| Message ID | 1415839522.5124.58.camel@kernel.crashing.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
Hi Ben, On Thu, 13 Nov 2014 11:45:22 +1100 Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote: > > What about this one instead ? I want to cache it because that function > can be called quite a while and doing two additional property lookup > and string compares every time might hurt some platforms. Looks good to me.
On Thu, Nov 13, 2014 at 12:45 AM, Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote: > What about this one instead ? I want to cache it because that function > can be called quite a while and doing two additional property lookup > and string compares every time might hurt some platforms. > > ---- > > We have a historical hack that treats missing ranges properties as the > equivalent of an empty one. This is needed for ancient PowerMac "bad" > device-trees, and shouldn't be enabled for any other PowerPC platform, > otherwise we get some nasty layout of devices in sysfs or even > duplication when a set of otherwise identically named devices is > created multiple times under a different parent node with no ranges > property. > > This fix is needed for the PowerNV i2c busses to be exposed properly > and will fix a number of other embedded cases. > > Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> > CC: <stable@vger.kernel.org> How far back does this need to go? I assume I need to get this in for v3.18. > > diff --git a/drivers/of/address.c b/drivers/of/address.c > index e371825..5eae0cd 100644 > --- a/drivers/of/address.c > +++ b/drivers/of/address.c > @@ -403,6 +403,17 @@ static struct of_bus *of_match_bus(struct device_node *np) > return NULL; > } > > +static int of_empty_ranges_quirk(void) > +{ > + /* To save cycles, we cache the result */ > + static int quirk_state = -1; > + if (IS_ENABLED(CONFIG_POWERPC)) { > + if (quirk_state < 0) > + quirk_state = of_machine_is_compatible("Power Macintosh") || > + of_machine_is_compatible("MacRISC"); > + return quirk_state; } return 0; So it gets compiled out for non powerpc. > +} > + > static int of_translate_one(struct device_node *parent, struct of_bus *bus, > struct of_bus *pbus, __be32 *addr, > int na, int ns, int pna, const char *rprop) > @@ -428,12 +439,10 @@ static int of_translate_one(struct device_node *parent, struct of_bus *bus, > * This code is only enabled on powerpc. --gcl > */ > ranges = of_get_property(parent, rprop, &rlen); > -#if !defined(CONFIG_PPC) > - if (ranges == NULL) { > + if (ranges == NULL && !of_empty_ranges_quirk()) { > pr_err("OF: no ranges; cannot translate\n"); > return 1; > } > -#endif /* !defined(CONFIG_PPC) */ > if (ranges == NULL || rlen == 0) { > offset = of_read_number(addr, na); > memset(addr, 0, pna * 4); > >
On Thu, 2014-11-13 at 12:44 +0000, Grant Likely wrote: > On Thu, Nov 13, 2014 at 12:45 AM, Benjamin Herrenschmidt > <benh@kernel.crashing.org> wrote: > > What about this one instead ? I want to cache it because that function > > can be called quite a while and doing two additional property lookup > > and string compares every time might hurt some platforms. > > > > ---- > > > > We have a historical hack that treats missing ranges properties as the > > equivalent of an empty one. This is needed for ancient PowerMac "bad" > > device-trees, and shouldn't be enabled for any other PowerPC platform, > > otherwise we get some nasty layout of devices in sysfs or even > > duplication when a set of otherwise identically named devices is > > created multiple times under a different parent node with no ranges > > property. > > > > This fix is needed for the PowerNV i2c busses to be exposed properly > > and will fix a number of other embedded cases. > > > > Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> > > CC: <stable@vger.kernel.org> > > How far back does this need to go? I assume I need to get this in for v3.18. I'd like some distro to pick it up in 3.16 > > diff --git a/drivers/of/address.c b/drivers/of/address.c > > index e371825..5eae0cd 100644 > > --- a/drivers/of/address.c > > +++ b/drivers/of/address.c > > @@ -403,6 +403,17 @@ static struct of_bus *of_match_bus(struct device_node *np) > > return NULL; > > } > > > > +static int of_empty_ranges_quirk(void) > > +{ > > + /* To save cycles, we cache the result */ > > + static int quirk_state = -1; > > + > > if (IS_ENABLED(CONFIG_POWERPC)) { > > > + if (quirk_state < 0) > > + quirk_state = of_machine_is_compatible("Power Macintosh") || > > + of_machine_is_compatible("MacRISC"); > > + return quirk_state; > > } > return 0; > > So it gets compiled out for non powerpc. Yeah, I'm set in my ways, keep forgetting about all the shiny new stuff. > > +} > > + > > static int of_translate_one(struct device_node *parent, struct of_bus *bus, > > struct of_bus *pbus, __be32 *addr, > > int na, int ns, int pna, const char *rprop) > > @@ -428,12 +439,10 @@ static int of_translate_one(struct device_node *parent, struct of_bus *bus, > > * This code is only enabled on powerpc. --gcl > > */ > > ranges = of_get_property(parent, rprop, &rlen); > > -#if !defined(CONFIG_PPC) > > - if (ranges == NULL) { > > + if (ranges == NULL && !of_empty_ranges_quirk()) { > > pr_err("OF: no ranges; cannot translate\n"); > > return 1; > > } > > -#endif /* !defined(CONFIG_PPC) */ > > if (ranges == NULL || rlen == 0) { > > offset = of_read_number(addr, na); > > memset(addr, 0, pna * 4); > > > > > -- > 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/drivers/of/address.c b/drivers/of/address.c index e371825..5eae0cd 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -403,6 +403,17 @@ static struct of_bus *of_match_bus(struct device_node *np) return NULL; } +static int of_empty_ranges_quirk(void) +{ + /* To save cycles, we cache the result */ + static int quirk_state = -1; + + if (quirk_state < 0) + quirk_state = of_machine_is_compatible("Power Macintosh") || + of_machine_is_compatible("MacRISC"); + return quirk_state; +} + static int of_translate_one(struct device_node *parent, struct of_bus *bus, struct of_bus *pbus, __be32 *addr, int na, int ns, int pna, const char *rprop) @@ -428,12 +439,10 @@ static int of_translate_one(struct device_node *parent, struct of_bus *bus, * This code is only enabled on powerpc. --gcl */ ranges = of_get_property(parent, rprop, &rlen); -#if !defined(CONFIG_PPC) - if (ranges == NULL) { + if (ranges == NULL && !of_empty_ranges_quirk()) { pr_err("OF: no ranges; cannot translate\n"); return 1; } -#endif /* !defined(CONFIG_PPC) */ if (ranges == NULL || rlen == 0) { offset = of_read_number(addr, na); memset(addr, 0, pna * 4);
What about this one instead ? I want to cache it because that function can be called quite a while and doing two additional property lookup and string compares every time might hurt some platforms. ---- We have a historical hack that treats missing ranges properties as the equivalent of an empty one. This is needed for ancient PowerMac "bad" device-trees, and shouldn't be enabled for any other PowerPC platform, otherwise we get some nasty layout of devices in sysfs or even duplication when a set of otherwise identically named devices is created multiple times under a different parent node with no ranges property. This fix is needed for the PowerNV i2c busses to be exposed properly and will fix a number of other embedded cases. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: <stable@vger.kernel.org>