--- /dev/null
+/*
+ * Copyright 2018 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: AMD
+ *
+ */
+
+#include "vm_helper.h"
+
+static void mark_vmid_used(struct vm_helper *vm_helper, unsigned int pos, uint8_t hubp_idx)
+{
+ struct vmid_usage vmids = vm_helper->hubp_vmid_usage[hubp_idx];
+
+ vmids.vmid_usage[0] = vmids.vmid_usage[1];
+ vmids.vmid_usage[1] = 1 << pos;
+}
+
+static void add_ptb_to_table(struct vm_helper *vm_helper, unsigned int vmid, uint64_t ptb)
+{
+ vm_helper->ptb_assigned_to_vmid[vmid] = ptb;
+ vm_helper->num_vmids_available--;
+}
+
+static void clear_entry_from_vmid_table(struct vm_helper *vm_helper, unsigned int vmid)
+{
+ vm_helper->ptb_assigned_to_vmid[vmid] = 0;
+ vm_helper->num_vmids_available++;
+}
+
+static void evict_vmids(struct vm_helper *vm_helper)
+{
+ int i;
+ uint16_t ord = 0;
+
+ for (i = 0; i < vm_helper->num_vmid; i++)
+ ord |= vm_helper->hubp_vmid_usage[i].vmid_usage[0] | vm_helper->hubp_vmid_usage[i].vmid_usage[1];
+
+ // At this point any positions with value 0 are unused vmids, evict them
+ for (i = 1; i < vm_helper->num_vmid; i++) {
+ if (ord & (1u << i))
+ clear_entry_from_vmid_table(vm_helper, i);
+ }
+}
+
+// Return value of -1 indicates vmid table unitialized or ptb dne in the table
+static int get_existing_vmid_for_ptb(struct vm_helper *vm_helper, uint64_t ptb)
+{
+ int i;
+
+ for (i = 0; i < vm_helper->num_vmid; i++) {
+ if (vm_helper->ptb_assigned_to_vmid[i] == ptb)
+ return i;
+ }
+
+ return -1;
+}
+
+// Expected to be called only when there's an available vmid
+static int get_next_available_vmid(struct vm_helper *vm_helper)
+{
+ int i;
+
+ for (i = 1; i < vm_helper->num_vmid; i++) {
+ if (vm_helper->ptb_assigned_to_vmid[i] == 0)
+ return i;
+ }
+
+ return -1;
+}
+
+uint8_t get_vmid_for_ptb(struct vm_helper *vm_helper, int64_t ptb, uint8_t hubp_idx)
+{
+ unsigned int vmid = 0;
+ int vmid_exists = -1;
+
+ // Physical address gets vmid 0
+ if (ptb == 0)
+ return 0;
+
+ vmid_exists = get_existing_vmid_for_ptb(vm_helper, ptb);
+
+ if (vmid_exists != -1) {
+ mark_vmid_used(vm_helper, vmid_exists, hubp_idx);
+ vmid = vmid_exists;
+ } else {
+ if (vm_helper->num_vmids_available == 0)
+ evict_vmids(vm_helper);
+
+ vmid = get_next_available_vmid(vm_helper);
+ mark_vmid_used(vm_helper, vmid, hubp_idx);
+ add_ptb_to_table(vm_helper, vmid, ptb);
+ }
+
+ return vmid;
+}
+
+void init_vm_helper(struct vm_helper *vm_helper, unsigned int num_vmid, unsigned int num_hubp)
+{
+ vm_helper->num_vmid = num_vmid;
+ vm_helper->num_hubp = num_hubp;
+ vm_helper->num_vmids_available = num_vmid - 1;
+
+ memset(vm_helper->hubp_vmid_usage, 0, sizeof(vm_helper->hubp_vmid_usage[0]) * MAX_HUBP);
+ memset(vm_helper->ptb_assigned_to_vmid, 0, sizeof(vm_helper->ptb_assigned_to_vmid[0]) * MAX_VMID);
+}
git.samba.org / sfrench / cifs-2.6.git / commitdiff