Re: [PATCH v2 2/8] remoteproc: qcom: Introduce driver to store pil info in IMEM

From: Mathieu Poirier
Date: Fri Jan 10 2020 - 16:18:52 EST


Hi Bjorn,

On Thu, Dec 26, 2019 at 09:32:09PM -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@xxxxxxxxxx>
> ---
>
> Changes since v1:
> - Added helper to probe defer clients
> - Fixed logical bug in slot scan
> - Added SPDX header in header file
>
> drivers/remoteproc/Kconfig | 3 +
> drivers/remoteproc/Makefile | 1 +
> drivers/remoteproc/qcom_pil_info.c | 150 +++++++++++++++++++++++++++++
> drivers/remoteproc/qcom_pil_info.h | 8 ++
> 4 files changed, 162 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 94afdde4bc9f..0798602e355a 100644
> --- a/drivers/remoteproc/Kconfig
> +++ b/drivers/remoteproc/Kconfig
> @@ -85,6 +85,9 @@ 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 00f09e658cb3..c1b46e9033cb 100644
> --- a/drivers/remoteproc/Makefile
> +++ b/drivers/remoteproc/Makefile
> @@ -14,6 +14,7 @@ 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..b0897ae9eae5
> --- /dev/null
> +++ b/drivers/remoteproc/qcom_pil_info.c
> @@ -0,0 +1,150 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2019 Linaro Ltd.
> + */
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/mutex.h>
> +#include <linux/regmap.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/slab.h>

These should be in alphabetical order if there is no depencencies
between them, something checkpatch complains about.

> +
> +struct pil_reloc_entry {
> + char name[8];

Please add a #define for the name length and reuse it in qcom_pil_info_store()

> + __le64 base;
> + __le32 size;
> +} __packed;
> +
> +#define PIL_INFO_SIZE 200
> +#define PIL_INFO_ENTRIES (PIL_INFO_SIZE / sizeof(struct pil_reloc_entry))
> +
> +struct pil_reloc {
> + struct device *dev;
> + struct regmap *map;
> + u32 offset;
> + int val_bytes;
> +
> + struct pil_reloc_entry entries[PIL_INFO_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
> + */
> +void qcom_pil_info_store(const char *image, phys_addr_t base, size_t size)
> +{
> + struct pil_reloc_entry *entry;
> + int idx = -1;
> + int i;
> +
> + mutex_lock(&reloc_mutex);
> + if (!_reloc)

Since it is available, I would use function qcom_pil_info_available(). Also
checkpatch complains about indentation problems related to the 'if' condition
but I can't see what makes it angry.

> + goto unlock;
> +
> + for (i = 0; i < PIL_INFO_ENTRIES; i++) {
> + if (!_reloc->entries[i].name[0]) {
> + if (idx == -1)
> + idx = i;
> + continue;
> + }
> +
> + if (!strncmp(_reloc->entries[i].name, image, 8)) {
> + idx = i;
> + goto found;
> + }
> + }
> +
> + if (idx == -1) {
> + dev_warn(_reloc->dev, "insufficient PIL info slots\n");
> + goto unlock;

Given how this function is used in the next patch I think an error should be
reported to the caller.

> + }
> +
> +found:
> + entry = &_reloc->entries[idx];
> + stracpy(entry->name, image);

Function stracpy() isn't around in mainline.

> + entry->base = base;
> + entry->size = size;
> +
> + regmap_bulk_write(_reloc->map, _reloc->offset + idx * sizeof(*entry),
> + entry, sizeof(*entry) / _reloc->val_bytes);

Same here - the error code should be handled and reported to the caller.

> +
> +unlock:
> + mutex_unlock(&reloc_mutex);
> +}
> +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)
> +{
> + struct pil_reloc *reloc;
> +
> + reloc = devm_kzalloc(&pdev->dev, sizeof(*reloc), 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);
> +
> + if (of_property_read_u32(pdev->dev.of_node, "offset", &reloc->offset))
> + return -EINVAL;
> +
> + reloc->val_bytes = regmap_get_val_bytes(reloc->map);
> + if (reloc->val_bytes < 0)
> + return -EINVAL;
> +
> + regmap_bulk_write(reloc->map, reloc->offset, reloc->entries,
> + sizeof(reloc->entries) / reloc->val_bytes);

Error code handling.

Thanks,
Mathieu

> +
> + 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..0372602fae1d
> --- /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__
> +
> +void qcom_pil_info_store(const char *image, phys_addr_t base, size_t size);
> +bool qcom_pil_info_available(void);
> +
> +#endif
> --
> 2.24.0
>