--- /dev/null
+/* Broadcom NetXtreme-C/E network driver.
+ * *
+ * * Copyright (c) 2016-2017 Broadcom Limited
+ * *
+ * * This program is free software; you can redistribute it and/or modify
+ * * it under the terms of the GNU General Public License as published by
+ * * the Free Software Foundation.
+ * */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/pci.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/if_vlan.h>
+#include <linux/bpf.h>
+#include <linux/filter.h>
+
+#define PCI_EXP_LNKCAP2_SLS_16_0GB 0x00000010 /* Supported Speed 16GT/s */
+#define PCI_EXP_LNKCAP_SLS_16_0GB 0x00000004 /* LNKCAP2 SLS Vector bit 3 */
+#define PCI_EXP_LNKCAP_SLS_8_0GB 0x00000003 /* LNKCAP2 SLS Vector bit 2 */
+
+#define pci_info(pdev, fmt, arg...) dev_info(&(pdev)->dev, fmt, ##arg)
+
+const unsigned char pcie_link_speed[] = {
+ PCI_SPEED_UNKNOWN, /* 0 */
+ PCIE_SPEED_2_5GT, /* 1 */
+ PCIE_SPEED_5_0GT, /* 2 */
+ PCIE_SPEED_8_0GT, /* 3 */
+ PCI_SPEED_UNKNOWN, /* 4 */
+ PCI_SPEED_UNKNOWN, /* 5 */
+ PCI_SPEED_UNKNOWN, /* 6 */
+ PCI_SPEED_UNKNOWN, /* 7 */
+ PCI_SPEED_UNKNOWN, /* 8 */
+ PCI_SPEED_UNKNOWN, /* 9 */
+ PCI_SPEED_UNKNOWN, /* A */
+ PCI_SPEED_UNKNOWN, /* B */
+ PCI_SPEED_UNKNOWN, /* C */
+ PCI_SPEED_UNKNOWN, /* D */
+ PCI_SPEED_UNKNOWN, /* E */
+ PCI_SPEED_UNKNOWN /* F */
+};
+
+/* PCIe link information */
+#define PCIE_SPEED2STR(speed) \
+ ((speed) == PCIE_SPEED_8_0GT ? "8 GT/s" : \
+ (speed) == PCIE_SPEED_5_0GT ? "5 GT/s" : \
+ (speed) == PCIE_SPEED_2_5GT ? "2.5 GT/s" : \
+ "Unknown speed")
+
+/* PCIe speed to Mb/s reduced by encoding overhead */
+#define PCIE_SPEED2MBS_ENC(speed) \
+ ((speed) == PCIE_SPEED_8_0GT ? 8000*128/130 : \
+ (speed) == PCIE_SPEED_5_0GT ? 5000*8/10 : \
+ (speed) == PCIE_SPEED_2_5GT ? 2500*8/10 : \
+ 0)
+
+/**
+ * pcie_get_width_cap - query for the PCI device's link width capability
+ * @dev: PCI device to query
+ *
+ * Query the PCI device width capability. Return the maximum link width
+ * supported by the device.
+ */
+enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev)
+{
+ u32 lnkcap;
+
+ pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
+ if (lnkcap)
+ return (lnkcap & PCI_EXP_LNKCAP_MLW) >> 4;
+
+ return PCIE_LNK_WIDTH_UNKNOWN;
+}
+
+/**
+ * pcie_get_speed_cap - query for the PCI device's link speed capability
+ * @dev: PCI device to query
+ *
+ * Query the PCI device speed capability. Return the maximum link speed
+ * supported by the device.
+ */
+enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev)
+{
+ u32 lnkcap2, lnkcap;
+
+ /*
+ * PCIe r4.0 sec 7.5.3.18 recommends using the Supported Link
+ * Speeds Vector in Link Capabilities 2 when supported, falling
+ * back to Max Link Speed in Link Capabilities otherwise.
+ */
+ pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2);
+ if (lnkcap2) { /* PCIe r3.0-compliant */
+ if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB)
+ return PCIE_SPEED_8_0GT;
+ else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_5_0GB)
+ return PCIE_SPEED_5_0GT;
+ else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_2_5GB)
+ return PCIE_SPEED_2_5GT;
+ return PCI_SPEED_UNKNOWN;
+ }
+
+ pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
+ if (lnkcap) {
+ if (lnkcap & PCI_EXP_LNKCAP_SLS_8_0GB)
+ return PCIE_SPEED_8_0GT;
+ else if (lnkcap & PCI_EXP_LNKCAP_SLS_5_0GB)
+ return PCIE_SPEED_5_0GT;
+ else if (lnkcap & PCI_EXP_LNKCAP_SLS_2_5GB)
+ return PCIE_SPEED_2_5GT;
+ }
+
+ return PCI_SPEED_UNKNOWN;
+}
+
+
+/**
+ * pcie_bandwidth_capable - calculate a PCI device's link bandwidth capability
+ * @dev: PCI device
+ * @speed: storage for link speed
+ * @width: storage for link width
+ *
+ * Calculate a PCI device's link bandwidth by querying for its link speed
+ * and width, multiplying them, and applying encoding overhead. The result
+ * is in Mb/s, i.e., megabits/second of raw bandwidth.
+ */
+u32 pcie_bandwidth_capable(struct pci_dev *dev, enum pci_bus_speed *speed,
+ enum pcie_link_width *width)
+{
+ *speed = pcie_get_speed_cap(dev);
+ *width = pcie_get_width_cap(dev);
+
+ if (*speed == PCI_SPEED_UNKNOWN || *width == PCIE_LNK_WIDTH_UNKNOWN)
+ return 0;
+
+ return *width * PCIE_SPEED2MBS_ENC(*speed);
+}
+
+/**
+ * pcie_bandwidth_available - determine minimum link settings of a PCIe
+ * device and its bandwidth limitation
+ * @dev: PCI device to query
+ * @limiting_dev: storage for device causing the bandwidth limitation
+ * @speed: storage for speed of limiting device
+ * @width: storage for width of limiting device
+ *
+ * Walk up the PCI device chain and find the point where the minimum
+ * bandwidth is available. Return the bandwidth available there and (if
+ * limiting_dev, speed, and width pointers are supplied) information about
+ * that point. The bandwidth returned is in Mb/s, i.e., megabits/second of
+ * raw bandwidth.
+ */
+u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
+ enum pci_bus_speed *speed,
+ enum pcie_link_width *width)
+{
+ u16 lnksta;
+ enum pci_bus_speed next_speed;
+ enum pcie_link_width next_width;
+ u32 bw, next_bw;
+
+ if (speed)
+ *speed = PCI_SPEED_UNKNOWN;
+ if (width)
+ *width = PCIE_LNK_WIDTH_UNKNOWN;
+
+ bw = 0;
+
+ while (dev) {
+ pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
+
+ next_speed = pcie_link_speed[lnksta & PCI_EXP_LNKSTA_CLS];
+ next_width = (lnksta & PCI_EXP_LNKSTA_NLW) >>
+ PCI_EXP_LNKSTA_NLW_SHIFT;
+
+ next_bw = next_width * PCIE_SPEED2MBS_ENC(next_speed);
+
+ /* Check if current device limits the total bandwidth */
+ if (!bw || next_bw <= bw) {
+ bw = next_bw;
+
+ if (limiting_dev)
+ *limiting_dev = dev;
+ if (speed)
+ *speed = next_speed;
+ if (width)
+ *width = next_width;
+ }
+
+ dev = pci_upstream_bridge(dev);
+ }
+
+ return bw;
+}
+
+/**
+ * __pcie_print_link_status - Report the PCI device's link speed and width
+ * @dev: PCI device to query
+ * @verbose: Print info even when enough bandwidth is available
+ *
+ * If the available bandwidth at the device is less than the device is
+ * capable of, report the device's maximum possible bandwidth and the
+ * upstream link that limits its performance. If @verbose, always print
+ * the available bandwidth, even if the device isn't constrained.
+ */
+void __pcie_print_link_status(struct pci_dev *dev, bool verbose)
+{
+ enum pcie_link_width width, width_cap;
+ enum pci_bus_speed speed, speed_cap;
+ struct pci_dev *limiting_dev = NULL;
+ u32 bw_avail, bw_cap;
+
+ bw_cap = pcie_bandwidth_capable(dev, &speed_cap, &width_cap);
+ bw_avail = pcie_bandwidth_available(dev, &limiting_dev, &speed, &width);
+
+ if (bw_avail >= bw_cap && verbose)
+ pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth (%s x%d link)\n",
+ bw_cap / 1000, bw_cap % 1000,
+ PCIE_SPEED2STR(speed_cap), width_cap);
+ else if (bw_avail < bw_cap)
+ pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth, limited by %s x%d link at %s (capable of %u.%03u Gb/s with %s x%d link)\n",
+ bw_avail / 1000, bw_avail % 1000,
+ PCIE_SPEED2STR(speed), width,
+ limiting_dev ? pci_name(limiting_dev) : "<unknown>",
+ bw_cap / 1000, bw_cap % 1000,
+ PCIE_SPEED2STR(speed_cap), width_cap);
+}
+
+/**
+ * pcie_print_link_status - Report the PCI device's link speed and width
+ * @dev: PCI device to query
+ *
+ * Report the available bandwidth at the device.
+ */
+void pcie_print_link_status(struct pci_dev *dev)
+{
+ __pcie_print_link_status(dev, true);
+}
+
projects / users / jedix / linux-maple.git / commitdiff