Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

1 files changed, 290 insertions, 0 deletions

diff --git a/arch/mips/mm/context.c b/arch/mips/mm/context.c
new file mode 100644
index 000000000..966f40066
--- /dev/null
+++ b/arch/mips/mm/context.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/atomic.h>
+#include <linux/mmu_context.h>
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+
+static DEFINE_RAW_SPINLOCK(cpu_mmid_lock);
+
+static atomic64_t mmid_version;
+static unsigned int num_mmids;
+static unsigned long *mmid_map;
+
+static DEFINE_PER_CPU(u64, reserved_mmids);
+static cpumask_t tlb_flush_pending;
+
+static bool asid_versions_eq(int cpu, u64 a, u64 b)
+{
+	return ((a ^ b) & asid_version_mask(cpu)) == 0;
+}
+
+void get_new_mmu_context(struct mm_struct *mm)
+{
+	unsigned int cpu;
+	u64 asid;
+
+	/*
+	 * This function is specific to ASIDs, and should not be called when
+	 * MMIDs are in use.
+	 */
+	if (WARN_ON(IS_ENABLED(CONFIG_DEBUG_VM) && cpu_has_mmid))
+		return;
+
+	cpu = smp_processor_id();
+	asid = asid_cache(cpu);
+
+	if (!((asid += cpu_asid_inc()) & cpu_asid_mask(&cpu_data[cpu]))) {
+		if (cpu_has_vtag_icache)
+			flush_icache_all();
+		local_flush_tlb_all();	/* start new asid cycle */
+	}
+
+	set_cpu_context(cpu, mm, asid);
+	asid_cache(cpu) = asid;
+}
+EXPORT_SYMBOL_GPL(get_new_mmu_context);
+
+void check_mmu_context(struct mm_struct *mm)
+{
+	unsigned int cpu = smp_processor_id();
+
+	/*
+	 * This function is specific to ASIDs, and should not be called when
+	 * MMIDs are in use.
+	 */
+	if (WARN_ON(IS_ENABLED(CONFIG_DEBUG_VM) && cpu_has_mmid))
+		return;
+
+	/* Check if our ASID is of an older version and thus invalid */
+	if (!asid_versions_eq(cpu, cpu_context(cpu, mm), asid_cache(cpu)))
+		get_new_mmu_context(mm);
+}
+EXPORT_SYMBOL_GPL(check_mmu_context);
+
+static void flush_context(void)
+{
+	u64 mmid;
+	int cpu;
+
+	/* Update the list of reserved MMIDs and the MMID bitmap */
+	bitmap_zero(mmid_map, num_mmids);
+
+	/* Reserve an MMID for kmap/wired entries */
+	__set_bit(MMID_KERNEL_WIRED, mmid_map);
+
+	for_each_possible_cpu(cpu) {
+		mmid = xchg_relaxed(&cpu_data[cpu].asid_cache, 0);
+
+		/*
+		 * If this CPU has already been through a
+		 * rollover, but hasn't run another task in
+		 * the meantime, we must preserve its reserved
+		 * MMID, as this is the only trace we have of
+		 * the process it is still running.
+		 */
+		if (mmid == 0)
+			mmid = per_cpu(reserved_mmids, cpu);
+
+		__set_bit(mmid & cpu_asid_mask(&cpu_data[cpu]), mmid_map);
+		per_cpu(reserved_mmids, cpu) = mmid;
+	}
+
+	/*
+	 * Queue a TLB invalidation for each CPU to perform on next
+	 * context-switch
+	 */
+	cpumask_setall(&tlb_flush_pending);
+}
+
+static bool check_update_reserved_mmid(u64 mmid, u64 newmmid)
+{
+	bool hit;
+	int cpu;
+
+	/*
+	 * Iterate over the set of reserved MMIDs looking for a match.
+	 * If we find one, then we can update our mm to use newmmid
+	 * (i.e. the same MMID in the current generation) but we can't
+	 * exit the loop early, since we need to ensure that all copies
+	 * of the old MMID are updated to reflect the mm. Failure to do
+	 * so could result in us missing the reserved MMID in a future
+	 * generation.
+	 */
+	hit = false;
+	for_each_possible_cpu(cpu) {
+		if (per_cpu(reserved_mmids, cpu) == mmid) {
+			hit = true;
+			per_cpu(reserved_mmids, cpu) = newmmid;
+		}
+	}
+
+	return hit;
+}
+
+static u64 get_new_mmid(struct mm_struct *mm)
+{
+	static u32 cur_idx = MMID_KERNEL_WIRED + 1;
+	u64 mmid, version, mmid_mask;
+
+	mmid = cpu_context(0, mm);
+	version = atomic64_read(&mmid_version);
+	mmid_mask = cpu_asid_mask(&boot_cpu_data);
+
+	if (!asid_versions_eq(0, mmid, 0)) {
+		u64 newmmid = version | (mmid & mmid_mask);
+
+		/*
+		 * If our current MMID was active during a rollover, we
+		 * can continue to use it and this was just a false alarm.
+		 */
+		if (check_update_reserved_mmid(mmid, newmmid)) {
+			mmid = newmmid;
+			goto set_context;
+		}
+
+		/*
+		 * We had a valid MMID in a previous life, so try to re-use
+		 * it if possible.
+		 */
+		if (!__test_and_set_bit(mmid & mmid_mask, mmid_map)) {
+			mmid = newmmid;
+			goto set_context;
+		}
+	}
+
+	/* Allocate a free MMID */
+	mmid = find_next_zero_bit(mmid_map, num_mmids, cur_idx);
+	if (mmid != num_mmids)
+		goto reserve_mmid;
+
+	/* We're out of MMIDs, so increment the global version */
+	version = atomic64_add_return_relaxed(asid_first_version(0),
+					      &mmid_version);
+
+	/* Note currently active MMIDs & mark TLBs as requiring flushes */
+	flush_context();
+
+	/* We have more MMIDs than CPUs, so this will always succeed */
+	mmid = find_first_zero_bit(mmid_map, num_mmids);
+
+reserve_mmid:
+	__set_bit(mmid, mmid_map);
+	cur_idx = mmid;
+	mmid |= version;
+set_context:
+	set_cpu_context(0, mm, mmid);
+	return mmid;
+}
+
+void check_switch_mmu_context(struct mm_struct *mm)
+{
+	unsigned int cpu = smp_processor_id();
+	u64 ctx, old_active_mmid;
+	unsigned long flags;
+
+	if (!cpu_has_mmid) {
+		check_mmu_context(mm);
+		write_c0_entryhi(cpu_asid(cpu, mm));
+		goto setup_pgd;
+	}
+
+	/*
+	 * MMID switch fast-path, to avoid acquiring cpu_mmid_lock when it's
+	 * unnecessary.
+	 *
+	 * The memory ordering here is subtle. If our active_mmids is non-zero
+	 * and the MMID matches the current version, then we update the CPU's
+	 * asid_cache 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
+	 *   cpu_mmid_lock in check_mmu_context(). Taking the lock synchronises
+	 *   with the rollover and so we are forced to see the updated
+	 *   generation.
+	 *
+	 * - We get a valid MMID 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.
+	 */
+	ctx = cpu_context(cpu, mm);
+	old_active_mmid = READ_ONCE(cpu_data[cpu].asid_cache);
+	if (!old_active_mmid ||
+	    !asid_versions_eq(cpu, ctx, atomic64_read(&mmid_version)) ||
+	    !cmpxchg_relaxed(&cpu_data[cpu].asid_cache, old_active_mmid, ctx)) {
+		raw_spin_lock_irqsave(&cpu_mmid_lock, flags);
+
+		ctx = cpu_context(cpu, mm);
+		if (!asid_versions_eq(cpu, ctx, atomic64_read(&mmid_version)))
+			ctx = get_new_mmid(mm);
+
+		WRITE_ONCE(cpu_data[cpu].asid_cache, ctx);
+		raw_spin_unlock_irqrestore(&cpu_mmid_lock, flags);
+	}
+
+	/*
+	 * Invalidate the local TLB if needed. Note that we must only clear our
+	 * bit in tlb_flush_pending after this is complete, so that the
+	 * cpu_has_shared_ftlb_entries case below isn't misled.
+	 */
+	if (cpumask_test_cpu(cpu, &tlb_flush_pending)) {
+		if (cpu_has_vtag_icache)
+			flush_icache_all();
+		local_flush_tlb_all();
+		cpumask_clear_cpu(cpu, &tlb_flush_pending);
+	}
+
+	write_c0_memorymapid(ctx & cpu_asid_mask(&boot_cpu_data));
+
+	/*
+	 * If this CPU shares FTLB entries with its siblings and one or more of
+	 * those siblings hasn't yet invalidated its TLB following a version
+	 * increase then we need to invalidate any TLB entries for our MMID
+	 * that we might otherwise pick up from a sibling.
+	 *
+	 * We ifdef on CONFIG_SMP because cpu_sibling_map isn't defined in
+	 * CONFIG_SMP=n kernels.
+	 */
+#ifdef CONFIG_SMP
+	if (cpu_has_shared_ftlb_entries &&
+	    cpumask_intersects(&tlb_flush_pending, &cpu_sibling_map[cpu])) {
+		/* Ensure we operate on the new MMID */
+		mtc0_tlbw_hazard();
+
+		/*
+		 * Invalidate all TLB entries associated with the new
+		 * MMID, and wait for the invalidation to complete.
+		 */
+		ginvt_mmid();
+		sync_ginv();
+	}
+#endif
+
+setup_pgd:
+	TLBMISS_HANDLER_SETUP_PGD(mm->pgd);
+}
+EXPORT_SYMBOL_GPL(check_switch_mmu_context);
+
+static int mmid_init(void)
+{
+	if (!cpu_has_mmid)
+		return 0;
+
+	/*
+	 * Expect allocation after rollover to fail if we don't have at least
+	 * one more MMID than CPUs.
+	 */
+	num_mmids = asid_first_version(0);
+	WARN_ON(num_mmids <= num_possible_cpus());
+
+	atomic64_set(&mmid_version, asid_first_version(0));
+	mmid_map = bitmap_zalloc(num_mmids, GFP_KERNEL);
+	if (!mmid_map)
+		panic("Failed to allocate bitmap for %u MMIDs\n", num_mmids);
+
+	/* Reserve an MMID for kmap/wired entries */
+	__set_bit(MMID_KERNEL_WIRED, mmid_map);
+
+	pr_info("MMID allocator initialised with %u entries\n", num_mmids);
+	return 0;
+}
+early_initcall(mmid_init);