powerpc/mm/radix: Add tlbflush routines

Core kernel doesn't track the page size of the VA range that we are
invalidating. Hence we end up flushing TLB for the entire mm here. Later
patches will improve this.

We also don't flush page walk cache separetly instead use RIC=2 when
flushing TLB, because we do a MMU gather flush after freeing page table.

MMU_NO_CONTEXT is updated for hash.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 242 insertions, 0 deletions

diff --git a/arch/powerpc/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c
new file mode 100644
index 000000000000..ecfa00f81f1e
--- /dev/null
+++ b/arch/powerpc/mm/tlb-radix.c
@@ -0,0 +1,242 @@
+/*
+ * TLB flush routines for radix kernels.
+ *
+ * Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/memblock.h>
+
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+
+static DEFINE_RAW_SPINLOCK(native_tlbie_lock);
+
+static inline void __tlbiel_pid(unsigned long pid, int set)
+{
+	unsigned long rb,rs,ric,prs,r;
+
+	rb = PPC_BIT(53); /* IS = 1 */
+	rb |= set << PPC_BITLSHIFT(51);
+	rs = ((unsigned long)pid) << PPC_BITLSHIFT(31);
+	prs = 1; /* process scoped */
+	r = 1;   /* raidx format */
+	ric = 2;  /* invalidate all the caches */
+
+	asm volatile("ptesync": : :"memory");
+	asm volatile(".long 0x7c000224 | (%0 << 11) | (%1 << 16) |"
+		     "(%2 << 17) | (%3 << 18) | (%4 << 21)"
+		     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory");
+	asm volatile("ptesync": : :"memory");
+}
+
+/*
+ * We use 128 set in radix mode and 256 set in hpt mode.
+ */
+static inline void _tlbiel_pid(unsigned long pid)
+{
+	int set;
+
+	for (set = 0; set < POWER9_TLB_SETS_RADIX ; set++) {
+		__tlbiel_pid(pid, set);
+	}
+	return;
+}
+
+static inline void _tlbie_pid(unsigned long pid)
+{
+	unsigned long rb,rs,ric,prs,r;
+
+	rb = PPC_BIT(53); /* IS = 1 */
+	rs = pid << PPC_BITLSHIFT(31);
+	prs = 1; /* process scoped */
+	r = 1;   /* raidx format */
+	ric = 2;  /* invalidate all the caches */
+
+	asm volatile("ptesync": : :"memory");
+	asm volatile(".long 0x7c000264 | (%0 << 11) | (%1 << 16) |"
+		     "(%2 << 17) | (%3 << 18) | (%4 << 21)"
+		     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory");
+	asm volatile("eieio; tlbsync; ptesync": : :"memory");
+}
+
+static inline void _tlbiel_va(unsigned long va, unsigned long pid,
+			      unsigned long ap)
+{
+	unsigned long rb,rs,ric,prs,r;
+
+	rb = va & ~(PPC_BITMASK(52, 63));
+	rb |= ap << PPC_BITLSHIFT(58);
+	rs = pid << PPC_BITLSHIFT(31);
+	prs = 1; /* process scoped */
+	r = 1;   /* raidx format */
+	ric = 0;  /* no cluster flush yet */
+
+	asm volatile("ptesync": : :"memory");
+	asm volatile(".long 0x7c000224 | (%0 << 11) | (%1 << 16) |"
+		     "(%2 << 17) | (%3 << 18) | (%4 << 21)"
+		     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory");
+	asm volatile("ptesync": : :"memory");
+}
+
+static inline void _tlbie_va(unsigned long va, unsigned long pid,
+			     unsigned long ap)
+{
+	unsigned long rb,rs,ric,prs,r;
+
+	rb = va & ~(PPC_BITMASK(52, 63));
+	rb |= ap << PPC_BITLSHIFT(58);
+	rs = pid << PPC_BITLSHIFT(31);
+	prs = 1; /* process scoped */
+	r = 1;   /* raidx format */
+	ric = 0;  /* no cluster flush yet */
+
+	asm volatile("ptesync": : :"memory");
+	asm volatile(".long 0x7c000264 | (%0 << 11) | (%1 << 16) |"
+		     "(%2 << 17) | (%3 << 18) | (%4 << 21)"
+		     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory");
+	asm volatile("eieio; tlbsync; ptesync": : :"memory");
+}
+
+/*
+ * 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
+ */
+void radix__local_flush_tlb_mm(struct mm_struct *mm)
+{
+	unsigned int pid;
+
+	preempt_disable();
+	pid = mm->context.id;
+	if (pid != MMU_NO_CONTEXT)
+		_tlbiel_pid(pid);
+	preempt_enable();
+}
+EXPORT_SYMBOL(radix__local_flush_tlb_mm);
+
+void radix___local_flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
+			    unsigned long ap, int nid)
+{
+	unsigned int pid;
+
+	preempt_disable();
+	pid = mm ? mm->context.id : 0;
+	if (pid != MMU_NO_CONTEXT)
+		_tlbiel_va(vmaddr, pid, ap);
+	preempt_enable();
+}
+
+void radix__local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
+{
+	radix___local_flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr,
+			       mmu_get_ap(mmu_virtual_psize), 0);
+}
+EXPORT_SYMBOL(radix__local_flush_tlb_page);
+
+#ifdef CONFIG_SMP
+static int mm_is_core_local(struct mm_struct *mm)
+{
+	return cpumask_subset(mm_cpumask(mm),
+			      topology_sibling_cpumask(smp_processor_id()));
+}
+
+void radix__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)) {
+		int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
+
+		if (lock_tlbie)
+			raw_spin_lock(&native_tlbie_lock);
+		_tlbie_pid(pid);
+		if (lock_tlbie)
+			raw_spin_unlock(&native_tlbie_lock);
+	} else
+		_tlbiel_pid(pid);
+no_context:
+	preempt_enable();
+}
+EXPORT_SYMBOL(radix__flush_tlb_mm);
+
+void radix___flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
+		       unsigned long ap, int nid)
+{
+	unsigned int pid;
+
+	preempt_disable();
+	pid = mm ? mm->context.id : 0;
+	if (unlikely(pid == MMU_NO_CONTEXT))
+		goto bail;
+	if (!mm_is_core_local(mm)) {
+		int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
+
+		if (lock_tlbie)
+			raw_spin_lock(&native_tlbie_lock);
+		_tlbie_va(vmaddr, pid, ap);
+		if (lock_tlbie)
+			raw_spin_unlock(&native_tlbie_lock);
+	} else
+		_tlbiel_va(vmaddr, pid, ap);
+bail:
+	preempt_enable();
+}
+
+void radix__flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
+{
+	radix___flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr,
+			 mmu_get_ap(mmu_virtual_psize), 0);
+}
+EXPORT_SYMBOL(radix__flush_tlb_page);
+
+#endif /* CONFIG_SMP */
+
+void radix__flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+	int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
+
+	if (lock_tlbie)
+		raw_spin_lock(&native_tlbie_lock);
+	_tlbie_pid(0);
+	if (lock_tlbie)
+		raw_spin_unlock(&native_tlbie_lock);
+}
+EXPORT_SYMBOL(radix__flush_tlb_kernel_range);
+
+/*
+ * Currently, for range flushing, we just do a full mm flush. Because
+ * we use this in code path where we don' track the page size.
+ */
+void radix__flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+		     unsigned long end)
+
+{
+	struct mm_struct *mm = vma->vm_mm;
+	radix__flush_tlb_mm(mm);
+}
+EXPORT_SYMBOL(radix__flush_tlb_range);
+
+
+void radix__tlb_flush(struct mmu_gather *tlb)
+{
+	struct mm_struct *mm = tlb->mm;
+	radix__flush_tlb_mm(mm);
+}