| Message ID | 20170622204445.14930-1-robh@kernel.org |
|---|---|
| State | New |
| Headers | show |
On Thu, 2017-06-22 at 15:44 -0500, Rob Herring wrote: > From: Pantelis Antoniou <pantelis.antoniou@konsulko.com> > > 90% of the usage of device node's full_name is printing it out in a > kernel message. However, storing the full path for every node is > wasteful and redundant. With a custom format specifier, we can generate > the full path at run-time and eventually remove the full path from every > node. > > For instance typical use is: > pr_info("Frobbing node %s\n", node->full_name); > > Which can be written now as: > pr_info("Frobbing node %pOF\n", node); I still think this should use another identifier like %pO for object then another letter for type of object maybe N for node. And F is flags, f is name > diff --git a/lib/vsprintf.c b/lib/vsprintf.c [] > @@ -1470,6 +1471,131 @@ char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt) > return format_flags(buf, end, flags, names); > } > > +static int device_node_calc_depth(const struct device_node *np) > +{ > + int d; > + > + for (d = 0; np; d++) > + np = np->parent; > + > + return d; > +} > + > +static noinline_for_stack > +char *device_node_gen_full_name(const struct device_node *np, char *buf, char *end) > +{ > + int i; > + int depth = device_node_calc_depth(np); > + static const struct printf_spec strspec = { > + .field_width = -1, > + .precision = -1, > + }; > + const struct device_node *nodes[depth]; > + > + if (!depth) > + returnuf; > + /* special case for root node */ > + if (depth == 1) > + return string(buf, end, "/", strspec); > + > + depth--; > + for (i = depth - 1; i >= 0; i--) { > + nodes[i] = np; > + np = np->parent; > + } > + for (i = 0; i < depth; i++) { > + buf = string(buf, end, "/", strspec); > + buf = string(buf, end, kbasename(nodes[i]->full_name), strspec); > + } > + return buf; > +} I think there should be another function to get a particular struct device_node * at a particular depth to avoid all the pointers on stack. Basically, adapt the for (i = depth - 1 loop to a function that returns nodes[i] -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jun 22, 2017 at 5:44 PM, Randy Dunlap <rdunlap@infradead.org> wrote: > On 06/22/2017 01:44 PM, Rob Herring wrote: >> From: Pantelis Antoniou <pantelis.antoniou@konsulko.com> >> >> 90% of the usage of device node's full_name is printing it out in a >> kernel message. However, storing the full path for every node is >> wasteful and redundant. With a custom format specifier, we can generate >> the full path at run-time and eventually remove the full path from every >> node. >> >> For instance typical use is: >> pr_info("Frobbing node %s\n", node->full_name); >> >> Which can be written now as: >> pr_info("Frobbing node %pOF\n", node); > > > isn't OF for flags -- and Of for full name? > Typo or a change in the last 2 years? It changed in the discussion 2 years ago. The intent is: %pO - kobj %pOF - device_node, defaulting to full name There's no support of base kobj's, but I guess I should make that intent clear in the documentation. Rob -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jun 22, 2017 at 10:01 PM, Joe Perches <joe@perches.com> wrote: > On Thu, 2017-06-22 at 15:44 -0500, Rob Herring wrote: >> From: Pantelis Antoniou <pantelis.antoniou@konsulko.com> >> >> 90% of the usage of device node's full_name is printing it out in a >> kernel message. However, storing the full path for every node is >> wasteful and redundant. With a custom format specifier, we can generate >> the full path at run-time and eventually remove the full path from every >> node. >> >> For instance typical use is: >> pr_info("Frobbing node %s\n", node->full_name); >> >> Which can be written now as: >> pr_info("Frobbing node %pOF\n", node); > > I still think this should use another identifier like > %pO for object then another letter for type of object > maybe N for node. It is. O is for kobj and F is for device node. It doesn't make a much sense separately, but OF together makes sense as Open Firmware. > > And F is flags, f is name > >> diff --git a/lib/vsprintf.c b/lib/vsprintf.c > [] >> @@ -1470,6 +1471,131 @@ char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt) >> return format_flags(buf, end, flags, names); >> } >> >> +static int device_node_calc_depth(const struct device_node *np) >> +{ >> + int d; >> + >> + for (d = 0; np; d++) >> + np = np->parent; >> + >> + return d; >> +} >> + >> +static noinline_for_stack >> +char *device_node_gen_full_name(const struct device_node *np, char *buf, char *end) >> +{ >> + int i; >> + int depth = device_node_calc_depth(np); >> + static const struct printf_spec strspec = { >> + .field_width = -1, >> + .precision = -1, >> + }; >> + const struct device_node *nodes[depth]; >> + >> + if (!depth) >> + returnuf; >> + /* special case for root node */ >> + if (depth == 1) >> + return string(buf, end, "/", strspec); >> + >> + depth--; >> + for (i = depth - 1; i >= 0; i--) { >> + nodes[i] = np; >> + np = np->parent; >> + } >> + for (i = 0; i < depth; i++) { >> + buf = string(buf, end, "/", strspec); >> + buf = string(buf, end, kbasename(nodes[i]->full_name), strspec); >> + } >> + return buf; >> +} > > I think there should be another function to get > a particular struct device_node * at a particular > depth to avoid all the pointers on stack. > > Basically, adapt the for (i = depth - 1 loop to > a function that returns nodes[i] Okay. Rob -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, 2017-06-23 at 12:30 -0500, Rob Herring wrote: > From: Pantelis Antoniou <pantelis.antoniou@konsulko.com> > > 90% of the usage of device node's full_name is printing it out in a > kernel message. However, storing the full path for every node is > wasteful and redundant. With a custom format specifier, we can generate > the full path at run-time and eventually remove the full path from every > node. > > For instance typical use is: > pr_info("Frobbing node %s\n", node->full_name); > > Which can be written now as: > pr_info("Frobbing node %pOF\n", node); > > '%pO' is the base specifier to represent kobjects with '%pOF' > representing struct device_node. Currently, struct device_node is the > only supported type of kobject. > > More fine-grained control of formatting includes printing the name, > flags, path-spec name and others, explained in the documentation entry. > > Originally written by Pantelis, but pretty much rewrote the core > function using existing string/number functions. The 2 passes were > unnecessary and have been removed. Also, updated the checkpatch.pl > check. The unittest code was written by Grant Likely. > > Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> > Signed-off-by: Rob Herring <robh@kernel.org> > --- > v3: > - Fix missing documentation updates using '%pOF' as the device_node > specifier. > - Update the commit msg and documentation to clearly define '%pO' is the > base specifier for kobjects. > - Rework device_node_gen_full_name() to avoid creating an array of node > pointers on the stack. Thanks Rob. This all seems sensible to me now. If you want: Acked-by: Joe Perches <joe@perches.com> cheers, Joe -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt index 5962949944fd..c7af38188f12 100644 --- a/Documentation/printk-formats.txt +++ b/Documentation/printk-formats.txt @@ -275,6 +275,36 @@ struct va_format: Passed by reference. +Device tree nodes: + + %pOn[fnpPcCF] + + For printing device tree nodes. The optional arguments are: + f device node full_name + n device node name + p device node phandle + P device node path spec (name + @unit) + F device node flags + c major compatible string + C full compatible string + Without any arguments prints full_name (same as %pOFf) + The separator when using multiple arguments is ':' + + Examples: + + %pOn /foo/bar@0 - Node full name + %pOnf /foo/bar@0 - Same as above + %pOnfp /foo/bar@0:10 - Node full name + phandle + %pOnfcF /foo/bar@0:foo,device:--P- - Node full name + + major compatible string + + node flags + D - dynamic + d - detached + P - Populated + B - Populated bus + + Passed by reference. + struct clk: %pC pll1 diff --git a/drivers/of/unittest-data/tests-platform.dtsi b/drivers/of/unittest-data/tests-platform.dtsi index eb20eeb2b062..a0c93822aee3 100644 --- a/drivers/of/unittest-data/tests-platform.dtsi +++ b/drivers/of/unittest-data/tests-platform.dtsi @@ -26,7 +26,9 @@ #size-cells = <0>; dev@100 { - compatible = "test-sub-device"; + compatible = "test-sub-device", + "test-compat2", + "test-compat3"; reg = <0x100>; }; }; diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c index 987a1530282a..8f611e9844db 100644 --- a/drivers/of/unittest.c +++ b/drivers/of/unittest.c @@ -239,6 +239,63 @@ static void __init of_unittest_check_tree_linkage(void) pr_debug("allnodes list size (%i); sibling lists size (%i)\n", allnode_count, child_count); } +static void __init of_unittest_printf_one(struct device_node *np, const char *fmt, + const char *expected) +{ + char buf[strlen(expected)+10]; + int size, i; + + /* Baseline; check conversion with a large size limit */ + memset(buf, 0xff, sizeof(buf)); + size = snprintf(buf, sizeof(buf) - 2, fmt, np); + + /* use strcmp() instead of strncmp() here to be absolutely sure strings match */ + unittest((strcmp(buf, expected) == 0) && (buf[size+1] == 0xff), + "sprintf failed; fmt='%s' expected='%s' rslt='%s'\n", + fmt, expected, buf); + + /* Make sure length limits work */ + size++; + for (i = 0; i < 2; i++, size--) { + /* Clear the buffer, and make sure it works correctly still */ + memset(buf, 0xff, sizeof(buf)); + snprintf(buf, size+1, fmt, np); + unittest(strncmp(buf, expected, size) == 0 && (buf[size+1] == 0xff), + "snprintf failed; size=%i fmt='%s' expected='%s' rslt='%s'\n", + size, fmt, expected, buf); + } +} + +static void __init of_unittest_printf(void) +{ + struct device_node *np; + const char *full_name = "/testcase-data/platform-tests/test-device@1/dev@100"; + char phandle_str[16] = ""; + + np = of_find_node_by_path(full_name); + if (!np) { + unittest(np, "testcase data missing\n"); + return; + } + + num_to_str(phandle_str, sizeof(phandle_str), np->phandle); + + of_unittest_printf_one(np, "%pOF", full_name); + of_unittest_printf_one(np, "%pOFf", full_name); + of_unittest_printf_one(np, "%pOFp", phandle_str); + of_unittest_printf_one(np, "%pOFP", "dev@100"); + of_unittest_printf_one(np, "ABC %pOFP ABC", "ABC dev@100 ABC"); + of_unittest_printf_one(np, "%10pOFP", " dev@100"); + of_unittest_printf_one(np, "%-10pOFP", "dev@100 "); + of_unittest_printf_one(of_root, "%pOFP", "/"); + of_unittest_printf_one(np, "%pOFF", "----"); + of_unittest_printf_one(np, "%pOFPF", "dev@100:----"); + of_unittest_printf_one(np, "%pOFPFPc", "dev@100:----:dev@100:test-sub-device"); + of_unittest_printf_one(np, "%pOFc", "test-sub-device"); + of_unittest_printf_one(np, "%pOFC", + "\"test-sub-device\",\"test-compat2\",\"test-compat3\""); +} + struct node_hash { struct hlist_node node; struct device_node *np; @@ -2269,6 +2326,7 @@ static int __init of_unittest(void) of_unittest_find_node_by_name(); of_unittest_dynamic(); of_unittest_parse_phandle_with_args(); + of_unittest_printf(); of_unittest_property_string(); of_unittest_property_copy(); of_unittest_changeset(); diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 2d41de3f98a1..2343b2ca47c5 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -31,6 +31,7 @@ #include <linux/dcache.h> #include <linux/cred.h> #include <linux/uuid.h> +#include <linux/of.h> #include <net/addrconf.h> #ifdef CONFIG_BLOCK #include <linux/blkdev.h> @@ -1470,6 +1471,131 @@ char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt) return format_flags(buf, end, flags, names); } +static int device_node_calc_depth(const struct device_node *np) +{ + int d; + + for (d = 0; np; d++) + np = np->parent; + + return d; +} + +static noinline_for_stack +char *device_node_gen_full_name(const struct device_node *np, char *buf, char *end) +{ + int i; + int depth = device_node_calc_depth(np); + static const struct printf_spec strspec = { + .field_width = -1, + .precision = -1, + }; + const struct device_node *nodes[depth]; + + if (!depth) + return buf; + /* special case for root node */ + if (depth == 1) + return string(buf, end, "/", strspec); + + depth--; + for (i = depth - 1; i >= 0; i--) { + nodes[i] = np; + np = np->parent; + } + for (i = 0; i < depth; i++) { + buf = string(buf, end, "/", strspec); + buf = string(buf, end, kbasename(nodes[i]->full_name), strspec); + } + return buf; +} + +static noinline_for_stack +char *device_node_string(char *buf, char *end, struct device_node *dn, + struct printf_spec spec, const char *fmt) +{ + char tbuf[sizeof("xxxx") + 1]; + const char *p; + int ret; + char *buf_start = buf; + struct property *prop; + bool has_mult, pass; + static const struct printf_spec num_spec = { + .flags = SMALL, + .field_width = -1, + .precision = -1, + .base = 10, + }; + + struct printf_spec str_spec = spec; + str_spec.field_width = -1; + + if (!IS_ENABLED(CONFIG_OF)) + return string(buf, end, "(!OF)", spec); + + if ((unsigned long)dn < PAGE_SIZE) + return string(buf, end, "(null)", spec); + + /* simple case without anything any more format specifiers */ + fmt++; + if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0) + fmt = "f"; + + for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) { + if (pass) { + if (buf < end) + *buf = ':'; + buf++; + } + + switch (*fmt) { + case 'f': /* full_name */ + buf = device_node_gen_full_name(dn, buf, end); + break; + case 'n': /* name */ + buf = string(buf, end, dn->name, str_spec); + break; + case 'p': /* phandle */ + buf = number(buf, end, (unsigned int)dn->phandle, num_spec); + break; + case 'P': /* path-spec */ + p = kbasename(of_node_full_name(dn)); + if (!p[1]) + p = "/"; + buf = string(buf, end, p, str_spec); + break; + case 'F': /* flags */ + tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-'; + tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-'; + tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-'; + tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-'; + buf = string(buf, end, tbuf, str_spec); + break; + case 'c': /* major compatible string */ + ret = of_property_read_string(dn, "compatible", &p); + if (!ret) + buf = string(buf, end, p, str_spec); + break; + case 'C': /* full compatible string */ + has_mult = false; + of_property_for_each_string(dn, "compatible", prop, p) { + if (has_mult) + buf = string(buf, end, ",", str_spec); + buf = string(buf, end, "\"", str_spec); + buf = string(buf, end, p, str_spec); + buf = string(buf, end, "\"", str_spec); + + has_mult = true; + } + break; + default: + break; + } + } + + return widen_string(buf, buf - buf_start, end, spec); +} + int kptr_restrict __read_mostly; /* @@ -1566,6 +1692,15 @@ int kptr_restrict __read_mostly; * p page flags (see struct page) given as pointer to unsigned long * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t * v vma flags (VM_*) given as pointer to unsigned long + * - 'OF[fnpPcCF]' For a device tree object + * Without any optional arguments prints the full_name + * f device node full_name + * n device node name + * p device node phandle + * P device node path spec (name + @unit) + * F device node flags + * c major compatible string + * C full compatible string * * ** Please update also Documentation/printk-formats.txt when making changes ** * @@ -1721,6 +1856,11 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, case 'G': return flags_string(buf, end, ptr, fmt); + case 'O': + switch (fmt[1]) { + case 'F': + return device_node_string(buf, end, ptr, spec, fmt + 1); + } } spec.flags |= SMALL; if (spec.field_width == -1) { diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 4b9569fa931b..411f2098fa6b 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -5709,7 +5709,7 @@ sub process { for (my $count = $linenr; $count <= $lc; $count++) { my $fmt = get_quoted_string($lines[$count - 1], raw_line($count, 0)); $fmt =~ s/%%//g; - if ($fmt =~ /(\%[\*\d\.]*p(?![\WFfSsBKRraEhMmIiUDdgVCbGN]).)/) { + if ($fmt =~ /(\%[\*\d\.]*p(?![\WFfSsBKRraEhMmIiUDdgVCbGNO]).)/) { $bad_extension = $1; last; }