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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 /drivers/misc/cxl/fault.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 'drivers/misc/cxl/fault.c')
-rw-r--r--drivers/misc/cxl/fault.c341
1 files changed, 341 insertions, 0 deletions
diff --git a/drivers/misc/cxl/fault.c b/drivers/misc/cxl/fault.c
new file mode 100644
index 000000000..2c64f55cf
--- /dev/null
+++ b/drivers/misc/cxl/fault.c
@@ -0,0 +1,341 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2014 IBM Corp.
+ */
+
+#include <linux/workqueue.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/mm.h>
+#include <linux/pid.h>
+#include <linux/mm.h>
+#include <linux/moduleparam.h>
+
+#undef MODULE_PARAM_PREFIX
+#define MODULE_PARAM_PREFIX "cxl" "."
+#include <asm/current.h>
+#include <asm/copro.h>
+#include <asm/mmu.h>
+
+#include "cxl.h"
+#include "trace.h"
+
+static bool sste_matches(struct cxl_sste *sste, struct copro_slb *slb)
+{
+ return ((sste->vsid_data == cpu_to_be64(slb->vsid)) &&
+ (sste->esid_data == cpu_to_be64(slb->esid)));
+}
+
+/*
+ * This finds a free SSTE for the given SLB, or returns NULL if it's already in
+ * the segment table.
+ */
+static struct cxl_sste *find_free_sste(struct cxl_context *ctx,
+ struct copro_slb *slb)
+{
+ struct cxl_sste *primary, *sste, *ret = NULL;
+ unsigned int mask = (ctx->sst_size >> 7) - 1; /* SSTP0[SegTableSize] */
+ unsigned int entry;
+ unsigned int hash;
+
+ if (slb->vsid & SLB_VSID_B_1T)
+ hash = (slb->esid >> SID_SHIFT_1T) & mask;
+ else /* 256M */
+ hash = (slb->esid >> SID_SHIFT) & mask;
+
+ primary = ctx->sstp + (hash << 3);
+
+ for (entry = 0, sste = primary; entry < 8; entry++, sste++) {
+ if (!ret && !(be64_to_cpu(sste->esid_data) & SLB_ESID_V))
+ ret = sste;
+ if (sste_matches(sste, slb))
+ return NULL;
+ }
+ if (ret)
+ return ret;
+
+ /* Nothing free, select an entry to cast out */
+ ret = primary + ctx->sst_lru;
+ ctx->sst_lru = (ctx->sst_lru + 1) & 0x7;
+
+ return ret;
+}
+
+static void cxl_load_segment(struct cxl_context *ctx, struct copro_slb *slb)
+{
+ /* mask is the group index, we search primary and secondary here. */
+ struct cxl_sste *sste;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ctx->sste_lock, flags);
+ sste = find_free_sste(ctx, slb);
+ if (!sste)
+ goto out_unlock;
+
+ pr_devel("CXL Populating SST[%li]: %#llx %#llx\n",
+ sste - ctx->sstp, slb->vsid, slb->esid);
+ trace_cxl_ste_write(ctx, sste - ctx->sstp, slb->esid, slb->vsid);
+
+ sste->vsid_data = cpu_to_be64(slb->vsid);
+ sste->esid_data = cpu_to_be64(slb->esid);
+out_unlock:
+ spin_unlock_irqrestore(&ctx->sste_lock, flags);
+}
+
+static int cxl_fault_segment(struct cxl_context *ctx, struct mm_struct *mm,
+ u64 ea)
+{
+ struct copro_slb slb = {0,0};
+ int rc;
+
+ if (!(rc = copro_calculate_slb(mm, ea, &slb))) {
+ cxl_load_segment(ctx, &slb);
+ }
+
+ return rc;
+}
+
+static void cxl_ack_ae(struct cxl_context *ctx)
+{
+ unsigned long flags;
+
+ cxl_ops->ack_irq(ctx, CXL_PSL_TFC_An_AE, 0);
+
+ spin_lock_irqsave(&ctx->lock, flags);
+ ctx->pending_fault = true;
+ ctx->fault_addr = ctx->dar;
+ ctx->fault_dsisr = ctx->dsisr;
+ spin_unlock_irqrestore(&ctx->lock, flags);
+
+ wake_up_all(&ctx->wq);
+}
+
+static int cxl_handle_segment_miss(struct cxl_context *ctx,
+ struct mm_struct *mm, u64 ea)
+{
+ int rc;
+
+ pr_devel("CXL interrupt: Segment fault pe: %i ea: %#llx\n", ctx->pe, ea);
+ trace_cxl_ste_miss(ctx, ea);
+
+ if ((rc = cxl_fault_segment(ctx, mm, ea)))
+ cxl_ack_ae(ctx);
+ else {
+
+ mb(); /* Order seg table write to TFC MMIO write */
+ cxl_ops->ack_irq(ctx, CXL_PSL_TFC_An_R, 0);
+ }
+
+ return IRQ_HANDLED;
+}
+
+int cxl_handle_mm_fault(struct mm_struct *mm, u64 dsisr, u64 dar)
+{
+ vm_fault_t flt = 0;
+ int result;
+ unsigned long access, flags, inv_flags = 0;
+
+ /*
+ * Add the fault handling cpu to task mm cpumask so that we
+ * can do a safe lockless page table walk when inserting the
+ * hash page table entry. This function get called with a
+ * valid mm for user space addresses. Hence using the if (mm)
+ * check is sufficient here.
+ */
+ if (mm && !cpumask_test_cpu(smp_processor_id(), mm_cpumask(mm))) {
+ cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
+ /*
+ * We need to make sure we walk the table only after
+ * we update the cpumask. The other side of the barrier
+ * is explained in serialize_against_pte_lookup()
+ */
+ smp_mb();
+ }
+ if ((result = copro_handle_mm_fault(mm, dar, dsisr, &flt))) {
+ pr_devel("copro_handle_mm_fault failed: %#x\n", result);
+ return result;
+ }
+
+ if (!radix_enabled()) {
+ /*
+ * update_mmu_cache() will not have loaded the hash since current->trap
+ * is not a 0x400 or 0x300, so just call hash_page_mm() here.
+ */
+ access = _PAGE_PRESENT | _PAGE_READ;
+ if (dsisr & CXL_PSL_DSISR_An_S)
+ access |= _PAGE_WRITE;
+
+ if (!mm && (get_region_id(dar) != USER_REGION_ID))
+ access |= _PAGE_PRIVILEGED;
+
+ if (dsisr & DSISR_NOHPTE)
+ inv_flags |= HPTE_NOHPTE_UPDATE;
+
+ local_irq_save(flags);
+ hash_page_mm(mm, dar, access, 0x300, inv_flags);
+ local_irq_restore(flags);
+ }
+ return 0;
+}
+
+static void cxl_handle_page_fault(struct cxl_context *ctx,
+ struct mm_struct *mm,
+ u64 dsisr, u64 dar)
+{
+ trace_cxl_pte_miss(ctx, dsisr, dar);
+
+ if (cxl_handle_mm_fault(mm, dsisr, dar)) {
+ cxl_ack_ae(ctx);
+ } else {
+ pr_devel("Page fault successfully handled for pe: %i!\n", ctx->pe);
+ cxl_ops->ack_irq(ctx, CXL_PSL_TFC_An_R, 0);
+ }
+}
+
+/*
+ * Returns the mm_struct corresponding to the context ctx.
+ * mm_users == 0, the context may be in the process of being closed.
+ */
+static struct mm_struct *get_mem_context(struct cxl_context *ctx)
+{
+ if (ctx->mm == NULL)
+ return NULL;
+
+ if (!mmget_not_zero(ctx->mm))
+ return NULL;
+
+ return ctx->mm;
+}
+
+static bool cxl_is_segment_miss(struct cxl_context *ctx, u64 dsisr)
+{
+ if ((cxl_is_power8() && (dsisr & CXL_PSL_DSISR_An_DS)))
+ return true;
+
+ return false;
+}
+
+static bool cxl_is_page_fault(struct cxl_context *ctx, u64 dsisr)
+{
+ if ((cxl_is_power8()) && (dsisr & CXL_PSL_DSISR_An_DM))
+ return true;
+
+ if (cxl_is_power9())
+ return true;
+
+ return false;
+}
+
+void cxl_handle_fault(struct work_struct *fault_work)
+{
+ struct cxl_context *ctx =
+ container_of(fault_work, struct cxl_context, fault_work);
+ u64 dsisr = ctx->dsisr;
+ u64 dar = ctx->dar;
+ struct mm_struct *mm = NULL;
+
+ if (cpu_has_feature(CPU_FTR_HVMODE)) {
+ if (cxl_p2n_read(ctx->afu, CXL_PSL_DSISR_An) != dsisr ||
+ cxl_p2n_read(ctx->afu, CXL_PSL_DAR_An) != dar ||
+ cxl_p2n_read(ctx->afu, CXL_PSL_PEHandle_An) != ctx->pe) {
+ /* Most likely explanation is harmless - a dedicated
+ * process has detached and these were cleared by the
+ * PSL purge, but warn about it just in case
+ */
+ dev_notice(&ctx->afu->dev, "cxl_handle_fault: Translation fault regs changed\n");
+ return;
+ }
+ }
+
+ /* Early return if the context is being / has been detached */
+ if (ctx->status == CLOSED) {
+ cxl_ack_ae(ctx);
+ return;
+ }
+
+ pr_devel("CXL BOTTOM HALF handling fault for afu pe: %i. "
+ "DSISR: %#llx DAR: %#llx\n", ctx->pe, dsisr, dar);
+
+ if (!ctx->kernel) {
+
+ mm = get_mem_context(ctx);
+ if (mm == NULL) {
+ pr_devel("%s: unable to get mm for pe=%d pid=%i\n",
+ __func__, ctx->pe, pid_nr(ctx->pid));
+ cxl_ack_ae(ctx);
+ return;
+ } else {
+ pr_devel("Handling page fault for pe=%d pid=%i\n",
+ ctx->pe, pid_nr(ctx->pid));
+ }
+ }
+
+ if (cxl_is_segment_miss(ctx, dsisr))
+ cxl_handle_segment_miss(ctx, mm, dar);
+ else if (cxl_is_page_fault(ctx, dsisr))
+ cxl_handle_page_fault(ctx, mm, dsisr, dar);
+ else
+ WARN(1, "cxl_handle_fault has nothing to handle\n");
+
+ if (mm)
+ mmput(mm);
+}
+
+static u64 next_segment(u64 ea, u64 vsid)
+{
+ if (vsid & SLB_VSID_B_1T)
+ ea |= (1ULL << 40) - 1;
+ else
+ ea |= (1ULL << 28) - 1;
+
+ return ea + 1;
+}
+
+static void cxl_prefault_vma(struct cxl_context *ctx, struct mm_struct *mm)
+{
+ u64 ea, last_esid = 0;
+ struct copro_slb slb;
+ VMA_ITERATOR(vmi, mm, 0);
+ struct vm_area_struct *vma;
+ int rc;
+
+ mmap_read_lock(mm);
+ for_each_vma(vmi, vma) {
+ for (ea = vma->vm_start; ea < vma->vm_end;
+ ea = next_segment(ea, slb.vsid)) {
+ rc = copro_calculate_slb(mm, ea, &slb);
+ if (rc)
+ continue;
+
+ if (last_esid == slb.esid)
+ continue;
+
+ cxl_load_segment(ctx, &slb);
+ last_esid = slb.esid;
+ }
+ }
+ mmap_read_unlock(mm);
+}
+
+void cxl_prefault(struct cxl_context *ctx, u64 wed)
+{
+ struct mm_struct *mm = get_mem_context(ctx);
+
+ if (mm == NULL) {
+ pr_devel("cxl_prefault unable to get mm %i\n",
+ pid_nr(ctx->pid));
+ return;
+ }
+
+ switch (ctx->afu->prefault_mode) {
+ case CXL_PREFAULT_WED:
+ cxl_fault_segment(ctx, mm, wed);
+ break;
+ case CXL_PREFAULT_ALL:
+ cxl_prefault_vma(ctx, mm);
+ break;
+ default:
+ break;
+ }
+
+ mmput(mm);
+}