From 5bba49f5397c012d873c73860ad7b50c526e613b Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Thu, 9 May 2013 19:20:43 +0530 Subject: [PATCH] ARC: [mm] Aliasing VIPT dcache support 4/4 Enforce congruency of userspace shared mappings Signed-off-by: Vineet Gupta --- arch/arc/include/asm/Kbuild | 1 - arch/arc/include/asm/cache.h | 3 -- arch/arc/include/asm/cacheflush.h | 1 + arch/arc/include/asm/pgtable.h | 3 ++ arch/arc/include/asm/shmparam.h | 18 +++++++++ arch/arc/mm/Makefile | 2 +- arch/arc/mm/mmap.c | 78 +++++++++++++++++++++++++++++++++++++++ 7 files changed, 101 insertions(+), 5 deletions(-) create mode 100644 arch/arc/include/asm/shmparam.h create mode 100644 arch/arc/mm/mmap.c diff --git a/arch/arc/include/asm/Kbuild b/arch/arc/include/asm/Kbuild index 48af742..d8dd660 100644 --- a/arch/arc/include/asm/Kbuild +++ b/arch/arc/include/asm/Kbuild @@ -32,7 +32,6 @@ generic-y += resource.h generic-y += scatterlist.h generic-y += sembuf.h generic-y += shmbuf.h -generic-y += shmparam.h generic-y += siginfo.h generic-y += socket.h generic-y += sockios.h diff --git a/arch/arc/include/asm/cache.h b/arch/arc/include/asm/cache.h index 6632273..d5555fe 100644 --- a/arch/arc/include/asm/cache.h +++ b/arch/arc/include/asm/cache.h @@ -55,9 +55,6 @@ : "r"(data), "r"(ptr)); \ }) -/* used to give SHMLBA a value to avoid Cache Aliasing */ -extern unsigned int ARC_shmlba; - #define ARCH_DMA_MINALIGN L1_CACHE_BYTES /* diff --git a/arch/arc/include/asm/cacheflush.h b/arch/arc/include/asm/cacheflush.h index 14a0fea..9f841af 100644 --- a/arch/arc/include/asm/cacheflush.h +++ b/arch/arc/include/asm/cacheflush.h @@ -19,6 +19,7 @@ #define _ASM_CACHEFLUSH_H #include +#include /* * Semantically we need this because icache doesn't snoop dcache/dma. diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h index b7e3668..1cc4720 100644 --- a/arch/arc/include/asm/pgtable.h +++ b/arch/arc/include/asm/pgtable.h @@ -395,6 +395,9 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, #include +/* to cope with aliasing VIPT cache */ +#define HAVE_ARCH_UNMAPPED_AREA + /* * No page table caches to initialise */ diff --git a/arch/arc/include/asm/shmparam.h b/arch/arc/include/asm/shmparam.h new file mode 100644 index 0000000..fffeecc --- /dev/null +++ b/arch/arc/include/asm/shmparam.h @@ -0,0 +1,18 @@ +/* + * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com) + * + * 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. + */ + +#ifndef __ARC_ASM_SHMPARAM_H +#define __ARC_ASM_SHMPARAM_H + +/* Handle upto 2 cache bins */ +#define SHMLBA (2 * PAGE_SIZE) + +/* Enforce SHMLBA in shmat */ +#define __ARCH_FORCE_SHMLBA + +#endif diff --git a/arch/arc/mm/Makefile b/arch/arc/mm/Makefile index 168dc14..ac95cc2 100644 --- a/arch/arc/mm/Makefile +++ b/arch/arc/mm/Makefile @@ -7,4 +7,4 @@ # obj-y := extable.o ioremap.o dma.o fault.o init.o -obj-y += tlb.o tlbex.o cache_arc700.o +obj-y += tlb.o tlbex.o cache_arc700.o mmap.o diff --git a/arch/arc/mm/mmap.c b/arch/arc/mm/mmap.c new file mode 100644 index 0000000..2e06d56 --- /dev/null +++ b/arch/arc/mm/mmap.c @@ -0,0 +1,78 @@ +/* + * ARC700 mmap + * + * (started from arm version - for VIPT alias handling) + * + * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com) + * + * 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. + */ + +#include +#include +#include +#include +#include + +#define COLOUR_ALIGN(addr, pgoff) \ + ((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \ + (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1))) + +/* + * Ensure that shared mappings are correctly aligned to + * avoid aliasing issues with VIPT caches. + * We need to ensure that + * a specific page of an object is always mapped at a multiple of + * SHMLBA bytes. + */ +unsigned long +arch_get_unmapped_area(struct file *filp, unsigned long addr, + unsigned long len, unsigned long pgoff, unsigned long flags) +{ + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + int do_align = 0; + int aliasing = cache_is_vipt_aliasing(); + struct vm_unmapped_area_info info; + + /* + * We only need to do colour alignment if D cache aliases. + */ + if (aliasing) + do_align = filp || (flags & MAP_SHARED); + + /* + * We enforce the MAP_FIXED case. + */ + if (flags & MAP_FIXED) { + if (aliasing && flags & MAP_SHARED && + (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)) + return -EINVAL; + return addr; + } + + if (len > TASK_SIZE) + return -ENOMEM; + + if (addr) { + if (do_align) + addr = COLOUR_ALIGN(addr, pgoff); + else + addr = PAGE_ALIGN(addr); + + vma = find_vma(mm, addr); + if (TASK_SIZE - len >= addr && + (!vma || addr + len <= vma->vm_start)) + return addr; + } + + info.flags = 0; + info.length = len; + info.low_limit = mm->mmap_base; + info.high_limit = TASK_SIZE; + info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0; + info.align_offset = pgoff << PAGE_SHIFT; + return vm_unmapped_area(&info); +} -- 2.7.4