| Message ID | 199290403.sj4aYrj8FC@diego (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Am Sonntag, 16. März 2014, 22:22:02 schrieb Heiko Stübner: > From: Heiko Stuebner <heiko.stuebner@bq.com> > > On i.MX, which carries a lot of pin-groups of which most are unused on > individual boards, they noticed that this plethora of nodes also results > in the runtime-lookup-performance also degrading [0]. > > A i.MX-specific solution defining the pingroups in the board files but > using macros to reference the pingroup-data was not well received. > > This patch is trying to solve this issue in a more general way, by > adding the ability to mark nodes as needing to be referenced somewhere > in the tree. > > To mark a node a needing to be referenced it must be prefixed with > /delete-unreferenced/. This makes dtc check the nodes reference-status > when creating the flattened tree, dropping it if unreferenced. > > For example, the i.MX6SL pingroup > > /delete-unreferenced/ pinctrl_ecspi1_1: ecspi1grp-1 { > fsl,pins = < > MX6SL_PAD_ECSPI1_MISO__ECSPI1_MISO 0x100b1 > MX6SL_PAD_ECSPI1_MOSI__ECSPI1_MOSI 0x100b1 > MX6SL_PAD_ECSPI1_SCLK__ECSPI1_SCLK 0x100b1 > > >; > > }; > > would only be included in the dtb if it got referenced somewhere > as pingroup via > > node { > pinctrl-0 <&pinctrl_ecscpi1_1>; > }; > > [0] http://thread.gmane.org/gmane.linux.ports.arm.kernel/275912/ > > Signed-off-by: Heiko Stuebner <heiko.stuebner@bq.com> ping? Is this ok, bad, something else entirely? :-) Thanks Heiko
On Sun, Mar 16, 2014 at 10:22:02PM +0100, Heiko Stübner wrote: > From: Heiko Stuebner <heiko.stuebner@bq.com> > > On i.MX, which carries a lot of pin-groups of which most are unused on > individual boards, they noticed that this plethora of nodes also results > in the runtime-lookup-performance also degrading [0]. > > A i.MX-specific solution defining the pingroups in the board files but > using macros to reference the pingroup-data was not well received. > > This patch is trying to solve this issue in a more general way, by > adding the ability to mark nodes as needing to be referenced somewhere > in the tree. > > To mark a node a needing to be referenced it must be prefixed with > /delete-unreferenced/. This makes dtc check the nodes reference-status > when creating the flattened tree, dropping it if unreferenced. > > For example, the i.MX6SL pingroup > > /delete-unreferenced/ pinctrl_ecspi1_1: ecspi1grp-1 { > fsl,pins = < > MX6SL_PAD_ECSPI1_MISO__ECSPI1_MISO 0x100b1 > MX6SL_PAD_ECSPI1_MOSI__ECSPI1_MOSI 0x100b1 > MX6SL_PAD_ECSPI1_SCLK__ECSPI1_SCLK 0x100b1 > >; > }; > > would only be included in the dtb if it got referenced somewhere > as pingroup via > > node { > pinctrl-0 <&pinctrl_ecscpi1_1>; > }; Sorry for the delay - I'm pretty busy with non-dtc things. Concept looks fine to me. It's perhaps a bit special use case, but the syntax is well isolated (that is, unlikely to mix badly with other possible syntax changes), so I'm happy enough to include it for those who want it. Maybe change the keyword to /delete-if-unreferenced/, it's a little bit more accurate. It's a bit long-winded, but I can't think of a more succinct term, so it will do. It needs testcases. There are a few minor problems in the implementation. With those things fixed, I'd be happy to apply. Some detailed comments on the implementation below: [snip] > @@ -472,6 +472,8 @@ static void fixup_phandle_references(struct check *c, struct node *dt, > > phandle = get_node_phandle(dt, refnode); > *((cell_t *)(prop->val.val + m->offset)) = cpu_to_fdt32(phandle); > + > + reference_node(refnode); This may have some slightly unexpected behaviour when combined with /delete-node/ and or /delete-prop/. At worst it should include the unnecessary node though, so I don't think it's a big problem. [snip] > +struct node *check_node_referenced(struct node *node) This function needs a different name, since it doesn't actually check anything (it just triggers a later check). Maybe mark_node_needs_reference().
diff --git a/checks.c b/checks.c index 47eda65..a82ba8d 100644 --- a/checks.c +++ b/checks.c @@ -472,6 +472,8 @@ static void fixup_phandle_references(struct check *c, struct node *dt, phandle = get_node_phandle(dt, refnode); *((cell_t *)(prop->val.val + m->offset)) = cpu_to_fdt32(phandle); + + reference_node(refnode); } } ERROR(phandle_references, NULL, NULL, fixup_phandle_references, NULL, diff --git a/dtc-lexer.l b/dtc-lexer.l index 0821bde..6d7865d 100644 --- a/dtc-lexer.l +++ b/dtc-lexer.l @@ -140,6 +140,13 @@ static void lexical_error(const char *fmt, ...); return DT_DEL_NODE; } +<*>"/delete-unreferenced/" { + DPRINT("Keyword: /delete-unreferenced/\n"); + DPRINT("<PROPNODENAME>\n"); + BEGIN(PROPNODENAME); + return DT_DEL_UNREFERENCED; + } + <*>{LABEL}: { DPRINT("Label: %s\n", yytext); yylval.labelref = xstrdup(yytext); diff --git a/dtc-parser.y b/dtc-parser.y index ea57e0a..a203bed 100644 --- a/dtc-parser.y +++ b/dtc-parser.y @@ -60,6 +60,7 @@ extern bool treesource_error; %token DT_BITS %token DT_DEL_PROP %token DT_DEL_NODE +%token DT_DEL_UNREFERENCED %token <propnodename> DT_PROPNODENAME %token <integer> DT_LITERAL %token <integer> DT_CHAR_LITERAL @@ -450,6 +451,10 @@ subnode: { $$ = name_node(build_node_delete(), $2); } + | DT_DEL_UNREFERENCED subnode + { + $$ = check_node_referenced($2); + } | DT_LABEL subnode { add_label(&$2->labels, $1); diff --git a/dtc.h b/dtc.h index 20de073..ff45059 100644 --- a/dtc.h +++ b/dtc.h @@ -158,6 +158,8 @@ struct node { int addr_cells, size_cells; struct label *labels; + + int needs_reference, is_referenced; }; #define for_each_label_withdel(l0, l) \ @@ -192,6 +194,8 @@ struct property *reverse_properties(struct property *first); struct node *build_node(struct property *proplist, struct node *children); struct node *build_node_delete(void); struct node *name_node(struct node *node, char *name); +struct node *check_node_referenced(struct node *node); +struct node *reference_node(struct node *node); struct node *chain_node(struct node *first, struct node *list); struct node *merge_nodes(struct node *old_node, struct node *new_node); diff --git a/flattree.c b/flattree.c index bd99fa2..105e8fa 100644 --- a/flattree.c +++ b/flattree.c @@ -266,6 +266,9 @@ static void flatten_tree(struct node *tree, struct emitter *emit, if (tree->deleted) return; + if (tree->needs_reference && !tree->is_referenced) + return; + emit->beginnode(etarget, tree->labels); if (vi->flags & FTF_FULLPATH) diff --git a/livetree.c b/livetree.c index b61465f..98bb33d 100644 --- a/livetree.c +++ b/livetree.c @@ -134,6 +134,20 @@ struct node *name_node(struct node *node, char *name) return node; } +struct node *check_node_referenced(struct node *node) +{ + node->needs_reference = 1; + + return node; +} + +struct node *reference_node(struct node *node) +{ + node->is_referenced = 1; + + return node; +} + struct node *merge_nodes(struct node *old_node, struct node *new_node) { struct property *new_prop, *old_prop;