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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/events/amd/brs.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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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/events/amd/brs.c')
-rw-r--r--arch/x86/events/amd/brs.c431
1 files changed, 431 insertions, 0 deletions
diff --git a/arch/x86/events/amd/brs.c b/arch/x86/events/amd/brs.c
new file mode 100644
index 000000000..ed3087192
--- /dev/null
+++ b/arch/x86/events/amd/brs.c
@@ -0,0 +1,431 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Implement support for AMD Fam19h Branch Sampling feature
+ * Based on specifications published in AMD PPR Fam19 Model 01
+ *
+ * Copyright 2021 Google LLC
+ * Contributed by Stephane Eranian <eranian@google.com>
+ */
+#include <linux/kernel.h>
+#include <linux/jump_label.h>
+#include <asm/msr.h>
+#include <asm/cpufeature.h>
+
+#include "../perf_event.h"
+
+#define BRS_POISON 0xFFFFFFFFFFFFFFFEULL /* mark limit of valid entries */
+
+/* Debug Extension Configuration register layout */
+union amd_debug_extn_cfg {
+ __u64 val;
+ struct {
+ __u64 rsvd0:2, /* reserved */
+ brsmen:1, /* branch sample enable */
+ rsvd4_3:2,/* reserved - must be 0x3 */
+ vb:1, /* valid branches recorded */
+ rsvd2:10, /* reserved */
+ msroff:4, /* index of next entry to write */
+ rsvd3:4, /* reserved */
+ pmc:3, /* #PMC holding the sampling event */
+ rsvd4:37; /* reserved */
+ };
+};
+
+static inline unsigned int brs_from(int idx)
+{
+ return MSR_AMD_SAMP_BR_FROM + 2 * idx;
+}
+
+static inline unsigned int brs_to(int idx)
+{
+ return MSR_AMD_SAMP_BR_FROM + 2 * idx + 1;
+}
+
+static __always_inline void set_debug_extn_cfg(u64 val)
+{
+ /* bits[4:3] must always be set to 11b */
+ __wrmsr(MSR_AMD_DBG_EXTN_CFG, val | 3ULL << 3, val >> 32);
+}
+
+static __always_inline u64 get_debug_extn_cfg(void)
+{
+ return __rdmsr(MSR_AMD_DBG_EXTN_CFG);
+}
+
+static bool __init amd_brs_detect(void)
+{
+ if (!cpu_feature_enabled(X86_FEATURE_BRS))
+ return false;
+
+ switch (boot_cpu_data.x86) {
+ case 0x19: /* AMD Fam19h (Zen3) */
+ x86_pmu.lbr_nr = 16;
+
+ /* No hardware filtering supported */
+ x86_pmu.lbr_sel_map = NULL;
+ x86_pmu.lbr_sel_mask = 0;
+ break;
+ default:
+ return false;
+ }
+
+ return true;
+}
+
+/*
+ * Current BRS implementation does not support branch type or privilege level
+ * filtering. Therefore, this function simply enforces these limitations. No need for
+ * a br_sel_map. Software filtering is not supported because it would not correlate well
+ * with a sampling period.
+ */
+static int amd_brs_setup_filter(struct perf_event *event)
+{
+ u64 type = event->attr.branch_sample_type;
+
+ /* No BRS support */
+ if (!x86_pmu.lbr_nr)
+ return -EOPNOTSUPP;
+
+ /* Can only capture all branches, i.e., no filtering */
+ if ((type & ~PERF_SAMPLE_BRANCH_PLM_ALL) != PERF_SAMPLE_BRANCH_ANY)
+ return -EINVAL;
+
+ return 0;
+}
+
+static inline int amd_is_brs_event(struct perf_event *e)
+{
+ return (e->hw.config & AMD64_RAW_EVENT_MASK) == AMD_FAM19H_BRS_EVENT;
+}
+
+int amd_brs_hw_config(struct perf_event *event)
+{
+ int ret = 0;
+
+ /*
+ * Due to interrupt holding, BRS is not recommended in
+ * counting mode.
+ */
+ if (!is_sampling_event(event))
+ return -EINVAL;
+
+ /*
+ * Due to the way BRS operates by holding the interrupt until
+ * lbr_nr entries have been captured, it does not make sense
+ * to allow sampling on BRS with an event that does not match
+ * what BRS is capturing, i.e., retired taken branches.
+ * Otherwise the correlation with the event's period is even
+ * more loose:
+ *
+ * With retired taken branch:
+ * Effective P = P + 16 + X
+ * With any other event:
+ * Effective P = P + Y + X
+ *
+ * Where X is the number of taken branches due to interrupt
+ * skid. Skid is large.
+ *
+ * Where Y is the occurences of the event while BRS is
+ * capturing the lbr_nr entries.
+ *
+ * By using retired taken branches, we limit the impact on the
+ * Y variable. We know it cannot be more than the depth of
+ * BRS.
+ */
+ if (!amd_is_brs_event(event))
+ return -EINVAL;
+
+ /*
+ * BRS implementation does not work with frequency mode
+ * reprogramming of the period.
+ */
+ if (event->attr.freq)
+ return -EINVAL;
+ /*
+ * The kernel subtracts BRS depth from period, so it must
+ * be big enough.
+ */
+ if (event->attr.sample_period <= x86_pmu.lbr_nr)
+ return -EINVAL;
+
+ /*
+ * Check if we can allow PERF_SAMPLE_BRANCH_STACK
+ */
+ ret = amd_brs_setup_filter(event);
+
+ /* only set in case of success */
+ if (!ret)
+ event->hw.flags |= PERF_X86_EVENT_AMD_BRS;
+
+ return ret;
+}
+
+/* tos = top of stack, i.e., last valid entry written */
+static inline int amd_brs_get_tos(union amd_debug_extn_cfg *cfg)
+{
+ /*
+ * msroff: index of next entry to write so top-of-stack is one off
+ * if BRS is full then msroff is set back to 0.
+ */
+ return (cfg->msroff ? cfg->msroff : x86_pmu.lbr_nr) - 1;
+}
+
+/*
+ * make sure we have a sane BRS offset to begin with
+ * especially with kexec
+ */
+void amd_brs_reset(void)
+{
+ if (!cpu_feature_enabled(X86_FEATURE_BRS))
+ return;
+
+ /*
+ * Reset config
+ */
+ set_debug_extn_cfg(0);
+
+ /*
+ * Mark first entry as poisoned
+ */
+ wrmsrl(brs_to(0), BRS_POISON);
+}
+
+int __init amd_brs_init(void)
+{
+ if (!amd_brs_detect())
+ return -EOPNOTSUPP;
+
+ pr_cont("%d-deep BRS, ", x86_pmu.lbr_nr);
+
+ return 0;
+}
+
+void amd_brs_enable(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ union amd_debug_extn_cfg cfg;
+
+ /* Activate only on first user */
+ if (++cpuc->brs_active > 1)
+ return;
+
+ cfg.val = 0; /* reset all fields */
+ cfg.brsmen = 1; /* enable branch sampling */
+
+ /* Set enable bit */
+ set_debug_extn_cfg(cfg.val);
+}
+
+void amd_brs_enable_all(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ if (cpuc->lbr_users)
+ amd_brs_enable();
+}
+
+void amd_brs_disable(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ union amd_debug_extn_cfg cfg;
+
+ /* Check if active (could be disabled via x86_pmu_disable_all()) */
+ if (!cpuc->brs_active)
+ return;
+
+ /* Only disable for last user */
+ if (--cpuc->brs_active)
+ return;
+
+ /*
+ * Clear the brsmen bit but preserve the others as they contain
+ * useful state such as vb and msroff
+ */
+ cfg.val = get_debug_extn_cfg();
+
+ /*
+ * When coming in on interrupt and BRS is full, then hw will have
+ * already stopped BRS, no need to issue wrmsr again
+ */
+ if (cfg.brsmen) {
+ cfg.brsmen = 0;
+ set_debug_extn_cfg(cfg.val);
+ }
+}
+
+void amd_brs_disable_all(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ if (cpuc->lbr_users)
+ amd_brs_disable();
+}
+
+static bool amd_brs_match_plm(struct perf_event *event, u64 to)
+{
+ int type = event->attr.branch_sample_type;
+ int plm_k = PERF_SAMPLE_BRANCH_KERNEL | PERF_SAMPLE_BRANCH_HV;
+ int plm_u = PERF_SAMPLE_BRANCH_USER;
+
+ if (!(type & plm_k) && kernel_ip(to))
+ return 0;
+
+ if (!(type & plm_u) && !kernel_ip(to))
+ return 0;
+
+ return 1;
+}
+
+/*
+ * Caller must ensure amd_brs_inuse() is true before calling
+ * return:
+ */
+void amd_brs_drain(void)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ struct perf_event *event = cpuc->events[0];
+ struct perf_branch_entry *br = cpuc->lbr_entries;
+ union amd_debug_extn_cfg cfg;
+ u32 i, nr = 0, num, tos, start;
+ u32 shift = 64 - boot_cpu_data.x86_virt_bits;
+
+ /*
+ * BRS event forced on PMC0,
+ * so check if there is an event.
+ * It is possible to have lbr_users > 0 but the event
+ * not yet scheduled due to long latency PMU irq
+ */
+ if (!event)
+ goto empty;
+
+ cfg.val = get_debug_extn_cfg();
+
+ /* Sanity check [0-x86_pmu.lbr_nr] */
+ if (WARN_ON_ONCE(cfg.msroff >= x86_pmu.lbr_nr))
+ goto empty;
+
+ /* No valid branch */
+ if (cfg.vb == 0)
+ goto empty;
+
+ /*
+ * msr.off points to next entry to be written
+ * tos = most recent entry index = msr.off - 1
+ * BRS register buffer saturates, so we know we have
+ * start < tos and that we have to read from start to tos
+ */
+ start = 0;
+ tos = amd_brs_get_tos(&cfg);
+
+ num = tos - start + 1;
+
+ /*
+ * BRS is only one pass (saturation) from MSROFF to depth-1
+ * MSROFF wraps to zero when buffer is full
+ */
+ for (i = 0; i < num; i++) {
+ u32 brs_idx = tos - i;
+ u64 from, to;
+
+ rdmsrl(brs_to(brs_idx), to);
+
+ /* Entry does not belong to us (as marked by kernel) */
+ if (to == BRS_POISON)
+ break;
+
+ /*
+ * Sign-extend SAMP_BR_TO to 64 bits, bits 61-63 are reserved.
+ * Necessary to generate proper virtual addresses suitable for
+ * symbolization
+ */
+ to = (u64)(((s64)to << shift) >> shift);
+
+ if (!amd_brs_match_plm(event, to))
+ continue;
+
+ rdmsrl(brs_from(brs_idx), from);
+
+ perf_clear_branch_entry_bitfields(br+nr);
+
+ br[nr].from = from;
+ br[nr].to = to;
+
+ nr++;
+ }
+empty:
+ /* Record number of sampled branches */
+ cpuc->lbr_stack.nr = nr;
+}
+
+/*
+ * Poison most recent entry to prevent reuse by next task
+ * required because BRS entry are not tagged by PID
+ */
+static void amd_brs_poison_buffer(void)
+{
+ union amd_debug_extn_cfg cfg;
+ unsigned int idx;
+
+ /* Get current state */
+ cfg.val = get_debug_extn_cfg();
+
+ /* idx is most recently written entry */
+ idx = amd_brs_get_tos(&cfg);
+
+ /* Poison target of entry */
+ wrmsrl(brs_to(idx), BRS_POISON);
+}
+
+/*
+ * On context switch in, we need to make sure no samples from previous user
+ * are left in the BRS.
+ *
+ * On ctxswin, sched_in = true, called after the PMU has started
+ * On ctxswout, sched_in = false, called before the PMU is stopped
+ */
+void amd_pmu_brs_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+
+ /* no active users */
+ if (!cpuc->lbr_users)
+ return;
+
+ /*
+ * On context switch in, we need to ensure we do not use entries
+ * from previous BRS user on that CPU, so we poison the buffer as
+ * a faster way compared to resetting all entries.
+ */
+ if (sched_in)
+ amd_brs_poison_buffer();
+}
+
+/*
+ * called from ACPI processor_idle.c or acpi_pad.c
+ * with interrupts disabled
+ */
+void noinstr perf_amd_brs_lopwr_cb(bool lopwr_in)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ union amd_debug_extn_cfg cfg;
+
+ /*
+ * on mwait in, we may end up in non C0 state.
+ * we must disable branch sampling to avoid holding the NMI
+ * for too long. We disable it in hardware but we
+ * keep the state in cpuc, so we can re-enable.
+ *
+ * The hardware will deliver the NMI if needed when brsmen cleared
+ */
+ if (cpuc->brs_active) {
+ cfg.val = get_debug_extn_cfg();
+ cfg.brsmen = !lopwr_in;
+ set_debug_extn_cfg(cfg.val);
+ }
+}
+
+DEFINE_STATIC_CALL_NULL(perf_lopwr_cb, perf_amd_brs_lopwr_cb);
+EXPORT_STATIC_CALL_TRAMP_GPL(perf_lopwr_cb);
+
+void __init amd_brs_lopwr_init(void)
+{
+ static_call_update(perf_lopwr_cb, perf_amd_brs_lopwr_cb);
+}