From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- arch/m68k/mm/cache.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) create mode 100644 arch/m68k/mm/cache.c (limited to 'arch/m68k/mm/cache.c') diff --git a/arch/m68k/mm/cache.c b/arch/m68k/mm/cache.c new file mode 100644 index 000000000..dde978e66 --- /dev/null +++ b/arch/m68k/mm/cache.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/arch/m68k/mm/cache.c + * + * Instruction cache handling + * + * Copyright (C) 1995 Hamish Macdonald + */ + +#include +#include +#include + + +static unsigned long virt_to_phys_slow(unsigned long vaddr) +{ + if (CPU_IS_060) { + unsigned long paddr; + + /* The PLPAR instruction causes an access error if the translation + * is not possible. To catch this we use the same exception mechanism + * as for user space accesses in . */ + asm volatile (".chip 68060\n" + "1: plpar (%0)\n" + ".chip 68k\n" + "2:\n" + ".section .fixup,\"ax\"\n" + " .even\n" + "3: sub.l %0,%0\n" + " jra 2b\n" + ".previous\n" + ".section __ex_table,\"a\"\n" + " .align 4\n" + " .long 1b,3b\n" + ".previous" + : "=a" (paddr) + : "0" (vaddr)); + return paddr; + } else if (CPU_IS_040) { + unsigned long mmusr; + + asm volatile (".chip 68040\n\t" + "ptestr (%1)\n\t" + "movec %%mmusr, %0\n\t" + ".chip 68k" + : "=r" (mmusr) + : "a" (vaddr)); + + if (mmusr & MMU_R_040) + return (mmusr & PAGE_MASK) | (vaddr & ~PAGE_MASK); + } else { + WARN_ON_ONCE(!CPU_IS_040_OR_060); + } + return 0; +} + +/* Push n pages at kernel virtual address and clear the icache */ +/* RZ: use cpush %bc instead of cpush %dc, cinv %ic */ +void flush_icache_user_range(unsigned long address, unsigned long endaddr) +{ + if (CPU_IS_COLDFIRE) { + unsigned long start, end; + start = address & ICACHE_SET_MASK; + end = endaddr & ICACHE_SET_MASK; + if (start > end) { + flush_cf_icache(0, end); + end = ICACHE_MAX_ADDR; + } + flush_cf_icache(start, end); + } else if (CPU_IS_040_OR_060) { + address &= PAGE_MASK; + + do { + asm volatile ("nop\n\t" + ".chip 68040\n\t" + "cpushp %%bc,(%0)\n\t" + ".chip 68k" + : : "a" (virt_to_phys_slow(address))); + address += PAGE_SIZE; + } while (address < endaddr); + } else { + unsigned long tmp; + asm volatile ("movec %%cacr,%0\n\t" + "orw %1,%0\n\t" + "movec %0,%%cacr" + : "=&d" (tmp) + : "di" (FLUSH_I)); + } +} + +void flush_icache_range(unsigned long address, unsigned long endaddr) +{ + set_fc(SUPER_DATA); + flush_icache_user_range(address, endaddr); + set_fc(USER_DATA); +} +EXPORT_SYMBOL(flush_icache_range); + +void flush_icache_user_page(struct vm_area_struct *vma, struct page *page, + unsigned long addr, int len) +{ + if (CPU_IS_COLDFIRE) { + unsigned long start, end; + start = addr & ICACHE_SET_MASK; + end = (addr + len) & ICACHE_SET_MASK; + if (start > end) { + flush_cf_icache(0, end); + end = ICACHE_MAX_ADDR; + } + flush_cf_icache(start, end); + + } else if (CPU_IS_040_OR_060) { + asm volatile ("nop\n\t" + ".chip 68040\n\t" + "cpushp %%bc,(%0)\n\t" + ".chip 68k" + : : "a" (page_to_phys(page))); + } else { + unsigned long tmp; + asm volatile ("movec %%cacr,%0\n\t" + "orw %1,%0\n\t" + "movec %0,%%cacr" + : "=&d" (tmp) + : "di" (FLUSH_I)); + } +} + -- cgit v1.3.1