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, 564 insertions, 0 deletions

diff --git a/arch/powerpc/mm/book3s64/hash_pgtable.c b/arch/powerpc/mm/book3s64/hash_pgtable.c
new file mode 100644
index 000000000..51f48984a
--- /dev/null
+++ b/arch/powerpc/mm/book3s64/hash_pgtable.c
@@ -0,0 +1,564 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2005, Paul Mackerras, IBM Corporation.
+ * Copyright 2009, Benjamin Herrenschmidt, IBM Corporation.
+ * Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
+ */
+
+#include <linux/sched.h>
+#include <linux/mm_types.h>
+#include <linux/mm.h>
+#include <linux/stop_machine.h>
+
+#include <asm/sections.h>
+#include <asm/mmu.h>
+#include <asm/tlb.h>
+#include <asm/firmware.h>
+
+#include <mm/mmu_decl.h>
+
+#include <trace/events/thp.h>
+
+#if H_PGTABLE_RANGE > (USER_VSID_RANGE * (TASK_SIZE_USER64 / TASK_CONTEXT_SIZE))
+#warning Limited user VSID range means pagetable space is wasted
+#endif
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+/*
+ * vmemmap is the starting address of the virtual address space where
+ * struct pages are allocated for all possible PFNs present on the system
+ * including holes and bad memory (hence sparse). These virtual struct
+ * pages are stored in sequence in this virtual address space irrespective
+ * of the fact whether the corresponding PFN is valid or not. This achieves
+ * constant relationship between address of struct page and its PFN.
+ *
+ * During boot or memory hotplug operation when a new memory section is
+ * added, physical memory allocation (including hash table bolting) will
+ * be performed for the set of struct pages which are part of the memory
+ * section. This saves memory by not allocating struct pages for PFNs
+ * which are not valid.
+ *
+ *		----------------------------------------------
+ *		| PHYSICAL ALLOCATION OF VIRTUAL STRUCT PAGES|
+ *		----------------------------------------------
+ *
+ *	   f000000000000000                  c000000000000000
+ * vmemmap +--------------+                  +--------------+
+ *  +      |  page struct | +--------------> |  page struct |
+ *  |      +--------------+                  +--------------+
+ *  |      |  page struct | +--------------> |  page struct |
+ *  |      +--------------+ |                +--------------+
+ *  |      |  page struct | +       +------> |  page struct |
+ *  |      +--------------+         |        +--------------+
+ *  |      |  page struct |         |   +--> |  page struct |
+ *  |      +--------------+         |   |    +--------------+
+ *  |      |  page struct |         |   |
+ *  |      +--------------+         |   |
+ *  |      |  page struct |         |   |
+ *  |      +--------------+         |   |
+ *  |      |  page struct |         |   |
+ *  |      +--------------+         |   |
+ *  |      |  page struct |         |   |
+ *  |      +--------------+         |   |
+ *  |      |  page struct | +-------+   |
+ *  |      +--------------+             |
+ *  |      |  page struct | +-----------+
+ *  |      +--------------+
+ *  |      |  page struct | No mapping
+ *  |      +--------------+
+ *  |      |  page struct | No mapping
+ *  v      +--------------+
+ *
+ *		-----------------------------------------
+ *		| RELATION BETWEEN STRUCT PAGES AND PFNS|
+ *		-----------------------------------------
+ *
+ * vmemmap +--------------+                 +---------------+
+ *  +      |  page struct | +-------------> |      PFN      |
+ *  |      +--------------+                 +---------------+
+ *  |      |  page struct | +-------------> |      PFN      |
+ *  |      +--------------+                 +---------------+
+ *  |      |  page struct | +-------------> |      PFN      |
+ *  |      +--------------+                 +---------------+
+ *  |      |  page struct | +-------------> |      PFN      |
+ *  |      +--------------+                 +---------------+
+ *  |      |              |
+ *  |      +--------------+
+ *  |      |              |
+ *  |      +--------------+
+ *  |      |              |
+ *  |      +--------------+                 +---------------+
+ *  |      |  page struct | +-------------> |      PFN      |
+ *  |      +--------------+                 +---------------+
+ *  |      |              |
+ *  |      +--------------+
+ *  |      |              |
+ *  |      +--------------+                 +---------------+
+ *  |      |  page struct | +-------------> |      PFN      |
+ *  |      +--------------+                 +---------------+
+ *  |      |  page struct | +-------------> |      PFN      |
+ *  v      +--------------+                 +---------------+
+ */
+/*
+ * On hash-based CPUs, the vmemmap is bolted in the hash table.
+ *
+ */
+int __meminit hash__vmemmap_create_mapping(unsigned long start,
+				       unsigned long page_size,
+				       unsigned long phys)
+{
+	int rc;
+
+	if ((start + page_size) >= H_VMEMMAP_END) {
+		pr_warn("Outside the supported range\n");
+		return -1;
+	}
+
+	rc = htab_bolt_mapping(start, start + page_size, phys,
+			       pgprot_val(PAGE_KERNEL),
+			       mmu_vmemmap_psize, mmu_kernel_ssize);
+	if (rc < 0) {
+		int rc2 = htab_remove_mapping(start, start + page_size,
+					      mmu_vmemmap_psize,
+					      mmu_kernel_ssize);
+		BUG_ON(rc2 && (rc2 != -ENOENT));
+	}
+	return rc;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+void hash__vmemmap_remove_mapping(unsigned long start,
+			      unsigned long page_size)
+{
+	int rc = htab_remove_mapping(start, start + page_size,
+				     mmu_vmemmap_psize,
+				     mmu_kernel_ssize);
+	BUG_ON((rc < 0) && (rc != -ENOENT));
+	WARN_ON(rc == -ENOENT);
+}
+#endif
+#endif /* CONFIG_SPARSEMEM_VMEMMAP */
+
+/*
+ * map_kernel_page currently only called by __ioremap
+ * map_kernel_page adds an entry to the ioremap page table
+ * and adds an entry to the HPT, possibly bolting it
+ */
+int hash__map_kernel_page(unsigned long ea, unsigned long pa, pgprot_t prot)
+{
+	pgd_t *pgdp;
+	p4d_t *p4dp;
+	pud_t *pudp;
+	pmd_t *pmdp;
+	pte_t *ptep;
+
+	BUILD_BUG_ON(TASK_SIZE_USER64 > H_PGTABLE_RANGE);
+	if (slab_is_available()) {
+		pgdp = pgd_offset_k(ea);
+		p4dp = p4d_offset(pgdp, ea);
+		pudp = pud_alloc(&init_mm, p4dp, ea);
+		if (!pudp)
+			return -ENOMEM;
+		pmdp = pmd_alloc(&init_mm, pudp, ea);
+		if (!pmdp)
+			return -ENOMEM;
+		ptep = pte_alloc_kernel(pmdp, ea);
+		if (!ptep)
+			return -ENOMEM;
+		set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, prot));
+	} else {
+		/*
+		 * If the mm subsystem is not fully up, we cannot create a
+		 * linux page table entry for this mapping.  Simply bolt an
+		 * entry in the hardware page table.
+		 *
+		 */
+		if (htab_bolt_mapping(ea, ea + PAGE_SIZE, pa, pgprot_val(prot),
+				      mmu_io_psize, mmu_kernel_ssize)) {
+			printk(KERN_ERR "Failed to do bolted mapping IO "
+			       "memory at %016lx !\n", pa);
+			return -ENOMEM;
+		}
+	}
+
+	smp_wmb();
+	return 0;
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+
+unsigned long hash__pmd_hugepage_update(struct mm_struct *mm, unsigned long addr,
+				    pmd_t *pmdp, unsigned long clr,
+				    unsigned long set)
+{
+	__be64 old_be, tmp;
+	unsigned long old;
+
+#ifdef CONFIG_DEBUG_VM
+	WARN_ON(!hash__pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp));
+	assert_spin_locked(pmd_lockptr(mm, pmdp));
+#endif
+
+	__asm__ __volatile__(
+	"1:	ldarx	%0,0,%3\n\
+		and.	%1,%0,%6\n\
+		bne-	1b \n\
+		andc	%1,%0,%4 \n\
+		or	%1,%1,%7\n\
+		stdcx.	%1,0,%3 \n\
+		bne-	1b"
+	: "=&r" (old_be), "=&r" (tmp), "=m" (*pmdp)
+	: "r" (pmdp), "r" (cpu_to_be64(clr)), "m" (*pmdp),
+	  "r" (cpu_to_be64(H_PAGE_BUSY)), "r" (cpu_to_be64(set))
+	: "cc" );
+
+	old = be64_to_cpu(old_be);
+
+	trace_hugepage_update(addr, old, clr, set);
+	if (old & H_PAGE_HASHPTE)
+		hpte_do_hugepage_flush(mm, addr, pmdp, old);
+	return old;
+}
+
+pmd_t hash__pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,
+			    pmd_t *pmdp)
+{
+	pmd_t pmd;
+
+	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+	VM_BUG_ON(pmd_trans_huge(*pmdp));
+	VM_BUG_ON(pmd_devmap(*pmdp));
+
+	pmd = *pmdp;
+	pmd_clear(pmdp);
+	/*
+	 * Wait for all pending hash_page to finish. This is needed
+	 * in case of subpage collapse. When we collapse normal pages
+	 * to hugepage, we first clear the pmd, then invalidate all
+	 * the PTE entries. The assumption here is that any low level
+	 * page fault will see a none pmd and take the slow path that
+	 * will wait on mmap_lock. But we could very well be in a
+	 * hash_page with local ptep pointer value. Such a hash page
+	 * can result in adding new HPTE entries for normal subpages.
+	 * That means we could be modifying the page content as we
+	 * copy them to a huge page. So wait for parallel hash_page
+	 * to finish before invalidating HPTE entries. We can do this
+	 * by sending an IPI to all the cpus and executing a dummy
+	 * function there.
+	 */
+	serialize_against_pte_lookup(vma->vm_mm);
+	/*
+	 * Now invalidate the hpte entries in the range
+	 * covered by pmd. This make sure we take a
+	 * fault and will find the pmd as none, which will
+	 * result in a major fault which takes mmap_lock and
+	 * hence wait for collapse to complete. Without this
+	 * the __collapse_huge_page_copy can result in copying
+	 * the old content.
+	 */
+	flush_hash_table_pmd_range(vma->vm_mm, &pmd, address);
+	return pmd;
+}
+
+/*
+ * We want to put the pgtable in pmd and use pgtable for tracking
+ * the base page size hptes
+ */
+void hash__pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+				  pgtable_t pgtable)
+{
+	pgtable_t *pgtable_slot;
+
+	assert_spin_locked(pmd_lockptr(mm, pmdp));
+	/*
+	 * we store the pgtable in the second half of PMD
+	 */
+	pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
+	*pgtable_slot = pgtable;
+	/*
+	 * expose the deposited pgtable to other cpus.
+	 * before we set the hugepage PTE at pmd level
+	 * hash fault code looks at the deposted pgtable
+	 * to store hash index values.
+	 */
+	smp_wmb();
+}
+
+pgtable_t hash__pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
+{
+	pgtable_t pgtable;
+	pgtable_t *pgtable_slot;
+
+	assert_spin_locked(pmd_lockptr(mm, pmdp));
+
+	pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
+	pgtable = *pgtable_slot;
+	/*
+	 * Once we withdraw, mark the entry NULL.
+	 */
+	*pgtable_slot = NULL;
+	/*
+	 * We store HPTE information in the deposited PTE fragment.
+	 * zero out the content on withdraw.
+	 */
+	memset(pgtable, 0, PTE_FRAG_SIZE);
+	return pgtable;
+}
+
+/*
+ * A linux hugepage PMD was changed and the corresponding hash table entries
+ * neesd to be flushed.
+ */
+void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr,
+			    pmd_t *pmdp, unsigned long old_pmd)
+{
+	int ssize;
+	unsigned int psize;
+	unsigned long vsid;
+	unsigned long flags = 0;
+
+	/* get the base page size,vsid and segment size */
+#ifdef CONFIG_DEBUG_VM
+	psize = get_slice_psize(mm, addr);
+	BUG_ON(psize == MMU_PAGE_16M);
+#endif
+	if (old_pmd & H_PAGE_COMBO)
+		psize = MMU_PAGE_4K;
+	else
+		psize = MMU_PAGE_64K;
+
+	if (!is_kernel_addr(addr)) {
+		ssize = user_segment_size(addr);
+		vsid = get_user_vsid(&mm->context, addr, ssize);
+		WARN_ON(vsid == 0);
+	} else {
+		vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
+		ssize = mmu_kernel_ssize;
+	}
+
+	if (mm_is_thread_local(mm))
+		flags |= HPTE_LOCAL_UPDATE;
+
+	return flush_hash_hugepage(vsid, addr, pmdp, psize, ssize, flags);
+}
+
+pmd_t hash__pmdp_huge_get_and_clear(struct mm_struct *mm,
+				unsigned long addr, pmd_t *pmdp)
+{
+	pmd_t old_pmd;
+	pgtable_t pgtable;
+	unsigned long old;
+	pgtable_t *pgtable_slot;
+
+	old = pmd_hugepage_update(mm, addr, pmdp, ~0UL, 0);
+	old_pmd = __pmd(old);
+	/*
+	 * We have pmd == none and we are holding page_table_lock.
+	 * So we can safely go and clear the pgtable hash
+	 * index info.
+	 */
+	pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
+	pgtable = *pgtable_slot;
+	/*
+	 * Let's zero out old valid and hash index details
+	 * hash fault look at them.
+	 */
+	memset(pgtable, 0, PTE_FRAG_SIZE);
+	return old_pmd;
+}
+
+int hash__has_transparent_hugepage(void)
+{
+
+	if (!mmu_has_feature(MMU_FTR_16M_PAGE))
+		return 0;
+	/*
+	 * We support THP only if PMD_SIZE is 16MB.
+	 */
+	if (mmu_psize_defs[MMU_PAGE_16M].shift != PMD_SHIFT)
+		return 0;
+	/*
+	 * We need to make sure that we support 16MB hugepage in a segment
+	 * with base page size 64K or 4K. We only enable THP with a PAGE_SIZE
+	 * of 64K.
+	 */
+	/*
+	 * If we have 64K HPTE, we will be using that by default
+	 */
+	if (mmu_psize_defs[MMU_PAGE_64K].shift &&
+	    (mmu_psize_defs[MMU_PAGE_64K].penc[MMU_PAGE_16M] == -1))
+		return 0;
+	/*
+	 * Ok we only have 4K HPTE
+	 */
+	if (mmu_psize_defs[MMU_PAGE_4K].penc[MMU_PAGE_16M] == -1)
+		return 0;
+
+	return 1;
+}
+EXPORT_SYMBOL_GPL(hash__has_transparent_hugepage);
+
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+#ifdef CONFIG_STRICT_KERNEL_RWX
+
+struct change_memory_parms {
+	unsigned long start, end, newpp;
+	unsigned int step, nr_cpus;
+	atomic_t master_cpu;
+	atomic_t cpu_counter;
+};
+
+// We'd rather this was on the stack but it has to be in the RMO
+static struct change_memory_parms chmem_parms;
+
+// And therefore we need a lock to protect it from concurrent use
+static DEFINE_MUTEX(chmem_lock);
+
+static void change_memory_range(unsigned long start, unsigned long end,
+				unsigned int step, unsigned long newpp)
+{
+	unsigned long idx;
+
+	pr_debug("Changing page protection on range 0x%lx-0x%lx, to 0x%lx, step 0x%x\n",
+		 start, end, newpp, step);
+
+	for (idx = start; idx < end; idx += step)
+		/* Not sure if we can do much with the return value */
+		mmu_hash_ops.hpte_updateboltedpp(newpp, idx, mmu_linear_psize,
+							mmu_kernel_ssize);
+}
+
+static int notrace chmem_secondary_loop(struct change_memory_parms *parms)
+{
+	unsigned long msr, tmp, flags;
+	int *p;
+
+	p = &parms->cpu_counter.counter;
+
+	local_irq_save(flags);
+	hard_irq_disable();
+
+	asm volatile (
+	// Switch to real mode and leave interrupts off
+	"mfmsr	%[msr]			;"
+	"li	%[tmp], %[MSR_IR_DR]	;"
+	"andc	%[tmp], %[msr], %[tmp]	;"
+	"mtmsrd %[tmp]			;"
+
+	// Tell the master we are in real mode
+	"1:				"
+	"lwarx	%[tmp], 0, %[p]		;"
+	"addic	%[tmp], %[tmp], -1	;"
+	"stwcx.	%[tmp], 0, %[p]		;"
+	"bne-	1b			;"
+
+	// Spin until the counter goes to zero
+	"2:				;"
+	"lwz	%[tmp], 0(%[p])		;"
+	"cmpwi	%[tmp], 0		;"
+	"bne-	2b			;"
+
+	// Switch back to virtual mode
+	"mtmsrd %[msr]			;"
+
+	: // outputs
+	  [msr] "=&r" (msr), [tmp] "=&b" (tmp), "+m" (*p)
+	: // inputs
+	  [p] "b" (p), [MSR_IR_DR] "i" (MSR_IR | MSR_DR)
+	: // clobbers
+	  "cc", "xer"
+	);
+
+	local_irq_restore(flags);
+
+	return 0;
+}
+
+static int change_memory_range_fn(void *data)
+{
+	struct change_memory_parms *parms = data;
+
+	// First CPU goes through, all others wait.
+	if (atomic_xchg(&parms->master_cpu, 1) == 1)
+		return chmem_secondary_loop(parms);
+
+	// Wait for all but one CPU (this one) to call-in
+	while (atomic_read(&parms->cpu_counter) > 1)
+		barrier();
+
+	change_memory_range(parms->start, parms->end, parms->step, parms->newpp);
+
+	mb();
+
+	// Signal the other CPUs that we're done
+	atomic_dec(&parms->cpu_counter);
+
+	return 0;
+}
+
+static bool hash__change_memory_range(unsigned long start, unsigned long end,
+				      unsigned long newpp)
+{
+	unsigned int step, shift;
+
+	shift = mmu_psize_defs[mmu_linear_psize].shift;
+	step = 1 << shift;
+
+	start = ALIGN_DOWN(start, step);
+	end = ALIGN(end, step); // aligns up
+
+	if (start >= end)
+		return false;
+
+	if (firmware_has_feature(FW_FEATURE_LPAR)) {
+		mutex_lock(&chmem_lock);
+
+		chmem_parms.start = start;
+		chmem_parms.end = end;
+		chmem_parms.step = step;
+		chmem_parms.newpp = newpp;
+		atomic_set(&chmem_parms.master_cpu, 0);
+
+		cpus_read_lock();
+
+		atomic_set(&chmem_parms.cpu_counter, num_online_cpus());
+
+		// Ensure state is consistent before we call the other CPUs
+		mb();
+
+		stop_machine_cpuslocked(change_memory_range_fn, &chmem_parms,
+					cpu_online_mask);
+
+		cpus_read_unlock();
+		mutex_unlock(&chmem_lock);
+	} else
+		change_memory_range(start, end, step, newpp);
+
+	return true;
+}
+
+void hash__mark_rodata_ro(void)
+{
+	unsigned long start, end, pp;
+
+	start = (unsigned long)_stext;
+	end = (unsigned long)__end_rodata;
+
+	pp = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL_ROX), HPTE_USE_KERNEL_KEY);
+
+	WARN_ON(!hash__change_memory_range(start, end, pp));
+}
+
+void hash__mark_initmem_nx(void)
+{
+	unsigned long start, end, pp;
+
+	start = (unsigned long)__init_begin;
+	end = (unsigned long)__init_end;
+
+	pp = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL), HPTE_USE_KERNEL_KEY);
+
+	WARN_ON(!hash__change_memory_range(start, end, pp));
+}
+#endif