On Mon, Oct 07, 2024 at 06:16:08PM -0500, Ira Weiny wrote: > The use of struct range in the CXL subsystem is growing. In particular, > the addition of Dynamic Capacity devices uses struct range in a number > of places which are reported in debug and error messages. > > To wit requiring the printing of the start/end fields in each print > became cumbersome. Dan Williams mentions in [1] that it might be time > to have a print specifier for struct range similar to struct resource > > A few alternatives were considered including '%par', '%r', and '%pn'. > %pra follows that struct range is similar to struct resource (%p[rR]) > but need to be different. Based on discussions with Petr and Andy > '%pra' was chosen.[2] > > Andy also suggested to keep the range prints similar to struct resource > though combined code. Add hex_range() to handle printing for both > pointer types. > > To: Petr Mladek <pmladek@xxxxxxxx> > To: Steven Rostedt <rostedt@xxxxxxxxxxx> > To: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > To: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> > To: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx> > To: Jonathan Corbet <corbet@xxxxxxx> (maintainer:DOCUMENTATION) > Cc: linux-doc@xxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx (open list) > Link: https://lore.kernel.org/all/663922b475e50_d54d72945b@xxxxxxxxxxxxxxxxxxxxxxxxx.notmuch/ [1] > Link: https://lore.kernel.org/all/66cea3bf3332f_f937b29424@iweiny-mobl.notmuch/ [2] > Suggested-by: "Dan Williams" <dan.j.williams@xxxxxxxxx> > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx> > > --- > Changes: > [Andy: create new hex_range() and use it in both range/resource] > [Petr/Andy: Use %pra] > [Andy: Add test case start > end] > [Petr: Update documentation] > [Petr: use 'range -'] > [Petr: fixup printf_spec specifiers] > [Petr: add lib/test_printf test] > --- > Documentation/core-api/printk-formats.rst | 13 ++++++++ > lib/test_printf.c | 26 +++++++++++++++ > lib/vsprintf.c | 55 +++++++++++++++++++++++++++---- > 3 files changed, 88 insertions(+), 6 deletions(-) > > diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst > index 14e093da3ccd..03b102fc60bb 100644 > --- a/Documentation/core-api/printk-formats.rst > +++ b/Documentation/core-api/printk-formats.rst > @@ -231,6 +231,19 @@ width of the CPU data path. > > Passed by reference. > > +Struct Range > +------------ > + > +:: > + > + %pra [range 0x0000000060000000-0x000000006fffffff] > + %pra [range 0x0000000060000000] > + > +For printing struct range. struct range holds an arbitrary range of u64 > +values. If start is equal to end only 1 value is printed. > + > +Passed by reference. > + > DMA address types dma_addr_t > ---------------------------- > > diff --git a/lib/test_printf.c b/lib/test_printf.c > index 5afdf5efc627..e3e75b6d10a0 100644 > --- a/lib/test_printf.c > +++ b/lib/test_printf.c > @@ -432,6 +432,31 @@ struct_resource(void) > "%pR", &test_resource); > } > > +static void __init > +struct_range(void) > +{ > + struct range test_range = { > + .start = 0xc0ffee00ba5eba11, > + .end = 0xc0ffee00ba5eba11, > + }; > + > + test("[range 0xc0ffee00ba5eba11]", "%pra", &test_range); > + > + test_range = (struct range) { > + .start = 0xc0ffee, > + .end = 0xba5eba11, > + }; > + test("[range 0x0000000000c0ffee-0x00000000ba5eba11]", > + "%pra", &test_range); > + > + test_range = (struct range) { > + .start = 0xba5eba11, > + .end = 0xc0ffee, > + }; > + test("[range 0x00000000ba5eba11-0x0000000000c0ffee]", > + "%pra", &test_range); > +} > + ... > static noinline_for_stack > char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec, > const char *fmt) > @@ -2277,6 +2314,7 @@ char *rust_fmt_argument(char *buf, char *end, void *ptr); > * - 'Bb' as above with module build ID (for use in backtraces) > * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref] > * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201] > + * - 'ra' struct ranges [range 0x00 - 0xff] Maybe follow the existing examples here, like 'ra" For struct ranges, e.g., ... fan > * - 'b[l]' For a bitmap, the number of bits is determined by the field > * width which must be explicitly specified either as part of the > * format string '%32b[l]' or through '%*b[l]', [l] selects > @@ -2399,8 +2437,13 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, > fallthrough; > case 'B': > return symbol_string(buf, end, ptr, spec, fmt); > - case 'R': > case 'r': > + switch (fmt[1]) { > + case 'a': > + return range_string(buf, end, ptr, spec, fmt); > + } > + fallthrough; > + case 'R': > return resource_string(buf, end, ptr, spec, fmt); > case 'h': > return hex_string(buf, end, ptr, spec, fmt); > > -- > 2.46.0 > -- Fan Ni
