PCI: Check pref compatible bit for mem64 resource of PCIe device

We still get "no compatible bridge window" warning on sparc T5-8
after we add support for 64bit resource parsing for root bus.

 PCI: scan_bus[/pci@300/pci@1/pci@0/pci@6] bus no 8
 PCI: Claiming 0000:00:01.0: Resource 15: 0000800100000000..00008004afffffff [220c]
 PCI: Claiming 0000:01:00.0: Resource 15: 0000800100000000..00008004afffffff [220c]
 PCI: Claiming 0000:02:04.0: Resource 15: 0000800100000000..000080012fffffff [220c]
 PCI: Claiming 0000:03:00.0: Resource 15: 0000800100000000..000080012fffffff [220c]
 PCI: Claiming 0000:04:06.0: Resource 14: 0000800100000000..000080010fffffff [220c]
 PCI: Claiming 0000:05:00.0: Resource 0: 0000800100000000..0000800100001fff [204]
 pci 0000:05:00.0: can't claim BAR 0 [mem 0x800100000000-0x800100001fff]: no compatible bridge window

All the bridges 64-bit resource have pref bit, but the device resource does not
have pref set, then we can not find parent for the device resource,
as we can not put non-pref mmio under pref mmio.

According to pcie spec errta
https://www.pcisig.com/specifications/pciexpress/base2/PCIe_Base_r2.1_Errata_08Jun10.pdf
page 13, in some case it is ok to mark some as pref.

Mark if the entire path from the host to the adapter is over PCI Express.
Set pref compatible bit for claim/sizing/assign for 64bit mem resource
on that pcie device.

-v2: set pref for mmio 64 when whole path is PCI Express, according to David Miller.
-v3: don't set pref directly, change to UNDER_PREF, and set PREF before
     sizing and assign resource, and cleart PREF afterwards. requested by BenH.
-v4: use on_all_pcie_path device flag instead.
-v6: update after pci_find_bus_resource() change

Link: http://lkml.kernel.org/r/CAE9FiQU1gJY1LYrxs+ma5LCTEEe4xmtjRG0aXJ9K_Tsu+m9Wuw@mail.gmail.com
Reported-by: David Ahern <david.ahern@oracle.com>
Tested-by: David Ahern <david.ahern@oracle.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=81431
Tested-by: TJ <linux@iam.tj>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Tested-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: sparclinux@vger.kernel.org
Orabug: 22855133

Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
(cherry picked from commit 44e098ad7113adb109fa2d95a29fe2ba9a846efd)
Signed-off-by: Allen Pais <allen.pais@oracle.com>

diff --git a/arch/sparc/kernel/pci_common.c b/arch/sparc/kernel/pci_common.c
index 1ebc7ff3e99e89efe9dc577ea18da4ec4806cd69..6f206a1d0c68058ffb9166ecbf308f8c5cf1d3d7 100644 (file)
--- a/arch/sparc/kernel/pci_common.c
+++ b/arch/sparc/kernel/pci_common.c
@@ -343,7 +343,7 @@ static void pci_register_region(struct pci_bus *bus, const char *name,
        region.start = rstart;
        region.end = rstart + size - 1UL;
        pcibios_bus_to_resource(bus, res, &region);
-       bus_res = pci_find_bus_resource(bus, res);
+       bus_res = pci_find_bus_resource(bus, res, res->flags);
        if (!bus_res) {
                kfree(res);
                return;

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 2ce0c6d8327647b9242d6231405bc145ea13cc77..eb7479929cee81267b4bd5fee6eb7b41fbcee5a2 100644 (file)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -404,7 +404,7 @@ int pci_find_ht_capability(struct pci_dev *dev, int ht_cap)
 EXPORT_SYMBOL_GPL(pci_find_ht_capability);
 
 struct resource *pci_find_bus_resource(const struct pci_bus *bus,
-                                       struct resource *res)
+                                       struct resource *res, int flags)
 {
        struct resource *r;
        int i;
@@ -419,7 +419,7 @@ struct resource *pci_find_bus_resource(const struct pci_bus *bus,
                         * not, the allocator made a mistake.
                         */
                        if (r->flags & IORESOURCE_PREFETCH &&
-                           !(res->flags & IORESOURCE_PREFETCH))
+                           !(flags & IORESOURCE_PREFETCH))
                                return NULL;
 
                        /*
@@ -447,7 +447,9 @@ struct resource *pci_find_bus_resource(const struct pci_bus *bus,
 struct resource *pci_find_parent_resource(const struct pci_dev *dev,
                                          struct resource *res)
 {
-       return pci_find_bus_resource(dev->bus, res);
+       int flags = pci_resource_pref_compatible(dev, res);
+
+       return pci_find_bus_resource(dev->bus, res, flags);
 }
 EXPORT_SYMBOL(pci_find_parent_resource);
 

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index d147dee82eeb5e3e6da7fe72ec1b5211f7893839..0573df2e866e78fac24fc6b53cb23da5eb897ff5 100644 (file)
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -325,4 +325,6 @@ static inline int pci_dev_specific_reset(struct pci_dev *dev, int probe)
 
 struct pci_host_bridge *pci_find_host_bridge(struct pci_bus *bus);
 
+int pci_resource_pref_compatible(const struct pci_dev *dev,
+                                struct resource *res);
 #endif /* DRIVERS_PCI_H */

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index f0157e2f447d9d8904999c4d861683ca03e95e6f..7d9ece4a07a04eef599ae7dcc350f65e1b3a3925 100644 (file)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1580,6 +1580,36 @@ static void pci_init_capabilities(struct pci_dev *dev)
        pci_enable_acs(dev);
 }
 
+static bool pci_up_path_over_pcie(struct pci_bus *bus)
+{
+       if (pci_is_root_bus(bus))
+               return true;
+
+       if (bus->self && !pci_is_pcie(bus->self))
+               return false;
+
+       return pci_up_path_over_pcie(bus->parent);
+}
+
+/*
+ * According to
+ * https://www.pcisig.com/specifications/pciexpress/base2/PCIe_Base_r2.1_Errata_08Jun10.pdf
+ * page 13, system firmware could put some 64bit non-pref under 64bit pref,
+ * on some cases.
+ * Let's mark if entire path from the host to the adapter is over PCI
+ * Express. later will use that compute pref compaitable bit.
+ */
+static void pci_set_on_all_pcie_path(struct pci_dev *dev)
+{
+       if (!pci_is_pcie(dev))
+               return;
+
+       if (!pci_up_path_over_pcie(dev->bus))
+               return;
+
+       dev->on_all_pcie_path = 1;
+}
+
 void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
 {
        int ret;
@@ -1610,6 +1640,9 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
        /* Initialize various capabilities */
        pci_init_capabilities(dev);
 
+       /* After pcie_cap is assigned */
+       pci_set_on_all_pcie_path(dev);
+
        /*
         * Add the device to our list of discovered devices
         * and the bus list for fixup functions, etc.

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 508cc56130e3f88d1b01716a7a00fead250fdf1c..6c43c43d5d610eda21a409b10a0df063a5f3ea06 100644 (file)
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -739,6 +739,20 @@ int pci_claim_bridge_resource(struct pci_dev *bridge, int i)
        return -EINVAL;
 }
 
+int pci_resource_pref_compatible(const struct pci_dev *dev,
+                                struct resource *res)
+{
+       if (res->flags & IORESOURCE_PREFETCH)
+               return res->flags;
+
+       if ((res->flags & IORESOURCE_MEM) &&
+           (res->flags & IORESOURCE_MEM_64) &&
+           dev->on_all_pcie_path)
+               return res->flags | IORESOURCE_PREFETCH;
+
+       return res->flags;
+}
+
 /* Check whether the bridge supports optional I/O and
    prefetchable memory ranges. If not, the respective
    base/limit registers must be read-only and read as 0. */
@@ -1036,10 +1050,11 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
                for (i = 0; i < PCI_NUM_RESOURCES; i++) {
                        struct resource *r = &dev->resource[i];
                        resource_size_t r_size;
+                       int flags = pci_resource_pref_compatible(dev, r);
 
-                       if (r->parent || ((r->flags & mask) != type &&
-                                         (r->flags & mask) != type2 &&
-                                         (r->flags & mask) != type3))
+                       if (r->parent || ((flags & mask) != type &&
+                                         (flags & mask) != type2 &&
+                                         (flags & mask) != type3))
                                continue;
                        r_size = resource_size(r);
 #ifdef CONFIG_PCI_IOV

diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 232f9254c11acf5b45d9b20f9fc4169dfad79084..b19aa5bec47e5e8bae898ade703a1aeda2e5a70d 100644 (file)
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -250,15 +250,19 @@ static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
 static int _pci_assign_resource(struct pci_dev *dev, int resno,
                                resource_size_t size, resource_size_t min_align)
 {
+       struct resource *res = dev->resource + resno;
+       int old_flags = res->flags;
        struct pci_bus *bus;
        int ret;
 
+       res->flags = pci_resource_pref_compatible(dev, res);
        bus = dev->bus;
        while ((ret = __pci_assign_resource(bus, dev, resno, size, min_align))) {
                if (!bus->parent || !bus->self->transparent)
                        break;
                bus = bus->parent;
        }
+       res->flags = old_flags;
 
        return ret;
 }

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 0301e37ae3452765eb02190e5c0c57fe1ca58232..b0563d7e7b5de77955686a4a9d10b6d94a22cefa 100644 (file)
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -311,6 +311,7 @@ struct pci_dev {
                                                   powered on/off by the
                                                   corresponding bridge */
        unsigned int    ignore_hotplug:1;       /* Ignore hotplug events */
+       unsigned int    on_all_pcie_path:1;     /* up to host-bridge all pcie */
        unsigned int    d3_delay;       /* D3->D0 transition time in ms */
        unsigned int    d3cold_delay;   /* D3cold->D0 transition time in ms */
 
@@ -787,7 +788,7 @@ void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
 void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
                             struct pci_bus_region *region);
 struct resource *pci_find_bus_resource(const struct pci_bus *bus,
-                                       struct resource *res);
+                                       struct resource *res, int flags);
 void pcibios_scan_specific_bus(int busn);
 struct pci_bus *pci_find_bus(int domain, int busnr);
 void pci_bus_add_devices(const struct pci_bus *bus);