1 files changed, 341 insertions, 0 deletions
diff --git a/arch/powerpc/mm/nohash/tlb.c b/arch/powerpc/mm/nohash/tlb.c
new file mode 100644
index 000000000000..0a650742f3a0
--- /dev/null
+++ b/arch/powerpc/mm/nohash/tlb.c
@@ -0,0 +1,341 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * This file contains the routines for TLB flushing.
+ * On machines where the MMU does not use a hash table to store virtual to
+ * physical translations (ie, SW loaded TLBs or Book3E compilant processors,
+ * this does -not- include 603 however which shares the implementation with
+ * hash based processors)
+ *
+ *  -- BenH
+ *
+ * Copyright 2008,2009 Ben Herrenschmidt <benh@kernel.crashing.org>
+ *                     IBM Corp.
+ *
+ *  Derived from arch/ppc/mm/init.c:
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
+ *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
+ *    Copyright (C) 1996 Paul Mackerras
+ *
+ *  Derived from "arch/i386/mm/init.c"
+ *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
+ */
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <linux/preempt.h>
+#include <linux/spinlock.h>
+#include <linux/memblock.h>
+#include <linux/of_fdt.h>
+#include <linux/hugetlb.h>
+
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+#include <asm/tlb.h>
+#include <asm/text-patching.h>
+#include <asm/cputhreads.h>
+#include <asm/hugetlb.h>
+#include <asm/paca.h>
+
+#include <mm/mmu_decl.h>
+
+/*
+ * This struct lists the sw-supported page sizes.  The hardawre MMU may support
+ * other sizes not listed here.   The .ind field is only used on MMUs that have
+ * indirect page table entries.
+ */
+#ifdef CONFIG_PPC_E500
+struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
+	[MMU_PAGE_4K] = {
+		.shift	= 12,
+	},
+	[MMU_PAGE_2M] = {
+		.shift	= 21,
+	},
+	[MMU_PAGE_4M] = {
+		.shift	= 22,
+	},
+	[MMU_PAGE_16M] = {
+		.shift	= 24,
+	},
+	[MMU_PAGE_64M] = {
+		.shift	= 26,
+	},
+	[MMU_PAGE_256M] = {
+		.shift	= 28,
+	},
+	[MMU_PAGE_1G] = {
+		.shift	= 30,
+	},
+};
+
+static inline int mmu_get_tsize(int psize)
+{
+	return mmu_psize_defs[psize].shift - 10;
+}
+#else
+static inline int mmu_get_tsize(int psize)
+{
+	/* This isn't used on !Book3E for now */
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_PPC_8xx
+struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
+	[MMU_PAGE_4K] = {
+		.shift	= 12,
+	},
+	[MMU_PAGE_16K] = {
+		.shift	= 14,
+	},
+	[MMU_PAGE_512K] = {
+		.shift	= 19,
+	},
+	[MMU_PAGE_8M] = {
+		.shift	= 23,
+	},
+};
+#endif
+
+#ifdef CONFIG_PPC_E500
+/* next_tlbcam_idx is used to round-robin tlbcam entry assignment */
+DEFINE_PER_CPU(int, next_tlbcam_idx);
+EXPORT_PER_CPU_SYMBOL(next_tlbcam_idx);
+#endif
+
+/*
+ * Base TLB flushing operations:
+ *
+ *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
+ *  - flush_tlb_page(vma, vmaddr) flushes one page
+ *  - flush_tlb_range(vma, start, end) flushes a range of pages
+ *  - flush_tlb_kernel_range(start, end) flushes kernel pages
+ *
+ *  - local_* variants of page and mm only apply to the current
+ *    processor
+ */
+
+#ifndef CONFIG_PPC_8xx
+/*
+ * These are the base non-SMP variants of page and mm flushing
+ */
+void local_flush_tlb_mm(struct mm_struct *mm)
+{
+	unsigned int pid;
+
+	preempt_disable();
+	pid = mm->context.id;
+	if (pid != MMU_NO_CONTEXT)
+		_tlbil_pid(pid);
+	preempt_enable();
+}
+EXPORT_SYMBOL(local_flush_tlb_mm);
+
+void __local_flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
+			    int tsize, int ind)
+{
+	unsigned int pid;
+
+	preempt_disable();
+	pid = mm ? mm->context.id : 0;
+	if (pid != MMU_NO_CONTEXT)
+		_tlbil_va(vmaddr, pid, tsize, ind);
+	preempt_enable();
+}
+
+void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
+{
+	__local_flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr,
+			       mmu_get_tsize(mmu_virtual_psize), 0);
+}
+EXPORT_SYMBOL(local_flush_tlb_page);
+
+void local_flush_tlb_page_psize(struct mm_struct *mm,
+				unsigned long vmaddr, int psize)
+{
+	__local_flush_tlb_page(mm, vmaddr, mmu_get_tsize(psize), 0);
+}
+EXPORT_SYMBOL(local_flush_tlb_page_psize);
+
+#endif
+
+/*
+ * And here are the SMP non-local implementations
+ */
+#ifdef CONFIG_SMP
+
+static DEFINE_RAW_SPINLOCK(tlbivax_lock);
+
+struct tlb_flush_param {
+	unsigned long addr;
+	unsigned int pid;
+	unsigned int tsize;
+	unsigned int ind;
+};
+
+static void do_flush_tlb_mm_ipi(void *param)
+{
+	struct tlb_flush_param *p = param;
+
+	_tlbil_pid(p ? p->pid : 0);
+}
+
+static void do_flush_tlb_page_ipi(void *param)
+{
+	struct tlb_flush_param *p = param;
+
+	_tlbil_va(p->addr, p->pid, p->tsize, p->ind);
+}
+
+
+/* Note on invalidations and PID:
+ *
+ * We snapshot the PID with preempt disabled. At this point, it can still
+ * change either because:
+ * - our context is being stolen (PID -> NO_CONTEXT) on another CPU
+ * - we are invaliating some target that isn't currently running here
+ *   and is concurrently acquiring a new PID on another CPU
+ * - some other CPU is re-acquiring a lost PID for this mm
+ * etc...
+ *
+ * However, this shouldn't be a problem as we only guarantee
+ * invalidation of TLB entries present prior to this call, so we
+ * don't care about the PID changing, and invalidating a stale PID
+ * is generally harmless.
+ */
+
+void flush_tlb_mm(struct mm_struct *mm)
+{
+	unsigned int pid;
+
+	preempt_disable();
+	pid = mm->context.id;
+	if (unlikely(pid == MMU_NO_CONTEXT))
+		goto no_context;
+	if (!mm_is_core_local(mm)) {
+		struct tlb_flush_param p = { .pid = pid };
+		/* Ignores smp_processor_id() even if set. */
+		smp_call_function_many(mm_cpumask(mm),
+				       do_flush_tlb_mm_ipi, &p, 1);
+	}
+	_tlbil_pid(pid);
+ no_context:
+	preempt_enable();
+}
+EXPORT_SYMBOL(flush_tlb_mm);
+
+void __flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
+		      int tsize, int ind)
+{
+	struct cpumask *cpu_mask;
+	unsigned int pid;
+
+	/*
+	 * This function as well as __local_flush_tlb_page() must only be called
+	 * for user contexts.
+	 */
+	if (WARN_ON(!mm))
+		return;
+
+	preempt_disable();
+	pid = mm->context.id;
+	if (unlikely(pid == MMU_NO_CONTEXT))
+		goto bail;
+	cpu_mask = mm_cpumask(mm);
+	if (!mm_is_core_local(mm)) {
+		/* If broadcast tlbivax is supported, use it */
+		if (mmu_has_feature(MMU_FTR_USE_TLBIVAX_BCAST)) {
+			int lock = mmu_has_feature(MMU_FTR_LOCK_BCAST_INVAL);
+			if (lock)
+				raw_spin_lock(&tlbivax_lock);
+			_tlbivax_bcast(vmaddr, pid, tsize, ind);
+			if (lock)
+				raw_spin_unlock(&tlbivax_lock);
+			goto bail;
+		} else {
+			struct tlb_flush_param p = {
+				.pid = pid,
+				.addr = vmaddr,
+				.tsize = tsize,
+				.ind = ind,
+			};
+			/* Ignores smp_processor_id() even if set in cpu_mask */
+			smp_call_function_many(cpu_mask,
+					       do_flush_tlb_page_ipi, &p, 1);
+		}
+	}
+	_tlbil_va(vmaddr, pid, tsize, ind);
+ bail:
+	preempt_enable();
+}
+
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
+{
+#ifdef CONFIG_HUGETLB_PAGE
+	if (vma && is_vm_hugetlb_page(vma))
+		flush_hugetlb_page(vma, vmaddr);
+#endif
+
+	__flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr,
+			 mmu_get_tsize(mmu_virtual_psize), 0);
+}
+EXPORT_SYMBOL(flush_tlb_page);
+
+#endif /* CONFIG_SMP */
+
+/*
+ * Flush kernel TLB entries in the given range
+ */
+#ifndef CONFIG_PPC_8xx
+void flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+#ifdef CONFIG_SMP
+	preempt_disable();
+	smp_call_function(do_flush_tlb_mm_ipi, NULL, 1);
+	_tlbil_pid(0);
+	preempt_enable();
+#else
+	_tlbil_pid(0);
+#endif
+}
+EXPORT_SYMBOL(flush_tlb_kernel_range);
+#endif
+
+/*
+ * Currently, for range flushing, we just do a full mm flush. This should
+ * be optimized based on a threshold on the size of the range, since
+ * some implementation can stack multiple tlbivax before a tlbsync but
+ * for now, we keep it that way
+ */
+void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+		     unsigned long end)
+
+{
+	if (end - start == PAGE_SIZE && !(start & ~PAGE_MASK))
+		flush_tlb_page(vma, start);
+	else
+		flush_tlb_mm(vma->vm_mm);
+}
+EXPORT_SYMBOL(flush_tlb_range);
+
+void tlb_flush(struct mmu_gather *tlb)
+{
+	flush_tlb_mm(tlb->mm);
+}
+
+#ifndef CONFIG_PPC64
+void __init early_init_mmu(void)
+{
+	unsigned long root = of_get_flat_dt_root();
+
+	if (IS_ENABLED(CONFIG_PPC_47x) && IS_ENABLED(CONFIG_SMP) &&
+	    of_get_flat_dt_prop(root, "cooperative-partition", NULL))
+		mmu_clear_feature(MMU_FTR_USE_TLBIVAX_BCAST);
+}
+#endif /* CONFIG_PPC64 */