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().
  ...

1 files changed, 814 insertions, 0 deletions

diff --git a/mm/highmem.c b/mm/highmem.c
new file mode 100644
index 000000000..db251e77f
--- /dev/null
+++ b/mm/highmem.c
@@ -0,0 +1,814 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * High memory handling common code and variables.
+ *
+ * (C) 1999 Andrea Arcangeli, SuSE GmbH, andrea@suse.de
+ *          Gerhard Wichert, Siemens AG, Gerhard.Wichert@pdb.siemens.de
+ *
+ *
+ * Redesigned the x86 32-bit VM architecture to deal with
+ * 64-bit physical space. With current x86 CPUs this
+ * means up to 64 Gigabytes physical RAM.
+ *
+ * Rewrote high memory support to move the page cache into
+ * high memory. Implemented permanent (schedulable) kmaps
+ * based on Linus' idea.
+ *
+ * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
+ */
+
+#include <linux/mm.h>
+#include <linux/export.h>
+#include <linux/swap.h>
+#include <linux/bio.h>
+#include <linux/pagemap.h>
+#include <linux/mempool.h>
+#include <linux/init.h>
+#include <linux/hash.h>
+#include <linux/highmem.h>
+#include <linux/kgdb.h>
+#include <asm/tlbflush.h>
+#include <linux/vmalloc.h>
+
+#ifdef CONFIG_KMAP_LOCAL
+static inline int kmap_local_calc_idx(int idx)
+{
+	return idx + KM_MAX_IDX * smp_processor_id();
+}
+
+#ifndef arch_kmap_local_map_idx
+#define arch_kmap_local_map_idx(idx, pfn)	kmap_local_calc_idx(idx)
+#endif
+#endif /* CONFIG_KMAP_LOCAL */
+
+/*
+ * Virtual_count is not a pure "count".
+ *  0 means that it is not mapped, and has not been mapped
+ *    since a TLB flush - it is usable.
+ *  1 means that there are no users, but it has been mapped
+ *    since the last TLB flush - so we can't use it.
+ *  n means that there are (n-1) current users of it.
+ */
+#ifdef CONFIG_HIGHMEM
+
+/*
+ * Architecture with aliasing data cache may define the following family of
+ * helper functions in its asm/highmem.h to control cache color of virtual
+ * addresses where physical memory pages are mapped by kmap.
+ */
+#ifndef get_pkmap_color
+
+/*
+ * Determine color of virtual address where the page should be mapped.
+ */
+static inline unsigned int get_pkmap_color(struct page *page)
+{
+	return 0;
+}
+#define get_pkmap_color get_pkmap_color
+
+/*
+ * Get next index for mapping inside PKMAP region for page with given color.
+ */
+static inline unsigned int get_next_pkmap_nr(unsigned int color)
+{
+	static unsigned int last_pkmap_nr;
+
+	last_pkmap_nr = (last_pkmap_nr + 1) & LAST_PKMAP_MASK;
+	return last_pkmap_nr;
+}
+
+/*
+ * Determine if page index inside PKMAP region (pkmap_nr) of given color
+ * has wrapped around PKMAP region end. When this happens an attempt to
+ * flush all unused PKMAP slots is made.
+ */
+static inline int no_more_pkmaps(unsigned int pkmap_nr, unsigned int color)
+{
+	return pkmap_nr == 0;
+}
+
+/*
+ * Get the number of PKMAP entries of the given color. If no free slot is
+ * found after checking that many entries, kmap will sleep waiting for
+ * someone to call kunmap and free PKMAP slot.
+ */
+static inline int get_pkmap_entries_count(unsigned int color)
+{
+	return LAST_PKMAP;
+}
+
+/*
+ * Get head of a wait queue for PKMAP entries of the given color.
+ * Wait queues for different mapping colors should be independent to avoid
+ * unnecessary wakeups caused by freeing of slots of other colors.
+ */
+static inline wait_queue_head_t *get_pkmap_wait_queue_head(unsigned int color)
+{
+	static DECLARE_WAIT_QUEUE_HEAD(pkmap_map_wait);
+
+	return &pkmap_map_wait;
+}
+#endif
+
+atomic_long_t _totalhigh_pages __read_mostly;
+EXPORT_SYMBOL(_totalhigh_pages);
+
+unsigned int __nr_free_highpages(void)
+{
+	struct zone *zone;
+	unsigned int pages = 0;
+
+	for_each_populated_zone(zone) {
+		if (is_highmem(zone))
+			pages += zone_page_state(zone, NR_FREE_PAGES);
+	}
+
+	return pages;
+}
+
+static int pkmap_count[LAST_PKMAP];
+static  __cacheline_aligned_in_smp DEFINE_SPINLOCK(kmap_lock);
+
+pte_t *pkmap_page_table;
+
+/*
+ * Most architectures have no use for kmap_high_get(), so let's abstract
+ * the disabling of IRQ out of the locking in that case to save on a
+ * potential useless overhead.
+ */
+#ifdef ARCH_NEEDS_KMAP_HIGH_GET
+#define lock_kmap()             spin_lock_irq(&kmap_lock)
+#define unlock_kmap()           spin_unlock_irq(&kmap_lock)
+#define lock_kmap_any(flags)    spin_lock_irqsave(&kmap_lock, flags)
+#define unlock_kmap_any(flags)  spin_unlock_irqrestore(&kmap_lock, flags)
+#else
+#define lock_kmap()             spin_lock(&kmap_lock)
+#define unlock_kmap()           spin_unlock(&kmap_lock)
+#define lock_kmap_any(flags)    \
+		do { spin_lock(&kmap_lock); (void)(flags); } while (0)
+#define unlock_kmap_any(flags)  \
+		do { spin_unlock(&kmap_lock); (void)(flags); } while (0)
+#endif
+
+struct page *__kmap_to_page(void *vaddr)
+{
+	unsigned long base = (unsigned long) vaddr & PAGE_MASK;
+	struct kmap_ctrl *kctrl = &current->kmap_ctrl;
+	unsigned long addr = (unsigned long)vaddr;
+	int i;
+
+	/* kmap() mappings */
+	if (WARN_ON_ONCE(addr >= PKMAP_ADDR(0) &&
+			 addr < PKMAP_ADDR(LAST_PKMAP)))
+		return pte_page(pkmap_page_table[PKMAP_NR(addr)]);
+
+	/* kmap_local_page() mappings */
+	if (WARN_ON_ONCE(base >= __fix_to_virt(FIX_KMAP_END) &&
+			 base < __fix_to_virt(FIX_KMAP_BEGIN))) {
+		for (i = 0; i < kctrl->idx; i++) {
+			unsigned long base_addr;
+			int idx;
+
+			idx = arch_kmap_local_map_idx(i, pte_pfn(pteval));
+			base_addr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+
+			if (base_addr == base)
+				return pte_page(kctrl->pteval[i]);
+		}
+	}
+
+	return virt_to_page(vaddr);
+}
+EXPORT_SYMBOL(__kmap_to_page);
+
+static void flush_all_zero_pkmaps(void)
+{
+	int i;
+	int need_flush = 0;
+
+	flush_cache_kmaps();
+
+	for (i = 0; i < LAST_PKMAP; i++) {
+		struct page *page;
+
+		/*
+		 * zero means we don't have anything to do,
+		 * >1 means that it is still in use. Only
+		 * a count of 1 means that it is free but
+		 * needs to be unmapped
+		 */
+		if (pkmap_count[i] != 1)
+			continue;
+		pkmap_count[i] = 0;
+
+		/* sanity check */
+		BUG_ON(pte_none(pkmap_page_table[i]));
+
+		/*
+		 * Don't need an atomic fetch-and-clear op here;
+		 * no-one has the page mapped, and cannot get at
+		 * its virtual address (and hence PTE) without first
+		 * getting the kmap_lock (which is held here).
+		 * So no dangers, even with speculative execution.
+		 */
+		page = pte_page(pkmap_page_table[i]);
+		pte_clear(&init_mm, PKMAP_ADDR(i), &pkmap_page_table[i]);
+
+		set_page_address(page, NULL);
+		need_flush = 1;
+	}
+	if (need_flush)
+		flush_tlb_kernel_range(PKMAP_ADDR(0), PKMAP_ADDR(LAST_PKMAP));
+}
+
+void __kmap_flush_unused(void)
+{
+	lock_kmap();
+	flush_all_zero_pkmaps();
+	unlock_kmap();
+}
+
+static inline unsigned long map_new_virtual(struct page *page)
+{
+	unsigned long vaddr;
+	int count;
+	unsigned int last_pkmap_nr;
+	unsigned int color = get_pkmap_color(page);
+
+start:
+	count = get_pkmap_entries_count(color);
+	/* Find an empty entry */
+	for (;;) {
+		last_pkmap_nr = get_next_pkmap_nr(color);
+		if (no_more_pkmaps(last_pkmap_nr, color)) {
+			flush_all_zero_pkmaps();
+			count = get_pkmap_entries_count(color);
+		}
+		if (!pkmap_count[last_pkmap_nr])
+			break;	/* Found a usable entry */
+		if (--count)
+			continue;
+
+		/*
+		 * Sleep for somebody else to unmap their entries
+		 */
+		{
+			DECLARE_WAITQUEUE(wait, current);
+			wait_queue_head_t *pkmap_map_wait =
+				get_pkmap_wait_queue_head(color);
+
+			__set_current_state(TASK_UNINTERRUPTIBLE);
+			add_wait_queue(pkmap_map_wait, &wait);
+			unlock_kmap();
+			schedule();
+			remove_wait_queue(pkmap_map_wait, &wait);
+			lock_kmap();
+
+			/* Somebody else might have mapped it while we slept */
+			if (page_address(page))
+				return (unsigned long)page_address(page);
+
+			/* Re-start */
+			goto start;
+		}
+	}
+	vaddr = PKMAP_ADDR(last_pkmap_nr);
+	set_pte_at(&init_mm, vaddr,
+		   &(pkmap_page_table[last_pkmap_nr]), mk_pte(page, kmap_prot));
+
+	pkmap_count[last_pkmap_nr] = 1;
+	set_page_address(page, (void *)vaddr);
+
+	return vaddr;
+}
+
+/**
+ * kmap_high - map a highmem page into memory
+ * @page: &struct page to map
+ *
+ * Returns the page's virtual memory address.
+ *
+ * We cannot call this from interrupts, as it may block.
+ */
+void *kmap_high(struct page *page)
+{
+	unsigned long vaddr;
+
+	/*
+	 * For highmem pages, we can't trust "virtual" until
+	 * after we have the lock.
+	 */
+	lock_kmap();
+	vaddr = (unsigned long)page_address(page);
+	if (!vaddr)
+		vaddr = map_new_virtual(page);
+	pkmap_count[PKMAP_NR(vaddr)]++;
+	BUG_ON(pkmap_count[PKMAP_NR(vaddr)] < 2);
+	unlock_kmap();
+	return (void *) vaddr;
+}
+EXPORT_SYMBOL(kmap_high);
+
+#ifdef ARCH_NEEDS_KMAP_HIGH_GET
+/**
+ * kmap_high_get - pin a highmem page into memory
+ * @page: &struct page to pin
+ *
+ * Returns the page's current virtual memory address, or NULL if no mapping
+ * exists.  If and only if a non null address is returned then a
+ * matching call to kunmap_high() is necessary.
+ *
+ * This can be called from any context.
+ */
+void *kmap_high_get(struct page *page)
+{
+	unsigned long vaddr, flags;
+
+	lock_kmap_any(flags);
+	vaddr = (unsigned long)page_address(page);
+	if (vaddr) {
+		BUG_ON(pkmap_count[PKMAP_NR(vaddr)] < 1);
+		pkmap_count[PKMAP_NR(vaddr)]++;
+	}
+	unlock_kmap_any(flags);
+	return (void *) vaddr;
+}
+#endif
+
+/**
+ * kunmap_high - unmap a highmem page into memory
+ * @page: &struct page to unmap
+ *
+ * If ARCH_NEEDS_KMAP_HIGH_GET is not defined then this may be called
+ * only from user context.
+ */
+void kunmap_high(struct page *page)
+{
+	unsigned long vaddr;
+	unsigned long nr;
+	unsigned long flags;
+	int need_wakeup;
+	unsigned int color = get_pkmap_color(page);
+	wait_queue_head_t *pkmap_map_wait;
+
+	lock_kmap_any(flags);
+	vaddr = (unsigned long)page_address(page);
+	BUG_ON(!vaddr);
+	nr = PKMAP_NR(vaddr);
+
+	/*
+	 * A count must never go down to zero
+	 * without a TLB flush!
+	 */
+	need_wakeup = 0;
+	switch (--pkmap_count[nr]) {
+	case 0:
+		BUG();
+	case 1:
+		/*
+		 * Avoid an unnecessary wake_up() function call.
+		 * The common case is pkmap_count[] == 1, but
+		 * no waiters.
+		 * The tasks queued in the wait-queue are guarded
+		 * by both the lock in the wait-queue-head and by
+		 * the kmap_lock.  As the kmap_lock is held here,
+		 * no need for the wait-queue-head's lock.  Simply
+		 * test if the queue is empty.
+		 */
+		pkmap_map_wait = get_pkmap_wait_queue_head(color);
+		need_wakeup = waitqueue_active(pkmap_map_wait);
+	}
+	unlock_kmap_any(flags);
+
+	/* do wake-up, if needed, race-free outside of the spin lock */
+	if (need_wakeup)
+		wake_up(pkmap_map_wait);
+}
+EXPORT_SYMBOL(kunmap_high);
+
+void zero_user_segments(struct page *page, unsigned start1, unsigned end1,
+		unsigned start2, unsigned end2)
+{
+	unsigned int i;
+
+	BUG_ON(end1 > page_size(page) || end2 > page_size(page));
+
+	if (start1 >= end1)
+		start1 = end1 = 0;
+	if (start2 >= end2)
+		start2 = end2 = 0;
+
+	for (i = 0; i < compound_nr(page); i++) {
+		void *kaddr = NULL;
+
+		if (start1 >= PAGE_SIZE) {
+			start1 -= PAGE_SIZE;
+			end1 -= PAGE_SIZE;
+		} else {
+			unsigned this_end = min_t(unsigned, end1, PAGE_SIZE);
+
+			if (end1 > start1) {
+				kaddr = kmap_local_page(page + i);
+				memset(kaddr + start1, 0, this_end - start1);
+			}
+			end1 -= this_end;
+			start1 = 0;
+		}
+
+		if (start2 >= PAGE_SIZE) {
+			start2 -= PAGE_SIZE;
+			end2 -= PAGE_SIZE;
+		} else {
+			unsigned this_end = min_t(unsigned, end2, PAGE_SIZE);
+
+			if (end2 > start2) {
+				if (!kaddr)
+					kaddr = kmap_local_page(page + i);
+				memset(kaddr + start2, 0, this_end - start2);
+			}
+			end2 -= this_end;
+			start2 = 0;
+		}
+
+		if (kaddr) {
+			kunmap_local(kaddr);
+			flush_dcache_page(page + i);
+		}
+
+		if (!end1 && !end2)
+			break;
+	}
+
+	BUG_ON((start1 | start2 | end1 | end2) != 0);
+}
+EXPORT_SYMBOL(zero_user_segments);
+#endif /* CONFIG_HIGHMEM */
+
+#ifdef CONFIG_KMAP_LOCAL
+
+#include <asm/kmap_size.h>
+
+/*
+ * With DEBUG_KMAP_LOCAL the stack depth is doubled and every second
+ * slot is unused which acts as a guard page
+ */
+#ifdef CONFIG_DEBUG_KMAP_LOCAL
+# define KM_INCR	2
+#else
+# define KM_INCR	1
+#endif
+
+static inline int kmap_local_idx_push(void)
+{
+	WARN_ON_ONCE(in_hardirq() && !irqs_disabled());
+	current->kmap_ctrl.idx += KM_INCR;
+	BUG_ON(current->kmap_ctrl.idx >= KM_MAX_IDX);
+	return current->kmap_ctrl.idx - 1;
+}
+
+static inline int kmap_local_idx(void)
+{
+	return current->kmap_ctrl.idx - 1;
+}
+
+static inline void kmap_local_idx_pop(void)
+{
+	current->kmap_ctrl.idx -= KM_INCR;
+	BUG_ON(current->kmap_ctrl.idx < 0);
+}
+
+#ifndef arch_kmap_local_post_map
+# define arch_kmap_local_post_map(vaddr, pteval)	do { } while (0)
+#endif
+
+#ifndef arch_kmap_local_pre_unmap
+# define arch_kmap_local_pre_unmap(vaddr)		do { } while (0)
+#endif
+
+#ifndef arch_kmap_local_post_unmap
+# define arch_kmap_local_post_unmap(vaddr)		do { } while (0)
+#endif
+
+#ifndef arch_kmap_local_unmap_idx
+#define arch_kmap_local_unmap_idx(idx, vaddr)	kmap_local_calc_idx(idx)
+#endif
+
+#ifndef arch_kmap_local_high_get
+static inline void *arch_kmap_local_high_get(struct page *page)
+{
+	return NULL;
+}
+#endif
+
+#ifndef arch_kmap_local_set_pte
+#define arch_kmap_local_set_pte(mm, vaddr, ptep, ptev)	\
+	set_pte_at(mm, vaddr, ptep, ptev)
+#endif
+
+/* Unmap a local mapping which was obtained by kmap_high_get() */
+static inline bool kmap_high_unmap_local(unsigned long vaddr)
+{
+#ifdef ARCH_NEEDS_KMAP_HIGH_GET
+	if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
+		kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
+		return true;
+	}
+#endif
+	return false;
+}
+
+static pte_t *__kmap_pte;
+
+static pte_t *kmap_get_pte(unsigned long vaddr, int idx)
+{
+	if (IS_ENABLED(CONFIG_KMAP_LOCAL_NON_LINEAR_PTE_ARRAY))
+		/*
+		 * Set by the arch if __kmap_pte[-idx] does not produce
+		 * the correct entry.
+		 */
+		return virt_to_kpte(vaddr);
+	if (!__kmap_pte)
+		__kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
+	return &__kmap_pte[-idx];
+}
+
+void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot)
+{
+	pte_t pteval, *kmap_pte;
+	unsigned long vaddr;
+	int idx;
+
+	/*
+	 * Disable migration so resulting virtual address is stable
+	 * across preemption.
+	 */
+	migrate_disable();
+	preempt_disable();
+	idx = arch_kmap_local_map_idx(kmap_local_idx_push(), pfn);
+	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+	kmap_pte = kmap_get_pte(vaddr, idx);
+	BUG_ON(!pte_none(*kmap_pte));
+	pteval = pfn_pte(pfn, prot);
+	arch_kmap_local_set_pte(&init_mm, vaddr, kmap_pte, pteval);
+	arch_kmap_local_post_map(vaddr, pteval);
+	current->kmap_ctrl.pteval[kmap_local_idx()] = pteval;
+	preempt_enable();
+
+	return (void *)vaddr;
+}
+EXPORT_SYMBOL_GPL(__kmap_local_pfn_prot);
+
+void *__kmap_local_page_prot(struct page *page, pgprot_t prot)
+{
+	void *kmap;
+
+	/*
+	 * To broaden the usage of the actual kmap_local() machinery always map
+	 * pages when debugging is enabled and the architecture has no problems
+	 * with alias mappings.
+	 */
+	if (!IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) && !PageHighMem(page))
+		return page_address(page);
+
+	/* Try kmap_high_get() if architecture has it enabled */
+	kmap = arch_kmap_local_high_get(page);
+	if (kmap)
+		return kmap;
+
+	return __kmap_local_pfn_prot(page_to_pfn(page), prot);
+}
+EXPORT_SYMBOL(__kmap_local_page_prot);
+
+void kunmap_local_indexed(const void *vaddr)
+{
+	unsigned long addr = (unsigned long) vaddr & PAGE_MASK;
+	pte_t *kmap_pte;
+	int idx;
+
+	if (addr < __fix_to_virt(FIX_KMAP_END) ||
+	    addr > __fix_to_virt(FIX_KMAP_BEGIN)) {
+		if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP)) {
+			/* This _should_ never happen! See above. */
+			WARN_ON_ONCE(1);
+			return;
+		}
+		/*
+		 * Handle mappings which were obtained by kmap_high_get()
+		 * first as the virtual address of such mappings is below
+		 * PAGE_OFFSET. Warn for all other addresses which are in
+		 * the user space part of the virtual address space.
+		 */
+		if (!kmap_high_unmap_local(addr))
+			WARN_ON_ONCE(addr < PAGE_OFFSET);
+		return;
+	}
+
+	preempt_disable();
+	idx = arch_kmap_local_unmap_idx(kmap_local_idx(), addr);
+	WARN_ON_ONCE(addr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
+
+	kmap_pte = kmap_get_pte(addr, idx);
+	arch_kmap_local_pre_unmap(addr);
+	pte_clear(&init_mm, addr, kmap_pte);
+	arch_kmap_local_post_unmap(addr);
+	current->kmap_ctrl.pteval[kmap_local_idx()] = __pte(0);
+	kmap_local_idx_pop();
+	preempt_enable();
+	migrate_enable();
+}
+EXPORT_SYMBOL(kunmap_local_indexed);
+
+/*
+ * Invoked before switch_to(). This is safe even when during or after
+ * clearing the maps an interrupt which needs a kmap_local happens because
+ * the task::kmap_ctrl.idx is not modified by the unmapping code so a
+ * nested kmap_local will use the next unused index and restore the index
+ * on unmap. The already cleared kmaps of the outgoing task are irrelevant
+ * because the interrupt context does not know about them. The same applies
+ * when scheduling back in for an interrupt which happens before the
+ * restore is complete.
+ */
+void __kmap_local_sched_out(void)
+{
+	struct task_struct *tsk = current;
+	pte_t *kmap_pte;
+	int i;
+
+	/* Clear kmaps */
+	for (i = 0; i < tsk->kmap_ctrl.idx; i++) {
+		pte_t pteval = tsk->kmap_ctrl.pteval[i];
+		unsigned long addr;
+		int idx;
+
+		/* With debug all even slots are unmapped and act as guard */
+		if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL) && !(i & 0x01)) {
+			WARN_ON_ONCE(pte_val(pteval) != 0);
+			continue;
+		}
+		if (WARN_ON_ONCE(pte_none(pteval)))
+			continue;
+
+		/*
+		 * This is a horrible hack for XTENSA to calculate the
+		 * coloured PTE index. Uses the PFN encoded into the pteval
+		 * and the map index calculation because the actual mapped
+		 * virtual address is not stored in task::kmap_ctrl.
+		 * For any sane architecture this is optimized out.
+		 */
+		idx = arch_kmap_local_map_idx(i, pte_pfn(pteval));
+
+		addr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+		kmap_pte = kmap_get_pte(addr, idx);
+		arch_kmap_local_pre_unmap(addr);
+		pte_clear(&init_mm, addr, kmap_pte);
+		arch_kmap_local_post_unmap(addr);
+	}
+}
+
+void __kmap_local_sched_in(void)
+{
+	struct task_struct *tsk = current;
+	pte_t *kmap_pte;
+	int i;
+
+	/* Restore kmaps */
+	for (i = 0; i < tsk->kmap_ctrl.idx; i++) {
+		pte_t pteval = tsk->kmap_ctrl.pteval[i];
+		unsigned long addr;
+		int idx;
+
+		/* With debug all even slots are unmapped and act as guard */
+		if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL) && !(i & 0x01)) {
+			WARN_ON_ONCE(pte_val(pteval) != 0);
+			continue;
+		}
+		if (WARN_ON_ONCE(pte_none(pteval)))
+			continue;
+
+		/* See comment in __kmap_local_sched_out() */
+		idx = arch_kmap_local_map_idx(i, pte_pfn(pteval));
+		addr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+		kmap_pte = kmap_get_pte(addr, idx);
+		set_pte_at(&init_mm, addr, kmap_pte, pteval);
+		arch_kmap_local_post_map(addr, pteval);
+	}
+}
+
+void kmap_local_fork(struct task_struct *tsk)
+{
+	if (WARN_ON_ONCE(tsk->kmap_ctrl.idx))
+		memset(&tsk->kmap_ctrl, 0, sizeof(tsk->kmap_ctrl));
+}
+
+#endif
+
+#if defined(HASHED_PAGE_VIRTUAL)
+
+#define PA_HASH_ORDER	7
+
+/*
+ * Describes one page->virtual association
+ */
+struct page_address_map {
+	struct page *page;
+	void *virtual;
+	struct list_head list;
+};
+
+static struct page_address_map page_address_maps[LAST_PKMAP];
+
+/*
+ * Hash table bucket
+ */
+static struct page_address_slot {
+	struct list_head lh;			/* List of page_address_maps */
+	spinlock_t lock;			/* Protect this bucket's list */
+} ____cacheline_aligned_in_smp page_address_htable[1<<PA_HASH_ORDER];
+
+static struct page_address_slot *page_slot(const struct page *page)
+{
+	return &page_address_htable[hash_ptr(page, PA_HASH_ORDER)];
+}
+
+/**
+ * page_address - get the mapped virtual address of a page
+ * @page: &struct page to get the virtual address of
+ *
+ * Returns the page's virtual address.
+ */
+void *page_address(const struct page *page)
+{
+	unsigned long flags;
+	void *ret;
+	struct page_address_slot *pas;
+
+	if (!PageHighMem(page))
+		return lowmem_page_address(page);
+
+	pas = page_slot(page);
+	ret = NULL;
+	spin_lock_irqsave(&pas->lock, flags);
+	if (!list_empty(&pas->lh)) {
+		struct page_address_map *pam;
+
+		list_for_each_entry(pam, &pas->lh, list) {
+			if (pam->page == page) {
+				ret = pam->virtual;
+				break;
+			}
+		}
+	}
+
+	spin_unlock_irqrestore(&pas->lock, flags);
+	return ret;
+}
+EXPORT_SYMBOL(page_address);
+
+/**
+ * set_page_address - set a page's virtual address
+ * @page: &struct page to set
+ * @virtual: virtual address to use
+ */
+void set_page_address(struct page *page, void *virtual)
+{
+	unsigned long flags;
+	struct page_address_slot *pas;
+	struct page_address_map *pam;
+
+	BUG_ON(!PageHighMem(page));
+
+	pas = page_slot(page);
+	if (virtual) {		/* Add */
+		pam = &page_address_maps[PKMAP_NR((unsigned long)virtual)];
+		pam->page = page;
+		pam->virtual = virtual;
+
+		spin_lock_irqsave(&pas->lock, flags);
+		list_add_tail(&pam->list, &pas->lh);
+		spin_unlock_irqrestore(&pas->lock, flags);
+	} else {		/* Remove */
+		spin_lock_irqsave(&pas->lock, flags);
+		list_for_each_entry(pam, &pas->lh, list) {
+			if (pam->page == page) {
+				list_del(&pam->list);
+				break;
+			}
+		}
+		spin_unlock_irqrestore(&pas->lock, flags);
+	}
+
+	return;
+}
+
+void __init page_address_init(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(page_address_htable); i++) {
+		INIT_LIST_HEAD(&page_address_htable[i].lh);
+		spin_lock_init(&page_address_htable[i].lock);
+	}
+}
+
+#endif	/* defined(HASHED_PAGE_VIRTUAL) */