Date:   Thu, 8 Sep 2022 12:42:02 -0700
From:   Tanmay Shah <tanmays@....com>
To:     Mathieu Poirier <mathieu.poirier@...aro.org>
Cc:     Tanmay Shah <tanmay.shah@....com>, bjorn.andersson@...aro.org,
        robh+dt@...nel.org, krzysztof.kozlowski+dt@...aro.org,
        michal.simek@...inx.com, ben.levinsky@...inx.com,
        tanmay.shah@...inx.com, michal.simek@....com,
        linux-remoteproc@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v9 6/6] drivers: remoteproc: Add Xilinx r5 remoteproc
 driver

Hi Mathieu,

Thanks for reviewing this patch-set. Ack to comments and will fix in new 
revision.

On 9/2/22 12:59 PM, Mathieu Poirier wrote:
> [...]
>
>>>> +
>>>> +static const struct rproc_ops zynqmp_r5_rproc_ops = {
>>>> +	.prepare	= zynqmp_r5_rproc_prepare,
>>>> +	.unprepare	= zynqmp_r5_rproc_unprepare,
>>>> +	.start		= zynqmp_r5_rproc_start,
>>>> +	.stop		= zynqmp_r5_rproc_stop,
>>>> +	.load		= rproc_elf_load_segments,
>>>> +	.parse_fw	= zynqmp_r5_parse_fw,
>>>> +	.find_loaded_rsc_table = rproc_elf_find_loaded_rsc_table,
>>>> +	.sanity_check	= rproc_elf_sanity_check,
>>>> +	.get_boot_addr	= rproc_elf_get_boot_addr,
>>>> +};
>>>> +
>>>> +/**
>>>> + * zynqmp_r5_add_rproc_core()
>>>> + * Probes ZynqMP R5 processor device node
>>>> + * this is called for each individual R5 core
>>>> + *
>>>> + * @cdev: Device node of each r5 core
>>>> + *
>>>> + * Return: zynqmp_r5_core object for success, error pointer in case of error.
>>>> + */
>>>> +static struct zynqmp_r5_core *zynqmp_r5_add_rproc_core(struct device *cdev)
>>>> +{
>>>> +	struct zynqmp_r5_core *r5_core;
>>>> +	struct rproc *r5_rproc;
>>>> +	int ret;
>>>> +
>>>> +	/* Set up DMA mask */
>>>> +	ret = dma_set_coherent_mask(cdev, DMA_BIT_MASK(32));
>>>> +	if (ret)
>>>> +		return ERR_PTR(ret);
>>>> +
>>>> +	/* Allocate remoteproc instance */
>>>> +	r5_rproc = rproc_alloc(cdev, dev_name(cdev),
>>>> +			       &zynqmp_r5_rproc_ops,
>>>> +			       NULL, sizeof(struct zynqmp_r5_core));
>>>> +	if (!r5_rproc) {
>>>> +		dev_err(cdev, "failed to allocate memory for rproc instance\n");
>>>> +		return ERR_PTR(-ENOMEM);
>>>> +	}
>>>> +
>>>> +	r5_rproc->auto_boot = false;
>>>> +	r5_core = (struct zynqmp_r5_core *)r5_rproc->priv;
>>>> +	r5_core->dev = cdev;
>>>> +	r5_core->np = dev_of_node(cdev);
>>>> +	if (!r5_core->np) {
>>>> +		dev_err(cdev, "can't get device node for r5 core\n");
>>>> +		return ERR_PTR(-EINVAL);
>>> Here @r5_rproc is leaked and r5_rproc->rproc never free'ed.
>> This function is only used in cluster_init.
>>
>> r5_rproc->rproc is free'ed in release_r5_core label in
>> zynqmp_r5_cluster_init function if this function fails.
> It would be the case if @r5_core was returned, but it is not.  A such
> @r5_core[i] zynqmp_r5_cluster_init() is still null and the memory leaked.

Ack. Yes you are right. Thanks!!

>
>> This avoids multiple free of same resource.
>>
>>>> +	}
>>>> +
>>>> +	/* Add R5 remoteproc core */
>>>> +	ret = rproc_add(r5_rproc);
>>>> +	if (ret) {
>>>> +		dev_err(cdev, "failed to add r5 remoteproc\n");
>>>> +		return ERR_PTR(ret);
>>> Same.
>> Same as above.
Ack. I will fix this.
>>>> +	}
>>>> +
>>>> +	r5_core->rproc = r5_rproc;
>>>> +	return r5_core;
>>>> +}
>>>> +
>>>> +/**
>>>> + * zynqmp_r5_get_tcm_node()
>>>> + * Ideally this function should parse tcm node and store information
>>>> + * in r5_core instance. We will use hardcoded TCM information from
>>>> + * driver for now in this function.
>>>> + *
>>> It would be a good idea to explain _why_ hardcoded values are used.
>> It is explained in function, but will add in description too.
>>>
>>>> + * @cluster: pointer to zynqmp_r5_cluster type object
>>>> + *
>>>> + * Return: 0 for success and error code for failure.
>>>> + */
>>>> +static int zynqmp_r5_get_tcm_node(struct zynqmp_r5_cluster *cluster)
>>>> +{
>>>> +	struct device *dev = cluster->dev;
>>>> +	struct zynqmp_r5_core *r5_core;
>>>> +	int tcm_bank_count, tcm_node;
>>>> +	int i, j;
>>>> +
>>>> +	/*
>>>> +	 * ToDo: Use predefined TCM address space values from driver while
>>> I'm not sure why there is a "ToDo" here since this is exactly what you are
>>> doing.
>> Ack. ToDo needs to go.
>>>> +	 * system-dt spec is not final for TCM
>>>> +	 */
>>>> +	tcm_bank_count = ARRAY_SIZE(zynqmp_tcm_banks);
>>>> +
>>>> +	/* count per core tcm banks */
>>>> +	tcm_bank_count = tcm_bank_count / cluster->core_count;
>>>> +
>>>> +	if (tcm_bank_count <= 0)
>>>> +		return -EINVAL;
>>> As far as I can tell this can't happen and as such should be removed.
>> I kept this check for future, when we add TCM dt nodes. I will remove it.
>>
>>>> +
>>>> +	/*
>>>> +	 * r5 core 0 will use all of TCM banks in lockstep mode.
>>>> +	 * In split mode, r5 core0 will use 128k and r5 core1 will use another
>>>> +	 * 128k. Assign TCM banks to each core accordingly
>>>> +	 */
>>>> +	tcm_node = 0;
>>>> +	for (i = 0; i < cluster->core_count; i++) {
>>>> +		r5_core = cluster->r5_cores[i];
>>>> +		r5_core->tcm_banks = devm_kcalloc(dev, tcm_bank_count,
>>>> +						  sizeof(struct mem_bank_data *),
>>>> +						  GFP_KERNEL);
>>>> +		if (!r5_core->tcm_banks)
>>>> +			return -ENOMEM;
>>>> +
>>>> +		for (j = 0; j < tcm_bank_count; j++) {
>>>> +			/*
>>>> +			 * Use pre-defined TCM reg values.
>>>> +			 * Eventually this should be replaced by values
>>>> +			 * parsed from dts.
>>>> +			 */
>>>> +			r5_core->tcm_banks[j] =
>>>> +				(struct mem_bank_data *)&zynqmp_tcm_banks[tcm_node];
>>>> +			tcm_node++;
>>>> +		}
>>>> +
>>>> +		r5_core->tcm_bank_count = tcm_bank_count;
>>>> +	}
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +/**
>>>> + * zynqmp_r5_get_mem_region_node()
>>>> + * parse memory-region property from dt node and add
>>>> + * memory region carveouts
>>>> + *
>>>> + * @r5_core: pointer to zynqmp_r5_core type object
>>>> + *
>>>> + * Return: 0 for success and error code for failure.
>>>> + */
>>>> +static int zynqmp_r5_get_mem_region_node(struct zynqmp_r5_core *r5_core)
>>>> +{
>>>> +	struct device_node *np, *rmem_np;
>>>> +	struct reserved_mem **rmem;
>>>> +	int res_mem_count, i;
>>>> +	struct device *dev;
>>>> +
>>>> +	dev = r5_core->dev;
>>>> +	np = r5_core->np;
>>>> +
>>>> +	res_mem_count = of_property_count_elems_of_size(np, "memory-region",
>>>> +							sizeof(phandle));
>>>> +	if (res_mem_count <= 0) {
>>>> +		dev_warn(dev, "failed to get memory-region property %d\n",
>>>> +			 res_mem_count);
>>>> +		r5_core->rmem_count = 0;
>>>> +		return 0;
>>>> +	}
>>>> +
>>>> +	rmem = devm_kcalloc(dev, res_mem_count,
>>>> +			    sizeof(struct reserved_mem *), GFP_KERNEL);
>>>> +	if (!rmem)
>>>> +		return -ENOMEM;
>>>> +
>>>> +	for (i = 0; i < res_mem_count; i++) {
>>>> +		rmem_np = of_parse_phandle(np, "memory-region", i);
>>>> +		if (!rmem_np)
>>>> +			goto release_rmem;
>>>> +
>>>> +		rmem[i] = of_reserved_mem_lookup(rmem_np);
>>>> +		if (!rmem[i]) {
>>>> +			of_node_put(rmem_np);
>>>> +			goto release_rmem;
>>>> +		}
>>>> +
>>>> +		of_node_put(rmem_np);
>>>> +	}
>>>> +
>>>> +	r5_core->rmem_count = res_mem_count;
>>>> +	r5_core->rmem = rmem;
>>>> +	return 0;
>>>> +
>>>> +release_rmem:
>>>> +	for (i--; i >= 0; i--)
>>>> +		kfree(rmem[i]);
>>> Function of_reserved_mem_lookup() doesn't allocate a new reserved_mem structure,
>>> you get a reference to an existing one.  As such there is no need to explicitly
>>> free individual elements of the rmem array.
>> Ack.
>>>> +	devm_kfree(dev, rmem);
>>>> +	return -ENOMEM;
>>>> +}
>>>> +
>>>> +/*
>>>> + * zynqmp_r5_core_init()
>>>> + * Create and initialize zynqmp_r5_core type object
>>>> + *
>>>> + * @cluster: pointer to zynqmp_r5_cluster type object
>>>> + *
>>>> + * Return: 0 for success and error code for failure.
>>>> + */
>>>> +static int zynqmp_r5_core_init(struct zynqmp_r5_cluster *cluster,
>>>> +			       enum rpu_oper_mode fw_reg_val,
>>>> +			       enum rpu_tcm_comb tcm_mode)
>>>> +{
>>>> +	struct device *dev = cluster->dev;
>>>> +	struct zynqmp_r5_core *r5_core;
>>>> +	int ret, i;
>>>> +
>>>> +	ret = zynqmp_r5_get_tcm_node(cluster);
>>>> +	if (ret < 0) {
>>>> +		dev_err(dev, "can't get tcm node, err %d\n", ret);
>>>> +		return ret;
>>>> +	}
>>>> +
>>>> +	for (i = 0; i < cluster->core_count; i++) {
>>>> +		r5_core = cluster->r5_cores[i];
>>>> +
>>>> +		ret = zynqmp_r5_get_mem_region_node(r5_core);
>>>> +		if (ret)
>>>> +			dev_warn(dev, "memory-region prop failed %d\n", ret);
>>>> +
>>>> +		/* Initialize r5 cores with power-domains parsed from dts */
>>>> +		ret = of_property_read_u32_index(r5_core->np, "power-domains",
>>>> +						 1, &r5_core->pm_domain_id);
>>>> +		if (ret) {
>>>> +			dev_err(dev, "failed to get power-domains property\n");
>>>> +			return ret;
>>>> +		}
>>>> +
>>>> +		ret = zynqmp_r5_set_mode(r5_core, fw_reg_val, tcm_mode);
>>>> +		if (ret) {
>>>> +			dev_err(dev, "failed to set r5 cluster mode %d, err %d\n",
>>>> +				cluster->mode, ret);
>>>> +			return ret;
>>>> +		}
>>>> +	}
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +/*
>>>> + * zynqmp_r5_cluster_init()
>>>> + * Create and initialize zynqmp_r5_cluster type object
>>>> + *
>>>> + * @cluster: pointer to zynqmp_r5_cluster type object
>>>> + *
>>>> + * Return: 0 for success and error code for failure.
>>>> + */
>>>> +static int zynqmp_r5_cluster_init(struct zynqmp_r5_cluster *cluster)
>>>> +{
>>>> +	enum zynqmp_r5_cluster_mode cluster_mode = LOCKSTEP_MODE;
>>>> +	struct device *dev = cluster->dev;
>>>> +	struct device_node *dev_node = dev_of_node(dev);
>>>> +	struct platform_device *child_pdev;
>>>> +	struct zynqmp_r5_core **r5_cores;
>>>> +	enum rpu_oper_mode fw_reg_val;
>>>> +	struct device **child_devs;
>>>> +	struct device_node *child;
>>>> +	enum rpu_tcm_comb tcm_mode;
>>>> +	int core_count, ret, i;
>>>> +
>>>> +	ret = of_property_read_u32(dev_node, "xlnx,cluster-mode", &cluster_mode);
>>>> +
>>>> +	/*
>>>> +	 * on success returns 0, if not defined then returns -EINVAL,
>>>> +	 * In that case, default is LOCKSTEP mode
>>>> +	 */
>>>> +	if (ret != -EINVAL && ret != 0) {
>>>> +		dev_err(dev, "Invalid xlnx,cluster-mode property\n");
>>>> +		return -EINVAL;
>>>> +	}
>>>> +
>>>> +	/*
>>>> +	 * For now driver only supports split mode and lockstep mode.
>>>> +	 * fail driver probe if either of that is not set in dts.
>>>> +	 */
>>>> +	if (cluster_mode == LOCKSTEP_MODE) {
>>> Why is are LOCKSTEP_MODE and LOCKSTEP_MODE defined when the same values were
>>> already added in xlnx-zynqmp.h in patch 3/6?
>> Actually LOCKSTEP_MODE defined in this driver is taken from dt-bindings of
>> this driver. However, PM_RPU_MODE_LOCKSTEP defined in firmware represents
>> value expected by firmware. They are not the same defines. LOCKSTEP_MODE = 1
>> which is defined as per xlnx,cluster-mode bindings and similar to ti
>> cluster-mode bindings. PM_RPU_MODE_LOCKSTEP = 0 which is expected from
>> firmware.
> Ah yes, you are correct.
>
>>
>>>     And why not add SINGLE_CPU_MODE
>>> there as well instead of duplicating things in enum zynqmp_r5_cluster_mode?
>>
>> SINGLE_CPU_MODE just represents xlnx,cluster-mode value from dt-bindings. It
>> is not supported in firmware.
>>
>> There are multiple ways to configure r5 cluster in single-cpu mode.
>>
>> 1) Add new EEMI call which asks firmware to configure cluster in single-cpu
>> mode.
>>
>> or 2) use existing EEMI calls and configure cores from driver. As
>> single-cpu-mode is not supported yet, I am not sure, how it will
>>
>> be implemented or what its design will look like. So, I haven't modified
>> anything in firmware driver related to single-cpu mode.
>>
>>
> That is fine.
>
>>>> +		tcm_mode = PM_RPU_TCM_COMB;
>>>> +		fw_reg_val = PM_RPU_MODE_LOCKSTEP;
>>>> +	} else if (cluster_mode == SPLIT_MODE) {
>>>> +		tcm_mode = PM_RPU_TCM_SPLIT;
>>>> +		fw_reg_val = PM_RPU_MODE_SPLIT;
>>>> +	} else {
>>>> +		dev_err(dev, "driver does not support cluster mode %d\n", cluster_mode);
>>>> +		return -EINVAL;
>>>> +	}
>>>> +
>>>> +	/*
>>>> +	 * Number of cores is decided by number of child nodes of
>>>> +	 * r5f subsystem node in dts. If Split mode is used in dts
>>>> +	 * 2 child nodes are expected.
>>>> +	 * In lockstep mode if two child nodes are available,
>>>> +	 * only use first child node and consider it as core0
>>>> +	 * and ignore core1 dt node.
>>>> +	 */
>>>> +	core_count = of_get_available_child_count(dev_node);
>>>> +	if (core_count <= 0) {
>>>> +		dev_err(dev, "Invalid number of r5 cores %d", core_count);
>>>> +		return -EINVAL;
>>>> +	} else if (cluster_mode == SPLIT_MODE && core_count != 2) {
>>>> +		dev_err(dev, "Invalid number of r5 cores for split mode\n");
>>>> +		return -EINVAL;
>>>> +	} else if (cluster_mode == LOCKSTEP_MODE && core_count == 2) {
>>>> +		dev_warn(dev, "Only r5 core0 will be used\n");
>>>> +		core_count = 1;
>>>> +	}
>>>> +
>>>> +	child_devs = kcalloc(core_count, sizeof(struct device *), GFP_KERNEL);
>>>> +	if (!child_devs)
>>>> +		return -ENOMEM;
>>>> +
>>>> +	r5_cores = kcalloc(core_count,
>>>> +			   sizeof(struct zynqmp_r5_core *), GFP_KERNEL);
>>>> +	if (!r5_cores) {
>>>> +		kfree(child_devs);
>>>> +		return -ENOMEM;
>>>> +	}
>>>> +
>>>> +	i = 0;
>>>> +	for_each_available_child_of_node(dev_node, child) {
>>>> +		child_pdev = of_find_device_by_node(child);
>>>> +		if (!child_pdev) {
>>>> +			of_node_put(child);
>>>> +			ret = -ENODEV;
>>>> +			goto release_r5_cores;
>>>> +		}
>>>> +
>>>> +		child_devs[i] = &child_pdev->dev;
>>>> +
>>>> +		/* create and add remoteproc instance of type struct rproc */
>>>> +		r5_cores[i] = zynqmp_r5_add_rproc_core(&child_pdev->dev);
>>>> +		if (IS_ERR(r5_cores[i])) {
>>>> +			of_node_put(child);
>>>> +			ret = PTR_ERR(r5_cores[i]);
>>>> +			goto release_r5_cores;
>>> If we are here and i == 0, we are leaking a reference to child_pdev since the
>>> loop in release_r5_cores won't execute.
>> Ack. I will check if i == 0 and put_device() before jumping to
>> release_r5_cores.
>>>> +		}
>>>> +
>>>> +		i++;
>>>> +
>>>> +		/*
>>>> +		 * If two child nodes are available in dts in lockstep mode,
>>>> +		 * then ignore second child node.
>>>> +		 */
>>>> +		if (i == core_count) {
>>>> +			of_node_put(child);
>>>> +			break;
>>>> +		}
>>> Instead of using the i to check the cores, simply break if cluster_mode ==
>>> LOCKSTEP_MODE.  That will avoid the fragile dance around the manipulation of
>>> variable i and simplify the release of resources in release_r5_cores.
>>>
>> Actually variable name "i" needs to be changed. I need that variable to
>> track how many cores  are added successfully.
>>
>> So, if first core is added and second core fails, then I can release
>> resources allocated for first core successfully.
>>
>> So, instead of "i" I can use meaningful variable name like "cores_added" or
>> "cores_allocated".
>
> You can still use variable @i, just don't use it to break out of the loop.  As I
> pointed out, it would be much easier to simply do that if in lockstep mode.

Ah! makes sense. I will check for lockstep mode instead of @i counts.

Thanks.

>>>> +	}
>>>> +
>>>> +	cluster->mode = cluster_mode;
>>>> +	cluster->core_count = core_count;
>>>> +	cluster->r5_cores = r5_cores;
>>>> +
>>>> +	ret = zynqmp_r5_core_init(cluster, fw_reg_val, tcm_mode);
>>>> +	if (ret < 0) {
>>>> +		dev_err(dev, "failed to init r5 core err %d\n", ret);
>>>> +		cluster->core_count = 0;
>>>> +		cluster->r5_cores = NULL;
>>>> +		goto release_r5_cores;
>>>> +	}
>>>> +
>>>> +	kfree(child_devs);
>>>> +	return 0;
>>>> +
>>>> +release_r5_cores:
>>>> +	for (i--; i >= 0; i--) {
>>>> +		put_device(child_devs[i]);
>>>> +		rproc_del(r5_cores[i]->rproc);
>>>> +		rproc_free(r5_cores[i]->rproc);
>>>> +	}
>>>> +	kfree(r5_cores);
>>>> +	kfree(child_devs);
>>>> +	return ret;
>>>> +}
>>>> +
>>>> +static void zynqmp_r5_cluster_exit(void *data)
>>>> +{
>>>> +	struct platform_device *pdev = (struct platform_device *)data;
>>>> +	struct zynqmp_r5_cluster *cluster;
>>>> +	struct zynqmp_r5_core *r5_core;
>>>> +	int i;
>>>> +
>>>> +	cluster = (struct zynqmp_r5_cluster *)platform_get_drvdata(pdev);
>>>> +	if (!cluster)
>>>> +		return;
>>>> +
>>>> +	for (i = 0; i < cluster->core_count; i++) {
>>>> +		r5_core = cluster->r5_cores[i];
>>>> +		put_device(r5_core->dev);
>>>> +		rproc_del(r5_core->rproc);
>>>> +		rproc_free(r5_core->rproc);
>>>> +	}
>>>> +
>>>> +	kfree(cluster->r5_cores);
>>>> +	kfree(cluster);
>>>> +	platform_set_drvdata(pdev, NULL);
>>>> +}
>>>> +
>>>> +/*
>>>> + * 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)
>>>> +{
>>>> +	struct zynqmp_r5_cluster *cluster;
>>>> +	struct device *dev = &pdev->dev;
>>>> +	int ret;
>>>> +
>>>> +	cluster = kzalloc(sizeof(*cluster), GFP_KERNEL);
>>>> +	if (!cluster)
>>>> +		return -ENOMEM;
>>>> +
>>>> +	cluster->dev = dev;
>>>> +
>>>> +	ret = devm_of_platform_populate(dev);
>>>> +	if (ret) {
>>>> +		dev_err_probe(dev, ret, "failed to populate platform dev\n");
>>>> +		kfree(cluster);
>>>> +		return ret;
>>>> +	}
>>>> +
>>>> +	/* wire in so each core can be cleaned up at driver remove */
>>>> +	platform_set_drvdata(pdev, cluster);
>>>> +
>>>> +	ret = zynqmp_r5_cluster_init(cluster);
>>>> +	if (ret) {
>>>> +		zynqmp_r5_cluster_exit(pdev);
>>>> +		dev_err_probe(dev, ret, "Invalid r5f subsystem device tree\n");
>>>> +		return ret;
>>>> +	}
>>>> +
>>>> +	ret = devm_add_action_or_reset(dev, zynqmp_r5_cluster_exit, pdev);
>>>> +	if (ret)
>>>> +		return ret;
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +/* Match table for OF platform binding */
>>>> +static const struct of_device_id zynqmp_r5_remoteproc_match[] = {
>>>> +	{ .compatible = "xlnx,zynqmp-r5fss", },
>>>> +	{ /* end of list */ },
>>>> +};
>>>> +MODULE_DEVICE_TABLE(of, zynqmp_r5_remoteproc_match);
>>>> +
>>>> +static struct platform_driver zynqmp_r5_remoteproc_driver = {
>>>> +	.probe = zynqmp_r5_remoteproc_probe,
>>>> +	.driver = {
>>>> +		.name = "zynqmp_r5_remoteproc",
>>>> +		.of_match_table = zynqmp_r5_remoteproc_match,
>>>> +	},
>>>> +};
>>>> +module_platform_driver(zynqmp_r5_remoteproc_driver);
>>>> +
>>>> +MODULE_DESCRIPTION("Xilinx R5F remote processor driver");
>>>> +MODULE_AUTHOR("Xilinx Inc.");
>>>> +MODULE_LICENSE("GPL");
>>> There is a discrepency between the GPL-2.0 in the SPDS identifier and the above.
>>>
>>> More comments tomorrow or Tuesday.
>>>
>>> Thanks,
>>> Mathieu
>>>
>>>> -- 
>>>> 2.25.1
>>>>

Powered by blists - more mailing lists