Re: [PATCH v7 2/5] remoteproc: qcom: Introduce helper to store pil info in IMEM
From: Nathan Chancellor
Date: Thu Jul 16 2020 - 01:03:43 EST
On Mon, Jun 22, 2020 at 12:19:39PM -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.
>
> Reviewed-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> Reviewed-by: Vinod Koul <vkoul@xxxxxxxxxx>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> ---
>
> Changes since v6:
> - Replaced entry struct and usage of offset_of with a comment and defined offsets
> - Renamed pil_reloc_lock
> - Write out upper 32 bits of the address
> - Include header from implementation
> - Add linux/types.h to the header file
>
> drivers/remoteproc/Kconfig | 3 +
> drivers/remoteproc/Makefile | 1 +
> drivers/remoteproc/qcom_pil_info.c | 129 +++++++++++++++++++++++++++++
> drivers/remoteproc/qcom_pil_info.h | 9 ++
> 4 files changed, 142 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 c4d1731295eb..f4bd96d1a1a3 100644
> --- a/drivers/remoteproc/Kconfig
> +++ b/drivers/remoteproc/Kconfig
> @@ -116,6 +116,9 @@ 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 e8b886e511f0..fe398f82d550 100644
> --- a/drivers/remoteproc/Makefile
> +++ b/drivers/remoteproc/Makefile
> @@ -16,6 +16,7 @@ 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..0536e3904669
> --- /dev/null
> +++ b/drivers/remoteproc/qcom_pil_info.c
> @@ -0,0 +1,129 @@
> +// 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>
> +#include "qcom_pil_info.h"
> +
> +/*
> + * The PIL relocation information region is used to communicate memory regions
> + * occupied by co-processor firmware for post mortem crash analysis.
> + *
> + * It consists of an array of entries with an 8 byte textual identifier of the
> + * region followed by a 64 bit base address and 32 bit size, both little
> + * endian.
> + */
> +#define PIL_RELOC_NAME_LEN 8
> +#define PIL_RELOC_ENTRY_SIZE (PIL_RELOC_NAME_LEN + sizeof(__le64) + sizeof(__le32))
> +
> +struct pil_reloc {
> + void __iomem *base;
> + size_t num_entries;
> +};
> +
> +static struct pil_reloc _reloc __read_mostly;
> +static DEFINE_MUTEX(pil_reloc_lock);
> +
> +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) / PIL_RELOC_ENTRY_SIZE;
> +
> + 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(&pil_reloc_lock);
> + ret = qcom_pil_info_init();
> + if (ret < 0) {
> + mutex_unlock(&pil_reloc_lock);
> + return ret;
> + }
> +
> + for (i = 0; i < _reloc.num_entries; i++) {
> + entry = _reloc.base + i * PIL_RELOC_ENTRY_SIZE;
> +
> + 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(&pil_reloc_lock);
> + return -ENOMEM;
> +
> +found_unused:
> + memcpy_toio(entry, image, PIL_RELOC_NAME_LEN);
> +found_existing:
> + /* Use two writel() as base is only aligned to 4 bytes on odd entries */
> + writel(base, entry + PIL_RELOC_NAME_LEN);
> + writel(base >> 32, entry + PIL_RELOC_NAME_LEN + 4);
I am not sure if this has been reported or not but this shift causes a
warning on arm 32-bit:
$ make -skj"$(nproc)" ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- distclean allyesconfig drivers/remoteproc/qcom_pil_info.o
In file included from ./include/linux/swab.h:5,
from ./include/uapi/linux/byteorder/big_endian.h:13,
from ./include/linux/byteorder/big_endian.h:5,
from ./arch/arm/include/uapi/asm/byteorder.h:20,
from ./include/asm-generic/bitops/le.h:6,
from ./arch/arm/include/asm/bitops.h:268,
from ./include/linux/bitops.h:29,
from ./include/linux/kernel.h:12,
from drivers/remoteproc/qcom_pil_info.c:5:
drivers/remoteproc/qcom_pil_info.c: In function 'qcom_pil_info_store':
drivers/remoteproc/qcom_pil_info.c:111:14: warning: right shift count >= width of type [-Wshift-count-overflow]
111 | writel(base >> 32, entry + PIL_RELOC_NAME_LEN + 4);
| ^~
./include/uapi/linux/swab.h:115:54: note: in definition of macro '__swab32'
115 | #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
| ^
./include/linux/byteorder/generic.h:88:21: note: in expansion of macro '__cpu_to_le32'
88 | #define cpu_to_le32 __cpu_to_le32
| ^~~~~~~~~~~~~
./arch/arm/include/asm/io.h:307:36: note: in expansion of macro 'writel_relaxed'
307 | #define writel(v,c) ({ __iowmb(); writel_relaxed(v,c); })
| ^~~~~~~~~~~~~~
drivers/remoteproc/qcom_pil_info.c:111:2: note: in expansion of macro 'writel'
111 | writel(base >> 32, entry + PIL_RELOC_NAME_LEN + 4);
| ^~~~~~
Cheers,
Nathan
> + writel(size, entry + PIL_RELOC_NAME_LEN + sizeof(__le64));
> + mutex_unlock(&pil_reloc_lock);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(qcom_pil_info_store);
> +
> +static void __exit pil_reloc_exit(void)
> +{
> + mutex_lock(&pil_reloc_lock);
> + iounmap(_reloc.base);
> + _reloc.base = NULL;
> + mutex_unlock(&pil_reloc_lock);
> +}
> +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..0dce6142935e
> --- /dev/null
> +++ b/drivers/remoteproc/qcom_pil_info.h
> @@ -0,0 +1,9 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __QCOM_PIL_INFO_H__
> +#define __QCOM_PIL_INFO_H__
> +
> +#include <linux/types.h>
> +
> +int qcom_pil_info_store(const char *image, phys_addr_t base, size_t size);
> +
> +#endif
> --
> 2.26.2
>