Hardware may lack a sane implementation of TLB invalidation
using broadcast TLBI command. Add a capability to enable TLB
invalidation using IPI.

Signed-off-by: David Daney <david.da...@cavium.com>
Signed-off-by: Robert Richter <rrich...@cavium.com>
Signed-off-by: Alexander Graf <ag...@suse.de>
Signed-off-by: Matthias Brugger <mbrug...@suse.com>
---
 arch/arm64/include/asm/cpufeature.h |  3 +-
 arch/arm64/include/asm/tlbflush.h   | 94 ++++++++++++++++++++++++++++++++-----
 arch/arm64/mm/flush.c               | 46 ++++++++++++++++++
 3 files changed, 129 insertions(+), 14 deletions(-)

diff --git a/arch/arm64/include/asm/cpufeature.h 
b/arch/arm64/include/asm/cpufeature.h
index 49dd1bd..c4bf72b 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -36,8 +36,9 @@
 #define ARM64_HAS_VIRT_HOST_EXTN               11
 #define ARM64_WORKAROUND_CAVIUM_27456          12
 #define ARM64_HAS_32BIT_EL0                    13
+#define ARM64_HAS_NO_BCAST_TLBI                        14
 
-#define ARM64_NCAPS                            14
+#define ARM64_NCAPS                            15
 
 #ifndef __ASSEMBLY__
 
diff --git a/arch/arm64/include/asm/tlbflush.h 
b/arch/arm64/include/asm/tlbflush.h
index b460ae2..edc5495 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -71,7 +71,10 @@ static inline void local_flush_tlb_all(void)
        isb();
 }
 
-static inline void flush_tlb_all(void)
+void __flush_tlb_all_ipi(void);
+void __flush_tlb_mm_ipi(struct mm_struct *mm);
+
+static inline void __flush_tlb_all_tlbi(void)
 {
        dsb(ishst);
        asm("tlbi       vmalle1is");
@@ -79,7 +82,17 @@ static inline void flush_tlb_all(void)
        isb();
 }
 
-static inline void flush_tlb_mm(struct mm_struct *mm)
+static inline void flush_tlb_all(void)
+{
+       if (cpus_have_cap(ARM64_HAS_NO_BCAST_TLBI)) {
+               __flush_tlb_all_ipi();
+               return;
+       }
+
+       __flush_tlb_all_tlbi();
+}
+
+static inline void __flush_tlb_mm_tlbi(struct mm_struct *mm)
 {
        unsigned long asid = ASID(mm) << 48;
 
@@ -88,8 +101,18 @@ static inline void flush_tlb_mm(struct mm_struct *mm)
        dsb(ish);
 }
 
-static inline void flush_tlb_page(struct vm_area_struct *vma,
-                                 unsigned long uaddr)
+static inline void flush_tlb_mm(struct mm_struct *mm)
+{
+       if (cpus_have_cap(ARM64_HAS_NO_BCAST_TLBI)) {
+               __flush_tlb_mm_ipi(mm);
+               return;
+       }
+
+       __flush_tlb_mm_tlbi(mm);
+}
+
+static inline void __flush_tlb_page_tlbi(struct vm_area_struct *vma,
+               unsigned long uaddr)
 {
        unsigned long addr = uaddr >> 12 | (ASID(vma->vm_mm) << 48);
 
@@ -98,15 +121,26 @@ static inline void flush_tlb_page(struct vm_area_struct 
*vma,
        dsb(ish);
 }
 
+static inline void flush_tlb_page(struct vm_area_struct *vma,
+               unsigned long uaddr)
+{
+       if (cpus_have_cap(ARM64_HAS_NO_BCAST_TLBI)) {
+               __flush_tlb_mm_ipi(vma->vm_mm);
+               return;
+       }
+
+       __flush_tlb_page_tlbi(vma, uaddr);
+}
+
 /*
  * This is meant to avoid soft lock-ups on large TLB flushing ranges and not
  * necessarily a performance improvement.
  */
 #define MAX_TLB_RANGE  (1024UL << PAGE_SHIFT)
 
-static inline void __flush_tlb_range(struct vm_area_struct *vma,
-                                    unsigned long start, unsigned long end,
-                                    bool last_level)
+static inline void __flush_tlb_range_tlbi(struct vm_area_struct *vma,
+               unsigned long start, unsigned long end,
+               bool last_level)
 {
        unsigned long asid = ASID(vma->vm_mm) << 48;
        unsigned long addr;
@@ -129,13 +163,26 @@ static inline void __flush_tlb_range(struct 
vm_area_struct *vma,
        dsb(ish);
 }
 
+static inline void __flush_tlb_range(struct vm_area_struct *vma,
+               unsigned long start, unsigned long end,
+               bool last_level)
+{
+       if (cpus_have_cap(ARM64_HAS_NO_BCAST_TLBI)) {
+               __flush_tlb_mm_ipi(vma->vm_mm);
+               return;
+       }
+
+       __flush_tlb_range_tlbi(vma, start, end, last_level);
+}
+
 static inline void flush_tlb_range(struct vm_area_struct *vma,
-                                  unsigned long start, unsigned long end)
+               unsigned long start, unsigned long end)
 {
        __flush_tlb_range(vma, start, end, false);
 }
 
-static inline void flush_tlb_kernel_range(unsigned long start, unsigned long 
end)
+static inline void __flush_tlb_kernel_range_tlbi(unsigned long start,
+               unsigned long end)
 {
        unsigned long addr;
 
@@ -154,17 +201,38 @@ static inline void flush_tlb_kernel_range(unsigned long 
start, unsigned long end
        isb();
 }
 
+static inline void flush_tlb_kernel_range(unsigned long start, unsigned long 
end)
+{
+       if (cpus_have_cap(ARM64_HAS_NO_BCAST_TLBI)) {
+               __flush_tlb_all_ipi();
+               return;
+       }
+
+       __flush_tlb_kernel_range_tlbi(start, end);
+}
+
+static inline void __flush_tlb_pgtable_tlbi(struct mm_struct *mm,
+               unsigned long uaddr)
+{
+       unsigned long addr = uaddr >> 12 | (ASID(mm) << 48);
+
+       asm("tlbi       vae1is, %0" : : "r" (addr));
+       dsb(ish);
+}
+
 /*
  * Used to invalidate the TLB (walk caches) corresponding to intermediate page
  * table levels (pgd/pud/pmd).
  */
 static inline void __flush_tlb_pgtable(struct mm_struct *mm,
-                                      unsigned long uaddr)
+               unsigned long uaddr)
 {
-       unsigned long addr = uaddr >> 12 | (ASID(mm) << 48);
+       if (cpus_have_cap(ARM64_HAS_NO_BCAST_TLBI)) {
+               __flush_tlb_mm_ipi(mm);
+               return;
+       }
 
-       asm("tlbi       vae1is, %0" : : "r" (addr));
-       dsb(ish);
+       __flush_tlb_pgtable_tlbi(mm, uaddr);
 }
 
 #endif
diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c
index 43a76b0..402036a 100644
--- a/arch/arm64/mm/flush.c
+++ b/arch/arm64/mm/flush.c
@@ -27,6 +27,24 @@
 
 #include "mm.h"
 
+static void flush_tlb_local(void *info)
+{
+       local_flush_tlb_all();
+}
+
+static void flush_tlb_mm_local(void *info)
+{
+       unsigned long asid = (unsigned long)info;
+
+       asm volatile("\n"
+       "  dsb     nshst\n"
+       "  tlbi    aside1, %0\n"
+       "  dsb     nsh\n"
+       "  isb     sy"
+       : : "r" (asid)
+       );
+}
+
 void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
                       unsigned long end)
 {
@@ -90,6 +108,34 @@ void flush_dcache_page(struct page *page)
 }
 EXPORT_SYMBOL(flush_dcache_page);
 
+void __flush_tlb_mm_ipi(struct mm_struct *mm)
+{
+       unsigned long asid;
+
+       if (!mm) {
+               flush_tlb_all();
+       } else {
+               asid = ASID(mm) << 48;
+               /* Make sure page table modifications are visible. */
+               dsb(ishst);
+               /* IPI to all CPUs to do local flush. */
+               on_each_cpu(flush_tlb_mm_local, (void *)asid, 1);
+       }
+}
+EXPORT_SYMBOL(__flush_tlb_mm_ipi);
+
+void __flush_tlb_all_ipi(void)
+{
+       /* Make sure page table modifications are visible. */
+       dsb(ishst);
+       if (num_online_cpus() <= 1)
+               local_flush_tlb_all();
+       else
+               /* IPI to all CPUs to do local flush. */
+               on_each_cpu(flush_tlb_local, NULL, 1);
+}
+EXPORT_SYMBOL(__flush_tlb_all_ipi);
+
 /*
  * Additional functions defined in assembly.
  */
-- 
2.6.6

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