From: Matthias Kaehlcke <mka@chromium.org> To: Georgi Djakov <georgi.djakov@linaro.org> Cc: linux-pm@vger.kernel.org, gregkh@linuxfoundation.org, rjw@rjwysocki.net, robh+dt@kernel.org, mturquette@baylibre.com, khilman@baylibre.com, vincent.guittot@linaro.org, skannan@codeaurora.org, bjorn.andersson@linaro.org, amit.kucheria@linaro.org, seansw@qti.qualcomm.com, daidavid1@codeaurora.org, evgreen@chromium.org, mark.rutland@arm.com, lorenzo.pieralisi@arm.com, abailon@baylibre.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH v5 1/8] interconnect: Add generic on-chip interconnect API Date: Tue, 26 Jun 2018 16:34:27 -0700 [thread overview] Message-ID: <20180626233427.GR129942@google.com> (raw) In-Reply-To: <20180620121141.15403-2-georgi.djakov@linaro.org> Hi Georgi, On Wed, Jun 20, 2018 at 03:11:34PM +0300, Georgi Djakov wrote: > This patch introduce a new API to get requirements and configure the nit: s/introduce/introduces/ > interconnect buses across the entire chipset to fit with the current > demand. > > The API is using a consumer/provider-based model, where the providers are > the interconnect buses and the consumers could be various drivers. > The consumers request interconnect resources (path) between endpoints and > set the desired constraints on this data flow path. The providers receive > requests from consumers and aggregate these requests for all master-slave > pairs on that path. Then the providers configure each participating in the > topology node according to the requested data flow path, physical links and > constraints. The topology could be complicated and multi-tiered and is SoC > specific. > > Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org> > --- > diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c > > ... > > +static struct icc_path *path_find(struct device *dev, struct icc_node *src, > + struct icc_node *dst) > +{ > + struct icc_node *n, *node = NULL; > + struct icc_provider *provider; > + struct list_head traverse_list; > + struct list_head edge_list; > + struct list_head visited_list; > + size_t i, depth = 0; > + bool found = false; > + int ret = -EPROBE_DEFER; > + > + INIT_LIST_HEAD(&traverse_list); > + INIT_LIST_HEAD(&edge_list); > + INIT_LIST_HEAD(&visited_list); > + > + list_add_tail(&src->search_list, &traverse_list); > + src->reverse = NULL; > + > + do { > + list_for_each_entry_safe(node, n, &traverse_list, search_list) { > + if (node == dst) { > + found = true; > + list_add(&node->search_list, &visited_list); > + break; > + } > + for (i = 0; i < node->num_links; i++) { > + struct icc_node *tmp = node->links[i]; > + > + if (!tmp) { > + ret = -ENOENT; > + goto out; > + } > + > + if (tmp->is_traversed) > + continue; > + > + tmp->is_traversed = true; > + tmp->reverse = node; > + list_add(&tmp->search_list, &edge_list); > + } > + } > + if (found) > + break; > + > + list_splice_init(&traverse_list, &visited_list); > + list_splice_init(&edge_list, &traverse_list); > + > + /* count the hops away from the source */ > + depth++; > + > + } while (!list_empty(&traverse_list)); > + > +out: > + /* reset the traversed state */ > + list_for_each_entry(provider, &icc_provider_list, provider_list) { > + list_for_each_entry(n, &provider->nodes, node_list) > + if (n->is_traversed) > + n->is_traversed = false; > + } > + > + if (found) { > + struct icc_path *path = path_allocate(dst, depth); > + > + if (IS_ERR(path)) > + return path; > + > + /* initialize the path */ > + for (i = 0; i < path->num_nodes; i++) { > + node = path->reqs[i].node; > + path->reqs[i].dev = dev; > + node->provider->users++; nit: doing the assignment of path->reqs[i].dev before assiging 'node' or after incrementing the 'users' would slightly improve readability. > +static int apply_constraints(struct icc_path *path) > +{ > + struct icc_node *next, *prev = NULL; > + int ret = 0; > + int i; > + > + for (i = 0; i < path->num_nodes; i++, prev = next) { > + struct icc_provider *p; > + > + next = path->reqs[i].node; > + /* > + * Both endpoints should be valid master-slave pairs of the > + * same interconnect provider that will be configured. > + */ > + if (!prev || next->provider != prev->provider) > + continue; > + > + p = next->provider; > + > + aggregate_provider(p); > + > + if (p->set) { > + /* set the constraints */ > + ret = p->set(prev, next, p->avg_bw, p->peak_bw); > + } remove curly brackets EDIT: actually the condition can be removed, icc_provider_add() fails when p->set is NULL. > +int icc_set(struct icc_path *path, u32 avg_bw, u32 peak_bw) > +{ > + struct icc_node *node; > + struct icc_provider *p; > + size_t i; > + int ret = 0; initialization is not necessary > +struct icc_path *icc_get(struct device *dev, const int src_id, const int dst_id) > +{ > + struct icc_node *src, *dst; > + struct icc_path *path = ERR_PTR(-EPROBE_DEFER); > + > + src = node_find(src_id); > + if (!src) { > + dev_err(dev, "%s: invalid src=%d\n", __func__, src_id); > + goto out; > + } > + > + dst = node_find(dst_id); > + if (!dst) { > + dev_err(dev, "%s: invalid dst=%d\n", __func__, dst_id); > + goto out; > + } > + > + mutex_lock(&icc_lock); > + path = path_find(dev, src, dst); > + mutex_unlock(&icc_lock); > + if (IS_ERR(path)) { > + dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path)); > + goto out; this goto isn't really needed > +struct icc_node *icc_node_create(int id) > +{ > + struct icc_node *node; > + > + /* check if node already exists */ > + node = node_find(id); > + if (node) > + goto out; > + > + node = kzalloc(sizeof(*node), GFP_KERNEL); > + if (!node) { > + node = ERR_PTR(-ENOMEM); > + goto out; > + } > + > + mutex_lock(&icc_lock); > + > + id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL); > + if (WARN(id < 0, "couldn't get idr")) { kfree(node); > +int icc_node_add(struct icc_node *node, struct icc_provider *provider) > +{ > + mutex_lock(&icc_lock); > + > + node->provider = provider; > + list_add(&node->node_list, &provider->nodes); > + > + mutex_unlock(&icc_lock); > + > + return 0; > +} The function returns always 0. Should probably be void so callers don't add pointless checks of the return value. > +int icc_provider_add(struct icc_provider *provider) > +{ > + if (WARN_ON(!provider->set)) > + return -EINVAL; > + > + mutex_init(&icc_lock); Shouldn't this be mutex_lock()? > +int icc_provider_del(struct icc_provider *provider) > +{ > + mutex_lock(&icc_lock); > + if (provider->users) { > + pr_warn("interconnect provider still has %d users\n", > + provider->users); > + mutex_unlock(&icc_lock); > + return -EBUSY; > + } > + > + if (!list_empty_careful(&provider->nodes)) { > + pr_warn("interconnect provider still has nodes\n"); > + mutex_unlock(&icc_lock); > + return -EEXIST; > + } Could this be just list_empty()? If I didn't miss something icc_lock is held in all paths that change p->nodes (assuming that all changes should be done through the interfaces in this file). Actually this check will always fail if icc_node_add() was called for this provider, it doesn't seem nodes are ever removed. Cheers Matthias
WARNING: multiple messages have this Message-ID (diff)
From: mka@chromium.org (Matthias Kaehlcke) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v5 1/8] interconnect: Add generic on-chip interconnect API Date: Tue, 26 Jun 2018 16:34:27 -0700 [thread overview] Message-ID: <20180626233427.GR129942@google.com> (raw) In-Reply-To: <20180620121141.15403-2-georgi.djakov@linaro.org> Hi Georgi, On Wed, Jun 20, 2018 at 03:11:34PM +0300, Georgi Djakov wrote: > This patch introduce a new API to get requirements and configure the nit: s/introduce/introduces/ > interconnect buses across the entire chipset to fit with the current > demand. > > The API is using a consumer/provider-based model, where the providers are > the interconnect buses and the consumers could be various drivers. > The consumers request interconnect resources (path) between endpoints and > set the desired constraints on this data flow path. The providers receive > requests from consumers and aggregate these requests for all master-slave > pairs on that path. Then the providers configure each participating in the > topology node according to the requested data flow path, physical links and > constraints. The topology could be complicated and multi-tiered and is SoC > specific. > > Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org> > --- > diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c > > ... > > +static struct icc_path *path_find(struct device *dev, struct icc_node *src, > + struct icc_node *dst) > +{ > + struct icc_node *n, *node = NULL; > + struct icc_provider *provider; > + struct list_head traverse_list; > + struct list_head edge_list; > + struct list_head visited_list; > + size_t i, depth = 0; > + bool found = false; > + int ret = -EPROBE_DEFER; > + > + INIT_LIST_HEAD(&traverse_list); > + INIT_LIST_HEAD(&edge_list); > + INIT_LIST_HEAD(&visited_list); > + > + list_add_tail(&src->search_list, &traverse_list); > + src->reverse = NULL; > + > + do { > + list_for_each_entry_safe(node, n, &traverse_list, search_list) { > + if (node == dst) { > + found = true; > + list_add(&node->search_list, &visited_list); > + break; > + } > + for (i = 0; i < node->num_links; i++) { > + struct icc_node *tmp = node->links[i]; > + > + if (!tmp) { > + ret = -ENOENT; > + goto out; > + } > + > + if (tmp->is_traversed) > + continue; > + > + tmp->is_traversed = true; > + tmp->reverse = node; > + list_add(&tmp->search_list, &edge_list); > + } > + } > + if (found) > + break; > + > + list_splice_init(&traverse_list, &visited_list); > + list_splice_init(&edge_list, &traverse_list); > + > + /* count the hops away from the source */ > + depth++; > + > + } while (!list_empty(&traverse_list)); > + > +out: > + /* reset the traversed state */ > + list_for_each_entry(provider, &icc_provider_list, provider_list) { > + list_for_each_entry(n, &provider->nodes, node_list) > + if (n->is_traversed) > + n->is_traversed = false; > + } > + > + if (found) { > + struct icc_path *path = path_allocate(dst, depth); > + > + if (IS_ERR(path)) > + return path; > + > + /* initialize the path */ > + for (i = 0; i < path->num_nodes; i++) { > + node = path->reqs[i].node; > + path->reqs[i].dev = dev; > + node->provider->users++; nit: doing the assignment of path->reqs[i].dev before assiging 'node' or after incrementing the 'users' would slightly improve readability. > +static int apply_constraints(struct icc_path *path) > +{ > + struct icc_node *next, *prev = NULL; > + int ret = 0; > + int i; > + > + for (i = 0; i < path->num_nodes; i++, prev = next) { > + struct icc_provider *p; > + > + next = path->reqs[i].node; > + /* > + * Both endpoints should be valid master-slave pairs of the > + * same interconnect provider that will be configured. > + */ > + if (!prev || next->provider != prev->provider) > + continue; > + > + p = next->provider; > + > + aggregate_provider(p); > + > + if (p->set) { > + /* set the constraints */ > + ret = p->set(prev, next, p->avg_bw, p->peak_bw); > + } remove curly brackets EDIT: actually the condition can be removed, icc_provider_add() fails when p->set is NULL. > +int icc_set(struct icc_path *path, u32 avg_bw, u32 peak_bw) > +{ > + struct icc_node *node; > + struct icc_provider *p; > + size_t i; > + int ret = 0; initialization is not necessary > +struct icc_path *icc_get(struct device *dev, const int src_id, const int dst_id) > +{ > + struct icc_node *src, *dst; > + struct icc_path *path = ERR_PTR(-EPROBE_DEFER); > + > + src = node_find(src_id); > + if (!src) { > + dev_err(dev, "%s: invalid src=%d\n", __func__, src_id); > + goto out; > + } > + > + dst = node_find(dst_id); > + if (!dst) { > + dev_err(dev, "%s: invalid dst=%d\n", __func__, dst_id); > + goto out; > + } > + > + mutex_lock(&icc_lock); > + path = path_find(dev, src, dst); > + mutex_unlock(&icc_lock); > + if (IS_ERR(path)) { > + dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path)); > + goto out; this goto isn't really needed > +struct icc_node *icc_node_create(int id) > +{ > + struct icc_node *node; > + > + /* check if node already exists */ > + node = node_find(id); > + if (node) > + goto out; > + > + node = kzalloc(sizeof(*node), GFP_KERNEL); > + if (!node) { > + node = ERR_PTR(-ENOMEM); > + goto out; > + } > + > + mutex_lock(&icc_lock); > + > + id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL); > + if (WARN(id < 0, "couldn't get idr")) { kfree(node); > +int icc_node_add(struct icc_node *node, struct icc_provider *provider) > +{ > + mutex_lock(&icc_lock); > + > + node->provider = provider; > + list_add(&node->node_list, &provider->nodes); > + > + mutex_unlock(&icc_lock); > + > + return 0; > +} The function returns always 0. Should probably be void so callers don't add pointless checks of the return value. > +int icc_provider_add(struct icc_provider *provider) > +{ > + if (WARN_ON(!provider->set)) > + return -EINVAL; > + > + mutex_init(&icc_lock); Shouldn't this be mutex_lock()? > +int icc_provider_del(struct icc_provider *provider) > +{ > + mutex_lock(&icc_lock); > + if (provider->users) { > + pr_warn("interconnect provider still has %d users\n", > + provider->users); > + mutex_unlock(&icc_lock); > + return -EBUSY; > + } > + > + if (!list_empty_careful(&provider->nodes)) { > + pr_warn("interconnect provider still has nodes\n"); > + mutex_unlock(&icc_lock); > + return -EEXIST; > + } Could this be just list_empty()? If I didn't miss something icc_lock is held in all paths that change p->nodes (assuming that all changes should be done through the interfaces in this file). Actually this check will always fail if icc_node_add() was called for this provider, it doesn't seem nodes are ever removed. Cheers Matthias
next prev parent reply other threads:[~2018-06-26 23:34 UTC|newest] Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-06-20 12:11 [PATCH v5 0/8] Introduce on-chip interconnect API Georgi Djakov 2018-06-20 12:11 ` Georgi Djakov 2018-06-20 12:11 ` [PATCH v5 1/8] interconnect: Add generic " Georgi Djakov 2018-06-20 12:11 ` Georgi Djakov 2018-06-26 20:57 ` Evan Green 2018-06-26 20:57 ` Evan Green 2018-06-26 20:57 ` Evan Green 2018-06-26 21:58 ` Matthias Kaehlcke 2018-06-26 21:58 ` Matthias Kaehlcke 2018-06-27 0:54 ` Rob Clark 2018-06-27 0:54 ` Rob Clark 2018-07-01 11:03 ` Georgi Djakov 2018-07-01 11:03 ` Georgi Djakov 2018-07-01 11:03 ` Georgi Djakov 2018-06-26 23:34 ` Matthias Kaehlcke [this message] 2018-06-26 23:34 ` Matthias Kaehlcke 2018-07-01 11:06 ` Georgi Djakov 2018-07-01 11:06 ` Georgi Djakov 2018-06-27 6:19 ` Vincent Guittot 2018-06-27 6:19 ` Vincent Guittot 2018-07-01 11:09 ` Georgi Djakov 2018-07-01 11:09 ` Georgi Djakov 2018-07-02 7:23 ` Vincent Guittot 2018-07-02 7:23 ` Vincent Guittot 2018-06-20 12:11 ` [PATCH v5 2/8] dt-bindings: Introduce interconnect provider bindings Georgi Djakov 2018-06-20 12:11 ` Georgi Djakov 2018-06-20 12:11 ` [PATCH v5 3/8] interconnect: Add debugfs support Georgi Djakov 2018-06-20 12:11 ` Georgi Djakov 2018-06-20 12:11 ` [PATCH v5 4/8] interconnect: qcom: Add RPM communication Georgi Djakov 2018-06-20 12:11 ` Georgi Djakov 2018-06-26 20:47 ` Evan Green 2018-06-26 20:47 ` Evan Green 2018-07-01 11:16 ` Georgi Djakov 2018-07-01 11:16 ` Georgi Djakov 2018-06-27 0:55 ` Matthias Kaehlcke 2018-06-27 0:55 ` Matthias Kaehlcke 2018-07-01 11:18 ` Georgi Djakov 2018-07-01 11:18 ` Georgi Djakov 2018-06-20 12:11 ` [PATCH v5 5/8] dt-bindings: interconnect: Document qcom,msm8916 NoC bindings Georgi Djakov 2018-06-20 12:11 ` [PATCH v5 5/8] dt-bindings: interconnect: Document qcom, msm8916 " Georgi Djakov 2018-06-20 12:11 ` [PATCH v5 6/8] interconnect: qcom: Add msm8916 interconnect provider driver Georgi Djakov 2018-06-20 12:11 ` Georgi Djakov 2018-06-26 20:48 ` Evan Green 2018-06-26 20:48 ` Evan Green 2018-07-01 12:12 ` Georgi Djakov 2018-07-01 12:12 ` Georgi Djakov 2018-07-02 17:08 ` Evan Green 2018-07-02 17:08 ` Evan Green 2018-07-02 17:08 ` Evan Green 2018-06-20 12:11 ` [PATCH v5 7/8] dt-bindings: Introduce interconnect consumers bindings Georgi Djakov 2018-06-20 12:11 ` Georgi Djakov 2018-06-20 12:11 ` Georgi Djakov 2018-06-20 12:11 ` [PATCH v5 8/8] interconnect: Allow endpoints translation via DT Georgi Djakov 2018-06-20 12:11 ` Georgi Djakov
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