From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laura Abbott Subject: Re: [RFC/PATCH v2 2/2] drivers: dma-contiguous: add initialization from device tree Date: Thu, 11 Apr 2013 10:56:02 -0700 Message-ID: <5166F932.9000003@codeaurora.org> References: <1365679330-2514-1-git-send-email-m.szyprowski@samsung.com> <1365679330-2514-3-git-send-email-m.szyprowski@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1365679330-2514-3-git-send-email-m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Marek Szyprowski Cc: Sascha Hauer , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, Nishanth Peethambaran , Michal Nazarewicz , linaro-mm-sig-cunTk1MwBs8s++Sfvej+rw@public.gmane.org, Marc , Kyungmin Park , Sylwester Nawrocki , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org Hi, On 4/11/2013 4:22 AM, Marek Szyprowski wrote: ... > + > diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c > index 01fe743..6a8abab 100644 > --- a/drivers/base/dma-contiguous.c > +++ b/drivers/base/dma-contiguous.c > @@ -24,6 +24,9 @@ > > #include > #include > +#include > +#include > +#include > #include > #include > #include > @@ -37,6 +40,7 @@ struct cma { > unsigned long base_pfn; > unsigned long count; > unsigned long *bitmap; > + char full_name[32]; > }; > > static DEFINE_MUTEX(cma_mutex); > @@ -133,6 +137,53 @@ static __init int cma_activate_area(struct cma *cma) > return 0; > } > > +/*****************************************************************************/ > + > +#ifdef CONFIG_OF > +int __init cma_fdt_scan(unsigned long node, const char *uname, > + int depth, void *data) > +{ > + static int level; > + phys_addr_t base, size; > + unsigned long len; > + struct cma *cma; > + __be32 *prop; > + > + if (depth == 1 && strcmp(uname, "chosen") == 0) { > + level = depth; > + return 0; > + } > + > + if (depth == 2 && strcmp(uname, "contiguous-memory") == 0) { > + level = depth; > + return 0; > + } > + > + if (level != 2 || depth != 3 || strncmp(uname, "region@", 7) != 0) > + return 0; > + Requiring the region@ label does not work if you want two dynamically placed regions (i.e. two region@0). The devicetree will take the last region@0 entry and ignore all the other ones > + prop = of_get_flat_dt_prop(node, "reg", &len); > + if (!prop || (len != 2 * sizeof(unsigned long))) > + return 0; > + > + base = be32_to_cpu(prop[0]); > + size = be32_to_cpu(prop[1]); > + > + pr_info("Found %s, memory base %lx, size %ld MiB\n", uname, > + (unsigned long)base, (unsigned long)size / SZ_1M); > + > + dma_contiguous_reserve_area(size, base, 0, &cma); > + Need to check the return of dma_contiguous_reserve_area, else there is an abort when trying to access cma->name on an error > + strcpy(cma->full_name, uname); > + > + if (of_get_flat_dt_prop(node, "linux,default-contiguous-region", NULL)) { > + > + dma_contiguous_default_area = cma; > + } > + return 0; > +} > +#endif > + > /** > * dma_contiguous_reserve() - reserve area(s) for contiguous memory handling > * @limit: End address of the reserved memory (optional, 0 for any). if the contiguous region isn't set via devicetree, default_area->full_name needs to be set in dma_contiguous_reserve, else we get wrong associations in scan_cma_node. > @@ -149,6 +200,10 @@ void __init dma_contiguous_reserve(phys_addr_t limit) > > pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit); > > +#ifdef CONFIG_OF > + of_scan_flat_dt(cma_fdt_scan, NULL); > +#endif > + > if (size_cmdline != -1) { > sel_size = size_cmdline; > } else { > @@ -265,6 +320,71 @@ int __init dma_contiguous_add_device(struct device *dev, struct cma *cma) > return 0; > } > > +#ifdef CONFIG_OF > +static struct cma_map { > + struct cma *cma; > + struct device_node *node; > +} cma_maps[MAX_CMA_AREAS]; > +static unsigned cma_map_count; > + > +static void cma_assign_device_from_dt(struct device *dev) > +{ > + int i; > + for (i=0; i + if (cma_maps[i].node == dev->of_node) { > + dev_set_cma_area(dev, cma_maps[i].cma); > + pr_info("Assigned CMA %s to %s device\n", > + cma_maps[i].cma->full_name, > + dev_name(dev)); > + } > + } > +} > + > +static int cma_device_init_notifier_call(struct notifier_block *nb, > + unsigned long event, void *data) > +{ > + struct device *dev = data; > + if (event == BUS_NOTIFY_ADD_DEVICE && dev->of_node) > + cma_assign_device_from_dt(dev); > + return NOTIFY_DONE; > +} > + > +static struct notifier_block cma_dev_init_nb = { > + .notifier_call = cma_device_init_notifier_call, > +}; > + > +void scan_cma_nodes(void) > +{ > + struct device_node *parent = of_find_node_by_path("/chosen/contiguous-memory"); > + struct device_node *child; > + > + if (!parent) > + return; > + > + for_each_child_of_node(parent, child) { > + struct cma *cma = NULL; > + int i; > + > + for (i=0; i + if (strstr(child->full_name, cma_areas[i].full_name)) > + cma = &cma_areas[i]; break out of the loop once the area is found? Also, how will the code deal with region names that are substrings of each other e.g. region@1000000 region@10000000 > + if (!cma) > + continue; > + > + for (i=0;; i++) { > + struct device_node *node; > + node = of_parse_phandle(child, "device", i); > + if (!node) > + break; > + > + cma_maps[cma_map_count].cma = cma; > + cma_maps[cma_map_count].node = node; > + cma_map_count++; Bounds check cma_map_count against MAX_CMA_AREAS? > + } > + } > +} > +#endif > + > static int __init cma_init_reserved_areas(void) > { > int i; > @@ -275,6 +395,10 @@ static int __init cma_init_reserved_areas(void) > return ret; > } > > +#ifdef CONFIG_OF > + scan_cma_nodes(); > + bus_register_notifier(&platform_bus_type, &cma_dev_init_nb); > +#endif > return 0; > } > core_initcall(cma_init_reserved_areas); > Thanks, Laura -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation