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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/arm/mm/copypage-xsc3.c
Initial import
Diffstat (limited to 'arch/arm/mm/copypage-xsc3.c')
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diff --git a/arch/arm/mm/copypage-xsc3.c b/arch/arm/mm/copypage-xsc3.c
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+++ b/arch/arm/mm/copypage-xsc3.c
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+/*
+ * linux/arch/arm/mm/copypage-xsc3.S
+ *
+ * Copyright (C) 2004 Intel Corp.
+ *
+ * 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.
+ *
+ * Adapted for 3rd gen XScale core, no more mini-dcache
+ * Author: Matt Gilbert (matthew.m.gilbert@intel.com)
+ */
+#include <linux/init.h>
+#include <linux/highmem.h>
+
+/*
+ * General note:
+ * We don't really want write-allocate cache behaviour for these functions
+ * since that will just eat through 8K of the cache.
+ */
+
+/*
+ * XSC3 optimised copy_user_highpage
+ * r0 = destination
+ * r1 = source
+ *
+ * The source page may have some clean entries in the cache already, but we
+ * can safely ignore them - break_cow() will flush them out of the cache
+ * if we eventually end up using our copied page.
+ *
+ */
+static void __naked
+xsc3_mc_copy_user_page(void *kto, const void *kfrom)
+{
+ asm("\
+ stmfd sp!, {r4, r5, lr} \n\
+ mov lr, %2 \n\
+ \n\
+ pld [r1, #0] \n\
+ pld [r1, #32] \n\
+1: pld [r1, #64] \n\
+ pld [r1, #96] \n\
+ \n\
+2: ldrd r2, [r1], #8 \n\
+ mov ip, r0 \n\
+ ldrd r4, [r1], #8 \n\
+ mcr p15, 0, ip, c7, c6, 1 @ invalidate\n\
+ strd r2, [r0], #8 \n\
+ ldrd r2, [r1], #8 \n\
+ strd r4, [r0], #8 \n\
+ ldrd r4, [r1], #8 \n\
+ strd r2, [r0], #8 \n\
+ strd r4, [r0], #8 \n\
+ ldrd r2, [r1], #8 \n\
+ mov ip, r0 \n\
+ ldrd r4, [r1], #8 \n\
+ mcr p15, 0, ip, c7, c6, 1 @ invalidate\n\
+ strd r2, [r0], #8 \n\
+ ldrd r2, [r1], #8 \n\
+ subs lr, lr, #1 \n\
+ strd r4, [r0], #8 \n\
+ ldrd r4, [r1], #8 \n\
+ strd r2, [r0], #8 \n\
+ strd r4, [r0], #8 \n\
+ bgt 1b \n\
+ beq 2b \n\
+ \n\
+ ldmfd sp!, {r4, r5, pc}"
+ :
+ : "r" (kto), "r" (kfrom), "I" (PAGE_SIZE / 64 - 1));
+}
+
+void xsc3_mc_copy_user_highpage(struct page *to, struct page *from,
+ unsigned long vaddr, struct vm_area_struct *vma)
+{
+ void *kto, *kfrom;
+
+ kto = kmap_atomic(to);
+ kfrom = kmap_atomic(from);
+ flush_cache_page(vma, vaddr, page_to_pfn(from));
+ xsc3_mc_copy_user_page(kto, kfrom);
+ kunmap_atomic(kfrom);
+ kunmap_atomic(kto);
+}
+
+/*
+ * XScale optimised clear_user_page
+ * r0 = destination
+ * r1 = virtual user address of ultimate destination page
+ */
+void xsc3_mc_clear_user_highpage(struct page *page, unsigned long vaddr)
+{
+ void *ptr, *kaddr = kmap_atomic(page);
+ asm volatile ("\
+ mov r1, %2 \n\
+ mov r2, #0 \n\
+ mov r3, #0 \n\
+1: mcr p15, 0, %0, c7, c6, 1 @ invalidate line\n\
+ strd r2, [%0], #8 \n\
+ strd r2, [%0], #8 \n\
+ strd r2, [%0], #8 \n\
+ strd r2, [%0], #8 \n\
+ subs r1, r1, #1 \n\
+ bne 1b"
+ : "=r" (ptr)
+ : "0" (kaddr), "I" (PAGE_SIZE / 32)
+ : "r1", "r2", "r3");
+ kunmap_atomic(kaddr);
+}
+
+struct cpu_user_fns xsc3_mc_user_fns __initdata = {
+ .cpu_clear_user_highpage = xsc3_mc_clear_user_highpage,
+ .cpu_copy_user_highpage = xsc3_mc_copy_user_highpage,
+};