sw: Add test to check AXI-REALM isolation

* Check successful manager isolation after running out of budget

sw/tests/axirt_budget_isolate.c

@@ -0,0 +1,88 @@
+// Copyright 2023 ETH Zurich and University of Bologna.
+// Licensed under the Apache License, Version 2.0, see LICENSE for details.
+// SPDX-License-Identifier: Apache-2.0
+//
+// Alessandro Ottaviano <[email protected]>
+//
+// Validate the isolation functionality of AXI-REALM
+
+#include "axirt.h"
+#include "dif/dma.h"
+#include "params.h"
+#include "regs/axi_rt.h"
+#include "regs/cheshire.h"
+#include "util.h"
+
+// transfer
+#define SIZE_BEAT_BYTES 8
+#define DMA_NUM_BEATS 32
+#define DMA_NUM_REPS 8
+#define DMA_SIZE_BYTES (SIZE_BEAT_BYTES * DMA_NUM_BEATS)
+#define DMA_TOTAL_SIZE_BYTES (DMA_SIZE_BYTES * DMA_NUM_REPS)
+#define DMA_SRC_STRIDE 0
+#define DMA_DST_STRIDE 0
+#define SRC_ADDR 0x0000000078000000 // L2
+#define DST_ADDR 0x0000000080000000 // DRAM
+
+// AXI-REALM
+#define CVA6_ALLOCATED_BUDGET 0x10000000
+#define CVA6_ALLOCATED_PERIOD 0x10000000
+#define DMA_ALLOCATED_BUDGET \
+    (DMA_TOTAL_SIZE_BYTES / 2) // Set budget as half of the number of bytes to
+                               // transfer intentionally
+#define DMA_ALLOCATED_PERIOD 0x10000000
+#define FRAGMENTATION_SIZE_BEATS 256 // No fragmentation applied to bursts
+
+int main(void) {
+
+    uint32_t cheshire_num_harts = *reg32(&__base_regs, CHESHIRE_NUM_INT_HARTS_REG_OFFSET);
+
+    // enable and configure axi rt with fragmentation of 8 beats
+    __axirt_claim(1, 1);
+    __axirt_set_len_limit_group(FRAGMENTATION_SIZE_BEATS, 0);
+    __axirt_set_len_limit_group(FRAGMENTATION_SIZE_BEATS, 1);
+    fence();
+
+    // configure CVA6 cores
+    for (enum axirealm_mngr_id id = AXIREALM_MNGR_ID_CVA60; id <= cheshire_num_harts; id++) {
+        __axirt_set_region(0, 0xffffffff, 0, id);
+        __axirt_set_region(0x100000000, 0xffffffffffffffff, 1, id);
+        __axirt_set_budget(CVA6_ALLOCATED_BUDGET, 0, id);
+        __axirt_set_budget(CVA6_ALLOCATED_BUDGET, 1, id);
+        __axirt_set_period(CVA6_ALLOCATED_PERIOD, 0, id);
+        __axirt_set_period(CVA6_ALLOCATED_PERIOD, 1, id);
+        fence();
+    }
+
+    // configure DMA
+    __axirt_set_region(0, 0xffffffff, 0, AXIREALM_MNGR_ID_DMA);
+    __axirt_set_region(0x100000000, 0xffffffffffffffff, 1, AXIREALM_MNGR_ID_DMA);
+    __axirt_set_budget(DMA_ALLOCATED_BUDGET, 0, AXIREALM_MNGR_ID_DMA);
+    __axirt_set_budget(DMA_ALLOCATED_BUDGET, 1, AXIREALM_MNGR_ID_DMA);
+    __axirt_set_period(DMA_ALLOCATED_PERIOD, 0, AXIREALM_MNGR_ID_DMA);
+    __axirt_set_period(DMA_ALLOCATED_PERIOD, 1, AXIREALM_MNGR_ID_DMA);
+    fence();
+
+    // enable RT unit for DMA and CVA6 cores
+    __axirt_enable((BIT(AXIREALM_MNGR_ID_CVA60) | BIT(AXIREALM_MNGR_ID_DMA)));
+    fence();
+
+    volatile uint64_t *sys_src = (volatile uint64_t *)SRC_ADDR;
+
+    // initialize src region
+    for (int i = 0; i < DMA_NUM_BEATS; i++) {
+        sys_src[i] = 0xcafedeadbaadf00d + i;
+        fence();
+    }
+
+    // launch non-blocking DMA transfer
+    sys_dma_2d_memcpy(DST_ADDR, SRC_ADDR, DMA_SIZE_BYTES, DMA_DST_STRIDE, DMA_SRC_STRIDE,
+                      DMA_NUM_REPS);
+
+    // Poll isolate to check if AXI-REALM isolates the dma when the budget is exceeded. Should
+    // return 1 if dma is isolated.
+    uint8_t isolate_status = __axirt_poll_isolate(AXIREALM_MNGR_ID_DMA);
+
+    // return 0 if manager was correctly isolated
+    return !isolate_status;
+}