+++ /dev/null
-From ed2888e906b56769b4ffabb9c577190438aa68b8 Mon Sep 17 00:00:00 2001
-From: Jon Mason <mason@myri.com>
-Date: Thu, 8 Sep 2011 16:41:18 -0500
-Subject: PCI: Remove MRRS modification from MPS setting code
-
-From: Jon Mason <mason@myri.com>
-
-commit ed2888e906b56769b4ffabb9c577190438aa68b8 upstream.
-
-Modifying the Maximum Read Request Size to 0 (value of 128Bytes) has
-massive negative ramifications on some devices. Without knowing which
-devices have this issue, do not modify from the default value when
-walking the PCI-E bus in pcie_bus_safe mode. Also, make pcie_bus_safe
-the default procedure.
-
-Tested-by: Sven Schnelle <svens@stackframe.org>
-Tested-by: Simon Kirby <sim@hostway.ca>
-Tested-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
-Reported-and-tested-by: Eric Dumazet <eric.dumazet@gmail.com>
-Reported-and-tested-by: Niels Ole Salscheider <niels_ole@salscheider-online.de>
-References: https://bugzilla.kernel.org/show_bug.cgi?id=42162
-Signed-off-by: Jon Mason <mason@myri.com>
-Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
-Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-
----
- drivers/pci/pci.c | 2 +-
- drivers/pci/probe.c | 45 ++++++++++++++++++++++++---------------------
- 2 files changed, 25 insertions(+), 22 deletions(-)
-
---- a/drivers/pci/pci.c
-+++ b/drivers/pci/pci.c
-@@ -77,7 +77,7 @@ unsigned long pci_cardbus_mem_size = DEF
- unsigned long pci_hotplug_io_size = DEFAULT_HOTPLUG_IO_SIZE;
- unsigned long pci_hotplug_mem_size = DEFAULT_HOTPLUG_MEM_SIZE;
-
--enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_PERFORMANCE;
-+enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_SAFE;
-
- /*
- * The default CLS is used if arch didn't set CLS explicitly and not
---- a/drivers/pci/probe.c
-+++ b/drivers/pci/probe.c
-@@ -1397,34 +1397,37 @@ static void pcie_write_mps(struct pci_de
-
- static void pcie_write_mrrs(struct pci_dev *dev, int mps)
- {
-- int rc, mrrs;
--
-- if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
-- int dev_mpss = 128 << dev->pcie_mpss;
--
-- /* For Max performance, the MRRS must be set to the largest
-- * supported value. However, it cannot be configured larger
-- * than the MPS the device or the bus can support. This assumes
-- * that the largest MRRS available on the device cannot be
-- * smaller than the device MPSS.
-- */
-- mrrs = mps < dev_mpss ? mps : dev_mpss;
-- } else
-- /* In the "safe" case, configure the MRRS for fairness on the
-- * bus by making all devices have the same size
-- */
-- mrrs = mps;
-+ int rc, mrrs, dev_mpss;
-
-+ /* In the "safe" case, do not configure the MRRS. There appear to be
-+ * issues with setting MRRS to 0 on a number of devices.
-+ */
-+
-+ if (pcie_bus_config != PCIE_BUS_PERFORMANCE)
-+ return;
-+
-+ dev_mpss = 128 << dev->pcie_mpss;
-+
-+ /* For Max performance, the MRRS must be set to the largest supported
-+ * value. However, it cannot be configured larger than the MPS the
-+ * device or the bus can support. This assumes that the largest MRRS
-+ * available on the device cannot be smaller than the device MPSS.
-+ */
-+ mrrs = min(mps, dev_mpss);
-
- /* MRRS is a R/W register. Invalid values can be written, but a
-- * subsiquent read will verify if the value is acceptable or not.
-+ * subsequent read will verify if the value is acceptable or not.
- * If the MRRS value provided is not acceptable (e.g., too large),
- * shrink the value until it is acceptable to the HW.
- */
- while (mrrs != pcie_get_readrq(dev) && mrrs >= 128) {
-+ dev_warn(&dev->dev, "Attempting to modify the PCI-E MRRS value"
-+ " to %d. If any issues are encountered, please try "
-+ "running with pci=pcie_bus_safe\n", mrrs);
- rc = pcie_set_readrq(dev, mrrs);
- if (rc)
-- dev_err(&dev->dev, "Failed attempting to set the MRRS\n");
-+ dev_err(&dev->dev,
-+ "Failed attempting to set the MRRS\n");
-
- mrrs /= 2;
- }
-@@ -1437,13 +1440,13 @@ static int pcie_bus_configure_set(struct
- if (!pci_is_pcie(dev))
- return 0;
-
-- dev_info(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n",
-+ dev_dbg(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n",
- pcie_get_mps(dev), 128<<dev->pcie_mpss, pcie_get_readrq(dev));
-
- pcie_write_mps(dev, mps);
- pcie_write_mrrs(dev, mps);
-
-- dev_info(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n",
-+ dev_dbg(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n",
- pcie_get_mps(dev), 128<<dev->pcie_mpss, pcie_get_readrq(dev));
-
- return 0;
+++ /dev/null
-From b03e7495a862b028294f59fc87286d6d78ee7fa1 Mon Sep 17 00:00:00 2001
-From: Jon Mason <mason@myri.com>
-Date: Wed, 20 Jul 2011 15:20:54 -0500
-Subject: PCI: Set PCI-E Max Payload Size on fabric
-
-From: Jon Mason <mason@myri.com>
-
-commit b03e7495a862b028294f59fc87286d6d78ee7fa1 upstream.
-
-On a given PCI-E fabric, each device, bridge, and root port can have a
-different PCI-E maximum payload size. There is a sizable performance
-boost for having the largest possible maximum payload size on each PCI-E
-device. However, if improperly configured, fatal bus errors can occur.
-Thus, it is important to ensure that PCI-E payloads sends by a device
-are never larger than the MPS setting of all devices on the way to the
-destination.
-
-This can be achieved two ways:
-
-- A conservative approach is to use the smallest common denominator of
- the entire tree below a root complex for every device on that fabric.
-
-This means for example that having a 128 bytes MPS USB controller on one
-leg of a switch will dramatically reduce performances of a video card or
-10GE adapter on another leg of that same switch.
-
-It also means that any hierarchy supporting hotplug slots (including
-expresscard or thunderbolt I suppose, dbl check that) will have to be
-entirely clamped to 128 bytes since we cannot predict what will be
-plugged into those slots, and we cannot change the MPS on a "live"
-system.
-
-- A more optimal way is possible, if it falls within a couple of
- constraints:
-* The top-level host bridge will never generate packets larger than the
- smallest TLP (or if it can be controlled independently from its MPS at
- least)
-* The device will never generate packets larger than MPS (which can be
- configured via MRRS)
-* No support of direct PCI-E <-> PCI-E transfers between devices without
- some additional code to specifically deal with that case
-
-Then we can use an approach that basically ignores downstream requests
-and focuses exclusively on upstream requests. In that case, all we need
-to care about is that a device MPS is no larger than its parent MPS,
-which allows us to keep all switches/bridges to the max MPS supported by
-their parent and eventually the PHB.
-
-In this case, your USB controller would no longer "starve" your 10GE
-Ethernet and your hotplug slots won't affect your global MPS.
-Additionally, the hotplugged devices themselves can be configured to a
-larger MPS up to the value configured in the hotplug bridge.
-
-To choose between the two available options, two PCI kernel boot args
-have been added to the PCI calls. "pcie_bus_safe" will provide the
-former behavior, while "pcie_bus_perf" will perform the latter behavior.
-By default, the latter behavior is used.
-
-NOTE: due to the location of the enablement, each arch will need to add
-calls to this function. This patch only enables x86.
-
-This patch includes a number of changes recommended by Benjamin
-Herrenschmidt.
-
-Tested-by: Jordan_Hargrave@dell.com
-Signed-off-by: Jon Mason <mason@myri.com>
-Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
-Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-
----
- arch/x86/pci/acpi.c | 9 ++
- drivers/pci/hotplug/pcihp_slot.c | 45 ------------
- drivers/pci/pci.c | 67 ++++++++++++++++++
- drivers/pci/probe.c | 145 +++++++++++++++++++++++++++++++++++++++
- include/linux/pci.h | 15 +++-
- 5 files changed, 236 insertions(+), 45 deletions(-)
-
---- a/arch/x86/pci/acpi.c
-+++ b/arch/x86/pci/acpi.c
-@@ -361,6 +361,15 @@ struct pci_bus * __devinit pci_acpi_scan
- }
- }
-
-+ /* After the PCI-E bus has been walked and all devices discovered,
-+ * configure any settings of the fabric that might be necessary.
-+ */
-+ if (bus) {
-+ struct pci_bus *child;
-+ list_for_each_entry(child, &bus->children, node)
-+ pcie_bus_configure_settings(child, child->self->pcie_mpss);
-+ }
-+
- if (!bus)
- kfree(sd);
-
---- a/drivers/pci/hotplug/pcihp_slot.c
-+++ b/drivers/pci/hotplug/pcihp_slot.c
-@@ -158,47 +158,6 @@ static void program_hpp_type2(struct pci
- */
- }
-
--/* Program PCIE MaxPayload setting on device: ensure parent maxpayload <= device */
--static int pci_set_payload(struct pci_dev *dev)
--{
-- int pos, ppos;
-- u16 pctl, psz;
-- u16 dctl, dsz, dcap, dmax;
-- struct pci_dev *parent;
--
-- parent = dev->bus->self;
-- pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
-- if (!pos)
-- return 0;
--
-- /* Read Device MaxPayload capability and setting */
-- pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &dctl);
-- pci_read_config_word(dev, pos + PCI_EXP_DEVCAP, &dcap);
-- dsz = (dctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5;
-- dmax = (dcap & PCI_EXP_DEVCAP_PAYLOAD);
--
-- /* Read Parent MaxPayload setting */
-- ppos = pci_find_capability(parent, PCI_CAP_ID_EXP);
-- if (!ppos)
-- return 0;
-- pci_read_config_word(parent, ppos + PCI_EXP_DEVCTL, &pctl);
-- psz = (pctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5;
--
-- /* If parent payload > device max payload -> error
-- * If parent payload > device payload -> set speed
-- * If parent payload <= device payload -> do nothing
-- */
-- if (psz > dmax)
-- return -1;
-- else if (psz > dsz) {
-- dev_info(&dev->dev, "Setting MaxPayload to %d\n", 128 << psz);
-- pci_write_config_word(dev, pos + PCI_EXP_DEVCTL,
-- (dctl & ~PCI_EXP_DEVCTL_PAYLOAD) +
-- (psz << 5));
-- }
-- return 0;
--}
--
- void pci_configure_slot(struct pci_dev *dev)
- {
- struct pci_dev *cdev;
-@@ -210,9 +169,7 @@ void pci_configure_slot(struct pci_dev *
- (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI)))
- return;
-
-- ret = pci_set_payload(dev);
-- if (ret)
-- dev_warn(&dev->dev, "could not set device max payload\n");
-+ pcie_bus_configure_settings(dev->bus, dev->bus->self->pcie_mpss);
-
- memset(&hpp, 0, sizeof(hpp));
- ret = pci_get_hp_params(dev, &hpp);
---- a/drivers/pci/pci.c
-+++ b/drivers/pci/pci.c
-@@ -77,6 +77,8 @@ unsigned long pci_cardbus_mem_size = DEF
- unsigned long pci_hotplug_io_size = DEFAULT_HOTPLUG_IO_SIZE;
- unsigned long pci_hotplug_mem_size = DEFAULT_HOTPLUG_MEM_SIZE;
-
-+enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_PERFORMANCE;
-+
- /*
- * The default CLS is used if arch didn't set CLS explicitly and not
- * all pci devices agree on the same value. Arch can override either
-@@ -3223,6 +3225,67 @@ out:
- EXPORT_SYMBOL(pcie_set_readrq);
-
- /**
-+ * pcie_get_mps - get PCI Express maximum payload size
-+ * @dev: PCI device to query
-+ *
-+ * Returns maximum payload size in bytes
-+ * or appropriate error value.
-+ */
-+int pcie_get_mps(struct pci_dev *dev)
-+{
-+ int ret, cap;
-+ u16 ctl;
-+
-+ cap = pci_pcie_cap(dev);
-+ if (!cap)
-+ return -EINVAL;
-+
-+ ret = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
-+ if (!ret)
-+ ret = 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5);
-+
-+ return ret;
-+}
-+
-+/**
-+ * pcie_set_mps - set PCI Express maximum payload size
-+ * @dev: PCI device to query
-+ * @rq: maximum payload size in bytes
-+ * valid values are 128, 256, 512, 1024, 2048, 4096
-+ *
-+ * If possible sets maximum payload size
-+ */
-+int pcie_set_mps(struct pci_dev *dev, int mps)
-+{
-+ int cap, err = -EINVAL;
-+ u16 ctl, v;
-+
-+ if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
-+ goto out;
-+
-+ v = ffs(mps) - 8;
-+ if (v > dev->pcie_mpss)
-+ goto out;
-+ v <<= 5;
-+
-+ cap = pci_pcie_cap(dev);
-+ if (!cap)
-+ goto out;
-+
-+ err = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
-+ if (err)
-+ goto out;
-+
-+ if ((ctl & PCI_EXP_DEVCTL_PAYLOAD) != v) {
-+ ctl &= ~PCI_EXP_DEVCTL_PAYLOAD;
-+ ctl |= v;
-+ err = pci_write_config_word(dev, cap + PCI_EXP_DEVCTL, ctl);
-+ }
-+out:
-+ return err;
-+}
-+
-+/**
- * pci_select_bars - Make BAR mask from the type of resource
- * @dev: the PCI device for which BAR mask is made
- * @flags: resource type mask to be selected
-@@ -3505,6 +3568,10 @@ static int __init pci_setup(char *str)
- pci_hotplug_io_size = memparse(str + 9, &str);
- } else if (!strncmp(str, "hpmemsize=", 10)) {
- pci_hotplug_mem_size = memparse(str + 10, &str);
-+ } else if (!strncmp(str, "pcie_bus_safe", 13)) {
-+ pcie_bus_config = PCIE_BUS_SAFE;
-+ } else if (!strncmp(str, "pcie_bus_perf", 13)) {
-+ pcie_bus_config = PCIE_BUS_PERFORMANCE;
- } else {
- printk(KERN_ERR "PCI: Unknown option `%s'\n",
- str);
---- a/drivers/pci/probe.c
-+++ b/drivers/pci/probe.c
-@@ -860,6 +860,8 @@ void set_pcie_port_type(struct pci_dev *
- pdev->pcie_cap = pos;
- pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, ®16);
- pdev->pcie_type = (reg16 & PCI_EXP_FLAGS_TYPE) >> 4;
-+ pci_read_config_word(pdev, pos + PCI_EXP_DEVCAP, ®16);
-+ pdev->pcie_mpss = reg16 & PCI_EXP_DEVCAP_PAYLOAD;
- }
-
- void set_pcie_hotplug_bridge(struct pci_dev *pdev)
-@@ -1327,6 +1329,149 @@ int pci_scan_slot(struct pci_bus *bus, i
- return nr;
- }
-
-+static int pcie_find_smpss(struct pci_dev *dev, void *data)
-+{
-+ u8 *smpss = data;
-+
-+ if (!pci_is_pcie(dev))
-+ return 0;
-+
-+ /* For PCIE hotplug enabled slots not connected directly to a
-+ * PCI-E root port, there can be problems when hotplugging
-+ * devices. This is due to the possibility of hotplugging a
-+ * device into the fabric with a smaller MPS that the devices
-+ * currently running have configured. Modifying the MPS on the
-+ * running devices could cause a fatal bus error due to an
-+ * incoming frame being larger than the newly configured MPS.
-+ * To work around this, the MPS for the entire fabric must be
-+ * set to the minimum size. Any devices hotplugged into this
-+ * fabric will have the minimum MPS set. If the PCI hotplug
-+ * slot is directly connected to the root port and there are not
-+ * other devices on the fabric (which seems to be the most
-+ * common case), then this is not an issue and MPS discovery
-+ * will occur as normal.
-+ */
-+ if (dev->is_hotplug_bridge && (!list_is_singular(&dev->bus->devices) ||
-+ dev->bus->self->pcie_type != PCI_EXP_TYPE_ROOT_PORT))
-+ *smpss = 0;
-+
-+ if (*smpss > dev->pcie_mpss)
-+ *smpss = dev->pcie_mpss;
-+
-+ return 0;
-+}
-+
-+static void pcie_write_mps(struct pci_dev *dev, int mps)
-+{
-+ int rc, dev_mpss;
-+
-+ dev_mpss = 128 << dev->pcie_mpss;
-+
-+ if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
-+ if (dev->bus->self) {
-+ dev_dbg(&dev->bus->dev, "Bus MPSS %d\n",
-+ 128 << dev->bus->self->pcie_mpss);
-+
-+ /* For "MPS Force Max", the assumption is made that
-+ * downstream communication will never be larger than
-+ * the MRRS. So, the MPS only needs to be configured
-+ * for the upstream communication. This being the case,
-+ * walk from the top down and set the MPS of the child
-+ * to that of the parent bus.
-+ */
-+ mps = 128 << dev->bus->self->pcie_mpss;
-+ if (mps > dev_mpss)
-+ dev_warn(&dev->dev, "MPS configured higher than"
-+ " maximum supported by the device. If"
-+ " a bus issue occurs, try running with"
-+ " pci=pcie_bus_safe.\n");
-+ }
-+
-+ dev->pcie_mpss = ffs(mps) - 8;
-+ }
-+
-+ rc = pcie_set_mps(dev, mps);
-+ if (rc)
-+ dev_err(&dev->dev, "Failed attempting to set the MPS\n");
-+}
-+
-+static void pcie_write_mrrs(struct pci_dev *dev, int mps)
-+{
-+ int rc, mrrs;
-+
-+ if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
-+ int dev_mpss = 128 << dev->pcie_mpss;
-+
-+ /* For Max performance, the MRRS must be set to the largest
-+ * supported value. However, it cannot be configured larger
-+ * than the MPS the device or the bus can support. This assumes
-+ * that the largest MRRS available on the device cannot be
-+ * smaller than the device MPSS.
-+ */
-+ mrrs = mps < dev_mpss ? mps : dev_mpss;
-+ } else
-+ /* In the "safe" case, configure the MRRS for fairness on the
-+ * bus by making all devices have the same size
-+ */
-+ mrrs = mps;
-+
-+
-+ /* MRRS is a R/W register. Invalid values can be written, but a
-+ * subsiquent read will verify if the value is acceptable or not.
-+ * If the MRRS value provided is not acceptable (e.g., too large),
-+ * shrink the value until it is acceptable to the HW.
-+ */
-+ while (mrrs != pcie_get_readrq(dev) && mrrs >= 128) {
-+ rc = pcie_set_readrq(dev, mrrs);
-+ if (rc)
-+ dev_err(&dev->dev, "Failed attempting to set the MRRS\n");
-+
-+ mrrs /= 2;
-+ }
-+}
-+
-+static int pcie_bus_configure_set(struct pci_dev *dev, void *data)
-+{
-+ int mps = 128 << *(u8 *)data;
-+
-+ if (!pci_is_pcie(dev))
-+ return 0;
-+
-+ dev_info(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n",
-+ pcie_get_mps(dev), 128<<dev->pcie_mpss, pcie_get_readrq(dev));
-+
-+ pcie_write_mps(dev, mps);
-+ pcie_write_mrrs(dev, mps);
-+
-+ dev_info(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n",
-+ pcie_get_mps(dev), 128<<dev->pcie_mpss, pcie_get_readrq(dev));
-+
-+ return 0;
-+}
-+
-+/* pcie_bus_configure_mps requires that pci_walk_bus work in a top-down,
-+ * parents then children fashion. If this changes, then this code will not
-+ * work as designed.
-+ */
-+void pcie_bus_configure_settings(struct pci_bus *bus, u8 mpss)
-+{
-+ u8 smpss = mpss;
-+
-+ if (!bus->self)
-+ return;
-+
-+ if (!pci_is_pcie(bus->self))
-+ return;
-+
-+ if (pcie_bus_config == PCIE_BUS_SAFE) {
-+ pcie_find_smpss(bus->self, &smpss);
-+ pci_walk_bus(bus, pcie_find_smpss, &smpss);
-+ }
-+
-+ pcie_bus_configure_set(bus->self, &smpss);
-+ pci_walk_bus(bus, pcie_bus_configure_set, &smpss);
-+}
-+
- unsigned int __devinit pci_scan_child_bus(struct pci_bus *bus)
- {
- unsigned int devfn, pass, max = bus->secondary;
---- a/include/linux/pci.h
-+++ b/include/linux/pci.h
-@@ -251,7 +251,8 @@ struct pci_dev {
- u8 revision; /* PCI revision, low byte of class word */
- u8 hdr_type; /* PCI header type (`multi' flag masked out) */
- u8 pcie_cap; /* PCI-E capability offset */
-- u8 pcie_type; /* PCI-E device/port type */
-+ u8 pcie_type:4; /* PCI-E device/port type */
-+ u8 pcie_mpss:3; /* PCI-E Max Payload Size Supported */
- u8 rom_base_reg; /* which config register controls the ROM */
- u8 pin; /* which interrupt pin this device uses */
-
-@@ -617,6 +618,16 @@ struct pci_driver {
- /* these external functions are only available when PCI support is enabled */
- #ifdef CONFIG_PCI
-
-+extern void pcie_bus_configure_settings(struct pci_bus *bus, u8 smpss);
-+
-+enum pcie_bus_config_types {
-+ PCIE_BUS_PERFORMANCE,
-+ PCIE_BUS_SAFE,
-+ PCIE_BUS_PEER2PEER,
-+};
-+
-+extern enum pcie_bus_config_types pcie_bus_config;
-+
- extern struct bus_type pci_bus_type;
-
- /* Do NOT directly access these two variables, unless you are arch specific pci
-@@ -796,6 +807,8 @@ int pcix_get_mmrbc(struct pci_dev *dev);
- int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc);
- int pcie_get_readrq(struct pci_dev *dev);
- int pcie_set_readrq(struct pci_dev *dev, int rq);
-+int pcie_get_mps(struct pci_dev *dev);
-+int pcie_set_mps(struct pci_dev *dev, int mps);
- int __pci_reset_function(struct pci_dev *dev);
- int pci_reset_function(struct pci_dev *dev);
- void pci_update_resource(struct pci_dev *dev, int resno);
projects / thirdparty / kernel / stable-queue.git / commitdiff
