| Message ID | 1446642770-4681-45-git-send-email-gwshan@linux.vnet.ibm.com |
|---|---|
| State | Not Applicable |
| Headers | show |
On Wed, Nov 4, 2015 at 7:12 AM, Gavin Shan <gwshan@linux.vnet.ibm.com> wrote: > The function unflatten_dt_node() is called recursively to unflatten > device nodes and properties in the FDT blob. It looks complicated > and hard to be understood. > > This splits the function into 3 functions: populate_properties(), > populate_node() and unflatten_dt_node(). populate_properties(), > which is called by populate_node(), creates properties for the > indicated device node. The later one creates the device nodes > from FDT blob. populate_node() gets the offset in FDT blob for > next device nodes and then calls populate_node(). No logical > changes introduced. > > Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> > --- > drivers/of/fdt.c | 275 ++++++++++++++++++++++++++++++++----------------------- > 1 file changed, 160 insertions(+), 115 deletions(-) > > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > index 6e82bc42..173b036 100644 > --- a/drivers/of/fdt.c > +++ b/drivers/of/fdt.c > @@ -160,39 +160,127 @@ static void *unflatten_dt_alloc(void **mem, unsigned long size, > return res; > } > > -/** > - * unflatten_dt_node - Alloc and populate a device_node from the flat tree > - * @blob: The parent device tree blob > - * @mem: Memory chunk to use for allocating device nodes and properties > - * @poffset: pointer to node in flat tree > - * @dad: Parent struct device_node > - * @nodepp: The device_node tree created by the call > - * @fpsize: Size of the node path up at the current depth. > - * @dryrun: If true, do not allocate device nodes but still calculate needed > - * memory size > - */ > -static void * unflatten_dt_node(const void *blob, > - void *mem, > - int *poffset, > - struct device_node *dad, > - struct device_node **nodepp, > - unsigned long fpsize, > +static void populate_properties(const void *blob, > + int offset, > + void **mem, > + struct device_node *np, > + const char *nodename, > bool dryrun) I'd like to make dryrun implicit. It is basically a function of NULL or near NULL pointers. > { > - const __be32 *p; > + struct property *pp, **pprev = NULL; > + int cur; > + bool has_name = false; > + > + pprev = &np->properties; > + cur = fdt_first_property_offset(blob, offset); > + while (cur >= 0) { This could be better written as a for loop to avoid the gotos: for (cur = fdt_first_property_offset(blob, offset); cur >=0; cur = fdt_next_property_offset(blob, cur)) > + const __be32 *val; > + const char *pname; > + u32 sz; > + > + val = fdt_getprop_by_offset(blob, cur, &pname, &sz); > + if (!val) { > + pr_warn("%s: Cannot locate property at 0x%x\n", > + __func__, cur); > + goto next; > + } > + > + if (!pname) { > + pr_warn("%s: Cannot find property name at 0x%x\n", > + __func__, cur); > + goto next; > + } else if (!strcmp(pname, "name")) { > + has_name = true; > + } > + > + pp = unflatten_dt_alloc(mem, sizeof(struct property), > + __alignof__(struct property)); > + if (!dryrun) { Then: if (dryrun) continue; to save some indentation and vertical code. > + /* We accept flattened tree phandles either in > + * ePAPR-style "phandle" properties, or the > + * legacy "linux,phandle" properties. If both > + * appear and have different values, things > + * will get weird. Don't do that. > + */ > + if (!strcmp(pname, "phandle") || > + !strcmp(pname, "linux,phandle")) { > + if (!np->phandle) > + np->phandle = be32_to_cpup(val); > + } > + > + /* And we process the "ibm,phandle" property > + * used in pSeries dynamic device tree > + * stuff > + */ > + if (!strcmp(pname, "ibm,phandle")) > + np->phandle = be32_to_cpup(val); > + > + pp->name = (char *)pname; > + pp->length = sz; > + pp->value = (__be32 *)val; > + *pprev = pp; > + pprev = &pp->next; > + } > +next: > + cur = fdt_next_property_offset(blob, cur); > + } > + > + /* With version 0x10 we may not have the name property, > + * recreate it here from the unit name if absent > + */ > + if (!has_name) { > + const char *p = nodename, *ps = p, *pa = NULL; > + int len; > + > + while (*p) { > + if ((*p) == '@') > + pa = p; > + else if ((*p) == '/') > + ps = p + 1; > + p++; > + } > + > + if (pa < ps) > + pa = p; > + len = (pa - ps) + 1; > + pp = unflatten_dt_alloc(mem, sizeof(struct property) + len, > + __alignof__(struct property)); > + if (!dryrun) { > + pp->name = "name"; > + pp->length = len; > + pp->value = pp + 1; > + *pprev = pp; > + pprev = &pp->next; > + memcpy(pp->value, ps, len - 1); > + ((char *)pp->value)[len - 1] = 0; > + pr_debug("fixed up name for %s -> %s\n", > + nodename, (char *)pp->value); > + } > + } > + > + if (!dryrun) > + *pprev = NULL; > +} > + > +static unsigned long populate_node(const void *blob, > + int offset, > + void **mem, > + struct device_node *dad, > + unsigned long fpsize, > + struct device_node **pnp, > + bool dryrun) I think dryrun could be implied here too. > +{ > struct device_node *np; > - struct property *pp, **prev_pp = NULL; > const char *pathp; > unsigned int l, allocl; > - static int depth = 0; > - int old_depth; > - int offset; > - int has_name = 0; > - int new_format = 0; > + bool new_format = false; > + char *fname; > > - pathp = fdt_get_name(blob, *poffset, &l); > - if (!pathp) > - return mem; > + pathp = fdt_get_name(blob, offset, &l); > + if (!pathp) { > + *pnp = NULL; Can't pnp be NULL? > + return 0; > + } > > allocl = ++l; > > @@ -202,7 +290,7 @@ static void * unflatten_dt_node(const void *blob, > * not '/'. > */ > if ((*pathp) != '/') { > - new_format = 1; > + new_format = true; > if (fpsize == 0) { > /* root node: special case. fpsize accounts for path > * plus terminating zero. root node only has '/', so > @@ -222,112 +310,38 @@ static void * unflatten_dt_node(const void *blob, > } > } > > - np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl, > + np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl, > __alignof__(struct device_node)); > if (!dryrun) { > - char *fn; > of_node_init(np); > - np->full_name = fn = ((char *)np) + sizeof(*np); > + np->full_name = fname = ((char *)np) + sizeof(*np); If you kept "fn" that would cut down the diff and make it a bit easier to review. > if (new_format) { > - /* rebuild full path for new format */ > + /* Rebuild full path for new format */ > if (dad && dad->parent) { > - strcpy(fn, dad->full_name); > + strcpy(fname, dad->full_name); > #ifdef DEBUG > - if ((strlen(fn) + l + 1) != allocl) { > + if ((strlen(fname) + l + 1) != allocl) { > pr_debug("%s: p: %d, l: %d, a: %d\n", > - pathp, (int)strlen(fn), > - l, allocl); > + pathp, (int)strlen(fn), This won't compile if enabled (should be fname). > + l, allocl); > } > #endif > - fn += strlen(fn); > + fname += strlen(fname); > } > - *(fn++) = '/'; > + *(fname++) = '/'; > } > - memcpy(fn, pathp, l); > + memcpy(fname, pathp, l); > > - prev_pp = &np->properties; > - if (dad != NULL) { > + if (dad) { > np->parent = dad; > np->sibling = dad->child; > dad->child = np; > } > } > - /* process properties */ > - for (offset = fdt_first_property_offset(blob, *poffset); > - (offset >= 0); > - (offset = fdt_next_property_offset(blob, offset))) { > - const char *pname; > - u32 sz; > > - if (!(p = fdt_getprop_by_offset(blob, offset, &pname, &sz))) { > - offset = -FDT_ERR_INTERNAL; > - break; > - } > - > - if (pname == NULL) { > - pr_info("Can't find property name in list !\n"); > - break; > - } > - if (strcmp(pname, "name") == 0) > - has_name = 1; > - pp = unflatten_dt_alloc(&mem, sizeof(struct property), > - __alignof__(struct property)); > - if (!dryrun) { > - /* We accept flattened tree phandles either in > - * ePAPR-style "phandle" properties, or the > - * legacy "linux,phandle" properties. If both > - * appear and have different values, things > - * will get weird. Don't do that. */ > - if ((strcmp(pname, "phandle") == 0) || > - (strcmp(pname, "linux,phandle") == 0)) { > - if (np->phandle == 0) > - np->phandle = be32_to_cpup(p); > - } > - /* And we process the "ibm,phandle" property > - * used in pSeries dynamic device tree > - * stuff */ > - if (strcmp(pname, "ibm,phandle") == 0) > - np->phandle = be32_to_cpup(p); > - pp->name = (char *)pname; > - pp->length = sz; > - pp->value = (__be32 *)p; > - *prev_pp = pp; > - prev_pp = &pp->next; > - } > - } > - /* with version 0x10 we may not have the name property, recreate > - * it here from the unit name if absent > - */ > - if (!has_name) { > - const char *p1 = pathp, *ps = pathp, *pa = NULL; > - int sz; > - > - while (*p1) { > - if ((*p1) == '@') > - pa = p1; > - if ((*p1) == '/') > - ps = p1 + 1; > - p1++; > - } > - if (pa < ps) > - pa = p1; > - sz = (pa - ps) + 1; > - pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz, > - __alignof__(struct property)); > - if (!dryrun) { > - pp->name = "name"; > - pp->length = sz; > - pp->value = pp + 1; > - *prev_pp = pp; > - prev_pp = &pp->next; > - memcpy(pp->value, ps, sz - 1); > - ((char *)pp->value)[sz - 1] = 0; > - pr_debug("fixed up name for %s -> %s\n", pathp, > - (char *)pp->value); > - } > - } > + /* Populate the properties */ Kind of a useless comment. > + populate_properties(blob, offset, mem, np, pathp, dryrun); > if (!dryrun) { > - *prev_pp = NULL; > np->name = of_get_property(np, "name", NULL); > np->type = of_get_property(np, "device_type", NULL); > > @@ -337,6 +351,37 @@ static void * unflatten_dt_node(const void *blob, > np->type = "<NULL>"; > } > > + *pnp = np; > + return fpsize; > +} > + > +/** > + * unflatten_dt_node - Alloc and populate a device_node from the flat tree > + * @blob: The parent device tree blob > + * @mem: Memory chunk to use for allocating device nodes and properties > + * @poffset: pointer to node in flat tree > + * @dad: Parent struct device_node > + * @nodepp: The device_node tree created by the call > + * @fpsize: Size of the node path up at the current depth. > + * @dryrun: If true, do not allocate device nodes but still calculate needed > + * memory size > + */ > +static void *unflatten_dt_node(const void *blob, > + void *mem, > + int *poffset, > + struct device_node *dad, > + struct device_node **nodepp, > + unsigned long fpsize, > + bool dryrun) > +{ > + struct device_node *np; > + static int depth; > + int old_depth; > + > + fpsize = populate_node(blob, *poffset, &mem, dad, fpsize, &np, dryrun); Doesn't this give a warning assigning a ptr to long? Looks like np can be moved internal to populate_node. > + if (!fpsize) > + return mem; > + > old_depth = depth; > *poffset = fdt_next_node(blob, *poffset, &depth); > if (depth < 0) > -- > 2.1.0 > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Nov 04, 2015 at 12:43:08PM -0600, Rob Herring wrote: >On Wed, Nov 4, 2015 at 7:12 AM, Gavin Shan <gwshan@linux.vnet.ibm.com> wrote: >> The function unflatten_dt_node() is called recursively to unflatten >> device nodes and properties in the FDT blob. It looks complicated >> and hard to be understood. >> >> This splits the function into 3 functions: populate_properties(), >> populate_node() and unflatten_dt_node(). populate_properties(), >> which is called by populate_node(), creates properties for the >> indicated device node. The later one creates the device nodes >> from FDT blob. populate_node() gets the offset in FDT blob for >> next device nodes and then calls populate_node(). No logical >> changes introduced. >> >> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> >> --- >> drivers/of/fdt.c | 275 ++++++++++++++++++++++++++++++++----------------------- >> 1 file changed, 160 insertions(+), 115 deletions(-) >> >> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c >> index 6e82bc42..173b036 100644 >> --- a/drivers/of/fdt.c >> +++ b/drivers/of/fdt.c >> @@ -160,39 +160,127 @@ static void *unflatten_dt_alloc(void **mem, unsigned long size, >> return res; >> } >> >> -/** >> - * unflatten_dt_node - Alloc and populate a device_node from the flat tree >> - * @blob: The parent device tree blob >> - * @mem: Memory chunk to use for allocating device nodes and properties >> - * @poffset: pointer to node in flat tree >> - * @dad: Parent struct device_node >> - * @nodepp: The device_node tree created by the call >> - * @fpsize: Size of the node path up at the current depth. >> - * @dryrun: If true, do not allocate device nodes but still calculate needed >> - * memory size >> - */ >> -static void * unflatten_dt_node(const void *blob, >> - void *mem, >> - int *poffset, >> - struct device_node *dad, >> - struct device_node **nodepp, >> - unsigned long fpsize, >> +static void populate_properties(const void *blob, >> + int offset, >> + void **mem, >> + struct device_node *np, >> + const char *nodename, >> bool dryrun) > >I'd like to make dryrun implicit. It is basically a function of NULL >or near NULL pointers. > [1] The condition would be something like below: if ((unsigned long)(*mem) < limit) dryrun = true; else dryrun = false; The question here is how to choose a sane @limit in practice. In !dryrun case, the memory is allocated from memblock at system booting time, or slab when system is up. memblock could assign memory in bottom-up fasion. When @limit is too small, the condition wouldn't be comprehensive in !dryrun case. When @limit is too large, the !dryrun cases can be regarded as dryrun case. >> { >> - const __be32 *p; >> + struct property *pp, **pprev = NULL; >> + int cur; >> + bool has_name = false; >> + >> + pprev = &np->properties; >> + cur = fdt_first_property_offset(blob, offset); >> + while (cur >= 0) { > >This could be better written as a for loop to avoid the gotos: > >for (cur = fdt_first_property_offset(blob, offset); cur >=0; cur = >fdt_next_property_offset(blob, cur)) > Thanks, the changes will be included in next revision. >> + const __be32 *val; >> + const char *pname; >> + u32 sz; >> + >> + val = fdt_getprop_by_offset(blob, cur, &pname, &sz); >> + if (!val) { >> + pr_warn("%s: Cannot locate property at 0x%x\n", >> + __func__, cur); >> + goto next; >> + } >> + >> + if (!pname) { >> + pr_warn("%s: Cannot find property name at 0x%x\n", >> + __func__, cur); >> + goto next; >> + } else if (!strcmp(pname, "name")) { >> + has_name = true; >> + } >> + >> + pp = unflatten_dt_alloc(mem, sizeof(struct property), >> + __alignof__(struct property)); >> + if (!dryrun) { > >Then: > >if (dryrun) > continue; > >to save some indentation and vertical code. > Good idea, it will be included in next revision. >> + /* We accept flattened tree phandles either in >> + * ePAPR-style "phandle" properties, or the >> + * legacy "linux,phandle" properties. If both >> + * appear and have different values, things >> + * will get weird. Don't do that. >> + */ >> + if (!strcmp(pname, "phandle") || >> + !strcmp(pname, "linux,phandle")) { >> + if (!np->phandle) >> + np->phandle = be32_to_cpup(val); >> + } >> + >> + /* And we process the "ibm,phandle" property >> + * used in pSeries dynamic device tree >> + * stuff >> + */ >> + if (!strcmp(pname, "ibm,phandle")) >> + np->phandle = be32_to_cpup(val); >> + >> + pp->name = (char *)pname; >> + pp->length = sz; >> + pp->value = (__be32 *)val; >> + *pprev = pp; >> + pprev = &pp->next; >> + } >> +next: >> + cur = fdt_next_property_offset(blob, cur); >> + } >> + >> + /* With version 0x10 we may not have the name property, >> + * recreate it here from the unit name if absent >> + */ >> + if (!has_name) { >> + const char *p = nodename, *ps = p, *pa = NULL; >> + int len; >> + >> + while (*p) { >> + if ((*p) == '@') >> + pa = p; >> + else if ((*p) == '/') >> + ps = p + 1; >> + p++; >> + } >> + >> + if (pa < ps) >> + pa = p; >> + len = (pa - ps) + 1; >> + pp = unflatten_dt_alloc(mem, sizeof(struct property) + len, >> + __alignof__(struct property)); >> + if (!dryrun) { >> + pp->name = "name"; >> + pp->length = len; >> + pp->value = pp + 1; >> + *pprev = pp; >> + pprev = &pp->next; >> + memcpy(pp->value, ps, len - 1); >> + ((char *)pp->value)[len - 1] = 0; >> + pr_debug("fixed up name for %s -> %s\n", >> + nodename, (char *)pp->value); >> + } >> + } >> + >> + if (!dryrun) >> + *pprev = NULL; >> +} >> + >> +static unsigned long populate_node(const void *blob, >> + int offset, >> + void **mem, >> + struct device_node *dad, >> + unsigned long fpsize, >> + struct device_node **pnp, >> + bool dryrun) > >I think dryrun could be implied here too. > I don't think so. Please refer to the explanation at [1]. >> +{ >> struct device_node *np; >> - struct property *pp, **prev_pp = NULL; >> const char *pathp; >> unsigned int l, allocl; >> - static int depth = 0; >> - int old_depth; >> - int offset; >> - int has_name = 0; >> - int new_format = 0; >> + bool new_format = false; >> + char *fname; >> >> - pathp = fdt_get_name(blob, *poffset, &l); >> - if (!pathp) >> - return mem; >> + pathp = fdt_get_name(blob, offset, &l); >> + if (!pathp) { >> + *pnp = NULL; > >Can't pnp be NULL? > It can't be NULL in both dryrun and !dryrun cases. >> + return 0; >> + } >> >> allocl = ++l; >> >> @@ -202,7 +290,7 @@ static void * unflatten_dt_node(const void *blob, >> * not '/'. >> */ >> if ((*pathp) != '/') { >> - new_format = 1; >> + new_format = true; >> if (fpsize == 0) { >> /* root node: special case. fpsize accounts for path >> * plus terminating zero. root node only has '/', so >> @@ -222,112 +310,38 @@ static void * unflatten_dt_node(const void *blob, >> } >> } >> >> - np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl, >> + np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl, >> __alignof__(struct device_node)); >> if (!dryrun) { >> - char *fn; >> of_node_init(np); >> - np->full_name = fn = ((char *)np) + sizeof(*np); >> + np->full_name = fname = ((char *)np) + sizeof(*np); > >If you kept "fn" that would cut down the diff and make it a bit easier >to review. > Agree, I'll drop the rename in next revision. I perhaps have separate patch to do the renaming after this patch. In that way, unrelated code changes will be avoided in this one. >> if (new_format) { >> - /* rebuild full path for new format */ >> + /* Rebuild full path for new format */ >> if (dad && dad->parent) { >> - strcpy(fn, dad->full_name); >> + strcpy(fname, dad->full_name); >> #ifdef DEBUG >> - if ((strlen(fn) + l + 1) != allocl) { >> + if ((strlen(fname) + l + 1) != allocl) { >> pr_debug("%s: p: %d, l: %d, a: %d\n", >> - pathp, (int)strlen(fn), >> - l, allocl); >> + pathp, (int)strlen(fn), > >This won't compile if enabled (should be fname). > Indeed, I even didn't try to compile this piece of debugging code. Will change accordingly in next revision. >> + l, allocl); >> } >> #endif >> - fn += strlen(fn); >> + fname += strlen(fname); >> } >> - *(fn++) = '/'; >> + *(fname++) = '/'; >> } >> - memcpy(fn, pathp, l); >> + memcpy(fname, pathp, l); >> >> - prev_pp = &np->properties; >> - if (dad != NULL) { >> + if (dad) { >> np->parent = dad; >> np->sibling = dad->child; >> dad->child = np; >> } >> } >> - /* process properties */ >> - for (offset = fdt_first_property_offset(blob, *poffset); >> - (offset >= 0); >> - (offset = fdt_next_property_offset(blob, offset))) { >> - const char *pname; >> - u32 sz; >> >> - if (!(p = fdt_getprop_by_offset(blob, offset, &pname, &sz))) { >> - offset = -FDT_ERR_INTERNAL; >> - break; >> - } >> - >> - if (pname == NULL) { >> - pr_info("Can't find property name in list !\n"); >> - break; >> - } >> - if (strcmp(pname, "name") == 0) >> - has_name = 1; >> - pp = unflatten_dt_alloc(&mem, sizeof(struct property), >> - __alignof__(struct property)); >> - if (!dryrun) { >> - /* We accept flattened tree phandles either in >> - * ePAPR-style "phandle" properties, or the >> - * legacy "linux,phandle" properties. If both >> - * appear and have different values, things >> - * will get weird. Don't do that. */ >> - if ((strcmp(pname, "phandle") == 0) || >> - (strcmp(pname, "linux,phandle") == 0)) { >> - if (np->phandle == 0) >> - np->phandle = be32_to_cpup(p); >> - } >> - /* And we process the "ibm,phandle" property >> - * used in pSeries dynamic device tree >> - * stuff */ >> - if (strcmp(pname, "ibm,phandle") == 0) >> - np->phandle = be32_to_cpup(p); >> - pp->name = (char *)pname; >> - pp->length = sz; >> - pp->value = (__be32 *)p; >> - *prev_pp = pp; >> - prev_pp = &pp->next; >> - } >> - } >> - /* with version 0x10 we may not have the name property, recreate >> - * it here from the unit name if absent >> - */ >> - if (!has_name) { >> - const char *p1 = pathp, *ps = pathp, *pa = NULL; >> - int sz; >> - >> - while (*p1) { >> - if ((*p1) == '@') >> - pa = p1; >> - if ((*p1) == '/') >> - ps = p1 + 1; >> - p1++; >> - } >> - if (pa < ps) >> - pa = p1; >> - sz = (pa - ps) + 1; >> - pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz, >> - __alignof__(struct property)); >> - if (!dryrun) { >> - pp->name = "name"; >> - pp->length = sz; >> - pp->value = pp + 1; >> - *prev_pp = pp; >> - prev_pp = &pp->next; >> - memcpy(pp->value, ps, sz - 1); >> - ((char *)pp->value)[sz - 1] = 0; >> - pr_debug("fixed up name for %s -> %s\n", pathp, >> - (char *)pp->value); >> - } >> - } >> + /* Populate the properties */ > >Kind of a useless comment. > Agree, will drop in next revision. >> + populate_properties(blob, offset, mem, np, pathp, dryrun); >> if (!dryrun) { >> - *prev_pp = NULL; >> np->name = of_get_property(np, "name", NULL); >> np->type = of_get_property(np, "device_type", NULL); >> >> @@ -337,6 +351,37 @@ static void * unflatten_dt_node(const void *blob, >> np->type = "<NULL>"; >> } >> >> + *pnp = np; >> + return fpsize; >> +} >> + >> +/** >> + * unflatten_dt_node - Alloc and populate a device_node from the flat tree >> + * @blob: The parent device tree blob >> + * @mem: Memory chunk to use for allocating device nodes and properties >> + * @poffset: pointer to node in flat tree >> + * @dad: Parent struct device_node >> + * @nodepp: The device_node tree created by the call >> + * @fpsize: Size of the node path up at the current depth. >> + * @dryrun: If true, do not allocate device nodes but still calculate needed >> + * memory size >> + */ >> +static void *unflatten_dt_node(const void *blob, >> + void *mem, >> + int *poffset, >> + struct device_node *dad, >> + struct device_node **nodepp, >> + unsigned long fpsize, >> + bool dryrun) >> +{ >> + struct device_node *np; >> + static int depth; >> + int old_depth; >> + >> + fpsize = populate_node(blob, *poffset, &mem, dad, fpsize, &np, dryrun); > >Doesn't this give a warning assigning a ptr to long? > >Looks like np can be moved internal to populate_node. > @fpsize and the return value of populate_node() are "unsigned long". Nope, @np will be used in next patch in this function, which tracks the device node unflattened in last level of depth. > >> + if (!fpsize) >> + return mem; >> + >> old_depth = depth; >> *poffset = fdt_next_node(blob, *poffset, &depth); >> if (depth < 0) Thanks, Gavin -- To unsubscribe from this list: send the line "unsubscribe linux-pci" 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/drivers/of/fdt.c b/drivers/of/fdt.c index 6e82bc42..173b036 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -160,39 +160,127 @@ static void *unflatten_dt_alloc(void **mem, unsigned long size, return res; } -/** - * unflatten_dt_node - Alloc and populate a device_node from the flat tree - * @blob: The parent device tree blob - * @mem: Memory chunk to use for allocating device nodes and properties - * @poffset: pointer to node in flat tree - * @dad: Parent struct device_node - * @nodepp: The device_node tree created by the call - * @fpsize: Size of the node path up at the current depth. - * @dryrun: If true, do not allocate device nodes but still calculate needed - * memory size - */ -static void * unflatten_dt_node(const void *blob, - void *mem, - int *poffset, - struct device_node *dad, - struct device_node **nodepp, - unsigned long fpsize, +static void populate_properties(const void *blob, + int offset, + void **mem, + struct device_node *np, + const char *nodename, bool dryrun) { - const __be32 *p; + struct property *pp, **pprev = NULL; + int cur; + bool has_name = false; + + pprev = &np->properties; + cur = fdt_first_property_offset(blob, offset); + while (cur >= 0) { + const __be32 *val; + const char *pname; + u32 sz; + + val = fdt_getprop_by_offset(blob, cur, &pname, &sz); + if (!val) { + pr_warn("%s: Cannot locate property at 0x%x\n", + __func__, cur); + goto next; + } + + if (!pname) { + pr_warn("%s: Cannot find property name at 0x%x\n", + __func__, cur); + goto next; + } else if (!strcmp(pname, "name")) { + has_name = true; + } + + pp = unflatten_dt_alloc(mem, sizeof(struct property), + __alignof__(struct property)); + if (!dryrun) { + /* We accept flattened tree phandles either in + * ePAPR-style "phandle" properties, or the + * legacy "linux,phandle" properties. If both + * appear and have different values, things + * will get weird. Don't do that. + */ + if (!strcmp(pname, "phandle") || + !strcmp(pname, "linux,phandle")) { + if (!np->phandle) + np->phandle = be32_to_cpup(val); + } + + /* And we process the "ibm,phandle" property + * used in pSeries dynamic device tree + * stuff + */ + if (!strcmp(pname, "ibm,phandle")) + np->phandle = be32_to_cpup(val); + + pp->name = (char *)pname; + pp->length = sz; + pp->value = (__be32 *)val; + *pprev = pp; + pprev = &pp->next; + } +next: + cur = fdt_next_property_offset(blob, cur); + } + + /* With version 0x10 we may not have the name property, + * recreate it here from the unit name if absent + */ + if (!has_name) { + const char *p = nodename, *ps = p, *pa = NULL; + int len; + + while (*p) { + if ((*p) == '@') + pa = p; + else if ((*p) == '/') + ps = p + 1; + p++; + } + + if (pa < ps) + pa = p; + len = (pa - ps) + 1; + pp = unflatten_dt_alloc(mem, sizeof(struct property) + len, + __alignof__(struct property)); + if (!dryrun) { + pp->name = "name"; + pp->length = len; + pp->value = pp + 1; + *pprev = pp; + pprev = &pp->next; + memcpy(pp->value, ps, len - 1); + ((char *)pp->value)[len - 1] = 0; + pr_debug("fixed up name for %s -> %s\n", + nodename, (char *)pp->value); + } + } + + if (!dryrun) + *pprev = NULL; +} + +static unsigned long populate_node(const void *blob, + int offset, + void **mem, + struct device_node *dad, + unsigned long fpsize, + struct device_node **pnp, + bool dryrun) +{ struct device_node *np; - struct property *pp, **prev_pp = NULL; const char *pathp; unsigned int l, allocl; - static int depth = 0; - int old_depth; - int offset; - int has_name = 0; - int new_format = 0; + bool new_format = false; + char *fname; - pathp = fdt_get_name(blob, *poffset, &l); - if (!pathp) - return mem; + pathp = fdt_get_name(blob, offset, &l); + if (!pathp) { + *pnp = NULL; + return 0; + } allocl = ++l; @@ -202,7 +290,7 @@ static void * unflatten_dt_node(const void *blob, * not '/'. */ if ((*pathp) != '/') { - new_format = 1; + new_format = true; if (fpsize == 0) { /* root node: special case. fpsize accounts for path * plus terminating zero. root node only has '/', so @@ -222,112 +310,38 @@ static void * unflatten_dt_node(const void *blob, } } - np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl, + np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl, __alignof__(struct device_node)); if (!dryrun) { - char *fn; of_node_init(np); - np->full_name = fn = ((char *)np) + sizeof(*np); + np->full_name = fname = ((char *)np) + sizeof(*np); if (new_format) { - /* rebuild full path for new format */ + /* Rebuild full path for new format */ if (dad && dad->parent) { - strcpy(fn, dad->full_name); + strcpy(fname, dad->full_name); #ifdef DEBUG - if ((strlen(fn) + l + 1) != allocl) { + if ((strlen(fname) + l + 1) != allocl) { pr_debug("%s: p: %d, l: %d, a: %d\n", - pathp, (int)strlen(fn), - l, allocl); + pathp, (int)strlen(fn), + l, allocl); } #endif - fn += strlen(fn); + fname += strlen(fname); } - *(fn++) = '/'; + *(fname++) = '/'; } - memcpy(fn, pathp, l); + memcpy(fname, pathp, l); - prev_pp = &np->properties; - if (dad != NULL) { + if (dad) { np->parent = dad; np->sibling = dad->child; dad->child = np; } } - /* process properties */ - for (offset = fdt_first_property_offset(blob, *poffset); - (offset >= 0); - (offset = fdt_next_property_offset(blob, offset))) { - const char *pname; - u32 sz; - if (!(p = fdt_getprop_by_offset(blob, offset, &pname, &sz))) { - offset = -FDT_ERR_INTERNAL; - break; - } - - if (pname == NULL) { - pr_info("Can't find property name in list !\n"); - break; - } - if (strcmp(pname, "name") == 0) - has_name = 1; - pp = unflatten_dt_alloc(&mem, sizeof(struct property), - __alignof__(struct property)); - if (!dryrun) { - /* We accept flattened tree phandles either in - * ePAPR-style "phandle" properties, or the - * legacy "linux,phandle" properties. If both - * appear and have different values, things - * will get weird. Don't do that. */ - if ((strcmp(pname, "phandle") == 0) || - (strcmp(pname, "linux,phandle") == 0)) { - if (np->phandle == 0) - np->phandle = be32_to_cpup(p); - } - /* And we process the "ibm,phandle" property - * used in pSeries dynamic device tree - * stuff */ - if (strcmp(pname, "ibm,phandle") == 0) - np->phandle = be32_to_cpup(p); - pp->name = (char *)pname; - pp->length = sz; - pp->value = (__be32 *)p; - *prev_pp = pp; - prev_pp = &pp->next; - } - } - /* with version 0x10 we may not have the name property, recreate - * it here from the unit name if absent - */ - if (!has_name) { - const char *p1 = pathp, *ps = pathp, *pa = NULL; - int sz; - - while (*p1) { - if ((*p1) == '@') - pa = p1; - if ((*p1) == '/') - ps = p1 + 1; - p1++; - } - if (pa < ps) - pa = p1; - sz = (pa - ps) + 1; - pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz, - __alignof__(struct property)); - if (!dryrun) { - pp->name = "name"; - pp->length = sz; - pp->value = pp + 1; - *prev_pp = pp; - prev_pp = &pp->next; - memcpy(pp->value, ps, sz - 1); - ((char *)pp->value)[sz - 1] = 0; - pr_debug("fixed up name for %s -> %s\n", pathp, - (char *)pp->value); - } - } + /* Populate the properties */ + populate_properties(blob, offset, mem, np, pathp, dryrun); if (!dryrun) { - *prev_pp = NULL; np->name = of_get_property(np, "name", NULL); np->type = of_get_property(np, "device_type", NULL); @@ -337,6 +351,37 @@ static void * unflatten_dt_node(const void *blob, np->type = "<NULL>"; } + *pnp = np; + return fpsize; +} + +/** + * unflatten_dt_node - Alloc and populate a device_node from the flat tree + * @blob: The parent device tree blob + * @mem: Memory chunk to use for allocating device nodes and properties + * @poffset: pointer to node in flat tree + * @dad: Parent struct device_node + * @nodepp: The device_node tree created by the call + * @fpsize: Size of the node path up at the current depth. + * @dryrun: If true, do not allocate device nodes but still calculate needed + * memory size + */ +static void *unflatten_dt_node(const void *blob, + void *mem, + int *poffset, + struct device_node *dad, + struct device_node **nodepp, + unsigned long fpsize, + bool dryrun) +{ + struct device_node *np; + static int depth; + int old_depth; + + fpsize = populate_node(blob, *poffset, &mem, dad, fpsize, &np, dryrun); + if (!fpsize) + return mem; + old_depth = depth; *poffset = fdt_next_node(blob, *poffset, &depth); if (depth < 0)
The function unflatten_dt_node() is called recursively to unflatten device nodes and properties in the FDT blob. It looks complicated and hard to be understood. This splits the function into 3 functions: populate_properties(), populate_node() and unflatten_dt_node(). populate_properties(), which is called by populate_node(), creates properties for the indicated device node. The later one creates the device nodes from FDT blob. populate_node() gets the offset in FDT blob for next device nodes and then calls populate_node(). No logical changes introduced. Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> --- drivers/of/fdt.c | 275 ++++++++++++++++++++++++++++++++----------------------- 1 file changed, 160 insertions(+), 115 deletions(-)