From 51c48b310183ab6ba5419edfc6a8de889cc04521 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Sat, 19 Jan 2019 11:35:04 -0600 Subject: PCI: Probe bridge window attributes once at enumeration-time pci_bridge_check_ranges() determines whether a bridge supports the optional I/O and prefetchable memory windows and sets the flag bits in the bridge resources. This *could* be done once during enumeration except that the resource allocation code completely clears the flag bits, e.g., in the pci_assign_unassigned_bridge_resources() path. The problem with pci_bridge_check_ranges() in the resource allocation path is that we may allocate resources after devices have been claimed by drivers, and pci_bridge_check_ranges() *changes* the window registers to determine whether they're writable. This may break concurrent accesses to devices behind the bridge. Add a new pci_read_bridge_windows() to determine whether a bridge supports the optional windows, call it once during enumeration, remember the results, and change pci_bridge_check_ranges() so it doesn't touch the bridge windows but sets the flag bits based on those remembered results. Link: https://lore.kernel.org/linux-pci/1506151482-113560-1-git-send-email-wangzhou1@hisilicon.com Link: https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg02082.html Reported-by: Yandong Xu Tested-by: Yandong Xu Signed-off-by: Bjorn Helgaas Cc: Michael S. Tsirkin Cc: Sagi Grimberg Cc: Ofer Hayut Cc: Roy Shterman Cc: Keith Busch Cc: Zhou Wang --- drivers/pci/probe.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++ drivers/pci/setup-bus.c | 45 ++++-------------------------------------- include/linux/pci.h | 3 +++ 3 files changed, 59 insertions(+), 41 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 257b9f6f2ebb..2ef8b954c65a 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -348,6 +348,57 @@ static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom) } } +static void pci_read_bridge_windows(struct pci_dev *bridge) +{ + u16 io; + u32 pmem, tmp; + + pci_read_config_word(bridge, PCI_IO_BASE, &io); + if (!io) { + pci_write_config_word(bridge, PCI_IO_BASE, 0xe0f0); + pci_read_config_word(bridge, PCI_IO_BASE, &io); + pci_write_config_word(bridge, PCI_IO_BASE, 0x0); + } + if (io) + bridge->io_window = 1; + + /* + * DECchip 21050 pass 2 errata: the bridge may miss an address + * disconnect boundary by one PCI data phase. Workaround: do not + * use prefetching on this device. + */ + if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001) + return; + + pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem); + if (!pmem) { + pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, + 0xffe0fff0); + pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem); + pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0); + } + if (!pmem) + return; + + bridge->pref_window = 1; + + if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) { + + /* + * Bridge claims to have a 64-bit prefetchable memory + * window; verify that the upper bits are actually + * writable. + */ + pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &pmem); + pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, + 0xffffffff); + pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp); + pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, pmem); + if (tmp) + bridge->pref_64_window = 1; + } +} + static void pci_read_bridge_io(struct pci_bus *child) { struct pci_dev *dev = child->self; @@ -1739,6 +1790,7 @@ int pci_setup_device(struct pci_dev *dev) pci_read_irq(dev); dev->transparent = ((dev->class & 0xff) == 1); pci_read_bases(dev, 2, PCI_ROM_ADDRESS1); + pci_read_bridge_windows(dev); set_pcie_hotplug_bridge(dev); pos = pci_find_capability(dev, PCI_CAP_ID_SSVID); if (pos) { diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index ed960436df5e..1941bb0a6c13 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -735,58 +735,21 @@ int pci_claim_bridge_resource(struct pci_dev *bridge, int i) base/limit registers must be read-only and read as 0. */ static void pci_bridge_check_ranges(struct pci_bus *bus) { - u16 io; - u32 pmem; struct pci_dev *bridge = bus->self; - struct resource *b_res; + struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES]; - b_res = &bridge->resource[PCI_BRIDGE_RESOURCES]; b_res[1].flags |= IORESOURCE_MEM; - pci_read_config_word(bridge, PCI_IO_BASE, &io); - if (!io) { - pci_write_config_word(bridge, PCI_IO_BASE, 0xe0f0); - pci_read_config_word(bridge, PCI_IO_BASE, &io); - pci_write_config_word(bridge, PCI_IO_BASE, 0x0); - } - if (io) + if (bridge->io_window) b_res[0].flags |= IORESOURCE_IO; - /* DECchip 21050 pass 2 errata: the bridge may miss an address - disconnect boundary by one PCI data phase. - Workaround: do not use prefetching on this device. */ - if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001) - return; - - pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem); - if (!pmem) { - pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, - 0xffe0fff0); - pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem); - pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0); - } - if (pmem) { + if (bridge->pref_window) { b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH; - if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == - PCI_PREF_RANGE_TYPE_64) { + if (bridge->pref_64_window) { b_res[2].flags |= IORESOURCE_MEM_64; b_res[2].flags |= PCI_PREF_RANGE_TYPE_64; } } - - /* double check if bridge does support 64 bit pref */ - if (b_res[2].flags & IORESOURCE_MEM_64) { - u32 mem_base_hi, tmp; - pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, - &mem_base_hi); - pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, - 0xffffffff); - pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp); - if (!tmp) - b_res[2].flags &= ~IORESOURCE_MEM_64; - pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, - mem_base_hi); - } } /* Helper function for sizing routines: find first available diff --git a/include/linux/pci.h b/include/linux/pci.h index 65f1d8c2f082..40b327b814aa 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -373,6 +373,9 @@ struct pci_dev { bool match_driver; /* Skip attaching driver */ unsigned int transparent:1; /* Subtractive decode bridge */ + unsigned int io_window:1; /* Bridge has I/O window */ + unsigned int pref_window:1; /* Bridge has pref mem window */ + unsigned int pref_64_window:1; /* Pref mem window is 64-bit */ unsigned int multifunction:1; /* Multi-function device */ unsigned int is_busmaster:1; /* Is busmaster */ -- cgit 1.4.1 From 01b37f851ca150554496fd6e79c6d9a67992a2c0 Mon Sep 17 00:00:00 2001 From: Du Changbin Date: Sat, 13 Oct 2018 08:49:19 +0800 Subject: PCI: Make pci_size() return real BAR size Currently, the pci_size() function actually returns 'size-1'. Make it return real size to avoid confusion. Signed-off-by: Du Changbin Signed-off-by: Bjorn Helgaas --- drivers/pci/probe.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 2ef8b954c65a..8e2e4154cdd9 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -121,13 +121,13 @@ static u64 pci_size(u64 base, u64 maxbase, u64 mask) * Get the lowest of them to find the decode size, and from that * the extent. */ - size = (size & ~(size-1)) - 1; + size = size & ~(size-1); /* * base == maxbase can be valid only if the BAR has already been * programmed with all 1s. */ - if (base == maxbase && ((base | size) & mask) != mask) + if (base == maxbase && ((base | (size - 1)) & mask) != mask) return 0; return size; @@ -278,7 +278,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, /* Above 32-bit boundary; try to reallocate */ res->flags |= IORESOURCE_UNSET; res->start = 0; - res->end = sz64; + res->end = sz64 - 1; pci_info(dev, "reg 0x%x: can't handle BAR above 4GB (bus address %#010llx)\n", pos, (unsigned long long)l64); goto out; @@ -286,7 +286,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, } region.start = l64; - region.end = l64 + sz64; + region.end = l64 + sz64 - 1; pcibios_bus_to_resource(dev->bus, res, ®ion); pcibios_resource_to_bus(dev->bus, &inverted_region, res); -- cgit 1.4.1 From b2fb5cc574695a32361a6c1878816b3d6563aa0f Mon Sep 17 00:00:00 2001 From: Honghui Zhang Date: Tue, 16 Oct 2018 18:44:43 +0800 Subject: PCI: Rely on config space header type, not class code The PCI configuration space header type tells us whether the device is a bridge, a CardBus bridge, or a normal device, and defines the layout of the rest of the header (PCI r3.0 sec 6.1, PCIe r4.0 sec 7.5.1.1.9). When we rely on the header format, e.g., when we're dealing with bridge windows, we should check the header type, not the class code. The class code is loosely related to the header type, but is often incorrect and the spec doesn't actually require it to be related to the header format. Suggested-by: Bjorn Helgaas Signed-off-by: Honghui Zhang [bhelgaas: changelog, keep the PCI_CLASS_BRIDGE_HOST check] Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 3 +-- drivers/pci/probe.c | 3 --- drivers/pci/setup-bus.c | 18 +++++++++--------- 3 files changed, 10 insertions(+), 14 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index c9d8e3c837de..e9d938e14ba8 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -6000,8 +6000,7 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev) * to enable the kernel to reassign new resource * window later on. */ - if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE && - (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) { + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) { r = &dev->resource[i]; if (!(r->flags & IORESOURCE_MEM)) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 8e2e4154cdd9..128459a0ffba 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1779,9 +1779,6 @@ int pci_setup_device(struct pci_dev *dev) break; case PCI_HEADER_TYPE_BRIDGE: /* bridge header */ - if (class != PCI_CLASS_BRIDGE_PCI) - goto bad; - /* * The PCI-to-PCI bridge spec requires that subtractive * decoding (i.e. transparent) bridge must have programming diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 1941bb0a6c13..ec44a0f3a7ac 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1186,12 +1186,12 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head) if (!b) continue; - switch (dev->class >> 8) { - case PCI_CLASS_BRIDGE_CARDBUS: + switch (dev->hdr_type) { + case PCI_HEADER_TYPE_CARDBUS: pci_bus_size_cardbus(b, realloc_head); break; - case PCI_CLASS_BRIDGE_PCI: + case PCI_HEADER_TYPE_BRIDGE: default: __pci_bus_size_bridges(b, realloc_head); break; @@ -1202,12 +1202,12 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head) if (pci_is_root_bus(bus)) return; - switch (bus->self->class >> 8) { - case PCI_CLASS_BRIDGE_CARDBUS: + switch (bus->self->hdr_type) { + case PCI_HEADER_TYPE_CARDBUS: /* don't size cardbuses yet. */ break; - case PCI_CLASS_BRIDGE_PCI: + case PCI_HEADER_TYPE_BRIDGE: pci_bridge_check_ranges(bus); if (bus->self->is_hotplug_bridge) { additional_io_size = pci_hotplug_io_size; @@ -1356,13 +1356,13 @@ void __pci_bus_assign_resources(const struct pci_bus *bus, __pci_bus_assign_resources(b, realloc_head, fail_head); - switch (dev->class >> 8) { - case PCI_CLASS_BRIDGE_PCI: + switch (dev->hdr_type) { + case PCI_HEADER_TYPE_BRIDGE: if (!pci_is_enabled(dev)) pci_setup_bridge(b); break; - case PCI_CLASS_BRIDGE_CARDBUS: + case PCI_HEADER_TYPE_CARDBUS: pci_setup_cardbus(b); break; -- cgit 1.4.1 From 2e095ce7b6ecce2f3e2ff330527f12056ed1e1a1 Mon Sep 17 00:00:00 2001 From: Alexander Shishkin Date: Thu, 7 Feb 2019 15:30:05 +0200 Subject: x86/PCI: Fixup RTIT_BAR of Intel Denverton Trace Hub MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On Denverton's integration of the Intel(R) Trace Hub (for a reference and overview see Documentation/trace/intel_th.rst) the reported size of one of its resources (RTIT_BAR) doesn't match its actual size, which leads to overlaps with other devices' resources. In practice, it overlaps with XHCI MMIO space, which results in the xhci driver bailing out after seeing its registers as 0xffffffff, and perceived disappearance of all USB devices: intel_th_pci 0000:00:1f.7: enabling device (0004 -> 0006) xhci_hcd 0000:00:15.0: xHCI host controller not responding, assume dead xhci_hcd 0000:00:15.0: xHC not responding in xhci_irq, assume controller is dead xhci_hcd 0000:00:15.0: HC died; cleaning up usb 1-1: USB disconnect, device number 2 For this reason, we need to resize the RTIT_BAR on Denverton to its actual size, which in this case is 4MB. The corresponding erratum is DNV36 at the link below: DNV36. Processor Host Root Complex May Incorrectly Route Memory Accesses to Intel® Trace Hub Problem: The Intel® Trace Hub RTIT_BAR (B0:D31:F7 offset 20h) is reported as a 2KB memory range. Due to this erratum, the processor Host Root Complex will forward addresses from RTIT_BAR to RTIT_BAR + 4MB -1 to Intel® Trace Hub. Implication: Devices assigned within the RTIT_BAR to RTIT_BAR + 4MB -1 space may not function correctly. Workaround: A BIOS code change has been identified and may be implemented as a workaround for this erratum. Status: No Fix. Note that 5118ccd34780 ("intel_th: pci: Add Denverton SOC support") updates the Trace Hub driver so it claims the Denverton device, but the resource overlap exists regardless of whether that driver is loaded or that commit is included. Link: https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/atom-c3000-family-spec-update.pdf Signed-off-by: Alexander Shishkin [bhelgaas: include erratum text, clarify relationship with 5118ccd34780] Signed-off-by: Bjorn Helgaas Cc: stable@vger.kernel.org --- arch/x86/pci/fixup.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c index 30a5111ae5fd..527e69b12002 100644 --- a/arch/x86/pci/fixup.c +++ b/arch/x86/pci/fixup.c @@ -635,6 +635,22 @@ static void quirk_no_aersid(struct pci_dev *pdev) DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, PCI_CLASS_BRIDGE_PCI, 8, quirk_no_aersid); +static void quirk_intel_th_dnv(struct pci_dev *dev) +{ + struct resource *r = &dev->resource[4]; + + /* + * Denverton reports 2k of RTIT_BAR (intel_th resource 4), which + * appears to be 4 MB in reality. + */ + if (r->end == r->start + 0x7ff) { + r->start = 0; + r->end = 0x3fffff; + r->flags |= IORESOURCE_UNSET; + } +} +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x19e1, quirk_intel_th_dnv); + #ifdef CONFIG_PHYS_ADDR_T_64BIT #define AMD_141b_MMIO_BASE(x) (0x80 + (x) * 0x8) -- cgit 1.4.1