_LOCKSTEP ? "lockstep" : "split");
> +
> + /*
> + * if 2 RPUs provided but one is lockstep, then we have an
> + * invalid configuration.
> + */
> +
> + core_count = of_get_available_child_count(dev->of_node);
> + if ((rpu_mode == PM_RPU_MODE_LOCKSTEP && core_count != 1) ||
> + core_count > MAX_RPROCS)
> + return -EINVAL;
> +
> + cluster = devm_kzalloc(dev, sizeof(*cluster), GFP_KERNEL);
> + if (!cluster)
> + return -ENOMEM;
> + INIT_LIST_HEAD(cluster);
> +
> + ret = devm_of_platform_populate(dev);
> + if (ret) {
> + dev_err(dev, "devm_of_platform_populate failed, ret = %d\n", ret);
> + return ret;
> + }
> +
> + /* probe each individual r5 core's remoteproc-related info */
> + for_each_available_child_of_node(dev->of_node, nc) {
> + child_pdev = of_find_device_by_node(nc);
> + if (!child_pdev) {
> + dev_err(dev, "could not get R5 core platform device\n");
> + ret = -ENODEV;
> + goto out;
> + }
> +
> + z_rproc = zynqmp_r5_probe(child_pdev, nc, rpu_mode);
> + dev_dbg(dev, "%s to probe rpu %pOF\n",
> + ret ? "Failed" : "Able", nc);
> + if (IS_ERR(z_rproc)) {
> + ret = PTR_ERR(z_rproc);
> + goto out;
> + }
> + list_add_tail(&z_rproc->elem, cluster);
> + }
> + /* wire in so each core can be cleaned up at driver remove */
> + platform_set_drvdata(pdev, cluster);
> + return 0;
> +out:
> + list_for_each(pos, cluster) {
> + z_rproc = list_entry(pos, struct zynqmp_r5_rproc, elem);
> + zynqmp_r5_cleanup_mbox(z_rproc);
> + }
> + return ret;
> +}
> +
> +/*
> + * zynqmp_r5_remoteproc_remove
> + *
> + * @pdev: domain platform device for R5 cluster
> + *
> + * When the driver is unloaded, clean up the mailboxes for each
> + * remoteproc that was initially probed.
> + */
> +static int zynqmp_r5_remoteproc_remove(struct platform_device *pdev)
> +{
> + struct list_head *pos, *temp, *cluster = (struct list_head *)
> + platform_get_drvdata(pdev);
> + struct zynqmp_r5_rproc *z_rproc = NULL;
> +
> + list_for_each_safe(pos, temp, cluster) {
> + z_rproc = list_entry(pos, struct zynqmp_r5_rproc, elem);
> + zynqmp_r5_cleanup_mbox(z_rproc);
> + }
> + return 0;
> +}
> +
> +/* Match table for OF platform binding */
> +static const struct of_device_id zynqmp_r5_remoteproc_match[] = {
> + { .compatible = "xlnx,zynqmp-r5-remoteproc", },
> + { /* end of list */ },
> +};
> +MODULE_DEVICE_TABLE(of, zynqmp_r5_remoteproc_match);
> +
> +static struct platform_driver zynqmp_r5_remoteproc_driver = {
> + .probe = zynqmp_r5_remoteproc_probe,
> + .remove = zynqmp_r5_remoteproc_remove,
> + .driver = {
> + .name = "zynqmp_r5_remoteproc",
> + .of_match_table = zynqmp_r5_remoteproc_match,
> + },
> +};
> +module_platform_driver(zynqmp_r5_remoteproc_driver);
> +
> +MODULE_AUTHOR("Ben Levinsky <ben.levinsky@xxxxxxxxxx>");
> +MODULE_LICENSE("GPL v2");
> --
> 2.17.1
>
