target/linux/layerscape/patches-5.4/811-kvm-0001-arm64-KVM-support-flushing-device-memory.patch

   1 From aa9e99f77f92814a0d83af8e6ed3148458d0f611 Mon Sep 17 00:00:00 2001
   2 From: Laurentiu Tudor <laurentiu.tudor@nxp.com>
   3 Date: Tue, 26 Jul 2016 15:43:43 +0300
   4 Subject: [PATCH] arm64: KVM: support flushing device memory
   5
   6 In the current implementation, trying to flush
   7 memory not covered by the linear map (e.g. device
   8 memory) causes a crash. Add support for flushing
   9 "non-normal" memory by explicitly ioremap()-ing
  10 it when such a case appears and do the cache flush
  11 through this temporary mapping.
  12 This allows dropping the special checks for qman
  13 cacheable region when doing cache flushes.
  14
  15 Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
  16 [fixed formatting issue]
  17 Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
  18 ---
  19  arch/arm64/include/asm/kvm_mmu.h | 12 ++++++++++--
  20  1 file changed, 10 insertions(+), 2 deletions(-)
  21
  22 --- a/arch/arm64/include/asm/kvm_mmu.h
  23 +++ b/arch/arm64/include/asm/kvm_mmu.h
  24 @@ -341,8 +341,16 @@ static inline void __invalidate_icache_g
  25  static inline void __kvm_flush_dcache_pte(pte_t pte)
  26  {
  27         if (!cpus_have_const_cap(ARM64_HAS_STAGE2_FWB)) {
  28 -               struct page *page = pte_page(pte);
  29 -               kvm_flush_dcache_to_poc(page_address(page), PAGE_SIZE);
  30 +               if (pfn_valid(pte_pfn(pte))) {
  31 +                       struct page *page = pte_page(pte);
  32 +
  33 +                       kvm_flush_dcache_to_poc(page_address(page), PAGE_SIZE);
  34 +               } else {
  35 +                       void __iomem *va = ioremap_cache_ns(pte_pfn(pte) << PAGE_SHIFT, PAGE_SIZE);
  36 +
  37 +                       kvm_flush_dcache_to_poc(va, PAGE_SIZE);
  38 +                       iounmap(va);
  39 +               }
  40         }
  41  }
  42