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 '%pn' for 'print raNge' but %par follows that struct range is most often used to store a range of physical addresses. So use '%par' for 'print address range'. To: Petr Mladek <pmla...@suse.com> (maintainer:VSPRINTF) To: Steven Rostedt <rost...@goodmis.org> (maintainer:VSPRINTF) To: Jonathan Corbet <cor...@lwn.net> (maintainer:DOCUMENTATION) Cc: linux-...@vger.kernel.org (open list:DOCUMENTATION) Cc: linux-ker...@vger.kernel.org (open list) Link: https://lore.kernel.org/all/663922b475e50_d54d729...@dwillia2-xfh.jf.intel.com.notmuch/ [1] Suggested-by: "Dan Williams" <dan.j.willi...@intel.com> Signed-off-by: Ira Weiny <ira.we...@intel.com> --- Documentation/core-api/printk-formats.rst | 14 ++++++++++++ lib/vsprintf.c | 37 +++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+) diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst index 4451ef501936..a02ef899b2a6 100644 --- a/Documentation/core-api/printk-formats.rst +++ b/Documentation/core-api/printk-formats.rst @@ -231,6 +231,20 @@ width of the CPU data path. Passed by reference. +Struct Range +------------ + +:: + + %par [range 0x60000000-0x6fffffff] or + [range 0x0000000060000000-0x000000006fffffff] + +For printing struct range. A variation of printing a physical address is to +print the value of struct range which are often used to hold a physical address +range. + +Passed by reference. + DMA address types dma_addr_t ---------------------------- diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 2d71b1115916..c132178fac07 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -1140,6 +1140,39 @@ char *resource_string(char *buf, char *end, struct resource *res, return string_nocheck(buf, end, sym, spec); } +static noinline_for_stack +char *range_string(char *buf, char *end, const struct range *range, + struct printf_spec spec, const char *fmt) +{ +#define RANGE_PRINTK_SIZE 16 +#define RANGE_DECODED_BUF_SIZE ((2 * sizeof(struct range)) + 4) +#define RANGE_PRINT_BUF_SIZE sizeof("[range - ]") + char sym[RANGE_DECODED_BUF_SIZE + RANGE_PRINT_BUF_SIZE]; + char *p = sym, *pend = sym + sizeof(sym); + + static const struct printf_spec str_spec = { + .field_width = -1, + .precision = 10, + .flags = LEFT, + }; + static const struct printf_spec range_spec = { + .base = 16, + .field_width = RANGE_PRINTK_SIZE, + .precision = -1, + .flags = SPECIAL | SMALL | ZEROPAD, + }; + + *p++ = '['; + p = string_nocheck(p, pend, "range ", str_spec); + p = number(p, pend, range->start, range_spec); + *p++ = '-'; + p = number(p, pend, range->end, range_spec); + *p++ = ']'; + *p = '\0'; + + return string_nocheck(buf, end, sym, spec); +} + static noinline_for_stack char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec, const char *fmt) @@ -1802,6 +1835,8 @@ char *address_val(char *buf, char *end, const void *addr, return buf; switch (fmt[1]) { + case 'r': + return range_string(buf, end, addr, spec, fmt); case 'd': num = *(const dma_addr_t *)addr; size = sizeof(dma_addr_t); @@ -2364,6 +2399,8 @@ char *rust_fmt_argument(char *buf, char *end, void *ptr); * to use print_hex_dump() for the larger input. * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives * (default assumed to be phys_addr_t, passed by reference) + * - 'ar' For decoded struct ranges (a variation of physical address which are + * most often stored in struct ranges. * - 'd[234]' For a dentry name (optionally 2-4 last components) * - 'D[234]' Same as 'd' but for a struct file * - 'g' For block_device name (gendisk + partition number) -- 2.45.2
