| Message ID | 1516740188-3580-1-git-send-email-ulf.hansson@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] PM / Domains: Fixup domain-idle-states OF parsing | expand |
On Tue, Jan 23 2018 at 20:43 +0000, Ulf Hansson wrote: >The commit b539cc82d493 ("PM / Domains: Ignore domain-idle-states that are >not compatible"), made it possible to ignore non-compatible >domain-idle-states OF nodes. However, in case that happens while doing the >OF parsing, the number of elements in the allocated array would exceed the >numbers actually needed, thus wasting memory. > >Fix this by pre-iterating the genpd OF node and counting the number of >compatible domain-idle-states nodes, before doing the allocation. While >doing this, it makes sense to rework the code a bit to avoid open coding, >of parts responsible for the OF node iteration. > >Let's also take the opportunity to clarify the function header for >of_genpd_parse_idle_states(), about what is being returned in case of >errors. > >Fixes: b539cc82d493 ("PM / Domains: Ignore domain-idle-states that are not compatible") >Cc: Lina Iyer <ilina@codeaurora.org> >Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> >--- > >Changes in v2: > - Updated changelog to clarify the problem is really about avoiding to > waste memory, according to comment from Lina. > >--- Reviewed-by: Lina Iyer <ilina@codeaurora.org>
On Tuesday, January 23, 2018 10:01:28 PM CET Lina Iyer wrote: > On Tue, Jan 23 2018 at 20:43 +0000, Ulf Hansson wrote: > >The commit b539cc82d493 ("PM / Domains: Ignore domain-idle-states that are > >not compatible"), made it possible to ignore non-compatible > >domain-idle-states OF nodes. However, in case that happens while doing the > >OF parsing, the number of elements in the allocated array would exceed the > >numbers actually needed, thus wasting memory. > > > >Fix this by pre-iterating the genpd OF node and counting the number of > >compatible domain-idle-states nodes, before doing the allocation. While > >doing this, it makes sense to rework the code a bit to avoid open coding, > >of parts responsible for the OF node iteration. > > > >Let's also take the opportunity to clarify the function header for > >of_genpd_parse_idle_states(), about what is being returned in case of > >errors. > > > >Fixes: b539cc82d493 ("PM / Domains: Ignore domain-idle-states that are not compatible") > >Cc: Lina Iyer <ilina@codeaurora.org> > >Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > >--- > > > >Changes in v2: > > - Updated changelog to clarify the problem is really about avoiding to > > waste memory, according to comment from Lina. > > > >--- > Reviewed-by: Lina Iyer <ilina@codeaurora.org> > Patch applied, thanks!
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 528b241..1ea0e25 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -2290,6 +2290,38 @@ static int genpd_parse_state(struct genpd_power_state *genpd_state, return 0; } +static int genpd_iterate_idle_states(struct device_node *dn, + struct genpd_power_state *states) +{ + int ret; + struct of_phandle_iterator it; + struct device_node *np; + int i = 0; + + ret = of_count_phandle_with_args(dn, "domain-idle-states", NULL); + if (ret <= 0) + return ret; + + /* Loop over the phandles until all the requested entry is found */ + of_for_each_phandle(&it, ret, dn, "domain-idle-states", NULL, 0) { + np = it.node; + if (!of_match_node(idle_state_match, np)) + continue; + if (states) { + ret = genpd_parse_state(&states[i], np); + if (ret) { + pr_err("Parsing idle state node %pOF failed with err %d\n", + np, ret); + of_node_put(np); + return ret; + } + } + i++; + } + + return i; +} + /** * of_genpd_parse_idle_states: Return array of idle states for the genpd. * @@ -2299,49 +2331,31 @@ static int genpd_parse_state(struct genpd_power_state *genpd_state, * * Returns the device states parsed from the OF node. The memory for the states * is allocated by this function and is the responsibility of the caller to - * free the memory after use. + * free the memory after use. If no domain idle states is found it returns + * -EINVAL and in case of errors, a negative error code. */ int of_genpd_parse_idle_states(struct device_node *dn, struct genpd_power_state **states, int *n) { struct genpd_power_state *st; - struct device_node *np; - int i = 0; - int err, ret; - int count; - struct of_phandle_iterator it; - const struct of_device_id *match_id; + int ret; - count = of_count_phandle_with_args(dn, "domain-idle-states", NULL); - if (count <= 0) - return -EINVAL; + ret = genpd_iterate_idle_states(dn, NULL); + if (ret <= 0) + return ret < 0 ? ret : -EINVAL; - st = kcalloc(count, sizeof(*st), GFP_KERNEL); + st = kcalloc(ret, sizeof(*st), GFP_KERNEL); if (!st) return -ENOMEM; - /* Loop over the phandles until all the requested entry is found */ - of_for_each_phandle(&it, err, dn, "domain-idle-states", NULL, 0) { - np = it.node; - match_id = of_match_node(idle_state_match, np); - if (!match_id) - continue; - ret = genpd_parse_state(&st[i++], np); - if (ret) { - pr_err - ("Parsing idle state node %pOF failed with err %d\n", - np, ret); - of_node_put(np); - kfree(st); - return ret; - } + ret = genpd_iterate_idle_states(dn, st); + if (ret <= 0) { + kfree(st); + return ret < 0 ? ret : -EINVAL; } - *n = i; - if (!i) - kfree(st); - else - *states = st; + *states = st; + *n = ret; return 0; }
The commit b539cc82d493 ("PM / Domains: Ignore domain-idle-states that are not compatible"), made it possible to ignore non-compatible domain-idle-states OF nodes. However, in case that happens while doing the OF parsing, the number of elements in the allocated array would exceed the numbers actually needed, thus wasting memory. Fix this by pre-iterating the genpd OF node and counting the number of compatible domain-idle-states nodes, before doing the allocation. While doing this, it makes sense to rework the code a bit to avoid open coding, of parts responsible for the OF node iteration. Let's also take the opportunity to clarify the function header for of_genpd_parse_idle_states(), about what is being returned in case of errors. Fixes: b539cc82d493 ("PM / Domains: Ignore domain-idle-states that are not compatible") Cc: Lina Iyer <ilina@codeaurora.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> --- Changes in v2: - Updated changelog to clarify the problem is really about avoiding to waste memory, according to comment from Lina. --- drivers/base/power/domain.c | 76 +++++++++++++++++++++++++++------------------ 1 file changed, 45 insertions(+), 31 deletions(-) -- 2.7.4