From mboxrd@z Thu Jan 1 00:00:00 1970 From: ulf.hansson@linaro.org (Ulf Hansson) Date: Fri, 5 Aug 2016 13:55:31 +0200 Subject: [RFC PATCH 6/8] PM / Domains: Remove a provider by referencing the data pointer In-Reply-To: <5769455C.9010809@nvidia.com> References: <1457090634-14785-1-git-send-email-jonathanh@nvidia.com> <1457090634-14785-7-git-send-email-jonathanh@nvidia.com> <5769455C.9010809@nvidia.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 21 June 2016 at 15:47, Jon Hunter wrote: > > On 15/06/16 15:38, Ulf Hansson wrote: >> On 4 March 2016 at 12:23, Jon Hunter wrote: >>> To remove a PM domain from the system, it is necessary to ensure >>> that any PM domain providers associated with the PM domain have >>> been removed. Otherwise it could be possible to obtain a pointer >>> to a PM domain structure that has been removed. >>> >>> PM domains now have a reference to the pointer for the PM domain >>> provider's data variable. Add a function so that a PM domain can >>> remove a PM domain provider by referencing the data pointer. >>> >>> Signed-off-by: Jon Hunter >>> --- >>> drivers/base/power/domain.c | 24 ++++++++++++++++++++++++ >>> include/linux/pm_domain.h | 2 ++ >>> 2 files changed, 26 insertions(+) >>> >>> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c >>> index 72055fef6256..438885f2455f 100644 >>> --- a/drivers/base/power/domain.c >>> +++ b/drivers/base/power/domain.c >>> @@ -1738,6 +1738,30 @@ void of_genpd_del_provider(struct device_node *np) >>> EXPORT_SYMBOL_GPL(of_genpd_del_provider); >>> >>> /** >>> + * of_genpd_del_provider_by_data() - Remove a registered PM domain provider >>> + * @data: Pointer to the data associated with the PM domain provider >>> + * >>> + * Look up a PM domain provider based upon a pointer to it's data and >>> + * remove the PM domain provider from the list of providers. >>> + */ >>> +void of_genpd_del_provider_by_data(void *data) >>> +{ >>> + struct of_genpd_provider *c, *cp; >>> + >>> + mutex_lock(&of_genpd_mutex); >>> + list_for_each_entry_safe(cp, c, &of_genpd_providers, link) { >>> + if (cp->data == data) { >>> + list_del(&cp->link); >>> + of_node_put(cp->node); >>> + kfree(cp); >>> + break; >>> + } >>> + } >>> + mutex_unlock(&of_genpd_mutex); >>> +} >>> +EXPORT_SYMBOL_GPL(of_genpd_del_provider_by_data); >>> + >>> +/** >>> * of_genpd_get_from_provider() - Look-up PM domain >>> * @genpdspec: OF phandle args to use for look-up >>> * >>> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h >>> index bed84413546f..7b7921a65cb0 100644 >>> --- a/include/linux/pm_domain.h >>> +++ b/include/linux/pm_domain.h >>> @@ -199,6 +199,7 @@ int of_genpd_add_provider_simple(struct device_node *np, >>> int of_genpd_add_provider_onecell(struct device_node *np, >>> struct genpd_onecell_data *data); >>> void of_genpd_del_provider(struct device_node *np); >> >> There's currently only one user of of_genpd_del_provider(). >> >> Could this patch just convert that user to the new API, so we don't >> need to keep both the legacy and new one? >> >> I guess we could then just stick to the name "of_genpd_del_provider()". > > I had a look at this and to do that we would end up with > of_genpd_del_provider(struct device_node *np, void *data) where the user > should only pass one of the arguments. It seems a bit odd. However, > unless I have forgotten something, I wonder if we should just make > of_genpd_del_provider_by_name() a local function and not export this at > all? It seems more natural for users to delete a provider by the > device_node than by name rather than the data argument. > > The only problem I see with making of_genpd_del_provider_by_name() local > is that I need to add a prototype for the function at the top of the > domain.c source file so that it builds because __pm_genpd_remove() is > defined above it. Yes I could move __pm_genpd_remove() to the bottom of > the file but then it is not located next to pm_genpd_init() which seems odd. > > Let me know what you think. Sorry for delay! I have now looked into this in more detail. When an genpd provider is added today, it's supposed to get a corresponding *unique* OF device node associated with it, right!? If we store this OF device node from the provider in the struct generic_pm_domain, instead of the "provider_data pointer", we wouldn't need to the add of_genpd_del_provider_by_data() at all. Because we can use the currently available of_genpd_del_provider(), right!? Or what am I missing? :-) Kind regards Uffe