Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753164AbaKGOzc (ORCPT ); Fri, 7 Nov 2014 09:55:32 -0500 Received: from service87.mimecast.com ([91.220.42.44]:35476 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753140AbaKGOza convert rfc822-to-8bit (ORCPT ); Fri, 7 Nov 2014 09:55:30 -0500 Date: Fri, 7 Nov 2014 14:55:25 +0000 From: Liviu Dudau To: Tomasz Nowicki Cc: Catalin Marinas , Will Deacon , "bhelgaas@google.com" , "tglx@linutronix.de" , "mingo@redhat.com" , "hpa@zytor.com" , "rjw@rjwysocki.net" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "x86@kernel.org" , "linux-pci@vger.kernel.org" , "linux-acpi@vger.kernel.org" , "linaro-acpi@lists.linaro.org" Subject: Re: [RFC PATCH 4/4] arm64, acpi, pci: Provide arch-specific calls for PCI host bridge dirver (PNP0A03). Message-ID: <20141107145525.GH8916@e106497-lin.cambridge.arm.com> References: <1415366876-30811-1-git-send-email-tomasz.nowicki@linaro.org> <1415366876-30811-5-git-send-email-tomasz.nowicki@linaro.org> MIME-Version: 1.0 In-Reply-To: <1415366876-30811-5-git-send-email-tomasz.nowicki@linaro.org> User-Agent: Mutt/1.5.22 (2013-10-16) X-OriginalArrivalTime: 07 Nov 2014 14:55:27.0145 (UTC) FILETIME=[DDE0F990:01CFFA9A] X-MC-Unique: 114110714552720201 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 07, 2014 at 01:27:56PM +0000, Tomasz Nowicki wrote: > Code inspired by arch/x86/pci/acpi.c and arch/ia64/pci/pci.c files. > The main reasons why we need this: > - parse and manage resources (BUS, IO and MEM) > - create pci root bus and enumerate its children > - provide PCI config space accessors (via MMCONFIG) Hi Tomasz, I have some comments to your code: > > Signed-off-by: Tomasz Nowicki > --- > arch/arm64/include/asm/pci.h | 8 + > arch/arm64/kernel/pci.c | 401 +++++++++++++++++++++++++++++++++++++++++-- > 2 files changed, 391 insertions(+), 18 deletions(-) > > diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h > index fded096..ecd940f 100644 > --- a/arch/arm64/include/asm/pci.h > +++ b/arch/arm64/include/asm/pci.h > @@ -33,6 +33,14 @@ static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel) > extern int isa_dma_bridge_buggy; > > #ifdef CONFIG_PCI > +struct pci_controller { > + struct acpi_device *companion; > + int segment; > + int node; /* nearest node with memory or NUMA_NO_NODE for global allocation */ > +}; > + > +#define PCI_CONTROLLER(busdev) ((struct pci_controller *) busdev->sysdata) I am trying to move away from the model where the architecture dictates the shape of the pci_controller structure. Can I suggest that you put all this code and the one under #ifdef CONFIG_ACPI in a separate file, say arch/arm64/kernel/pci-acpi.c ? Or that you add an #ifdef CONFIG_ACPI around this structure definition? I can't see anyone using this definition outside ACPI (due to struct acpi_device dependency) and I would like to avoid it conflicting with other host bridge drivers trying to define the same name structure. > + > static inline int pci_proc_domain(struct pci_bus *bus) > { > return 1; > diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c > index 42fb195..cc34ded 100644 > --- a/arch/arm64/kernel/pci.c > +++ b/arch/arm64/kernel/pci.c > @@ -1,6 +1,10 @@ > /* > - * Code borrowed from powerpc/kernel/pci-common.c > + * Code borrowed from powerpc/kernel/pci-common.c and arch/ia64/pci/pci.c > * > + * Copyright (c) 2002, 2005 Hewlett-Packard Development Company, L.P. > + * David Mosberger-Tang > + * Bjorn Helgaas > + * Copyright (C) 2004 Silicon Graphics, Inc. > * Copyright (C) 2003 Anton Blanchard , IBM > * Copyright (C) 2014 ARM Ltd. > * > @@ -17,10 +21,16 @@ > #include > #include > #include > +#include > #include > +#include > +#include > +#include > > #include > > +#define PREFIX "PCI: " Where is this used? > + > /* > * Called after each bus is probed, but before its children are examined > */ > @@ -43,7 +53,8 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res, > */ > int pcibios_add_device(struct pci_dev *dev) > { > - dev->irq = of_irq_parse_and_map_pci(dev, 0, 0); > + if (acpi_disabled) > + dev->irq = of_irq_parse_and_map_pci(dev, 0, 0); > > return 0; > } > @@ -54,45 +65,399 @@ static bool dt_domain_found = false; > > void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent) > { > - int domain = of_get_pci_domain_nr(parent->of_node); > + int domain = -1; > > - if (domain >= 0) { > - dt_domain_found = true; > - } else if (dt_domain_found == true) { > - dev_err(parent, "Node %s is missing \"linux,pci-domain\" property in DT\n", > - parent->of_node->full_name); > - return; > + if (acpi_disabled) { > + domain = of_get_pci_domain_nr(parent->of_node); > + > + if (domain >= 0) { > + dt_domain_found = true; > + } else if (dt_domain_found == true) { > + dev_err(parent, "Node %s is missing \"linux,pci-domain\" property in DT\n", > + parent->of_node->full_name); > + return; > + } else { > + domain = pci_get_new_domain_nr(); > + } > } else { > - domain = pci_get_new_domain_nr(); > + /* > + * Take the domain nr from associated private data. > + * Case where bus has parent is covered in pci_alloc_bus() > + */ > + if (!parent) > + domain = PCI_CONTROLLER(bus)->segment; I would also like to wrap this into an ACPI specific function. Reason for it is that when I get to split the pci_host_bridge creation out of pci_create_root_bus() this will become a pci_controller property. > } > > bus->domain_nr = domain; > } > #endif > > +static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, > + unsigned int devfn) > +{ > + struct pci_mmcfg_region *cfg = pci_mmconfig_lookup(seg, bus); > + > + if (cfg && cfg->virt) > + return cfg->virt + (PCI_MMCFG_BUS_OFFSET(bus) | (devfn << 12)); > + return NULL; > +} > + > /* > * raw_pci_read/write - Platform-specific PCI config space access. > - * > - * Default empty implementation. Replace with an architecture-specific setup > - * routine, if necessary. > */ > int raw_pci_read(unsigned int domain, unsigned int bus, > unsigned int devfn, int reg, int len, u32 *val) > { > - return -EINVAL; > + char __iomem *addr; > + > + if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) { > +err: *val = -1; I believe the general usage is to have labels on their own line. > + return -EINVAL; > + } > + > + rcu_read_lock(); > + addr = pci_dev_base(domain, bus, devfn); > + if (!addr) { > + rcu_read_unlock(); > + goto err; > + } > + > + switch (len) { > + case 1: > + *val = readb(addr + reg); > + break; > + case 2: > + *val = readw(addr + reg); > + break; > + case 4: > + *val = readl(addr + reg); > + break; > + } > + rcu_read_unlock(); > + > + return 0; > } > > int raw_pci_write(unsigned int domain, unsigned int bus, > unsigned int devfn, int reg, int len, u32 val) > { > - return -EINVAL; > + char __iomem *addr; > + > + if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) > + return -EINVAL; > + > + rcu_read_lock(); > + addr = pci_dev_base(domain, bus, devfn); > + if (!addr) { > + rcu_read_unlock(); > + return -EINVAL; > + } > + > + switch (len) { > + case 1: > + writeb(val, addr + reg); > + break; > + case 2: > + writew(val, addr + reg); > + break; > + case 4: > + writel(val, addr + reg); > + break; > + } > + rcu_read_unlock(); > + > + return 0; > } > These raw_pci_{read,write} functions are all ACPI specific so they can move into the new file as well. > #ifdef CONFIG_ACPI > +static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, > + int size, u32 *value) > +{ > + return raw_pci_read(pci_domain_nr(bus), bus->number, > + devfn, where, size, value); > +} > + > +static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, > + int size, u32 value) > +{ > + return raw_pci_write(pci_domain_nr(bus), bus->number, > + devfn, where, size, value); > +} > + > +struct pci_ops pci_root_ops = { > + .read = pci_read, > + .write = pci_write, > +}; > + > +static struct pci_controller *alloc_pci_controller(int seg) > +{ > + struct pci_controller *controller; > + > + controller = kzalloc(sizeof(*controller), GFP_KERNEL); > + if (!controller) > + return NULL; > + > + controller->segment = seg; > + return controller; > +} > + > +struct pci_root_info { > + struct acpi_device *bridge; > + struct pci_controller *controller; > + struct list_head resources; > + struct resource *res; > + resource_size_t *res_offset; Why do you need to keep an array of res_offsets here? You only seem to be using the values once when you add the resource to the host bridge windows. > + unsigned int res_num; > + char *name; > +}; > + > +static acpi_status resource_to_window(struct acpi_resource *resource, > + struct acpi_resource_address64 *addr) > +{ > + acpi_status status; > + > + /* > + * We're only interested in _CRS descriptors that are > + * - address space descriptors for memory > + * - non-zero size > + * - producers, i.e., the address space is routed downstream, > + * not consumed by the bridge itself > + */ > + status = acpi_resource_to_address64(resource, addr); > + if (ACPI_SUCCESS(status) && > + (addr->resource_type == ACPI_MEMORY_RANGE || > + addr->resource_type == ACPI_IO_RANGE) && > + addr->address_length && > + addr->producer_consumer == ACPI_PRODUCER) > + return AE_OK; > + > + return AE_ERROR; > +} > + > +static acpi_status count_window(struct acpi_resource *resource, void *data) > +{ > + unsigned int *windows = (unsigned int *) data; > + struct acpi_resource_address64 addr; > + acpi_status status; > + > + status = resource_to_window(resource, &addr); > + if (ACPI_SUCCESS(status)) > + (*windows)++; > + > + return AE_OK; > +} > + > +static acpi_status add_window(struct acpi_resource *res, void *data) > +{ > + struct pci_root_info *info = data; > + struct resource *resource; > + struct acpi_resource_address64 addr; > + acpi_status status; > + unsigned long flags; > + struct resource *root; > + u64 start; > + > + /* Return AE_OK for non-window resources to keep scanning for more */ > + status = resource_to_window(res, &addr); > + if (!ACPI_SUCCESS(status)) > + return AE_OK; > + > + if (addr.resource_type == ACPI_MEMORY_RANGE) { > + flags = IORESOURCE_MEM; > + root = &iomem_resource; > + } else if (addr.resource_type == ACPI_IO_RANGE) { > + flags = IORESOURCE_IO; > + root = &ioport_resource; > + } else > + return AE_OK; > + > + start = addr.minimum + addr.translation_offset; > + > + resource = &info->res[info->res_num]; > + resource->name = info->name; > + resource->flags = flags; > + resource->start = start; > + resource->end = resource->start + addr.address_length - 1; > + > + if (flags & IORESOURCE_IO) { > + unsigned long port; > + int err; > + > + err = pci_register_io_range(start, addr.address_length); > + if (err) > + return AE_OK; > + > + port = pci_address_to_pio(start); > + if (port == (unsigned long)-1) > + return AE_OK; > + > + resource->start = port; > + resource->end = port + addr.address_length - 1; > + > + if (pci_remap_iospace(resource, start) < 0) > + return AE_OK; You seem to leave around invalid resources every time you return in this code path due to your choice of ignoring error conditions. I think there are a few things that can be streamlined in this patch, but overall I think it looks promising. Best regards, Liviu > + > + info->res_offset[info->res_num] = 0; > + } else > + info->res_offset[info->res_num] = addr.translation_offset; > + > + if (insert_resource(root, resource)) { > + dev_err(&info->bridge->dev, > + "can't allocate host bridge window %pR\n", > + resource); > + } else { > + if (addr.translation_offset) > + dev_info(&info->bridge->dev, "host bridge window %pR " > + "(PCI address [%#llx-%#llx])\n", > + resource, > + resource->start - addr.translation_offset, > + resource->end - addr.translation_offset); > + else > + dev_info(&info->bridge->dev, > + "host bridge window %pR\n", resource); > + } > + > + pci_add_resource_offset(&info->resources, resource, > + info->res_offset[info->res_num]); > + info->res_num++; > + return AE_OK; > +} > + > +static void free_pci_root_info_res(struct pci_root_info *info) > +{ > + kfree(info->name); > + kfree(info->res); > + info->res = NULL; > + kfree(info->res_offset); > + info->res_offset = NULL; > + info->res_num = 0; > + kfree(info->controller); > + info->controller = NULL; > +} > + > +static void __release_pci_root_info(struct pci_root_info *info) > +{ > + int i; > + struct resource *res; > + > + for (i = 0; i < info->res_num; i++) { > + res = &info->res[i]; > + > + if (!res->parent) > + continue; > + > + if (!(res->flags & (IORESOURCE_MEM | IORESOURCE_IO))) > + continue; > + > + release_resource(res); > + } > + > + free_pci_root_info_res(info); > + kfree(info); > +} > + > +static void release_pci_root_info(struct pci_host_bridge *bridge) > +{ > + struct pci_root_info *info = bridge->release_data; > + > + __release_pci_root_info(info); > +} > + > +static int > +probe_pci_root_info(struct pci_root_info *info, struct acpi_device *device, > + int busnum, int domain) > +{ > + char *name; > + > + name = kmalloc(16, GFP_KERNEL); > + if (!name) > + return -ENOMEM; > + > + sprintf(name, "PCI Bus %04x:%02x", domain, busnum); > + info->bridge = device; > + info->name = name; > + > + acpi_walk_resources(device->handle, METHOD_NAME__CRS, count_window, > + &info->res_num); > + if (info->res_num) { > + info->res = > + kzalloc_node(sizeof(*info->res) * info->res_num, > + GFP_KERNEL, info->controller->node); > + if (!info->res) { > + kfree(name); > + return -ENOMEM; > + } > + > + info->res_offset = > + kzalloc_node(sizeof(*info->res_offset) * info->res_num, > + GFP_KERNEL, info->controller->node); > + if (!info->res_offset) { > + kfree(name); > + kfree(info->res); > + info->res = NULL; > + return -ENOMEM; > + } > + > + info->res_num = 0; > + acpi_walk_resources(device->handle, METHOD_NAME__CRS, > + add_window, info); > + } else > + kfree(name); > + > + return 0; > +} > + > /* Root bridge scanning */ > struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root) > { > - /* TODO: Should be revisited when implementing PCI on ACPI */ > - return NULL; > + struct acpi_device *device = root->device; > + int domain = root->segment; > + int bus = root->secondary.start; > + struct pci_controller *controller; > + struct pci_root_info *info = NULL; > + int busnum = root->secondary.start; > + struct pci_bus *pbus; > + int ret; > + > + controller = alloc_pci_controller(domain); > + if (!controller) > + return NULL; > + > + controller->companion = device; > + controller->node = acpi_get_node(device->handle); > + > + info = kzalloc(sizeof(*info), GFP_KERNEL); > + if (!info) { > + dev_err(&device->dev, > + "pci_bus %04x:%02x: ignored (out of memory)\n", > + domain, busnum); > + kfree(controller); > + return NULL; > + } > + > + info->controller = controller; > + INIT_LIST_HEAD(&info->resources); > + > + ret = probe_pci_root_info(info, device, busnum, domain); > + if (ret) { > + kfree(info->controller); > + kfree(info); > + return NULL; > + } > + /* insert busn resource at first */ > + pci_add_resource(&info->resources, &root->secondary); > + > + pbus = pci_create_root_bus(NULL, bus, &pci_root_ops, controller, > + &info->resources); > + if (!pbus) { > + pci_free_resource_list(&info->resources); > + __release_pci_root_info(info); > + return NULL; > + } > + > + pci_set_host_bridge_release(to_pci_host_bridge(pbus->bridge), > + release_pci_root_info, info); > + pci_scan_child_bus(pbus); > + return pbus; > } > -#endif > +#endif /* CONFIG_ACPI */ > -- > 1.9.1 > > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/