From 0464b7765aa4d1fc2178e443a3b37d19cfe541a0 Mon Sep 17 00:00:00 2001
From: Kimplul <kimi.h.kuparinen@gmail.com>
Date: Sun, 2 Mar 2025 21:45:51 +0200
Subject: add ideal allocation tracker

+ Kind of like CHERI, but uses out-of-line pointer information.
  The idea is that a core that is compatible with ALLOC_IF queries
  the allocation tracker if an address is legal and gets a response.
  This ideal tracker effectively has infinite memory and doesn't talk to
  any other components, but a real implementation might want to limit
  the allocations per process or chat with some reserved memory region
  somewhere else in the system to maintain a binary tree or something.
---
 tests/simple_ideal_alloc/testbench.c | 119 +++++++++++++++++++++++++++++++++++
 1 file changed, 119 insertions(+)
 create mode 100644 tests/simple_ideal_alloc/testbench.c

(limited to 'tests/simple_ideal_alloc/testbench.c')

diff --git a/tests/simple_ideal_alloc/testbench.c b/tests/simple_ideal_alloc/testbench.c
new file mode 100644
index 0000000..703c2a8
--- /dev/null
+++ b/tests/simple_ideal_alloc/testbench.c
@@ -0,0 +1,119 @@
+#include <gran/if/alloc.h>
+#include "testbench.h"
+
+struct reg {
+	struct packet pkt;
+	bool busy;
+};
+
+struct tb {
+	struct component component;
+	struct component *dut;
+	struct reg in;
+
+	enum {
+		ADD_REGION,
+		QUERY_EXISTING,
+		REMOVE_REGION,
+		QUERY_NONEXISTING,
+		FINAL
+	} state;
+};
+
+static stat tb_receive(struct tb *tb, struct component *from, struct packet pkt)
+{
+	assert(tb->dut == from);
+	tb->in.pkt = pkt;
+	tb->in.busy = true;
+	return OK;
+}
+
+static stat tb_clock(struct tb *tb)
+{
+	assert(tb->dut);
+
+	switch (tb->state) {
+	case ADD_REGION: {
+		struct alloc_if_new n = {.space = 0, .start = 0, .end = 10};
+		struct packet pkt = create_packet(0, ALLOC_IF_NEW, sizeof(n), &n, PACKET_WRITE);
+		assert(SEND(tb, tb->dut, pkt) == OK);
+		tb->state = QUERY_EXISTING;
+		break;
+	}
+
+	case QUERY_EXISTING: {
+		if (!tb->in.busy)
+			break;
+
+		struct alloc_if_r *r = (struct alloc_if_r *)&tb->in.pkt.data;
+		assert(r->r == ALLOC_IF_OK);
+
+		struct alloc_if_q q = {.space = 0, .addr = 5};
+		struct packet pkt = create_packet(0, ALLOC_IF_Q, sizeof(q), &q, PACKET_WRITE);
+		assert(SEND(tb, tb->dut, pkt) == OK);
+		tb->state = REMOVE_REGION;
+		tb->in.busy = false;
+		break;
+	}
+
+	case REMOVE_REGION: {
+		if (!tb->in.busy)
+			break;
+
+		struct alloc_if_r *r = (struct alloc_if_r *)&tb->in.pkt.data;
+		assert(r->r == ALLOC_IF_OK);
+		assert(r->start == 0);
+		assert(r->end == 10);
+
+		struct alloc_if_rm rm = {.space = 0, .start = 0, .end = 10};
+		struct packet pkt = create_packet(0, ALLOC_IF_RM, sizeof(rm), &rm, PACKET_WRITE);
+		assert(SEND(tb, tb->dut, pkt) == OK);
+		tb->state = QUERY_NONEXISTING;
+		tb->in.busy = false;
+		break;
+	}
+
+	case QUERY_NONEXISTING: {
+		if (!tb->in.busy)
+			break;
+
+		struct alloc_if_r *r = (struct alloc_if_r *)&tb->in.pkt.data;
+		assert(r->r == ALLOC_IF_OK);
+
+		struct alloc_if_q q = {.space = 0, .addr = 5};
+		struct packet pkt = create_packet(0, ALLOC_IF_Q, sizeof(q), &q, PACKET_WRITE);
+		assert(SEND(tb, tb->dut, pkt) == OK);
+		tb->state = FINAL;
+		tb->in.busy = false;
+		break;
+	}
+
+	case FINAL: {
+		if (!tb->in.busy)
+			break;
+
+		struct alloc_if_r *r = (struct alloc_if_r *)&tb->in.pkt.data;
+		assert(r->r != ALLOC_IF_OK);
+		return DONE;
+	}
+
+	default: abort();
+	}
+
+	return OK;
+}
+
+struct component *create_testbench()
+{
+	struct tb *tb = calloc(1, sizeof(struct tb));
+	tb->component.clock = (clock_callback)tb_clock;
+	tb->component.receive = (receive_callback)tb_receive;
+	return (struct component *)tb;
+}
+
+stat testbench_connect(struct component *tb, struct component *dut)
+{
+	struct tb *t = (struct tb *)tb;
+	t->dut = dut;
+	return OK;
+}
-- 
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