hw/arm/smmuv3: IOTLB emulation

We emulate a TLB cache of size SMMU_IOTLB_MAX_SIZE=256.
It is implemented as a hash table whose key is a combination
of the 16b asid and 48b IOVA (Jenkins hash).

Entries are invalidated on TLB invalidation commands, either
globally, or per asid, or per asid/iova.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Message-id: 1529653501-15358-4-git-send-email-eric.auger@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 60 insertions, 0 deletions

diff --git a/hw/arm/smmu-common.c b/hw/arm/smmu-common.c
index db242c73df..f66e444f6f 100644
--- a/hw/arm/smmu-common.c
+++ b/hw/arm/smmu-common.c
@@ -24,11 +24,43 @@
 #include "qom/cpu.h"
 #include "hw/qdev-properties.h"
 #include "qapi/error.h"
+#include "qemu/jhash.h"
 
 #include "qemu/error-report.h"
 #include "hw/arm/smmu-common.h"
 #include "smmu-internal.h"
 
+/* IOTLB Management */
+
+inline void smmu_iotlb_inv_all(SMMUState *s)
+{
+    trace_smmu_iotlb_inv_all();
+    g_hash_table_remove_all(s->iotlb);
+}
+
+static gboolean smmu_hash_remove_by_asid(gpointer key, gpointer value,
+                                         gpointer user_data)
+{
+    uint16_t asid = *(uint16_t *)user_data;
+    SMMUIOTLBKey *iotlb_key = (SMMUIOTLBKey *)key;
+
+    return iotlb_key->asid == asid;
+}
+
+inline void smmu_iotlb_inv_iova(SMMUState *s, uint16_t asid, dma_addr_t iova)
+{
+    SMMUIOTLBKey key = {.asid = asid, .iova = iova};
+
+    trace_smmu_iotlb_inv_iova(asid, iova);
+    g_hash_table_remove(s->iotlb, &key);
+}
+
+inline void smmu_iotlb_inv_asid(SMMUState *s, uint16_t asid)
+{
+    trace_smmu_iotlb_inv_asid(asid);
+    g_hash_table_foreach_remove(s->iotlb, smmu_hash_remove_by_asid, &asid);
+}
+
 /* VMSAv8-64 Translation */
 
 /**
@@ -328,6 +360,31 @@ IOMMUMemoryRegion *smmu_iommu_mr(SMMUState *s, uint32_t sid)
     return NULL;
 }
 
+static guint smmu_iotlb_key_hash(gconstpointer v)
+{
+    SMMUIOTLBKey *key = (SMMUIOTLBKey *)v;
+    uint32_t a, b, c;
+
+    /* Jenkins hash */
+    a = b = c = JHASH_INITVAL + sizeof(*key);
+    a += key->asid;
+    b += extract64(key->iova, 0, 32);
+    c += extract64(key->iova, 32, 32);
+
+    __jhash_mix(a, b, c);
+    __jhash_final(a, b, c);
+
+    return c;
+}
+
+static gboolean smmu_iotlb_key_equal(gconstpointer v1, gconstpointer v2)
+{
+    const SMMUIOTLBKey *k1 = v1;
+    const SMMUIOTLBKey *k2 = v2;
+
+    return (k1->asid == k2->asid) && (k1->iova == k2->iova);
+}
+
 static void smmu_base_realize(DeviceState *dev, Error **errp)
 {
     SMMUState *s = ARM_SMMU(dev);
@@ -340,6 +397,8 @@ static void smmu_base_realize(DeviceState *dev, Error **errp)
         return;
     }
     s->configs = g_hash_table_new_full(NULL, NULL, NULL, g_free);
+    s->iotlb = g_hash_table_new_full(smmu_iotlb_key_hash, smmu_iotlb_key_equal,
+                                     g_free, g_free);
     s->smmu_pcibus_by_busptr = g_hash_table_new(NULL, NULL);
 
     if (s->primary_bus) {
@@ -354,6 +413,7 @@ static void smmu_base_reset(DeviceState *dev)
     SMMUState *s = ARM_SMMU(dev);
 
     g_hash_table_remove_all(s->configs);
+    g_hash_table_remove_all(s->iotlb);
 }
 
 static Property smmu_dev_properties[] = {