PCI: Set under_pref 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 mem under pref mem.

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.

Only set pref for 64bit mmio when the entire path from the host to the adapter is
over PCI Express.

Fixes: commit d63e2e1f3df9 ("sparc/PCI: Clip bridge windows to fit in upstream windows")
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>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc:  <stable@vger.kernel.org> #3.19
(cherry picked from commit ab88cbba3f034f6b2da122280a8000b02fc841dd)

diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index 6fbd3f2b5992a2cdd53c759147629292463789fd..8bc5f0637362144323756c92c6b489411a95abbd 100644 (file)
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -139,6 +139,8 @@ static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
 
        type_mask |= IORESOURCE_TYPE_BITS;
 
+       pci_set_pref_under_pref(res);
+
        pci_bus_for_each_resource(bus, r, i) {
                if (!r)
                        continue;
@@ -170,9 +172,14 @@ static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
                /* Ok, try it out.. */
                ret = allocate_resource(r, res, size, min, max,
                                        align, alignf, alignf_data);
-               if (ret == 0)
+               if (ret == 0) {
+                       pci_clear_pref_under_pref(res);
                        return 0;
+               }
        }
+
+       pci_clear_pref_under_pref(res);
+
        return -ENOMEM;
 }
 

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 9bd762c237abe2fd679e8c7163947c7a0453c46b..53f6c470c97c8a05fe5423a9d2dc992ffcaae65e 100644 (file)
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -216,6 +216,17 @@ void __pci_bus_assign_resources(const struct pci_bus *bus,
                                struct list_head *fail_head);
 bool pci_bus_clip_resource(struct pci_dev *dev, int idx);
 
+static inline void pci_set_pref_under_pref(struct resource *res)
+{
+       if (res->flags & IORESOURCE_UNDER_PREF)
+               res->flags |= IORESOURCE_PREFETCH;
+}
+static inline void pci_clear_pref_under_pref(struct resource *res)
+{
+       if (res->flags & IORESOURCE_UNDER_PREF)
+               res->flags &= ~IORESOURCE_PREFETCH;
+}
+
 /**
  * pci_ari_enabled - query ARI forwarding status
  * @bus: the PCI bus

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index c91185721345b65f3e915a6539186f138c21781e..4b76731bf836e1e0dbc69f2f94e8c90701db5118 100644 (file)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1508,6 +1508,53 @@ 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 (!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 set pref bit for 64bit mmio when entire path from the host to
+ * the adapter is over PCI Express.
+ */
+static void set_pcie_64bit_under_pref(struct pci_dev *dev)
+{
+       int i;
+
+       if (!pci_is_pcie(dev))
+               return;
+
+       if (!pci_up_path_over_pcie(dev->bus))
+               return;
+
+       for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) {
+               struct resource *res = &dev->resource[i];
+               enum pci_bar_type type;
+               int reg;
+
+               if (!(res->flags & IORESOURCE_MEM_64))
+                       continue;
+
+               if (res->flags & IORESOURCE_PREFETCH)
+                       continue;
+
+               reg = pci_resource_bar(dev, i, &type);
+               dev_printk(KERN_DEBUG, &dev->dev, "reg 0x%x %pR + under_pref\n",
+                          reg, res);
+               res->flags |= IORESOURCE_UNDER_PREF;
+       }
+}
+
 void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
 {
        int ret;
@@ -1538,6 +1585,9 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
        /* Initialize various capabilities */
        pci_init_capabilities(dev);
 
+       /* After pcie_cap is assigned and sriov bar is probed */
+       set_pcie_64bit_under_pref(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..b2c780485a76fb123f6c4cf5945e292aa17e9e62 100644 (file)
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1037,10 +1037,13 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
                        struct resource *r = &dev->resource[i];
                        resource_size_t r_size;
 
+                       pci_set_pref_under_pref(r);
                        if (r->parent || ((r->flags & mask) != type &&
                                          (r->flags & mask) != type2 &&
-                                         (r->flags & mask) != type3))
+                                         (r->flags & mask) != type3)) {
+                               pci_clear_pref_under_pref(r);
                                continue;
+                       }
                        r_size = resource_size(r);
 #ifdef CONFIG_PCI_IOV
                        /* put SRIOV requested res to the optional list */
@@ -1050,6 +1053,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
                                r->end = r->start - 1;
                                add_to_list(realloc_head, dev, r, r_size, 0/* don't care */);
                                children_add_size += r_size;
+                               pci_clear_pref_under_pref(r);
                                continue;
                        }
 #endif
@@ -1082,6 +1086,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
                                children_add_align = get_res_add_align(realloc_head, r);
                                add_align = max(add_align, children_add_align);
                        }
+                       pci_clear_pref_under_pref(r);
                }
        }
 

diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 232f9254c11acf5b45d9b20f9fc4169dfad79084..a385b00320c67a84c4b94de6846a0670f94c82d0 100644 (file)
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -116,11 +116,14 @@ int pci_claim_resource(struct pci_dev *dev, int resource)
                return -EINVAL;
        }
 
+       pci_set_pref_under_pref(res);
+
        root = pci_find_parent_resource(dev, res);
        if (!root) {
                dev_info(&dev->dev, "can't claim BAR %d %pR: no compatible bridge window\n",
                         resource, res);
                res->flags |= IORESOURCE_UNSET;
+               pci_clear_pref_under_pref(res);
                return -EINVAL;
        }
 
@@ -129,9 +132,12 @@ int pci_claim_resource(struct pci_dev *dev, int resource)
                dev_info(&dev->dev, "can't claim BAR %d %pR: address conflict with %s %pR\n",
                         resource, res, conflict->name, conflict);
                res->flags |= IORESOURCE_UNSET;
+               pci_clear_pref_under_pref(res);
                return -EBUSY;
        }
 
+       pci_clear_pref_under_pref(res);
+
        return 0;
 }
 EXPORT_SYMBOL(pci_claim_resource);
@@ -250,9 +256,11 @@ 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;
        struct pci_bus *bus;
        int ret;
 
+       pci_set_pref_under_pref(res);
        bus = dev->bus;
        while ((ret = __pci_assign_resource(bus, dev, resno, size, min_align))) {
                if (!bus->parent || !bus->self->transparent)
@@ -260,6 +268,8 @@ static int _pci_assign_resource(struct pci_dev *dev, int resno,
                bus = bus->parent;
        }
 
+       pci_clear_pref_under_pref(res);
+
        return ret;
 }
 

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 388e3ae94f7a3b1c3c86d7ba45d6f9227ee31f0d..ec7451e175a7d66c70cf4efc6144ac86c585118e 100644 (file)
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -49,6 +49,8 @@ struct resource {
 #define IORESOURCE_WINDOW      0x00200000      /* forwarded by bridge */
 #define IORESOURCE_MUXED       0x00400000      /* Resource is software muxed */
 
+#define IORESOURCE_UNDER_PREF  0x00800000      /* non-pref could under pref */
+
 #define IORESOURCE_EXCLUSIVE   0x08000000      /* Userland may not map this resource */
 #define IORESOURCE_DISABLED    0x10000000
 #define IORESOURCE_UNSET       0x20000000      /* No address assigned yet */