Re: [PATCH v5 2/5] remoteproc: qcom: Introduce helper to store pil info in IMEM

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

On Tue, May 12, 2020 at 10:56:38PM -0700, Bjorn Andersson wrote:
> A region in IMEM is used to communicate load addresses of remoteproc to
> post mortem debug tools. Implement a helper function 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 v4:
> - Replaced platform_driver by just a single helper function
> - Lazy initialization of mapping
> - Cleaned up search loop
> - Replaced regmap access of IMEM with ioremap and normal accessors
> 
>  drivers/remoteproc/Kconfig         |   3 +
>  drivers/remoteproc/Makefile        |   1 +
>  drivers/remoteproc/qcom_pil_info.c | 124 +++++++++++++++++++++++++++++
>  drivers/remoteproc/qcom_pil_info.h |   7 ++
>  4 files changed, 135 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 fbaed079b299..8088ca4dd6dc 100644
> --- a/drivers/remoteproc/Kconfig
> +++ b/drivers/remoteproc/Kconfig
> @@ -107,6 +107,9 @@ 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 0effd3825035..cc0f631adb3b 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..0785c7cde2d3
> --- /dev/null
> +++ b/drivers/remoteproc/qcom_pil_info.c
> @@ -0,0 +1,124 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2019-2020 Linaro Ltd.
> + */
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of_address.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;
> +	void __iomem *base;
> +	size_t num_entries;
> +};
> +
> +static struct pil_reloc _reloc __read_mostly;
> +static DEFINE_MUTEX(reloc_mutex);
> +
> +static int qcom_pil_info_init(void)
> +{
> +	struct device_node *np;
> +	struct resource imem;
> +	void __iomem *base;
> +	int ret;
> +
> +	/* Already initialized? */
> +	if (_reloc.base)
> +		return 0;
> +
> +	np = of_find_compatible_node(NULL, NULL, "qcom,pil-reloc-info");
> +	if (!np)
> +		return -ENOENT;
> +
> +	ret = of_address_to_resource(np, 0, &imem);
> +	of_node_put(np);
> +	if (ret < 0)
> +		return ret;
> +
> +	base = ioremap(imem.start, resource_size(&imem));
> +	if (!base) {
> +		pr_err("failed to map PIL relocation info region\n");
> +		return -ENOMEM;
> +	}
> +
> +	memset_io(base, 0, resource_size(&imem));
> +
> +	_reloc.base = base;
> +	_reloc.num_entries = resource_size(&imem) / sizeof(struct pil_reloc_entry);
> +
> +	return 0;
> +}
> +
> +/**
> + * 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)
> +{
> +	char buf[PIL_RELOC_NAME_LEN];
> +	void __iomem *entry;
> +	int ret;
> +	int i;
> +
> +	mutex_lock(&reloc_mutex);
> +	ret = qcom_pil_info_init();
> +	if (ret < 0) {
> +		mutex_unlock(&reloc_mutex);
> +		return ret;
> +	}
> +
> +	for (i = 0; i < _reloc.num_entries; i++) {
> +		entry = _reloc.base + i * sizeof(struct pil_reloc_entry);
> +
> +		memcpy_fromio(buf, entry, PIL_RELOC_NAME_LEN);
> +
> +		/*
> +		 * An empty record means we didn't find it, given that the
> +		 * records are packed.
> +		 */
> +		if (!buf[0])
> +			goto found_unused;
> +
> +		if (!strncmp(buf, image, PIL_RELOC_NAME_LEN))
> +			goto found_existing;
> +	}
> +
> +	pr_warn("insufficient PIL info slots\n");
> +	mutex_unlock(&reloc_mutex);
> +	return -ENOMEM;
> +
> +found_unused:
> +	memcpy_toio(entry, image, PIL_RELOC_NAME_LEN);
> +found_existing:
> +	writel(base, entry + offsetof(struct pil_reloc_entry, base));
> +	writel(size, entry + offsetof(struct pil_reloc_entry, size));
> +	mutex_unlock(&reloc_mutex);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(qcom_pil_info_store);
> +
> +static void __exit pil_reloc_exit(void)
> +{
> +	mutex_lock(&reloc_mutex);
> +	iounmap(_reloc.base);
> +	_reloc.base = NULL;
> +	mutex_unlock(&reloc_mutex);
> +}
> +module_exit(pil_reloc_exit);
> +
> +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..1b89a63ba82f
> --- /dev/null
> +++ b/drivers/remoteproc/qcom_pil_info.h
> @@ -0,0 +1,7 @@
> +/* 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);
> +
> +#endif

Very clean an easy to understand.

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

> -- 
> 2.26.2
>