diff options
author | 2015-08-04 12:17:53 -0700 | |
---|---|---|
committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/arm/mm/copypage-v4mc.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/arm/mm/copypage-v4mc.c')
-rw-r--r-- | kernel/arch/arm/mm/copypage-v4mc.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/kernel/arch/arm/mm/copypage-v4mc.c b/kernel/arch/arm/mm/copypage-v4mc.c new file mode 100644 index 000000000..1267e6413 --- /dev/null +++ b/kernel/arch/arm/mm/copypage-v4mc.c @@ -0,0 +1,115 @@ +/* + * linux/arch/arm/lib/copypage-armv4mc.S + * + * Copyright (C) 1995-2005 Russell King + * + * 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 handles the mini data cache, as found on SA11x0 and XScale + * processors. When we copy a user page page, we map it in such a way + * that accesses to this page will not touch the main data cache, but + * will be cached in the mini data cache. This prevents us thrashing + * the main data cache on page faults. + */ +#include <linux/init.h> +#include <linux/mm.h> +#include <linux/highmem.h> + +#include <asm/pgtable.h> +#include <asm/tlbflush.h> +#include <asm/cacheflush.h> + +#include "mm.h" + +#define minicache_pgprot __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | \ + L_PTE_MT_MINICACHE) + +static DEFINE_RAW_SPINLOCK(minicache_lock); + +/* + * ARMv4 mini-dcache optimised copy_user_highpage + * + * We flush the destination cache lines just before we write the data into the + * corresponding address. Since the Dcache is read-allocate, this removes the + * Dcache aliasing issue. The writes will be forwarded to the write buffer, + * and merged as appropriate. + * + * Note: We rely on all ARMv4 processors implementing the "invalidate D line" + * instruction. If your processor does not supply this, you have to write your + * own copy_user_highpage that does the right thing. + */ +static void __naked +mc_copy_user_page(void *from, void *to) +{ + asm volatile( + "stmfd sp!, {r4, lr} @ 2\n\ + mov r4, %2 @ 1\n\ + ldmia %0!, {r2, r3, ip, lr} @ 4\n\ +1: mcr p15, 0, %1, c7, c6, 1 @ 1 invalidate D line\n\ + stmia %1!, {r2, r3, ip, lr} @ 4\n\ + ldmia %0!, {r2, r3, ip, lr} @ 4+1\n\ + stmia %1!, {r2, r3, ip, lr} @ 4\n\ + ldmia %0!, {r2, r3, ip, lr} @ 4\n\ + mcr p15, 0, %1, c7, c6, 1 @ 1 invalidate D line\n\ + stmia %1!, {r2, r3, ip, lr} @ 4\n\ + ldmia %0!, {r2, r3, ip, lr} @ 4\n\ + subs r4, r4, #1 @ 1\n\ + stmia %1!, {r2, r3, ip, lr} @ 4\n\ + ldmneia %0!, {r2, r3, ip, lr} @ 4\n\ + bne 1b @ 1\n\ + ldmfd sp!, {r4, pc} @ 3" + : + : "r" (from), "r" (to), "I" (PAGE_SIZE / 64)); +} + +void v4_mc_copy_user_highpage(struct page *to, struct page *from, + unsigned long vaddr, struct vm_area_struct *vma) +{ + void *kto = kmap_atomic(to); + + if (!test_and_set_bit(PG_dcache_clean, &from->flags)) + __flush_dcache_page(page_mapping(from), from); + + raw_spin_lock(&minicache_lock); + + set_top_pte(COPYPAGE_MINICACHE, mk_pte(from, minicache_pgprot)); + + mc_copy_user_page((void *)COPYPAGE_MINICACHE, kto); + + raw_spin_unlock(&minicache_lock); + + kunmap_atomic(kto); +} + +/* + * ARMv4 optimised clear_user_page + */ +void v4_mc_clear_user_highpage(struct page *page, unsigned long vaddr) +{ + void *ptr, *kaddr = kmap_atomic(page); + asm volatile("\ + mov r1, %2 @ 1\n\ + mov r2, #0 @ 1\n\ + mov r3, #0 @ 1\n\ + mov ip, #0 @ 1\n\ + mov lr, #0 @ 1\n\ +1: mcr p15, 0, %0, c7, c6, 1 @ 1 invalidate D line\n\ + stmia %0!, {r2, r3, ip, lr} @ 4\n\ + stmia %0!, {r2, r3, ip, lr} @ 4\n\ + mcr p15, 0, %0, c7, c6, 1 @ 1 invalidate D line\n\ + stmia %0!, {r2, r3, ip, lr} @ 4\n\ + stmia %0!, {r2, r3, ip, lr} @ 4\n\ + subs r1, r1, #1 @ 1\n\ + bne 1b @ 1" + : "=r" (ptr) + : "0" (kaddr), "I" (PAGE_SIZE / 64) + : "r1", "r2", "r3", "ip", "lr"); + kunmap_atomic(kaddr); +} + +struct cpu_user_fns v4_mc_user_fns __initdata = { + .cpu_clear_user_highpage = v4_mc_clear_user_highpage, + .cpu_copy_user_highpage = v4_mc_copy_user_highpage, +}; |