4.14-stable review patch. If anyone has any objections, please let me know.
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From: Ulf Hansson ulf.hansson@linaro.org
[ Upstream commit a3381e3a65cbaf612c8f584906c4dba27e84267c ]
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) Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Reviewed-by: Lina Iyer ilina@codeaurora.org Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/base/power/domain.c | 76 ++++++++++++++++++++++++++------------------ 1 file changed, 45 insertions(+), 31 deletions(-)
--- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -2206,6 +2206,38 @@ static int genpd_parse_state(struct genp 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. * @@ -2215,49 +2247,31 @@ static int genpd_parse_state(struct genp * * 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; }