[alsa-devel] [PATCH v3 10/11] ASoC: SOF: Provide probe debugfs support

[Sridharan, Ranjani]

On Tue, Jan 28, 2020 at 2:51 AM Cezary Rojewski <cezary.rojewski at intel.com>
wrote:

> Define debugfs subdirectory delegated for IPC communication with DSP.
> Input format: uint,uint,(...) which are later translated into DWORDS
> sequence and further into instances of struct of interest given the IPC
> type.
>
> For Extractor probes, following have been enabled:
> - PROBE_POINT_ADD (echo <..> probe_points)
> - PROBE_POINT_REMOVE (echo <..> probe_points_remove)
> - PROBE_POINT_INFO (cat probe_points)
>
> Signed-off-by: Cezary Rojewski <cezary.rojewski at intel.com>
> ---
>
> Changes in v2:
> - renamed debugfs probe functions as requested by Pierre
>
>
>  sound/soc/sof/debug.c | 208 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 208 insertions(+)
>
> diff --git a/sound/soc/sof/debug.c b/sound/soc/sof/debug.c
> index d2b3b99d3a20..d38ab59e9a98 100644
> --- a/sound/soc/sof/debug.c
> +++ b/sound/soc/sof/debug.c
> @@ -17,6 +17,203 @@
>  #include "sof-priv.h"
>  #include "ops.h"
>
> +#if IS_ENABLED(CONFIG_SND_SOC_SOF_DEBUG_PROBES)
> +#include "probe.h"
> +
> +/**
> + * strsplit_u32 - Split string into sequence of u32 tokens
> + * @buf:       String to split into tokens.
> + * @delim:     String containing delimiter characters.
> + * @tkns:      Returned u32 sequence pointer.
> + * @num_tkns:  Returned number of tokens obtained.
> + */
> +static int
> +strsplit_u32(char **buf, const char *delim, u32 **tkns, size_t *num_tkns)
> +{
> +       char *s;
> +       u32 *data, *tmp;
> +       size_t count = 0;
> +       size_t cap = 32;
> +       int ret = 0;
> +
> +       *tkns = NULL;
> +       *num_tkns = 0;
> +       data = kcalloc(cap, sizeof(*data), GFP_KERNEL);
> +       if (!data)
> +               return -ENOMEM;
> +
> +       while ((s = strsep(buf, delim)) != NULL) {
> +               ret = kstrtouint(s, 0, data + count);
> +               if (ret)
> +                       goto exit;
> +               if (++count >= cap) {
> +                       cap *= 2;
> +                       tmp = krealloc(data, cap * sizeof(*data),
> GFP_KERNEL);
> +                       if (!tmp) {
> +                               ret = -ENOMEM;
> +                               goto exit;
> +                       }
> +                       data = tmp;
> +               }
> +       }
> +
> +       if (!count)
> +               goto exit;
> +       *tkns = kmemdup(data, count * sizeof(*data), GFP_KERNEL);
> +       if (*tkns == NULL) {
> +               ret = -ENOMEM;
> +               goto exit;
> +       }
> +       *num_tkns = count;
> +
> +exit:
> +       kfree(data);
> +       return ret;
> +}
> +
> +static int tokenize_input(const char __user *from, size_t count,
> +               loff_t *ppos, u32 **tkns, size_t *num_tkns)
> +{
> +       char *buf;
> +       int ret;
> +
> +       buf = kmalloc(count + 1, GFP_KERNEL);
> +       if (!buf)
> +               return -ENOMEM;
> +
> +       ret = simple_write_to_buffer(buf, count, ppos, from, count);
> +       if (ret != count) {
> +               ret = ret >= 0 ? -EIO : ret;
> +               goto exit;
> +       }
> +
> +       buf[count] = '\0';
> +       ret = strsplit_u32((char **)&buf, ",", tkns, num_tkns);
> +exit:
> +       kfree(buf);
> +       return ret;
> +}
> +
> +static ssize_t probe_points_read(struct file *file,
> +               char __user *to, size_t count, loff_t *ppos)
> +{
> +       struct snd_sof_dfsentry *dfse = file->private_data;
> +       struct sof_probe_point_desc *desc;
> +       size_t num_desc, len = 0;
> +       char *buf;
> +       int i, ret;
> +
> +       buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
> +       if (!buf)
> +               return -ENOMEM;
> +
> +       ret = sof_ipc_probe_points_info(dfse->sdev, &desc, &num_desc);
> +       if (ret < 0)
> +               goto exit;
> +
> +       for (i = 0; i < num_desc; i++) {
> +               ret = snprintf(buf + len, PAGE_SIZE - len,
> +                       "Id: %#010x  Purpose: %d  Node id: %#x\n",
> +                       desc[i].buffer_id, desc[i].purpose,
> desc[i].stream_tag);
> +               if (ret < 0)
> +                       goto free_desc;
> +               len += ret;
> +       }
> +
> +       ret = simple_read_from_buffer(to, count, ppos, buf, len);
> +free_desc:
> +       kfree(desc);
> +exit:
> +       kfree(buf);
> +       return ret;
> +}
> +
> +static ssize_t probe_points_write(struct file *file,
> +               const char __user *from, size_t count, loff_t *ppos)
> +{
> +       struct snd_sof_dfsentry *dfse = file->private_data;
> +       struct sof_probe_point_desc *desc;
> +       size_t num_tkns, bytes;
> +       u32 *tkns;
> +       int ret;
> +
> +       ret = tokenize_input(from, count, ppos, &tkns, &num_tkns);
> +       if (ret < 0)
> +               return ret;
> +       bytes = sizeof(*tkns) * num_tkns;
> +       if (!num_tkns || (bytes % sizeof(*desc))) {
> +               ret = -EINVAL;
> +               goto exit;
> +       }
> +
> +       desc = (struct sof_probe_point_desc *)tkns;
> +       ret = sof_ipc_probe_points_add(dfse->sdev,
> +                       desc, bytes / sizeof(*desc));
> +       if (!ret)
> +               ret = count;
> +exit:
> +       kfree(tkns);
> +       return ret;
> +}
> +
> +static const struct file_operations probe_points_fops = {
> +       .open = simple_open,
> +       .read = probe_points_read,
> +       .write = probe_points_write,
> +       .llseek = default_llseek,
> +};
> +
> +static ssize_t probe_points_remove_write(struct file *file,
> +               const char __user *from, size_t count, loff_t *ppos)
> +{
> +       struct snd_sof_dfsentry *dfse = file->private_data;
> +       size_t num_tkns;
> +       u32 *tkns;
> +       int ret;
> +
> +       ret = tokenize_input(from, count, ppos, &tkns, &num_tkns);
> +       if (ret < 0)
> +               return ret;
> +       if (!num_tkns) {
> +               ret = -EINVAL;
> +               goto exit;
> +       }
> +
> +       ret = sof_ipc_probe_points_remove(dfse->sdev, tkns, num_tkns);
> +       if (!ret)
> +               ret = count;
> +exit:
> +       kfree(tkns);
> +       return ret;
> +}
> +
> +static const struct file_operations probe_points_remove_fops = {
> +       .open = simple_open,
> +       .write = probe_points_remove_write,
> +       .llseek = default_llseek,
> +};
> +
> +static int snd_sof_debugfs_probe_item(struct snd_sof_dev *sdev,
> +                                const char *name, mode_t mode,
> +                                const struct file_operations *fops)

Hi Cezary,

Any particular reason to not use the existing snd_sof_debugfs_buf_item()
and adding a new one that does pretty much the same thing?

Thanks,
Ranjani