From 3a92c319c44a7bcee9f48dff9d97d001943b54c6 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Wed, 8 Jun 2016 14:46:54 -0500 Subject: PCI: Ignore write combining when mapping I/O port space PCI exposes files like /proc/bus/pci/00/00.0 in procfs. These files support operations like this: ioctl(fd, PCIIOC_MMAP_IS_IO); # request I/O port space ioctl(fd, PCIIOC_WRITE_COMBINE, 1); # request write-combining mmap(fd, ...) Write combining is useful on PCI memory space, but I don't think it makes sense on PCI I/O port space. We *could* change proc_bus_pci_ioctl() to make it impossible to set mmap_state == pci_mmap_io and write_combine at the same time, but that would break the following sequence, which is currently legal: mmap(fd, ...) # default is I/O, non-combining ioctl(fd, PCIIOC_WRITE_COMBINE, 1); # request write-combining ioctl(fd, PCIIOC_MMAP_IS_MEM); # request memory space mmap(fd, ...) # get write-combining mapping Ignore the write-combining flag when mapping I/O port space. This patch should have no functional effect, based on this analysis of all implementations of pci_mmap_page_range(): - ia64 mips parisc sh unicore32 x86 do not support mapping of I/O port space at all. - arm cris microblaze mn10300 sparc xtensa support mapping of I/O port space, but ignore the write_combine argument to pci_mmap_page_range(). - powerpc supports mapping of I/O port space and uses write_combine, and it disables write combining for I/O port space in __pci_mmap_set_pgprot(). This patch makes it possible to remove __pci_mmap_set_pgprot() from powerpc, which simplifies that path. Signed-off-by: Bjorn Helgaas --- drivers/pci/proc.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c index 3f155e78513f..2408abe4ee8c 100644 --- a/drivers/pci/proc.c +++ b/drivers/pci/proc.c @@ -231,7 +231,7 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma) { struct pci_dev *dev = PDE_DATA(file_inode(file)); struct pci_filp_private *fpriv = file->private_data; - int i, ret; + int i, ret, write_combine; if (!capable(CAP_SYS_RAWIO)) return -EPERM; @@ -245,9 +245,12 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma) if (i >= PCI_ROM_RESOURCE) return -ENODEV; + if (fpriv->mmap_state == pci_mmap_mem) + write_combine = fpriv->write_combine; + else + write_combine = 0; ret = pci_mmap_page_range(dev, vma, - fpriv->mmap_state, - fpriv->write_combine); + fpriv->mmap_state, write_combine); if (ret < 0) return ret; -- cgit v1.2.3-58-ga151 From 644a544fd9bcd65f524768b85ab22f62ed08e107 Mon Sep 17 00:00:00 2001 From: "Koehrer Mathias (ETAS/ESW5)" Date: Tue, 7 Jun 2016 14:24:17 +0000 Subject: PCI: Extending pci=resource_alignment to specify device/vendor IDs Some uio-based PCI drivers, e.g., uio_cif do not work if the assigned PCI memory resources are not page aligned. By using the kernel option "pci=resource_alignment" it is possible to force single PCI boards to use page alignment for their memory resources. However, this is fairly cumbersome if several of these boards are in use as the specification of the cards has to be done via PCI bus/slot/function number which might change, e.g., by adding another board. Extend the kernel option "pci=resource_alignment" to allow specification of relevant devices via PCI device/vendor (and subdevice/subvendor) IDs. The specification of the devices via device/vendor is indicated by a leading string "pci:" as argument to "pci=resource_alignment". The format of the specification is pci::[::] Signed-off-by: Mathias Koehrer Signed-off-by: Bjorn Helgaas --- Documentation/kernel-parameters.txt | 2 ++ drivers/pci/pci.c | 66 ++++++++++++++++++++++++++----------- 2 files changed, 49 insertions(+), 19 deletions(-) (limited to 'drivers/pci') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 82b42c958d1c..0618cdd5707e 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2998,6 +2998,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. resource_alignment= Format: [@][:]:.[; ...] + [@]pci::\ + [::][; ...] Specifies alignment and device to reassign aligned memory resources. If is not specified, diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index c8b4dbdd1bdd..78de36f1b012 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4755,6 +4755,7 @@ static DEFINE_SPINLOCK(resource_alignment_lock); static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev) { int seg, bus, slot, func, align_order, count; + unsigned short vendor, device, subsystem_vendor, subsystem_device; resource_size_t align = 0; char *p; @@ -4768,28 +4769,55 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev) } else { align_order = -1; } - if (sscanf(p, "%x:%x:%x.%x%n", - &seg, &bus, &slot, &func, &count) != 4) { - seg = 0; - if (sscanf(p, "%x:%x.%x%n", - &bus, &slot, &func, &count) != 3) { - /* Invalid format */ - printk(KERN_ERR "PCI: Can't parse resource_alignment parameter: %s\n", - p); + if (strncmp(p, "pci:", 4) == 0) { + /* PCI vendor/device (subvendor/subdevice) ids are specified */ + p += 4; + if (sscanf(p, "%hx:%hx:%hx:%hx%n", + &vendor, &device, &subsystem_vendor, &subsystem_device, &count) != 4) { + if (sscanf(p, "%hx:%hx%n", &vendor, &device, &count) != 2) { + printk(KERN_ERR "PCI: Can't parse resource_alignment parameter: pci:%s\n", + p); + break; + } + subsystem_vendor = subsystem_device = 0; + } + p += count; + if ((!vendor || (vendor == dev->vendor)) && + (!device || (device == dev->device)) && + (!subsystem_vendor || (subsystem_vendor == dev->subsystem_vendor)) && + (!subsystem_device || (subsystem_device == dev->subsystem_device))) { + if (align_order == -1) + align = PAGE_SIZE; + else + align = 1 << align_order; + /* Found */ break; } } - p += count; - if (seg == pci_domain_nr(dev->bus) && - bus == dev->bus->number && - slot == PCI_SLOT(dev->devfn) && - func == PCI_FUNC(dev->devfn)) { - if (align_order == -1) - align = PAGE_SIZE; - else - align = 1 << align_order; - /* Found */ - break; + else { + if (sscanf(p, "%x:%x:%x.%x%n", + &seg, &bus, &slot, &func, &count) != 4) { + seg = 0; + if (sscanf(p, "%x:%x.%x%n", + &bus, &slot, &func, &count) != 3) { + /* Invalid format */ + printk(KERN_ERR "PCI: Can't parse resource_alignment parameter: %s\n", + p); + break; + } + } + p += count; + if (seg == pci_domain_nr(dev->bus) && + bus == dev->bus->number && + slot == PCI_SLOT(dev->devfn) && + func == PCI_FUNC(dev->devfn)) { + if (align_order == -1) + align = PAGE_SIZE; + else + align = 1 << align_order; + /* Found */ + break; + } } if (*p != ';' && *p != ',') { /* End of param or invalid format */ -- cgit v1.2.3-58-ga151 From 765bf9b739731b925ca26a8f05765b87f2bd9724 Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Wed, 8 Jun 2016 12:04:47 +0100 Subject: PCI: Add generic pci_bus_claim_resources() All PCI resources (bridge windows and BARs) should be inserted in the iomem_resource and ioport_resource trees so we know what space is occupied and what is available for other devices. There's nothing arch-specific about this, but it is currently done by arch-specific code. Add a generic pci_bus_claim_resources() interface so we can migrate away from the arch-specific code. [bhelgaas: changelog] Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas CC: Arnd Bergmann CC: Yinghai Lu --- drivers/pci/setup-bus.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 1 + 2 files changed, 69 insertions(+) (limited to 'drivers/pci') diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 55641a39a3e9..1d1a2c952c35 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1423,6 +1423,74 @@ void pci_bus_assign_resources(const struct pci_bus *bus) } EXPORT_SYMBOL(pci_bus_assign_resources); +static void pci_claim_device_resources(struct pci_dev *dev) +{ + int i; + + for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) { + struct resource *r = &dev->resource[i]; + + if (!r->flags || r->parent) + continue; + + pci_claim_resource(dev, i); + } +} + +static void pci_claim_bridge_resources(struct pci_dev *dev) +{ + int i; + + for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) { + struct resource *r = &dev->resource[i]; + + if (!r->flags || r->parent) + continue; + + pci_claim_bridge_resource(dev, i); + } +} + +static void pci_bus_allocate_dev_resources(struct pci_bus *b) +{ + struct pci_dev *dev; + struct pci_bus *child; + + list_for_each_entry(dev, &b->devices, bus_list) { + pci_claim_device_resources(dev); + + child = dev->subordinate; + if (child) + pci_bus_allocate_dev_resources(child); + } +} + +static void pci_bus_allocate_resources(struct pci_bus *b) +{ + struct pci_bus *child; + + /* + * Carry out a depth-first search on the PCI bus + * tree to allocate bridge apertures. Read the + * programmed bridge bases and recursively claim + * the respective bridge resources. + */ + if (b->self) { + pci_read_bridge_bases(b); + pci_claim_bridge_resources(b->self); + } + + list_for_each_entry(child, &b->children, node) + pci_bus_allocate_resources(child); +} + +void pci_bus_claim_resources(struct pci_bus *b) +{ + pci_bus_allocate_resources(b); + pci_bus_allocate_dev_resources(b); +} +EXPORT_SYMBOL(pci_bus_claim_resources); + static void __pci_bridge_assign_resources(const struct pci_dev *bridge, struct list_head *add_head, struct list_head *fail_head) diff --git a/include/linux/pci.h b/include/linux/pci.h index 6af3b93f0710..d6cfecfee864 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1114,6 +1114,7 @@ int pci_set_vpd_size(struct pci_dev *dev, size_t len); /* Helper functions for low-level code (drivers/pci/setup-[bus,res].c) */ resource_size_t pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx); void pci_bus_assign_resources(const struct pci_bus *bus); +void pci_bus_claim_resources(struct pci_bus *bus); void pci_bus_size_bridges(struct pci_bus *bus); int pci_claim_resource(struct pci_dev *, int); int pci_claim_bridge_resource(struct pci_dev *bridge, int i); -- cgit v1.2.3-58-ga151 From dcce0f153b63412291db4c5c5f714404a6e4f7a1 Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Wed, 8 Jun 2016 12:04:48 +0100 Subject: PCI: generic: Claim bus resources on PCI_PROBE_ONLY set-ups We claim PCI BAR and bridge window resources in pci_bus_assign_resources(), but when PCI_PROBE_ONLY is set, we treat those resources as immutable and don't call pci_bus_assign_resources(), so the resources aren't put in the resource tree. When the resources aren't in the tree, they don't show up in /proc/iomem, we can't detect conflicts, and we need special cases elsewhere for PCI_PROBE_ONLY or resources without a parent pointer. Claim all PCI BAR and window resources in the PCI_PROBE_ONLY case. If a PCI_PROBE_ONLY platform assigns conflicting resources, Linux can't fix the conflicts. Previously we didn't notice the conflicts, but now we will, which may expose new failures. [bhelgaas: changelog, summarize comment] Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Acked-by: Will Deacon CC: Arnd Bergmann CC: David Daney --- drivers/pci/host/pci-host-common.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'drivers/pci') diff --git a/drivers/pci/host/pci-host-common.c b/drivers/pci/host/pci-host-common.c index 8cba7ab73df9..c95d45dc5699 100644 --- a/drivers/pci/host/pci-host-common.c +++ b/drivers/pci/host/pci-host-common.c @@ -155,7 +155,14 @@ int pci_host_common_probe(struct platform_device *pdev, pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci); - if (!pci_has_flag(PCI_PROBE_ONLY)) { + /* + * We insert PCI resources into the iomem_resource and + * ioport_resource trees in either pci_bus_claim_resources() + * or pci_bus_assign_resources(). + */ + if (pci_has_flag(PCI_PROBE_ONLY)) { + pci_bus_claim_resources(bus); + } else { pci_bus_size_bridges(bus); pci_bus_assign_resources(bus); -- cgit v1.2.3-58-ga151