Re: [PATCH v3 2/8] remoteproc: qcom: Introduce driver to store pil info in IMEM

[Mathieu Poirier <mathieu.poirier@linaro.org>]

On Mon, Feb 10, 2020 at 04:50:53PM -0800, Bjorn Andersson wrote:
> A region in IMEM is used to communicate load addresses of remoteproc to
> post mortem debug tools. Implement a driver that can be used to store
> this information in order to enable these tools to process collected
> ramdumps.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
> 
> Changes since v2:
> - Sorted includes
> - Replace use of stracpy (still not landed upstream)
> - Fixed error handling in probe
> - Return error from store, to allow clients to decide action
> - Replace hard coded size with value read from reg property
> 
>  drivers/remoteproc/Kconfig         |   3 +
>  drivers/remoteproc/Makefile        |   1 +
>  drivers/remoteproc/qcom_pil_info.c | 168 +++++++++++++++++++++++++++++
>  drivers/remoteproc/qcom_pil_info.h |   8 ++
>  4 files changed, 180 insertions(+)
>  create mode 100644 drivers/remoteproc/qcom_pil_info.c
>  create mode 100644 drivers/remoteproc/qcom_pil_info.h
> 
> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
> index de3862c15fcc..20c8194e610e 100644
> --- a/drivers/remoteproc/Kconfig
> +++ b/drivers/remoteproc/Kconfig
> @@ -95,6 +95,9 @@ config KEYSTONE_REMOTEPROC
>  	  It's safe to say N here if you're not interested in the Keystone
>  	  DSPs or just want to use a bare minimum kernel.
>  
> +config QCOM_PIL_INFO
> +	tristate
> +
>  config QCOM_RPROC_COMMON
>  	tristate
>  
> diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
> index e30a1b15fbac..2ab32bd41b44 100644
> --- a/drivers/remoteproc/Makefile
> +++ b/drivers/remoteproc/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_OMAP_REMOTEPROC)		+= omap_remoteproc.o
>  obj-$(CONFIG_WKUP_M3_RPROC)		+= wkup_m3_rproc.o
>  obj-$(CONFIG_DA8XX_REMOTEPROC)		+= da8xx_remoteproc.o
>  obj-$(CONFIG_KEYSTONE_REMOTEPROC)	+= keystone_remoteproc.o
> +obj-$(CONFIG_QCOM_PIL_INFO)		+= qcom_pil_info.o
>  obj-$(CONFIG_QCOM_RPROC_COMMON)		+= qcom_common.o
>  obj-$(CONFIG_QCOM_Q6V5_COMMON)		+= qcom_q6v5.o
>  obj-$(CONFIG_QCOM_Q6V5_ADSP)		+= qcom_q6v5_adsp.o
> diff --git a/drivers/remoteproc/qcom_pil_info.c b/drivers/remoteproc/qcom_pil_info.c
> new file mode 100644
> index 000000000000..398aeb957f3c
> --- /dev/null
> +++ b/drivers/remoteproc/qcom_pil_info.c
> @@ -0,0 +1,168 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2019-2020 Linaro Ltd.
> + */
> +#include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +
> +#define PIL_RELOC_NAME_LEN	8
> +
> +struct pil_reloc_entry {
> +	char name[PIL_RELOC_NAME_LEN];
> +	__le64 base;
> +	__le32 size;
> +} __packed;
> +
> +struct pil_reloc {
> +	struct device *dev;
> +	struct regmap *map;
> +	size_t offset;
> +	size_t num_entries;
> +	int val_bytes;
> +
> +	struct pil_reloc_entry entries[];
> +};
> +
> +static struct pil_reloc *_reloc;
> +static DEFINE_MUTEX(reloc_mutex);
> +
> +/**
> + * qcom_pil_info_store() - store PIL information of image in IMEM
> + * @image:	name of the image
> + * @base:	base address of the loaded image
> + * @size:	size of the loaded image
> + *
> + * Return: 0 on success, negative errno on failure
> + */
> +int qcom_pil_info_store(const char *image, phys_addr_t base, size_t size)
> +{
> +	struct pil_reloc_entry *entry;
> +	int idx = -1;
> +	int ret;
> +	int i;
> +
> +	mutex_lock(&reloc_mutex);
> +	for (i = 0; i < _reloc->num_entries; i++) {
> +		if (!_reloc->entries[i].name[0]) {
> +			if (idx == -1)
> +				idx = i;
> +			continue;
> +		}
> +
> +		if (!strncmp(_reloc->entries[i].name, image, 8)) {

s/8/PIL_RELOC_NAME_LEN

> +			idx = i;
> +			goto found;
> +		}
> +	}
> +
> +	if (idx == -1) {
> +		dev_warn(_reloc->dev, "insufficient PIL info slots\n");
> +		ret = -ENOMEM;
> +		goto unlock;
> +	}
> +
> +found:
> +	entry = &_reloc->entries[idx];
> +	strscpy(entry->name, image, ARRAY_SIZE(entry->name));
> +	entry->base = base;
> +	entry->size = size;
> +
> +	ret = regmap_bulk_write(_reloc->map,
> +				_reloc->offset + idx * sizeof(*entry),
> +				entry, sizeof(*entry) / _reloc->val_bytes);
> +unlock:
> +	mutex_unlock(&reloc_mutex);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(qcom_pil_info_store);
> +
> +/**
> + * qcom_pil_info_available() - query if the pil info is probed
> + *
> + * Return: boolean indicating if the pil info device is probed
> + */
> +bool qcom_pil_info_available(void)
> +{
> +	return !!_reloc;
> +}
> +EXPORT_SYMBOL_GPL(qcom_pil_info_available);
> +
> +static int pil_reloc_probe(struct platform_device *pdev)
> +{
> +	unsigned int num_entries;
> +	struct pil_reloc *reloc;
> +	struct resource *res;
> +	int ret;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res)
> +		return -EINVAL;
> +
> +	num_entries = resource_size(res) / sizeof(struct pil_reloc_entry);
> +
> +	reloc = devm_kzalloc(&pdev->dev,
> +			     struct_size(reloc, entries, num_entries),
> +			     GFP_KERNEL);
> +	if (!reloc)
> +		return -ENOMEM;
> +
> +	reloc->dev = &pdev->dev;
> +	reloc->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
> +	if (IS_ERR(reloc->map))
> +		return PTR_ERR(reloc->map);
> +
> +	reloc->offset = res->start;
> +	reloc->num_entries = num_entries;
> +
> +	reloc->val_bytes = regmap_get_val_bytes(reloc->map);
> +	if (reloc->val_bytes < 0)
> +		return -EINVAL;
> +
> +	ret = regmap_bulk_write(reloc->map, reloc->offset, reloc->entries,
> +				reloc->num_entries *
> +				sizeof(struct pil_reloc_entry) /
> +				reloc->val_bytes);
> +	if (ret < 0)
> +		return ret;
> +
> +	mutex_lock(&reloc_mutex);
> +	_reloc = reloc;
> +	mutex_unlock(&reloc_mutex);
> +
> +	return 0;
> +}
> +
> +static int pil_reloc_remove(struct platform_device *pdev)
> +{
> +	mutex_lock(&reloc_mutex);
> +	_reloc = NULL;
> +	mutex_unlock(&reloc_mutex);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id pil_reloc_of_match[] = {
> +	{ .compatible = "qcom,pil-reloc-info" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, pil_reloc_of_match);
> +
> +static struct platform_driver pil_reloc_driver = {
> +	.probe = pil_reloc_probe,
> +	.remove = pil_reloc_remove,
> +	.driver = {
> +		.name = "qcom-pil-reloc-info",
> +		.of_match_table = pil_reloc_of_match,
> +	},
> +};
> +module_platform_driver(pil_reloc_driver);
> +
> +MODULE_DESCRIPTION("Qualcomm PIL relocation info");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/remoteproc/qcom_pil_info.h b/drivers/remoteproc/qcom_pil_info.h
> new file mode 100644
> index 000000000000..93aaaca8aed2
> --- /dev/null
> +++ b/drivers/remoteproc/qcom_pil_info.h
> @@ -0,0 +1,8 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __QCOM_PIL_INFO_H__
> +#define __QCOM_PIL_INFO_H__
> +
> +int qcom_pil_info_store(const char *image, phys_addr_t base, size_t size);
> +bool qcom_pil_info_available(void);
> +
> +#endif
> -- 
> 2.24.0
>