Splits UART tx/rx into separate CAmkES procedures

This ends the behavior where log messages would block on the prompt.

This change does not fix the potential race on dataports if
kata-uart-client read or write has multiple concurrent callers. A later
change will protect those using CAmkES mutexes, although the
alternative of having DebugConsole *own* the UART should also be
considered.

Change-Id: I8d5d8336cd58b9f22cca81ae6aca13b4ed57e7e4
GitOrigin-RevId: e781fd8454d22e0f829d788fe602e431551e259a

apps/system/components/DebugConsole/DebugConsole.camkes

@@ -6,9 +6,12 @@ import <SeL4DebugInterface.camkes>;
 
 component DebugConsole {
   control;
-  uses uart_inf uart;
+
   dataport Buf tx_dataport;
+  uses dataport_io_inf uart_tx;
+
   dataport Buf rx_dataport;
+  uses dataport_io_inf uart_rx;
 
   provides LoggerInterface logger;
   uses ProcessControlInterface proc_ctrl;

apps/system/components/DebugConsole/kata-uart-client/src/lib.rs

@@ -8,8 +8,8 @@ use kata_io as io;
 extern "C" {
     static rx_dataport: *mut cty::c_uchar;
     static tx_dataport: *mut cty::c_uchar;
-    fn uart_rx(n: cty::size_t);
-    fn uart_tx(n: cty::size_t);
+    fn uart_rx_update(n: cty::size_t);
+    fn uart_tx_update(n: cty::size_t);
 }
 
 // Console logging interface.
@@ -27,7 +27,7 @@ pub struct Rx {}
 impl io::Read for Rx {
     fn read(&mut self, buf: &mut [u8]) -> Result<usize, io::Error> {
         unsafe {
-            uart_rx(buf.len());
+            uart_rx_update(buf.len());
             let port = core::slice::from_raw_parts(rx_dataport, buf.len());
             buf.copy_from_slice(&port);
         }
@@ -42,7 +42,7 @@ impl io::Write for Tx {
         unsafe {
             let port = core::slice::from_raw_parts_mut(tx_dataport, buf.len());
             port.copy_from_slice(buf);
-            uart_tx(buf.len());
+            uart_tx_update(buf.len());
         }
         Ok(buf.len())
     }

apps/system/components/UartDriver/UartDriver.camkes

@@ -11,11 +11,10 @@
  */
 
 component UartDriver {
-	dataport Buf mem;
+  dataport Buf mmio_region;
   dataport Buf tx_dataport;
   dataport Buf rx_dataport;
 
-  // consumes Interrupt interrupt;
-
-	provides uart_inf uart;
+  provides dataport_io_inf uart_rx;
+  provides dataport_io_inf uart_tx;
 }

apps/system/components/UartDriver/src/driver.c

@@ -11,14 +11,14 @@
 #include "opentitan/uart.h"
 
 // Referenced by macros in the generated file opentitan/uart.h.
-#define UART0_BASE_ADDR (void *)mem
+#define UART0_BASE_ADDR (void *)mmio_region
 
 // Frequency of the primary clock clk_i.
 #define CLK_FIXED_FREQ_HZ (24ull * 1000 * 1000)
 
 #define REG32(addr) *((volatile uint32_t *)(addr))
 
-void uart__init() {
+void pre_init() {
   // Computes NCO value corresponding to baud rate.
   // nco = 2^20 * baud / fclk  (assuming NCO width is 16-bit)
   uint64_t baud = 115200ull;
@@ -75,7 +75,7 @@ static int uart_tx_ready() {
    */
 }
 
-void uart_rx(size_t n) {
+void uart_rx_update(size_t n) {
   char *c = (char *)rx_dataport;
   // TODO(mattharvey): Error return value for n > PAGE_SIZE
   for (size_t i = 0; i < n && i < PAGE_SIZE; ++i) {
@@ -87,7 +87,7 @@ void uart_rx(size_t n) {
   }
 }
 
-void uart_tx(size_t n) {
+void uart_tx_update(size_t n) {
   char *c = (char *)tx_dataport;
   // TODO(mattharvey): Error return value for n > PAGE_SIZE
   for (size_t i = 0; i < n && i < PAGE_SIZE; ++i) {

apps/system/interfaces/dataport_io.idl4

@@ -10,7 +10,6 @@
  * @TAG(DATA61_BSD)
  */
 
-procedure uart_inf {
-  void rx(in size_t n);
-  void tx(in size_t n);
+procedure dataport_io_inf {
+  void update(in size_t n);
 };

apps/system/system.camkes

@@ -12,7 +12,7 @@
 
 import <std_connector.camkes>;
 
-import "interfaces/uart.idl4";
+import "interfaces/dataport_io.idl4";
 import "interfaces/VectorCoreInterface.camkes";
 import "components/UartDriver/UartDriver.camkes";
 import "components/DebugConsole/DebugConsole.camkes";
@@ -23,9 +23,9 @@ import "components/VectorCoreDriver/VectorCoreDriver.camkes";
 
 component UART {
     hardware;
-    dataport Buf mem;
-    // TODO(mattharvey): Make receives wait on interrupt.
-    // emits Interrupt interrupt;
+    dataport Buf mmio_region;
+
+    emits Interrupt rx_watermark;
 }
 
 component VectorCoreHw {
@@ -35,22 +35,27 @@ component VectorCoreHw {
 
 assembly {
     composition {
-        component UART uart;
-        component UartDriver drv;
-        component DebugConsole debug_console;
-        component ProcessManager process_manager;
         component SeL4Debug sel4debug;
+
         component VectorCoreHw vctop;
         component VectorCoreDriver vc_drv;
+
+        component UART uart;
+        component UartDriver uart_driver;
+
+        component ProcessManager process_manager;
         component MlCoordinator ml_coordinator;
+        component DebugConsole debug_console;
 
-        connection seL4HardwareMMIO uart_mem(from drv.mem, to uart.mem);
-        connection seL4HardwareMMIO vc_csr(from vc_drv.csr, to vctop.csr);
-
+        // UartDriver
+        connection seL4HardwareMMIO uart_mem(from uart_driver.mmio_region,
+                                             to uart.mmio_region);
         // TODO(mattharvey): Make receives wait on interrupt.
-        // connection seL4HardwareInterrupt uart_interrupt(
-        //     from uart.interrupt, to drv.interrupt);
-        connection seL4RPCCall uart_inf(from debug_console.uart, to drv.uart);
+
+        // VectorCoreDriver
+        connection seL4HardwareMMIO vc_csr(from vc_drv.csr, to vctop.csr);
+        connection seL4RPCCall VectorCoreInterface(from ml_coordinator.vctop,
+                                                   to vc_drv.vctop);
 
         // Hookup ProcessManager to DebugConsole for shell commands.
         connection seL4RPCCall ProcessControlInterface(from debug_console.proc_ctrl,
@@ -58,6 +63,16 @@ assembly {
         connection seL4RPCCall PackageManagerInterface(from debug_console.pkg_mgmt,
                                                        to process_manager.pkg_mgmt);
 
+        // Connect the DebugConsole to the UartDriver.
+        connection seL4SharedData tx_channel(
+            from debug_console.tx_dataport, to uart_driver.tx_dataport);
+        connection seL4RPCCall tx_call(
+            from debug_console.uart_tx, to uart_driver.uart_tx);
+        connection seL4SharedData rx_channel(
+            from debug_console.rx_dataport, to uart_driver.rx_dataport);
+        connection seL4RPCCall rx_call(
+            from debug_console.uart_rx, to uart_driver.uart_rx);
+
         // Connect the LoggerInterface to each component that needs to log
         // to the console.
         connection seL4RPCCall LoggerInterface(from process_manager.logger,
@@ -72,25 +87,17 @@ assembly {
         connection seL4RPCCall MlCoordinatorInterface(from debug_console.mlcoord,
                                                       to ml_coordinator.mlcoord);
 
-        connection seL4RPCCall VectorCoreInterface(from ml_coordinator.vctop, to vc_drv.vctop);
-
-        connection seL4SharedData tx_channel(
-            from debug_console.tx_dataport, to drv.tx_dataport);
-        connection seL4SharedData rx_channel(
-            from debug_console.rx_dataport, to drv.rx_dataport);
     }
 
     configuration {
-        uart.mem_paddr = 0x40031000;
-        uart.mem_size = 0x1000;
-        // seL4 claims 10 is bigger than irqMax if this is uncommented.
-        // uart.interrupt_irq_number = 10;
+        uart.mmio_region_paddr = 0x40031000;
+        uart.mmio_region_size = 0x1000;
 
         vctop.csr_paddr = 0x48000000;
         vctop.csr_size = 0x1000;
 
         random.ID = 1;
 
-        uart.integrity_label = "drv";
+        uart.integrity_label = "uart_driver";
     }
 }