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.poir...@linaro.org>
> Reviewed-by: Vinod Koul <vk...@kernel.org>
> Signed-off-by: Bjorn Andersson <bjorn.anders...@linaro.org>
> ---
> 
> 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
> 

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