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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/powerpc/platforms/powernv/subcore.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/powerpc/platforms/powernv/subcore.c')
-rw-r--r--arch/powerpc/platforms/powernv/subcore.c441
1 files changed, 441 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/subcore.c b/arch/powerpc/platforms/powernv/subcore.c
new file mode 100644
index 000000000..7e98b00ea
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/subcore.c
@@ -0,0 +1,441 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2013, Michael (Ellerman|Neuling), IBM Corporation.
+ */
+
+#define pr_fmt(fmt) "powernv: " fmt
+
+#include <linux/kernel.h>
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <linux/device.h>
+#include <linux/gfp.h>
+#include <linux/smp.h>
+#include <linux/stop_machine.h>
+
+#include <asm/cputhreads.h>
+#include <asm/cpuidle.h>
+#include <asm/kvm_ppc.h>
+#include <asm/machdep.h>
+#include <asm/opal.h>
+#include <asm/smp.h>
+
+#include "subcore.h"
+#include "powernv.h"
+
+
+/*
+ * Split/unsplit procedure:
+ *
+ * A core can be in one of three states, unsplit, 2-way split, and 4-way split.
+ *
+ * The mapping to subcores_per_core is simple:
+ *
+ * State | subcores_per_core
+ * ------------|------------------
+ * Unsplit | 1
+ * 2-way split | 2
+ * 4-way split | 4
+ *
+ * The core is split along thread boundaries, the mapping between subcores and
+ * threads is as follows:
+ *
+ * Unsplit:
+ * ----------------------------
+ * Subcore | 0 |
+ * ----------------------------
+ * Thread | 0 1 2 3 4 5 6 7 |
+ * ----------------------------
+ *
+ * 2-way split:
+ * -------------------------------------
+ * Subcore | 0 | 1 |
+ * -------------------------------------
+ * Thread | 0 1 2 3 | 4 5 6 7 |
+ * -------------------------------------
+ *
+ * 4-way split:
+ * -----------------------------------------
+ * Subcore | 0 | 1 | 2 | 3 |
+ * -----------------------------------------
+ * Thread | 0 1 | 2 3 | 4 5 | 6 7 |
+ * -----------------------------------------
+ *
+ *
+ * Transitions
+ * -----------
+ *
+ * It is not possible to transition between either of the split states, the
+ * core must first be unsplit. The legal transitions are:
+ *
+ * ----------- ---------------
+ * | | <----> | 2-way split |
+ * | | ---------------
+ * | Unsplit |
+ * | | ---------------
+ * | | <----> | 4-way split |
+ * ----------- ---------------
+ *
+ * Unsplitting
+ * -----------
+ *
+ * Unsplitting is the simpler procedure. It requires thread 0 to request the
+ * unsplit while all other threads NAP.
+ *
+ * Thread 0 clears HID0_POWER8_DYNLPARDIS (Dynamic LPAR Disable). This tells
+ * the hardware that if all threads except 0 are napping, the hardware should
+ * unsplit the core.
+ *
+ * Non-zero threads are sent to a NAP loop, they don't exit the loop until they
+ * see the core unsplit.
+ *
+ * Core 0 spins waiting for the hardware to see all the other threads napping
+ * and perform the unsplit.
+ *
+ * Once thread 0 sees the unsplit, it IPIs the secondary threads to wake them
+ * out of NAP. They will then see the core unsplit and exit the NAP loop.
+ *
+ * Splitting
+ * ---------
+ *
+ * The basic splitting procedure is fairly straight forward. However it is
+ * complicated by the fact that after the split occurs, the newly created
+ * subcores are not in a fully initialised state.
+ *
+ * Most notably the subcores do not have the correct value for SDR1, which
+ * means they must not be running in virtual mode when the split occurs. The
+ * subcores have separate timebases SPRs but these are pre-synchronised by
+ * opal.
+ *
+ * To begin with secondary threads are sent to an assembly routine. There they
+ * switch to real mode, so they are immune to the uninitialised SDR1 value.
+ * Once in real mode they indicate that they are in real mode, and spin waiting
+ * to see the core split.
+ *
+ * Thread 0 waits to see that all secondaries are in real mode, and then begins
+ * the splitting procedure. It firstly sets HID0_POWER8_DYNLPARDIS, which
+ * prevents the hardware from unsplitting. Then it sets the appropriate HID bit
+ * to request the split, and spins waiting to see that the split has happened.
+ *
+ * Concurrently the secondaries will notice the split. When they do they set up
+ * their SPRs, notably SDR1, and then they can return to virtual mode and exit
+ * the procedure.
+ */
+
+/* Initialised at boot by subcore_init() */
+static int subcores_per_core;
+
+/*
+ * Used to communicate to offline cpus that we want them to pop out of the
+ * offline loop and do a split or unsplit.
+ *
+ * 0 - no split happening
+ * 1 - unsplit in progress
+ * 2 - split to 2 in progress
+ * 4 - split to 4 in progress
+ */
+static int new_split_mode;
+
+static cpumask_var_t cpu_offline_mask;
+
+struct split_state {
+ u8 step;
+ u8 master;
+};
+
+static DEFINE_PER_CPU(struct split_state, split_state);
+
+static void wait_for_sync_step(int step)
+{
+ int i, cpu = smp_processor_id();
+
+ for (i = cpu + 1; i < cpu + threads_per_core; i++)
+ while(per_cpu(split_state, i).step < step)
+ barrier();
+
+ /* Order the wait loop vs any subsequent loads/stores. */
+ mb();
+}
+
+static void update_hid_in_slw(u64 hid0)
+{
+ u64 idle_states = pnv_get_supported_cpuidle_states();
+
+ if (idle_states & OPAL_PM_WINKLE_ENABLED) {
+ /* OPAL call to patch slw with the new HID0 value */
+ u64 cpu_pir = hard_smp_processor_id();
+
+ opal_slw_set_reg(cpu_pir, SPRN_HID0, hid0);
+ }
+}
+
+static inline void update_power8_hid0(unsigned long hid0)
+{
+ /*
+ * The HID0 update on Power8 should at the very least be
+ * preceded by a SYNC instruction followed by an ISYNC
+ * instruction
+ */
+ asm volatile("sync; mtspr %0,%1; isync":: "i"(SPRN_HID0), "r"(hid0));
+}
+
+static void unsplit_core(void)
+{
+ u64 hid0, mask;
+ int i, cpu;
+
+ mask = HID0_POWER8_2LPARMODE | HID0_POWER8_4LPARMODE;
+
+ cpu = smp_processor_id();
+ if (cpu_thread_in_core(cpu) != 0) {
+ while (mfspr(SPRN_HID0) & mask)
+ power7_idle_type(PNV_THREAD_NAP);
+
+ per_cpu(split_state, cpu).step = SYNC_STEP_UNSPLIT;
+ return;
+ }
+
+ hid0 = mfspr(SPRN_HID0);
+ hid0 &= ~HID0_POWER8_DYNLPARDIS;
+ update_power8_hid0(hid0);
+ update_hid_in_slw(hid0);
+
+ while (mfspr(SPRN_HID0) & mask)
+ cpu_relax();
+
+ /* Wake secondaries out of NAP */
+ for (i = cpu + 1; i < cpu + threads_per_core; i++)
+ smp_send_reschedule(i);
+
+ wait_for_sync_step(SYNC_STEP_UNSPLIT);
+}
+
+static void split_core(int new_mode)
+{
+ struct { u64 value; u64 mask; } split_parms[2] = {
+ { HID0_POWER8_1TO2LPAR, HID0_POWER8_2LPARMODE },
+ { HID0_POWER8_1TO4LPAR, HID0_POWER8_4LPARMODE }
+ };
+ int i, cpu;
+ u64 hid0;
+
+ /* Convert new_mode (2 or 4) into an index into our parms array */
+ i = (new_mode >> 1) - 1;
+ BUG_ON(i < 0 || i > 1);
+
+ cpu = smp_processor_id();
+ if (cpu_thread_in_core(cpu) != 0) {
+ split_core_secondary_loop(&per_cpu(split_state, cpu).step);
+ return;
+ }
+
+ wait_for_sync_step(SYNC_STEP_REAL_MODE);
+
+ /* Write new mode */
+ hid0 = mfspr(SPRN_HID0);
+ hid0 |= HID0_POWER8_DYNLPARDIS | split_parms[i].value;
+ update_power8_hid0(hid0);
+ update_hid_in_slw(hid0);
+
+ /* Wait for it to happen */
+ while (!(mfspr(SPRN_HID0) & split_parms[i].mask))
+ cpu_relax();
+}
+
+static void cpu_do_split(int new_mode)
+{
+ /*
+ * At boot subcores_per_core will be 0, so we will always unsplit at
+ * boot. In the usual case where the core is already unsplit it's a
+ * nop, and this just ensures the kernel's notion of the mode is
+ * consistent with the hardware.
+ */
+ if (subcores_per_core != 1)
+ unsplit_core();
+
+ if (new_mode != 1)
+ split_core(new_mode);
+
+ mb();
+ per_cpu(split_state, smp_processor_id()).step = SYNC_STEP_FINISHED;
+}
+
+bool cpu_core_split_required(void)
+{
+ smp_rmb();
+
+ if (!new_split_mode)
+ return false;
+
+ cpu_do_split(new_split_mode);
+
+ return true;
+}
+
+void update_subcore_sibling_mask(void)
+{
+ int cpu;
+ /*
+ * sibling mask for the first cpu. Left shift this by required bits
+ * to get sibling mask for the rest of the cpus.
+ */
+ int sibling_mask_first_cpu = (1 << threads_per_subcore) - 1;
+
+ for_each_possible_cpu(cpu) {
+ int tid = cpu_thread_in_core(cpu);
+ int offset = (tid / threads_per_subcore) * threads_per_subcore;
+ int mask = sibling_mask_first_cpu << offset;
+
+ paca_ptrs[cpu]->subcore_sibling_mask = mask;
+
+ }
+}
+
+static int cpu_update_split_mode(void *data)
+{
+ int cpu, new_mode = *(int *)data;
+
+ if (this_cpu_ptr(&split_state)->master) {
+ new_split_mode = new_mode;
+ smp_wmb();
+
+ cpumask_andnot(cpu_offline_mask, cpu_present_mask,
+ cpu_online_mask);
+
+ /* This should work even though the cpu is offline */
+ for_each_cpu(cpu, cpu_offline_mask)
+ smp_send_reschedule(cpu);
+ }
+
+ cpu_do_split(new_mode);
+
+ if (this_cpu_ptr(&split_state)->master) {
+ /* Wait for all cpus to finish before we touch subcores_per_core */
+ for_each_present_cpu(cpu) {
+ if (cpu >= setup_max_cpus)
+ break;
+
+ while(per_cpu(split_state, cpu).step < SYNC_STEP_FINISHED)
+ barrier();
+ }
+
+ new_split_mode = 0;
+
+ /* Make the new mode public */
+ subcores_per_core = new_mode;
+ threads_per_subcore = threads_per_core / subcores_per_core;
+ update_subcore_sibling_mask();
+
+ /* Make sure the new mode is written before we exit */
+ mb();
+ }
+
+ return 0;
+}
+
+static int set_subcores_per_core(int new_mode)
+{
+ struct split_state *state;
+ int cpu;
+
+ if (kvm_hv_mode_active()) {
+ pr_err("Unable to change split core mode while KVM active.\n");
+ return -EBUSY;
+ }
+
+ /*
+ * We are only called at boot, or from the sysfs write. If that ever
+ * changes we'll need a lock here.
+ */
+ BUG_ON(new_mode < 1 || new_mode > 4 || new_mode == 3);
+
+ for_each_present_cpu(cpu) {
+ state = &per_cpu(split_state, cpu);
+ state->step = SYNC_STEP_INITIAL;
+ state->master = 0;
+ }
+
+ cpus_read_lock();
+
+ /* This cpu will update the globals before exiting stop machine */
+ this_cpu_ptr(&split_state)->master = 1;
+
+ /* Ensure state is consistent before we call the other cpus */
+ mb();
+
+ stop_machine_cpuslocked(cpu_update_split_mode, &new_mode,
+ cpu_online_mask);
+
+ cpus_read_unlock();
+
+ return 0;
+}
+
+static ssize_t __used store_subcores_per_core(struct device *dev,
+ struct device_attribute *attr, const char *buf,
+ size_t count)
+{
+ unsigned long val;
+ int rc;
+
+ /* We are serialised by the attribute lock */
+
+ rc = sscanf(buf, "%lx", &val);
+ if (rc != 1)
+ return -EINVAL;
+
+ switch (val) {
+ case 1:
+ case 2:
+ case 4:
+ if (subcores_per_core == val)
+ /* Nothing to do */
+ goto out;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ rc = set_subcores_per_core(val);
+ if (rc)
+ return rc;
+
+out:
+ return count;
+}
+
+static ssize_t show_subcores_per_core(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%x\n", subcores_per_core);
+}
+
+static DEVICE_ATTR(subcores_per_core, 0644,
+ show_subcores_per_core, store_subcores_per_core);
+
+static int subcore_init(void)
+{
+ unsigned pvr_ver;
+
+ pvr_ver = PVR_VER(mfspr(SPRN_PVR));
+
+ if (pvr_ver != PVR_POWER8 &&
+ pvr_ver != PVR_POWER8E &&
+ pvr_ver != PVR_POWER8NVL)
+ return 0;
+
+ /*
+ * We need all threads in a core to be present to split/unsplit so
+ * continue only if max_cpus are aligned to threads_per_core.
+ */
+ if (setup_max_cpus % threads_per_core)
+ return 0;
+
+ BUG_ON(!alloc_cpumask_var(&cpu_offline_mask, GFP_KERNEL));
+
+ set_subcores_per_core(1);
+
+ return device_create_file(cpu_subsys.dev_root,
+ &dev_attr_subcores_per_core);
+}
+machine_device_initcall(powernv, subcore_init);