On Thu, Aug 29, 2019 at 01:10:42PM +0300, Sakari Ailus wrote:
> Add support for %pfw conversion specifier (with "f" and "P" modifiers) to
> support printing full path of the node, including its name ("f") and only
> the node's name ("P") in the printk family of functions. The two flags
> have equivalent functionality to existing %pOF with the same two modifiers
> ("f" and "P") on OF based systems. The ability to do the same on ACPI
> based systems is added by this patch.
>
> On ACPI based systems the resulting strings look like
>
> \_SB.PCI0.CIO2.port@1.endpoint@0
>
> where the nodes are separated by a dot (".") and the first three are
> ACPI device nodes and the latter two ACPI data nodes.
Couple of comments below, FWIW,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
>
> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> ---
> Documentation/core-api/printk-formats.rst | 24 +++++++++++++++
> lib/vsprintf.c | 37 +++++++++++++++++++++++
> scripts/checkpatch.pl | 3 +-
> 3 files changed, 63 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst
> index 922a29eb70e6c..abba210f67567 100644
> --- a/Documentation/core-api/printk-formats.rst
> +++ b/Documentation/core-api/printk-formats.rst
> @@ -418,6 +418,30 @@ Examples::
>
> Passed by reference.
>
> +Fwnode handles
> +--------------
> +
> +::
> +
> + %pfw[fP]
I'm not familiar with all flavours of the OF case, the question is do we use
same letters for analogues?
> +
> +For printing information on fwnode handles. The default is to print the full
> +node name, including the path. The modifiers are functionally equivalent to
> +%pOF above.
> +
> + - f - full name of the node, including the path
> + - P - the name of the node including an address (if there is one)
> +
> +Examples (ACPI):
> +
> + %pfwf \_SB.PCI0.CIO2.port@1.endpoint@0 - Full node name
> + %pfwP endpoint@0 - Node name
> +
> +Examples (OF):
> +
> + %pfwf /ocp@68000000/i2c@48072000/camera@10/port/endpoint - Full name
> + %pfwP endpoint - Node name
> +
> Time and date (struct rtc_time)
> -------------------------------
>
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> index 19f9b3f30623e..79dacd0b9e124 100644
> --- a/lib/vsprintf.c
> +++ b/lib/vsprintf.c
> @@ -1978,6 +1978,37 @@ char *device_node_string(char *buf, char *end, struct device_node *dn,
> return widen_string(buf, buf - buf_start, end, spec);
> }
>
> +static noinline_for_stack
> +char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
> + struct printf_spec spec, const char *fmt)
> +{
> + struct printf_spec str_spec = spec;
> + char *buf_start = buf;
> +
> + str_spec.field_width = -1;
> +
> + if (*fmt != 'w')
> + return error_string(buf, end, "(%pfw?)", spec);
> +
> + if (check_pointer(&buf, end, fwnode, spec))
> + return buf;
> +
> + fmt++;
> +
> + switch (*fmt) {
> + case 'f': /* full_name */
> + default:
> + buf = fwnode_full_name_string(fwnode, buf, end);
> + break;
> + case 'P': /* name */
> + buf = string(buf, end, fwnode_get_name(fwnode),
> + str_spec);
Perfectly one line.
> + break;
> + }
> +
> + return widen_string(buf, buf - buf_start, end, spec);
> +}
> +
> /*
> * Show a '%p' thing. A kernel extension is that the '%p' is followed
> * by an extra set of alphanumeric characters that are extended format
> @@ -2080,6 +2111,10 @@ char *device_node_string(char *buf, char *end, struct device_node *dn,
> * F device node flags
> * c major compatible string
> * C full compatible string
> + * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer
> + * Without an option prints the full name of the node
> + * f full name
> + * P node name, including a possible unit address
> * - 'x' For printing the address. Equivalent to "%lx".
> *
> * ** When making changes please also update:
> @@ -2157,6 +2192,8 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
> return flags_string(buf, end, ptr, spec, fmt);
> case 'O':
> return device_node_string(buf, end, ptr, spec, fmt + 1);
> + case 'f':
> + return fwnode_string(buf, end, ptr, spec, fmt + 1);
> case 'x':
> return pointer_string(buf, end, ptr, spec);
> }
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index a60c241112cd4..8df50911ff4e9 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -5995,7 +5995,8 @@ sub process {
> while ($fmt =~ /(\%[\*\d\.]*p(\w))/g) {
> $specifier = $1;
> $extension = $2;
> - if ($extension !~ /[SsBKRraEhMmIiUDdgVCbGNOxt]/) {
> + if ($extension !~ /[SsBKRraEhMmIiUDdgVCbGNOxtf]/ ||
> + $extension =~ /^f[^w]/) {
> $bad_specifier = $specifier;
> last;
> }
> --
> 2.20.1
>
--
With Best Regards,
Andy Shevchenko
