From 0c2f0b121321ef2bc7b9213c9599a7966827027b Mon Sep 17 00:00:00 2001
From: Shupei Fan <dymarkfan@outlook.com>
Date: Tue, 3 Dec 2024 07:55:48 +0000
Subject: [PATCH] [difftest] axi inst fetch changed to 8x32

---
 difftest/dpi_t1rocketemu/src/dpi.rs   | 12 ++++++------
 difftest/dpi_t1rocketemu/src/drive.rs | 22 ++++++++++++++++++----
 2 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/difftest/dpi_t1rocketemu/src/dpi.rs b/difftest/dpi_t1rocketemu/src/dpi.rs
index 1d8a9c7a7..9c6f40956 100644
--- a/difftest/dpi_t1rocketemu/src/dpi.rs
+++ b/difftest/dpi_t1rocketemu/src/dpi.rs
@@ -127,7 +127,7 @@ unsafe extern "C" fn axi_read_highBandwidthAXI(
     assert_eq!(data_width as u32, dlen);
     assert_eq!(arlen, 0);
 
-    let response = driver.axi_read(araddr as u32, arsize as u32, dlen);
+    let response = driver.axi_read(araddr as u32, arsize as u32, 0, dlen);
     fill_axi_read_payload(payload, dlen, &response);
 
     driver.update_commit_cycle();
@@ -195,7 +195,7 @@ unsafe extern "C" fn axi_read_highOutstandingAXI(
     assert_eq!(data_width, 32);
     assert_eq!(arlen, 0);
 
-    let response = driver.axi_read(araddr as u32, arsize as u32, 32);
+    let response = driver.axi_read(araddr as u32, arsize as u32, 0, 32);
     fill_axi_read_payload(payload, 32, &response);
 
     driver.update_commit_cycle();
@@ -269,7 +269,7 @@ unsafe extern "C" fn axi_read_loadStoreAXI(
     assert_eq!(data_width, 32);
     assert_eq!(arlen, 0);
 
-    let response = driver.axi_read(araddr as u32, arsize as u32, 32);
+    let response = driver.axi_read(araddr as u32, arsize as u32, 0, 32);
     fill_axi_read_payload(payload, 8 * 32, &response);
 
     driver.update_commit_cycle();
@@ -306,12 +306,12 @@ unsafe extern "C" fn axi_read_instructionFetchAXI(
   arprot={arprot}, arqos={arqos}, arregion={arregion})"
   );
   TARGET.with(|driver| {
-    assert_eq!(data_width, 256);
-    assert_eq!(arlen, 0);
+    assert_eq!(data_width, 32);
+    assert_eq!(arlen, 7);
 
     assert_eq!(8 * (1 << arsize), data_width);
 
-    let response = driver.axi_read(araddr as u32, arsize as u32, 256);
+    let response = driver.axi_read(araddr as u32, arsize as u32, arlen as u32, 32);
     fill_axi_read_payload(payload, 256, &response);
   });
 }
diff --git a/difftest/dpi_t1rocketemu/src/drive.rs b/difftest/dpi_t1rocketemu/src/drive.rs
index 2ed461b86..c42e2e1cc 100644
--- a/difftest/dpi_t1rocketemu/src/drive.rs
+++ b/difftest/dpi_t1rocketemu/src/drive.rs
@@ -135,9 +135,16 @@ impl Driver {
   }
 
   // data_width: AXI width (count in bits)
-  // return: Vec<u8> with len=bus_size
+  // return: Vec<u8> with len=bus_size*(arlen+1)
   // if size < bus_size, the result is padded due to AXI narrow transfer rules
-  pub(crate) fn axi_read(&mut self, addr: u32, arsize: u32, data_width: u32) -> Vec<u8> {
+  // if size < bus_size, arlen must be 0 (narrow burst is NOT supported)
+  pub(crate) fn axi_read(
+    &mut self,
+    addr: u32,
+    arsize: u32,
+    arlen: u32,
+    data_width: u32,
+  ) -> Vec<u8> {
     let bus_size = data_width / 8;
     let size = 1 << arsize;
 
@@ -146,13 +153,20 @@ impl Driver {
       "unaligned read addr={addr:#x} size={size}B dlen={bus_size}B"
     );
 
-    let mut data = vec![0; bus_size as usize];
+    assert!(
+      !(size < bus_size && arlen > 0),
+      "narrow burst not supported, axsize={arsize}, axlen={arlen}, data_width={data_width}"
+    );
+    let transaction_size = bus_size * (arlen + 1);
+
+    let mut data = vec![0; transaction_size as usize];
     if size < bus_size {
+      assert_eq!(arlen, 0);
       let start = (addr % bus_size) as usize;
       let end = start + (size as usize);
       self.addr_space.read_mem(addr, size, &mut data[start..end]);
     } else {
-      self.addr_space.read_mem(addr, size, &mut data);
+      self.addr_space.read_mem(addr, transaction_size, &mut data);
     }
     data
   }