arm64: TLB maintenance functionality

This patch adds the TLB maintenance functions. There is no distinction
made between the I and D TLBs. TLB maintenance operations are
automatically broadcast between CPUs in hardware. The inner-shareable
operations are always present, even on UP systems.

NOTE: Large part of this patch to be dropped once Peter Z's generic
mmu_gather patches are merged.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 122 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
new file mode 100644
index 000000000000..122d6320f745
--- /dev/null
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -0,0 +1,122 @@
+/*
+ * Based on arch/arm/include/asm/tlbflush.h
+ *
+ * Copyright (C) 1999-2003 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_TLBFLUSH_H
+#define __ASM_TLBFLUSH_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/sched.h>
+#include <asm/cputype.h>
+
+extern void __cpu_flush_user_tlb_range(unsigned long, unsigned long, struct vm_area_struct *);
+extern void __cpu_flush_kern_tlb_range(unsigned long, unsigned long);
+
+extern struct cpu_tlb_fns cpu_tlb;
+
+/*
+ *	TLB Management
+ *	==============
+ *
+ *	The arch/arm64/mm/tlb.S files implement these methods.
+ *
+ *	The TLB specific code is expected to perform whatever tests it needs
+ *	to determine if it should invalidate the TLB for each call.  Start
+ *	addresses are inclusive and end addresses are exclusive; it is safe to
+ *	round these addresses down.
+ *
+ *	flush_tlb_all()
+ *
+ *		Invalidate the entire TLB.
+ *
+ *	flush_tlb_mm(mm)
+ *
+ *		Invalidate all TLB entries in a particular address space.
+ *		- mm	- mm_struct describing address space
+ *
+ *	flush_tlb_range(mm,start,end)
+ *
+ *		Invalidate a range of TLB entries in the specified address
+ *		space.
+ *		- mm	- mm_struct describing address space
+ *		- start - start address (may not be aligned)
+ *		- end	- end address (exclusive, may not be aligned)
+ *
+ *	flush_tlb_page(vaddr,vma)
+ *
+ *		Invalidate the specified page in the specified address range.
+ *		- vaddr - virtual address (may not be aligned)
+ *		- vma	- vma_struct describing address range
+ *
+ *	flush_kern_tlb_page(kaddr)
+ *
+ *		Invalidate the TLB entry for the specified page.  The address
+ *		will be in the kernels virtual memory space.  Current uses
+ *		only require the D-TLB to be invalidated.
+ *		- kaddr - Kernel virtual memory address
+ */
+static inline void flush_tlb_all(void)
+{
+	dsb();
+	asm("tlbi	vmalle1is");
+	dsb();
+	isb();
+}
+
+static inline void flush_tlb_mm(struct mm_struct *mm)
+{
+	unsigned long asid = (unsigned long)ASID(mm) << 48;
+
+	dsb();
+	asm("tlbi	aside1is, %0" : : "r" (asid));
+	dsb();
+}
+
+static inline void flush_tlb_page(struct vm_area_struct *vma,
+				  unsigned long uaddr)
+{
+	unsigned long addr = uaddr >> 12 |
+		((unsigned long)ASID(vma->vm_mm) << 48);
+
+	dsb();
+	asm("tlbi	vae1is, %0" : : "r" (addr));
+	dsb();
+}
+
+/*
+ * Convert calls to our calling convention.
+ */
+#define flush_tlb_range(vma,start,end)	__cpu_flush_user_tlb_range(start,end,vma)
+#define flush_tlb_kernel_range(s,e)	__cpu_flush_kern_tlb_range(s,e)
+
+/*
+ * On AArch64, the cache coherency is handled via the set_pte_at() function.
+ */
+static inline void update_mmu_cache(struct vm_area_struct *vma,
+				    unsigned long addr, pte_t *ptep)
+{
+	/*
+	 * set_pte() does not have a DSB, so make sure that the page table
+	 * write is visible.
+	 */
+	dsb();
+}
+
+#endif
+
+#endif