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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/arm64/mm/context.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/arm64/mm/context.c')
-rw-r--r--arch/arm64/mm/context.c422
1 files changed, 422 insertions, 0 deletions
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
new file mode 100644
index 000000000..e1e0dca01
--- /dev/null
+++ b/arch/arm64/mm/context.c
@@ -0,0 +1,422 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Based on arch/arm/mm/context.c
+ *
+ * Copyright (C) 2002-2003 Deep Blue Solutions Ltd, all rights reserved.
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+
+#include <asm/cpufeature.h>
+#include <asm/mmu_context.h>
+#include <asm/smp.h>
+#include <asm/tlbflush.h>
+
+static u32 asid_bits;
+static DEFINE_RAW_SPINLOCK(cpu_asid_lock);
+
+static atomic64_t asid_generation;
+static unsigned long *asid_map;
+
+static DEFINE_PER_CPU(atomic64_t, active_asids);
+static DEFINE_PER_CPU(u64, reserved_asids);
+static cpumask_t tlb_flush_pending;
+
+static unsigned long max_pinned_asids;
+static unsigned long nr_pinned_asids;
+static unsigned long *pinned_asid_map;
+
+#define ASID_MASK (~GENMASK(asid_bits - 1, 0))
+#define ASID_FIRST_VERSION (1UL << asid_bits)
+
+#define NUM_USER_ASIDS ASID_FIRST_VERSION
+#define ctxid2asid(asid) ((asid) & ~ASID_MASK)
+#define asid2ctxid(asid, genid) ((asid) | (genid))
+
+/* Get the ASIDBits supported by the current CPU */
+static u32 get_cpu_asid_bits(void)
+{
+ u32 asid;
+ int fld = cpuid_feature_extract_unsigned_field(read_cpuid(ID_AA64MMFR0_EL1),
+ ID_AA64MMFR0_EL1_ASIDBITS_SHIFT);
+
+ switch (fld) {
+ default:
+ pr_warn("CPU%d: Unknown ASID size (%d); assuming 8-bit\n",
+ smp_processor_id(), fld);
+ fallthrough;
+ case ID_AA64MMFR0_EL1_ASIDBITS_8:
+ asid = 8;
+ break;
+ case ID_AA64MMFR0_EL1_ASIDBITS_16:
+ asid = 16;
+ }
+
+ return asid;
+}
+
+/* Check if the current cpu's ASIDBits is compatible with asid_bits */
+void verify_cpu_asid_bits(void)
+{
+ u32 asid = get_cpu_asid_bits();
+
+ if (asid < asid_bits) {
+ /*
+ * We cannot decrease the ASID size at runtime, so panic if we support
+ * fewer ASID bits than the boot CPU.
+ */
+ pr_crit("CPU%d: smaller ASID size(%u) than boot CPU (%u)\n",
+ smp_processor_id(), asid, asid_bits);
+ cpu_panic_kernel();
+ }
+}
+
+static void set_kpti_asid_bits(unsigned long *map)
+{
+ unsigned int len = BITS_TO_LONGS(NUM_USER_ASIDS) * sizeof(unsigned long);
+ /*
+ * In case of KPTI kernel/user ASIDs are allocated in
+ * pairs, the bottom bit distinguishes the two: if it
+ * is set, then the ASID will map only userspace. Thus
+ * mark even as reserved for kernel.
+ */
+ memset(map, 0xaa, len);
+}
+
+static void set_reserved_asid_bits(void)
+{
+ if (pinned_asid_map)
+ bitmap_copy(asid_map, pinned_asid_map, NUM_USER_ASIDS);
+ else if (arm64_kernel_unmapped_at_el0())
+ set_kpti_asid_bits(asid_map);
+ else
+ bitmap_clear(asid_map, 0, NUM_USER_ASIDS);
+}
+
+#define asid_gen_match(asid) \
+ (!(((asid) ^ atomic64_read(&asid_generation)) >> asid_bits))
+
+static void flush_context(void)
+{
+ int i;
+ u64 asid;
+
+ /* Update the list of reserved ASIDs and the ASID bitmap. */
+ set_reserved_asid_bits();
+
+ for_each_possible_cpu(i) {
+ asid = atomic64_xchg_relaxed(&per_cpu(active_asids, i), 0);
+ /*
+ * If this CPU has already been through a
+ * rollover, but hasn't run another task in
+ * the meantime, we must preserve its reserved
+ * ASID, as this is the only trace we have of
+ * the process it is still running.
+ */
+ if (asid == 0)
+ asid = per_cpu(reserved_asids, i);
+ __set_bit(ctxid2asid(asid), asid_map);
+ per_cpu(reserved_asids, i) = asid;
+ }
+
+ /*
+ * Queue a TLB invalidation for each CPU to perform on next
+ * context-switch
+ */
+ cpumask_setall(&tlb_flush_pending);
+}
+
+static bool check_update_reserved_asid(u64 asid, u64 newasid)
+{
+ int cpu;
+ bool hit = false;
+
+ /*
+ * Iterate over the set of reserved ASIDs looking for a match.
+ * If we find one, then we can update our mm to use newasid
+ * (i.e. the same ASID in the current generation) but we can't
+ * exit the loop early, since we need to ensure that all copies
+ * of the old ASID are updated to reflect the mm. Failure to do
+ * so could result in us missing the reserved ASID in a future
+ * generation.
+ */
+ for_each_possible_cpu(cpu) {
+ if (per_cpu(reserved_asids, cpu) == asid) {
+ hit = true;
+ per_cpu(reserved_asids, cpu) = newasid;
+ }
+ }
+
+ return hit;
+}
+
+static u64 new_context(struct mm_struct *mm)
+{
+ static u32 cur_idx = 1;
+ u64 asid = atomic64_read(&mm->context.id);
+ u64 generation = atomic64_read(&asid_generation);
+
+ if (asid != 0) {
+ u64 newasid = asid2ctxid(ctxid2asid(asid), generation);
+
+ /*
+ * If our current ASID was active during a rollover, we
+ * can continue to use it and this was just a false alarm.
+ */
+ if (check_update_reserved_asid(asid, newasid))
+ return newasid;
+
+ /*
+ * If it is pinned, we can keep using it. Note that reserved
+ * takes priority, because even if it is also pinned, we need to
+ * update the generation into the reserved_asids.
+ */
+ if (refcount_read(&mm->context.pinned))
+ return newasid;
+
+ /*
+ * We had a valid ASID in a previous life, so try to re-use
+ * it if possible.
+ */
+ if (!__test_and_set_bit(ctxid2asid(asid), asid_map))
+ return newasid;
+ }
+
+ /*
+ * Allocate a free ASID. If we can't find one, take a note of the
+ * currently active ASIDs and mark the TLBs as requiring flushes. We
+ * always count from ASID #2 (index 1), as we use ASID #0 when setting
+ * a reserved TTBR0 for the init_mm and we allocate ASIDs in even/odd
+ * pairs.
+ */
+ asid = find_next_zero_bit(asid_map, NUM_USER_ASIDS, cur_idx);
+ if (asid != NUM_USER_ASIDS)
+ goto set_asid;
+
+ /* We're out of ASIDs, so increment the global generation count */
+ generation = atomic64_add_return_relaxed(ASID_FIRST_VERSION,
+ &asid_generation);
+ flush_context();
+
+ /* We have more ASIDs than CPUs, so this will always succeed */
+ asid = find_next_zero_bit(asid_map, NUM_USER_ASIDS, 1);
+
+set_asid:
+ __set_bit(asid, asid_map);
+ cur_idx = asid;
+ return asid2ctxid(asid, generation);
+}
+
+void check_and_switch_context(struct mm_struct *mm)
+{
+ unsigned long flags;
+ unsigned int cpu;
+ u64 asid, old_active_asid;
+
+ if (system_supports_cnp())
+ cpu_set_reserved_ttbr0();
+
+ asid = atomic64_read(&mm->context.id);
+
+ /*
+ * The memory ordering here is subtle.
+ * If our active_asids is non-zero and the ASID matches the current
+ * generation, then we update the active_asids entry with a relaxed
+ * cmpxchg. Racing with a concurrent rollover means that either:
+ *
+ * - We get a zero back from the cmpxchg and end up waiting on the
+ * lock. Taking the lock synchronises with the rollover and so
+ * we are forced to see the updated generation.
+ *
+ * - We get a valid ASID back from the cmpxchg, which means the
+ * relaxed xchg in flush_context will treat us as reserved
+ * because atomic RmWs are totally ordered for a given location.
+ */
+ old_active_asid = atomic64_read(this_cpu_ptr(&active_asids));
+ if (old_active_asid && asid_gen_match(asid) &&
+ atomic64_cmpxchg_relaxed(this_cpu_ptr(&active_asids),
+ old_active_asid, asid))
+ goto switch_mm_fastpath;
+
+ raw_spin_lock_irqsave(&cpu_asid_lock, flags);
+ /* Check that our ASID belongs to the current generation. */
+ asid = atomic64_read(&mm->context.id);
+ if (!asid_gen_match(asid)) {
+ asid = new_context(mm);
+ atomic64_set(&mm->context.id, asid);
+ }
+
+ cpu = smp_processor_id();
+ if (cpumask_test_and_clear_cpu(cpu, &tlb_flush_pending))
+ local_flush_tlb_all();
+
+ atomic64_set(this_cpu_ptr(&active_asids), asid);
+ raw_spin_unlock_irqrestore(&cpu_asid_lock, flags);
+
+switch_mm_fastpath:
+
+ arm64_apply_bp_hardening();
+
+ /*
+ * Defer TTBR0_EL1 setting for user threads to uaccess_enable() when
+ * emulating PAN.
+ */
+ if (!system_uses_ttbr0_pan())
+ cpu_switch_mm(mm->pgd, mm);
+}
+
+unsigned long arm64_mm_context_get(struct mm_struct *mm)
+{
+ unsigned long flags;
+ u64 asid;
+
+ if (!pinned_asid_map)
+ return 0;
+
+ raw_spin_lock_irqsave(&cpu_asid_lock, flags);
+
+ asid = atomic64_read(&mm->context.id);
+
+ if (refcount_inc_not_zero(&mm->context.pinned))
+ goto out_unlock;
+
+ if (nr_pinned_asids >= max_pinned_asids) {
+ asid = 0;
+ goto out_unlock;
+ }
+
+ if (!asid_gen_match(asid)) {
+ /*
+ * We went through one or more rollover since that ASID was
+ * used. Ensure that it is still valid, or generate a new one.
+ */
+ asid = new_context(mm);
+ atomic64_set(&mm->context.id, asid);
+ }
+
+ nr_pinned_asids++;
+ __set_bit(ctxid2asid(asid), pinned_asid_map);
+ refcount_set(&mm->context.pinned, 1);
+
+out_unlock:
+ raw_spin_unlock_irqrestore(&cpu_asid_lock, flags);
+
+ asid = ctxid2asid(asid);
+
+ /* Set the equivalent of USER_ASID_BIT */
+ if (asid && arm64_kernel_unmapped_at_el0())
+ asid |= 1;
+
+ return asid;
+}
+EXPORT_SYMBOL_GPL(arm64_mm_context_get);
+
+void arm64_mm_context_put(struct mm_struct *mm)
+{
+ unsigned long flags;
+ u64 asid = atomic64_read(&mm->context.id);
+
+ if (!pinned_asid_map)
+ return;
+
+ raw_spin_lock_irqsave(&cpu_asid_lock, flags);
+
+ if (refcount_dec_and_test(&mm->context.pinned)) {
+ __clear_bit(ctxid2asid(asid), pinned_asid_map);
+ nr_pinned_asids--;
+ }
+
+ raw_spin_unlock_irqrestore(&cpu_asid_lock, flags);
+}
+EXPORT_SYMBOL_GPL(arm64_mm_context_put);
+
+/* Errata workaround post TTBRx_EL1 update. */
+asmlinkage void post_ttbr_update_workaround(void)
+{
+ if (!IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456))
+ return;
+
+ asm(ALTERNATIVE("nop; nop; nop",
+ "ic iallu; dsb nsh; isb",
+ ARM64_WORKAROUND_CAVIUM_27456));
+}
+
+void cpu_do_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm)
+{
+ unsigned long ttbr1 = read_sysreg(ttbr1_el1);
+ unsigned long asid = ASID(mm);
+ unsigned long ttbr0 = phys_to_ttbr(pgd_phys);
+
+ /* Skip CNP for the reserved ASID */
+ if (system_supports_cnp() && asid)
+ ttbr0 |= TTBR_CNP_BIT;
+
+ /* SW PAN needs a copy of the ASID in TTBR0 for entry */
+ if (IS_ENABLED(CONFIG_ARM64_SW_TTBR0_PAN))
+ ttbr0 |= FIELD_PREP(TTBR_ASID_MASK, asid);
+
+ /* Set ASID in TTBR1 since TCR.A1 is set */
+ ttbr1 &= ~TTBR_ASID_MASK;
+ ttbr1 |= FIELD_PREP(TTBR_ASID_MASK, asid);
+
+ write_sysreg(ttbr1, ttbr1_el1);
+ isb();
+ write_sysreg(ttbr0, ttbr0_el1);
+ isb();
+ post_ttbr_update_workaround();
+}
+
+static int asids_update_limit(void)
+{
+ unsigned long num_available_asids = NUM_USER_ASIDS;
+
+ if (arm64_kernel_unmapped_at_el0()) {
+ num_available_asids /= 2;
+ if (pinned_asid_map)
+ set_kpti_asid_bits(pinned_asid_map);
+ }
+ /*
+ * Expect allocation after rollover to fail if we don't have at least
+ * one more ASID than CPUs. ASID #0 is reserved for init_mm.
+ */
+ WARN_ON(num_available_asids - 1 <= num_possible_cpus());
+ pr_info("ASID allocator initialised with %lu entries\n",
+ num_available_asids);
+
+ /*
+ * There must always be an ASID available after rollover. Ensure that,
+ * even if all CPUs have a reserved ASID and the maximum number of ASIDs
+ * are pinned, there still is at least one empty slot in the ASID map.
+ */
+ max_pinned_asids = num_available_asids - num_possible_cpus() - 2;
+ return 0;
+}
+arch_initcall(asids_update_limit);
+
+static int asids_init(void)
+{
+ asid_bits = get_cpu_asid_bits();
+ atomic64_set(&asid_generation, ASID_FIRST_VERSION);
+ asid_map = bitmap_zalloc(NUM_USER_ASIDS, GFP_KERNEL);
+ if (!asid_map)
+ panic("Failed to allocate bitmap for %lu ASIDs\n",
+ NUM_USER_ASIDS);
+
+ pinned_asid_map = bitmap_zalloc(NUM_USER_ASIDS, GFP_KERNEL);
+ nr_pinned_asids = 0;
+
+ /*
+ * We cannot call set_reserved_asid_bits() here because CPU
+ * caps are not finalized yet, so it is safer to assume KPTI
+ * and reserve kernel ASID's from beginning.
+ */
+ if (IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0))
+ set_kpti_asid_bits(asid_map);
+ return 0;
+}
+early_initcall(asids_init);