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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /arch/x86/kernel/tsc_msr.c
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Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'arch/x86/kernel/tsc_msr.c')
-rw-r--r--arch/x86/kernel/tsc_msr.c236
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diff --git a/arch/x86/kernel/tsc_msr.c b/arch/x86/kernel/tsc_msr.c
new file mode 100644
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+++ b/arch/x86/kernel/tsc_msr.c
@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TSC frequency enumeration via MSR
+ *
+ * Copyright (C) 2013, 2018 Intel Corporation
+ * Author: Bin Gao <bin.gao@intel.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/thread_info.h>
+
+#include <asm/apic.h>
+#include <asm/cpu_device_id.h>
+#include <asm/intel-family.h>
+#include <asm/msr.h>
+#include <asm/param.h>
+#include <asm/tsc.h>
+
+#define MAX_NUM_FREQS 16 /* 4 bits to select the frequency */
+
+/*
+ * The frequency numbers in the SDM are e.g. 83.3 MHz, which does not contain a
+ * lot of accuracy which leads to clock drift. As far as we know Bay Trail SoCs
+ * use a 25 MHz crystal and Cherry Trail uses a 19.2 MHz crystal, the crystal
+ * is the source clk for a root PLL which outputs 1600 and 100 MHz. It is
+ * unclear if the root PLL outputs are used directly by the CPU clock PLL or
+ * if there is another PLL in between.
+ * This does not matter though, we can model the chain of PLLs as a single PLL
+ * with a quotient equal to the quotients of all PLLs in the chain multiplied.
+ * So we can create a simplified model of the CPU clock setup using a reference
+ * clock of 100 MHz plus a quotient which gets us as close to the frequency
+ * from the SDM as possible.
+ * For the 83.3 MHz example from above this would give us 100 MHz * 5 / 6 =
+ * 83 and 1/3 MHz, which matches exactly what has been measured on actual hw.
+ */
+#define TSC_REFERENCE_KHZ 100000
+
+struct muldiv {
+ u32 multiplier;
+ u32 divider;
+};
+
+/*
+ * If MSR_PERF_STAT[31] is set, the maximum resolved bus ratio can be
+ * read in MSR_PLATFORM_ID[12:8], otherwise in MSR_PERF_STAT[44:40].
+ * Unfortunately some Intel Atom SoCs aren't quite compliant to this,
+ * so we need manually differentiate SoC families. This is what the
+ * field use_msr_plat does.
+ */
+struct freq_desc {
+ bool use_msr_plat;
+ struct muldiv muldiv[MAX_NUM_FREQS];
+ /*
+ * Some CPU frequencies in the SDM do not map to known PLL freqs, in
+ * that case the muldiv array is empty and the freqs array is used.
+ */
+ u32 freqs[MAX_NUM_FREQS];
+ u32 mask;
+};
+
+/*
+ * Penwell and Clovertrail use spread spectrum clock,
+ * so the freq number is not exactly the same as reported
+ * by MSR based on SDM.
+ */
+static const struct freq_desc freq_desc_pnw = {
+ .use_msr_plat = false,
+ .freqs = { 0, 0, 0, 0, 0, 99840, 0, 83200 },
+ .mask = 0x07,
+};
+
+static const struct freq_desc freq_desc_clv = {
+ .use_msr_plat = false,
+ .freqs = { 0, 133200, 0, 0, 0, 99840, 0, 83200 },
+ .mask = 0x07,
+};
+
+/*
+ * Bay Trail SDM MSR_FSB_FREQ frequencies simplified PLL model:
+ * 000: 100 * 5 / 6 = 83.3333 MHz
+ * 001: 100 * 1 / 1 = 100.0000 MHz
+ * 010: 100 * 4 / 3 = 133.3333 MHz
+ * 011: 100 * 7 / 6 = 116.6667 MHz
+ * 100: 100 * 4 / 5 = 80.0000 MHz
+ */
+static const struct freq_desc freq_desc_byt = {
+ .use_msr_plat = true,
+ .muldiv = { { 5, 6 }, { 1, 1 }, { 4, 3 }, { 7, 6 },
+ { 4, 5 } },
+ .mask = 0x07,
+};
+
+/*
+ * Cherry Trail SDM MSR_FSB_FREQ frequencies simplified PLL model:
+ * 0000: 100 * 5 / 6 = 83.3333 MHz
+ * 0001: 100 * 1 / 1 = 100.0000 MHz
+ * 0010: 100 * 4 / 3 = 133.3333 MHz
+ * 0011: 100 * 7 / 6 = 116.6667 MHz
+ * 0100: 100 * 4 / 5 = 80.0000 MHz
+ * 0101: 100 * 14 / 15 = 93.3333 MHz
+ * 0110: 100 * 9 / 10 = 90.0000 MHz
+ * 0111: 100 * 8 / 9 = 88.8889 MHz
+ * 1000: 100 * 7 / 8 = 87.5000 MHz
+ */
+static const struct freq_desc freq_desc_cht = {
+ .use_msr_plat = true,
+ .muldiv = { { 5, 6 }, { 1, 1 }, { 4, 3 }, { 7, 6 },
+ { 4, 5 }, { 14, 15 }, { 9, 10 }, { 8, 9 },
+ { 7, 8 } },
+ .mask = 0x0f,
+};
+
+/*
+ * Merriefield SDM MSR_FSB_FREQ frequencies simplified PLL model:
+ * 0001: 100 * 1 / 1 = 100.0000 MHz
+ * 0010: 100 * 4 / 3 = 133.3333 MHz
+ */
+static const struct freq_desc freq_desc_tng = {
+ .use_msr_plat = true,
+ .muldiv = { { 0, 0 }, { 1, 1 }, { 4, 3 } },
+ .mask = 0x07,
+};
+
+/*
+ * Moorefield SDM MSR_FSB_FREQ frequencies simplified PLL model:
+ * 0000: 100 * 5 / 6 = 83.3333 MHz
+ * 0001: 100 * 1 / 1 = 100.0000 MHz
+ * 0010: 100 * 4 / 3 = 133.3333 MHz
+ * 0011: 100 * 1 / 1 = 100.0000 MHz
+ */
+static const struct freq_desc freq_desc_ann = {
+ .use_msr_plat = true,
+ .muldiv = { { 5, 6 }, { 1, 1 }, { 4, 3 }, { 1, 1 } },
+ .mask = 0x0f,
+};
+
+/*
+ * 24 MHz crystal? : 24 * 13 / 4 = 78 MHz
+ * Frequency step for Lightning Mountain SoC is fixed to 78 MHz,
+ * so all the frequency entries are 78000.
+ */
+static const struct freq_desc freq_desc_lgm = {
+ .use_msr_plat = true,
+ .freqs = { 78000, 78000, 78000, 78000, 78000, 78000, 78000, 78000,
+ 78000, 78000, 78000, 78000, 78000, 78000, 78000, 78000 },
+ .mask = 0x0f,
+};
+
+static const struct x86_cpu_id tsc_msr_cpu_ids[] = {
+ X86_MATCH_INTEL_FAM6_MODEL(ATOM_SALTWELL_MID, &freq_desc_pnw),
+ X86_MATCH_INTEL_FAM6_MODEL(ATOM_SALTWELL_TABLET,&freq_desc_clv),
+ X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT, &freq_desc_byt),
+ X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_MID, &freq_desc_tng),
+ X86_MATCH_INTEL_FAM6_MODEL(ATOM_AIRMONT, &freq_desc_cht),
+ X86_MATCH_INTEL_FAM6_MODEL(ATOM_AIRMONT_MID, &freq_desc_ann),
+ X86_MATCH_INTEL_FAM6_MODEL(ATOM_AIRMONT_NP, &freq_desc_lgm),
+ {}
+};
+
+/*
+ * MSR-based CPU/TSC frequency discovery for certain CPUs.
+ *
+ * Set global "lapic_timer_period" to bus_clock_cycles/jiffy
+ * Return processor base frequency in KHz, or 0 on failure.
+ */
+unsigned long cpu_khz_from_msr(void)
+{
+ u32 lo, hi, ratio, freq, tscref;
+ const struct freq_desc *freq_desc;
+ const struct x86_cpu_id *id;
+ const struct muldiv *md;
+ unsigned long res;
+ int index;
+
+ id = x86_match_cpu(tsc_msr_cpu_ids);
+ if (!id)
+ return 0;
+
+ freq_desc = (struct freq_desc *)id->driver_data;
+ if (freq_desc->use_msr_plat) {
+ rdmsr(MSR_PLATFORM_INFO, lo, hi);
+ ratio = (lo >> 8) & 0xff;
+ } else {
+ rdmsr(MSR_IA32_PERF_STATUS, lo, hi);
+ ratio = (hi >> 8) & 0x1f;
+ }
+
+ /* Get FSB FREQ ID */
+ rdmsr(MSR_FSB_FREQ, lo, hi);
+ index = lo & freq_desc->mask;
+ md = &freq_desc->muldiv[index];
+
+ /*
+ * Note this also catches cases where the index points to an unpopulated
+ * part of muldiv, in that case the else will set freq and res to 0.
+ */
+ if (md->divider) {
+ tscref = TSC_REFERENCE_KHZ * md->multiplier;
+ freq = DIV_ROUND_CLOSEST(tscref, md->divider);
+ /*
+ * Multiplying by ratio before the division has better
+ * accuracy than just calculating freq * ratio.
+ */
+ res = DIV_ROUND_CLOSEST(tscref * ratio, md->divider);
+ } else {
+ freq = freq_desc->freqs[index];
+ res = freq * ratio;
+ }
+
+ if (freq == 0)
+ pr_err("Error MSR_FSB_FREQ index %d is unknown\n", index);
+
+#ifdef CONFIG_X86_LOCAL_APIC
+ lapic_timer_period = (freq * 1000) / HZ;
+#endif
+
+ /*
+ * TSC frequency determined by MSR is always considered "known"
+ * because it is reported by HW.
+ * Another fact is that on MSR capable platforms, PIT/HPET is
+ * generally not available so calibration won't work at all.
+ */
+ setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
+
+ /*
+ * Unfortunately there is no way for hardware to tell whether the
+ * TSC is reliable. We were told by silicon design team that TSC
+ * on Atom SoCs are always "reliable". TSC is also the only
+ * reliable clocksource on these SoCs (HPET is either not present
+ * or not functional) so mark TSC reliable which removes the
+ * requirement for a watchdog clocksource.
+ */
+ setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
+
+ return res;
+}