[Qemu-devel] [PATCH for-4.2 01/24] cputlb: Add tlb_set_asid_for_mmuidx

[Richard Henderson <richard.henderson@linaro.org>]

Although we can't do much with ASIDs except remember them, this
will allow cleanups within target/ that should make things clearer.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
v2: Assert cpu_is_self; only flush idx w/ asid mismatch.
---
 include/exec/cpu-all.h  | 11 +++++++++++
 include/exec/cpu-defs.h |  2 ++
 include/exec/exec-all.h | 19 +++++++++++++++++++
 accel/tcg/cputlb.c      | 26 ++++++++++++++++++++++++++
 4 files changed, 58 insertions(+)

diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
index 536ea58f81..40b140cbba 100644
--- a/include/exec/cpu-all.h
+++ b/include/exec/cpu-all.h
@@ -439,4 +439,15 @@ static inline CPUTLB *env_tlb(CPUArchState *env)
     return &env_neg(env)->tlb;
 }
 
+/**
+ * cpu_tlb(env)
+ * @cpu: The generic CPUState
+ *
+ * Return the CPUTLB state associated with the cpu.
+ */
+static inline CPUTLB *cpu_tlb(CPUState *cpu)
+{
+    return &cpu_neg(cpu)->tlb;
+}
+
 #endif /* CPU_ALL_H */
diff --git a/include/exec/cpu-defs.h b/include/exec/cpu-defs.h
index 9bc713a70b..73584841c0 100644
--- a/include/exec/cpu-defs.h
+++ b/include/exec/cpu-defs.h
@@ -169,6 +169,8 @@ typedef struct CPUTLBDesc {
     size_t n_used_entries;
     /* The next index to use in the tlb victim table.  */
     size_t vindex;
+    /* The current ASID for this tlb.  */
+    uint32_t asid;
     /* The tlb victim table, in two parts.  */
     CPUTLBEntry vtable[CPU_VTLB_SIZE];
     CPUIOTLBEntry viotlb[CPU_VTLB_SIZE];
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index 16034ee651..9c77aa5bf9 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -225,6 +225,21 @@ void tlb_flush_by_mmuidx_all_cpus(CPUState *cpu, uint16_t idxmap);
  * depend on when the guests translation ends the TB.
  */
 void tlb_flush_by_mmuidx_all_cpus_synced(CPUState *cpu, uint16_t idxmap);
+/**
+ * tlb_set_asid_for_mmuidx:
+ * @cpu: Originating cpu
+ * @asid: Address Space Identifier
+ * @idxmap: bitmap of MMU indexes to set to @asid
+ * @depmap: bitmap of dependent MMU indexes
+ *
+ * Set an ASID for all of @idxmap.  If any previous ASID was different,
+ * then we will flush the mmu idx.  If a flush is required, then also flush
+ * all dependent mmu indicies in @depmap.  This latter is typically used
+ * for secondary page resolution, for implementing virtualization within
+ * the guest.
+ */
+void tlb_set_asid_for_mmuidx(CPUState *cpu, uint32_t asid,
+                             uint16_t idxmap, uint16_t dep_idxmap);
 /**
  * tlb_set_page_with_attrs:
  * @cpu: CPU to add this TLB entry for
@@ -310,6 +325,10 @@ static inline void tlb_flush_by_mmuidx_all_cpus_synced(CPUState *cpu,
                                                        uint16_t idxmap)
 {
 }
+static inline void tlb_set_asid_for_mmuidx(CPUState *cpu, uint32_t asid,
+                                           uint16_t idxmap, uint16_t depmap)
+{
+}
 #endif
 
 #define CODE_GEN_ALIGN           16 /* must be >= of the size of a icache line */
diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
index bb9897b25a..c68f57755b 100644
--- a/accel/tcg/cputlb.c
+++ b/accel/tcg/cputlb.c
@@ -540,6 +540,32 @@ void tlb_flush_page_all_cpus_synced(CPUState *src, target_ulong addr)
     tlb_flush_page_by_mmuidx_all_cpus_synced(src, addr, ALL_MMUIDX_BITS);
 }
 
+void tlb_set_asid_for_mmuidx(CPUState *cpu, uint32_t asid, uint16_t idxmap,
+                             uint16_t depmap)
+{
+    CPUTLB *tlb = cpu_tlb(cpu);
+    uint16_t work, to_flush = 0;
+
+    /* It doesn't make sense to set context across cpus.  */
+    assert_cpu_is_self(cpu);
+
+    /*
+     * We don't support ASIDs except for trivially.
+     * If there is any change, then we must flush the TLB.
+     */
+    for (work = idxmap; work != 0; work &= work - 1) {
+        int mmu_idx = ctz32(work);
+        if (tlb->d[mmu_idx].asid != asid) {
+            tlb->d[mmu_idx].asid = asid;
+            to_flush |= 1 << mmu_idx;
+        }
+    }
+    if (to_flush) {
+        to_flush |= depmap;
+        tlb_flush_by_mmuidx_async_work(cpu, RUN_ON_CPU_HOST_INT(to_flush));
+    }
+}
+
 /* update the TLBs so that writes to code in the virtual page 'addr'
    can be detected */
 void tlb_protect_code(ram_addr_t ram_addr)
-- 
2.17.1