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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 /mm/mmu_gather.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 'mm/mmu_gather.c')
-rw-r--r--mm/mmu_gather.c397
1 files changed, 397 insertions, 0 deletions
diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c
new file mode 100644
index 000000000..2b93cf6ac
--- /dev/null
+++ b/mm/mmu_gather.c
@@ -0,0 +1,397 @@
+#include <linux/gfp.h>
+#include <linux/highmem.h>
+#include <linux/kernel.h>
+#include <linux/mmdebug.h>
+#include <linux/mm_types.h>
+#include <linux/mm_inline.h>
+#include <linux/pagemap.h>
+#include <linux/rcupdate.h>
+#include <linux/smp.h>
+#include <linux/swap.h>
+#include <linux/rmap.h>
+
+#include <asm/pgalloc.h>
+#include <asm/tlb.h>
+
+#ifndef CONFIG_MMU_GATHER_NO_GATHER
+
+static bool tlb_next_batch(struct mmu_gather *tlb)
+{
+ struct mmu_gather_batch *batch;
+
+ /* Limit batching if we have delayed rmaps pending */
+ if (tlb->delayed_rmap && tlb->active != &tlb->local)
+ return false;
+
+ batch = tlb->active;
+ if (batch->next) {
+ tlb->active = batch->next;
+ return true;
+ }
+
+ if (tlb->batch_count == MAX_GATHER_BATCH_COUNT)
+ return false;
+
+ batch = (void *)__get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0);
+ if (!batch)
+ return false;
+
+ tlb->batch_count++;
+ batch->next = NULL;
+ batch->nr = 0;
+ batch->max = MAX_GATHER_BATCH;
+
+ tlb->active->next = batch;
+ tlb->active = batch;
+
+ return true;
+}
+
+#ifdef CONFIG_SMP
+static void tlb_flush_rmap_batch(struct mmu_gather_batch *batch, struct vm_area_struct *vma)
+{
+ for (int i = 0; i < batch->nr; i++) {
+ struct encoded_page *enc = batch->encoded_pages[i];
+
+ if (encoded_page_flags(enc)) {
+ struct page *page = encoded_page_ptr(enc);
+ page_remove_rmap(page, vma, false);
+ }
+ }
+}
+
+/**
+ * tlb_flush_rmaps - do pending rmap removals after we have flushed the TLB
+ * @tlb: the current mmu_gather
+ *
+ * Note that because of how tlb_next_batch() above works, we will
+ * never start multiple new batches with pending delayed rmaps, so
+ * we only need to walk through the current active batch and the
+ * original local one.
+ */
+void tlb_flush_rmaps(struct mmu_gather *tlb, struct vm_area_struct *vma)
+{
+ if (!tlb->delayed_rmap)
+ return;
+
+ tlb_flush_rmap_batch(&tlb->local, vma);
+ if (tlb->active != &tlb->local)
+ tlb_flush_rmap_batch(tlb->active, vma);
+ tlb->delayed_rmap = 0;
+}
+#endif
+
+static void tlb_batch_pages_flush(struct mmu_gather *tlb)
+{
+ struct mmu_gather_batch *batch;
+
+ for (batch = &tlb->local; batch && batch->nr; batch = batch->next) {
+ struct encoded_page **pages = batch->encoded_pages;
+
+ do {
+ /*
+ * limit free batch count when PAGE_SIZE > 4K
+ */
+ unsigned int nr = min(512U, batch->nr);
+
+ free_pages_and_swap_cache(pages, nr);
+ pages += nr;
+ batch->nr -= nr;
+
+ cond_resched();
+ } while (batch->nr);
+ }
+ tlb->active = &tlb->local;
+}
+
+static void tlb_batch_list_free(struct mmu_gather *tlb)
+{
+ struct mmu_gather_batch *batch, *next;
+
+ for (batch = tlb->local.next; batch; batch = next) {
+ next = batch->next;
+ free_pages((unsigned long)batch, 0);
+ }
+ tlb->local.next = NULL;
+}
+
+bool __tlb_remove_page_size(struct mmu_gather *tlb, struct encoded_page *page, int page_size)
+{
+ struct mmu_gather_batch *batch;
+
+ VM_BUG_ON(!tlb->end);
+
+#ifdef CONFIG_MMU_GATHER_PAGE_SIZE
+ VM_WARN_ON(tlb->page_size != page_size);
+#endif
+
+ batch = tlb->active;
+ /*
+ * Add the page and check if we are full. If so
+ * force a flush.
+ */
+ batch->encoded_pages[batch->nr++] = page;
+ if (batch->nr == batch->max) {
+ if (!tlb_next_batch(tlb))
+ return true;
+ batch = tlb->active;
+ }
+ VM_BUG_ON_PAGE(batch->nr > batch->max, encoded_page_ptr(page));
+
+ return false;
+}
+
+#endif /* MMU_GATHER_NO_GATHER */
+
+#ifdef CONFIG_MMU_GATHER_TABLE_FREE
+
+static void __tlb_remove_table_free(struct mmu_table_batch *batch)
+{
+ int i;
+
+ for (i = 0; i < batch->nr; i++)
+ __tlb_remove_table(batch->tables[i]);
+
+ free_page((unsigned long)batch);
+}
+
+#ifdef CONFIG_MMU_GATHER_RCU_TABLE_FREE
+
+/*
+ * Semi RCU freeing of the page directories.
+ *
+ * This is needed by some architectures to implement software pagetable walkers.
+ *
+ * gup_fast() and other software pagetable walkers do a lockless page-table
+ * walk and therefore needs some synchronization with the freeing of the page
+ * directories. The chosen means to accomplish that is by disabling IRQs over
+ * the walk.
+ *
+ * Architectures that use IPIs to flush TLBs will then automagically DTRT,
+ * since we unlink the page, flush TLBs, free the page. Since the disabling of
+ * IRQs delays the completion of the TLB flush we can never observe an already
+ * freed page.
+ *
+ * Architectures that do not have this (PPC) need to delay the freeing by some
+ * other means, this is that means.
+ *
+ * What we do is batch the freed directory pages (tables) and RCU free them.
+ * We use the sched RCU variant, as that guarantees that IRQ/preempt disabling
+ * holds off grace periods.
+ *
+ * However, in order to batch these pages we need to allocate storage, this
+ * allocation is deep inside the MM code and can thus easily fail on memory
+ * pressure. To guarantee progress we fall back to single table freeing, see
+ * the implementation of tlb_remove_table_one().
+ *
+ */
+
+static void tlb_remove_table_smp_sync(void *arg)
+{
+ /* Simply deliver the interrupt */
+}
+
+void tlb_remove_table_sync_one(void)
+{
+ /*
+ * This isn't an RCU grace period and hence the page-tables cannot be
+ * assumed to be actually RCU-freed.
+ *
+ * It is however sufficient for software page-table walkers that rely on
+ * IRQ disabling.
+ */
+ smp_call_function(tlb_remove_table_smp_sync, NULL, 1);
+}
+
+static void tlb_remove_table_rcu(struct rcu_head *head)
+{
+ __tlb_remove_table_free(container_of(head, struct mmu_table_batch, rcu));
+}
+
+static void tlb_remove_table_free(struct mmu_table_batch *batch)
+{
+ call_rcu(&batch->rcu, tlb_remove_table_rcu);
+}
+
+#else /* !CONFIG_MMU_GATHER_RCU_TABLE_FREE */
+
+static void tlb_remove_table_free(struct mmu_table_batch *batch)
+{
+ __tlb_remove_table_free(batch);
+}
+
+#endif /* CONFIG_MMU_GATHER_RCU_TABLE_FREE */
+
+/*
+ * If we want tlb_remove_table() to imply TLB invalidates.
+ */
+static inline void tlb_table_invalidate(struct mmu_gather *tlb)
+{
+ if (tlb_needs_table_invalidate()) {
+ /*
+ * Invalidate page-table caches used by hardware walkers. Then
+ * we still need to RCU-sched wait while freeing the pages
+ * because software walkers can still be in-flight.
+ */
+ tlb_flush_mmu_tlbonly(tlb);
+ }
+}
+
+static void tlb_remove_table_one(void *table)
+{
+ tlb_remove_table_sync_one();
+ __tlb_remove_table(table);
+}
+
+static void tlb_table_flush(struct mmu_gather *tlb)
+{
+ struct mmu_table_batch **batch = &tlb->batch;
+
+ if (*batch) {
+ tlb_table_invalidate(tlb);
+ tlb_remove_table_free(*batch);
+ *batch = NULL;
+ }
+}
+
+void tlb_remove_table(struct mmu_gather *tlb, void *table)
+{
+ struct mmu_table_batch **batch = &tlb->batch;
+
+ if (*batch == NULL) {
+ *batch = (struct mmu_table_batch *)__get_free_page(GFP_NOWAIT | __GFP_NOWARN);
+ if (*batch == NULL) {
+ tlb_table_invalidate(tlb);
+ tlb_remove_table_one(table);
+ return;
+ }
+ (*batch)->nr = 0;
+ }
+
+ (*batch)->tables[(*batch)->nr++] = table;
+ if ((*batch)->nr == MAX_TABLE_BATCH)
+ tlb_table_flush(tlb);
+}
+
+static inline void tlb_table_init(struct mmu_gather *tlb)
+{
+ tlb->batch = NULL;
+}
+
+#else /* !CONFIG_MMU_GATHER_TABLE_FREE */
+
+static inline void tlb_table_flush(struct mmu_gather *tlb) { }
+static inline void tlb_table_init(struct mmu_gather *tlb) { }
+
+#endif /* CONFIG_MMU_GATHER_TABLE_FREE */
+
+static void tlb_flush_mmu_free(struct mmu_gather *tlb)
+{
+ tlb_table_flush(tlb);
+#ifndef CONFIG_MMU_GATHER_NO_GATHER
+ tlb_batch_pages_flush(tlb);
+#endif
+}
+
+void tlb_flush_mmu(struct mmu_gather *tlb)
+{
+ tlb_flush_mmu_tlbonly(tlb);
+ tlb_flush_mmu_free(tlb);
+}
+
+static void __tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
+ bool fullmm)
+{
+ tlb->mm = mm;
+ tlb->fullmm = fullmm;
+
+#ifndef CONFIG_MMU_GATHER_NO_GATHER
+ tlb->need_flush_all = 0;
+ tlb->local.next = NULL;
+ tlb->local.nr = 0;
+ tlb->local.max = ARRAY_SIZE(tlb->__pages);
+ tlb->active = &tlb->local;
+ tlb->batch_count = 0;
+#endif
+ tlb->delayed_rmap = 0;
+
+ tlb_table_init(tlb);
+#ifdef CONFIG_MMU_GATHER_PAGE_SIZE
+ tlb->page_size = 0;
+#endif
+
+ __tlb_reset_range(tlb);
+ inc_tlb_flush_pending(tlb->mm);
+}
+
+/**
+ * tlb_gather_mmu - initialize an mmu_gather structure for page-table tear-down
+ * @tlb: the mmu_gather structure to initialize
+ * @mm: the mm_struct of the target address space
+ *
+ * Called to initialize an (on-stack) mmu_gather structure for page-table
+ * tear-down from @mm.
+ */
+void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm)
+{
+ __tlb_gather_mmu(tlb, mm, false);
+}
+
+/**
+ * tlb_gather_mmu_fullmm - initialize an mmu_gather structure for page-table tear-down
+ * @tlb: the mmu_gather structure to initialize
+ * @mm: the mm_struct of the target address space
+ *
+ * In this case, @mm is without users and we're going to destroy the
+ * full address space (exit/execve).
+ *
+ * Called to initialize an (on-stack) mmu_gather structure for page-table
+ * tear-down from @mm.
+ */
+void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm)
+{
+ __tlb_gather_mmu(tlb, mm, true);
+}
+
+/**
+ * tlb_finish_mmu - finish an mmu_gather structure
+ * @tlb: the mmu_gather structure to finish
+ *
+ * Called at the end of the shootdown operation to free up any resources that
+ * were required.
+ */
+void tlb_finish_mmu(struct mmu_gather *tlb)
+{
+ /*
+ * If there are parallel threads are doing PTE changes on same range
+ * under non-exclusive lock (e.g., mmap_lock read-side) but defer TLB
+ * flush by batching, one thread may end up seeing inconsistent PTEs
+ * and result in having stale TLB entries. So flush TLB forcefully
+ * if we detect parallel PTE batching threads.
+ *
+ * However, some syscalls, e.g. munmap(), may free page tables, this
+ * needs force flush everything in the given range. Otherwise this
+ * may result in having stale TLB entries for some architectures,
+ * e.g. aarch64, that could specify flush what level TLB.
+ */
+ if (mm_tlb_flush_nested(tlb->mm)) {
+ /*
+ * The aarch64 yields better performance with fullmm by
+ * avoiding multiple CPUs spamming TLBI messages at the
+ * same time.
+ *
+ * On x86 non-fullmm doesn't yield significant difference
+ * against fullmm.
+ */
+ tlb->fullmm = 1;
+ __tlb_reset_range(tlb);
+ tlb->freed_tables = 1;
+ }
+
+ tlb_flush_mmu(tlb);
+
+#ifndef CONFIG_MMU_GATHER_NO_GATHER
+ tlb_batch_list_free(tlb);
+#endif
+ dec_tlb_flush_pending(tlb->mm);
+}