Changeset 457 for trunk/hal/tsar_mips32/drivers

Timestamp:

Aug 2, 2018, 11:47:13 AM (6 years ago)

Author:

alain

Message:

This version modifies the exec syscall and fixes a large number of small bugs.
The version number has been updated (0.1)

Location:

trunk/hal/tsar_mips32/drivers

Files:

• soclib_pic.c (modified) (9 diffs)
• soclib_tty.c (modified) (3 diffs)
• soclib_tty.h (modified) (3 diffs)

trunk/hal/tsar_mips32/drivers/soclib_pic.c

@@ -137 +137 @@
 #endif
 
-    // analyse status and handle up to 3 pending IRQ (one WTI, one HWI, one PTI)
+    // analyse status and handle up to 3 pending IRQs (one WTI, one HWI, one PTI)
 
     if( wti_status )          // pending WTI 
@@ -150 +150 @@
 #if DEBUG_HAL_IRQS
 if (DEBUG_HAL_IRQS < cycle )
-printk("\n[DBG] %s : core[%x,%d] received an IPI\n", __FUNCTION__ , local_cxy , core->lid );
+printk("\n[DBG] %s : core[%x,%d] handling IPI\n", __FUNCTION__ , local_cxy , core->lid );
 #endif
             // acknowledge IRQ (this require an XCU read)
@@ -156 +156 @@
 
             // check RPC FIFO,  and activate or create a RPC thread
-            // condition is always true, but we must use the ack value
+            // condition is always true, but we use the ack value
+            // to avoid a GCC warning
             if( ack + 1 ) rpc_check();
         }
@@ -182 +183 @@
 #if DEBUG_HAL_IRQS
 if (DEBUG_HAL_IRQS < cycle )
-printk("\n[DBG] %s : core[%x,%d] received external WTI %d\n",
+printk("\n[DBG] %s : core[%x,%d] handling external WTI %d\n",
 __FUNCTION__ , local_cxy , core->lid , index );
 #endif
@@ -216 +217 @@
 #if DEBUG_HAL_IRQS
 if (DEBUG_HAL_IRQS < cycle )
-printk("\n[DBG] %s : core[%x,%d] received HWI %d\n",
+printk("\n[DBG] %s : core[%x,%d] handling HWI %d\n",
 __FUNCTION__ , local_cxy , core->lid , index );
 #endif
@@ -232 +233 @@
 #if DEBUG_HAL_IRQS
 if (DEBUG_HAL_IRQS < cycle )
-printk("\n[DBG] %s : core[%x,%d] received PTI %d\n",
+printk("\n[DBG] %s : core[%x,%d] handling PTI %d\n",
 __FUNCTION__ , core->lid , local_cxy , index );
 #endif
@@ -239 +240 @@
 
         // execute all actions related to TICK event
-        // condition is always true, but we must use the ack value
+        // condition is always true, but we use the ack value
+        // to avoid a GCC warning
         if( ack + 1 ) core_clock( core );
         }
@@ -515 +517 @@
 {
     // calling core local index
-    lid_t  lid = CURRENT_CORE->lid;
+    lid_t  lid = CURRENT_THREAD->core->lid;
 
     // get XCU segment base
@@ -533 +535 @@
 {
     // calling core local index
-    lid_t  lid = CURRENT_CORE->lid;
+    lid_t  lid = CURRENT_THREAD->core->lid;
 
     // get XCU segment base

trunk/hal/tsar_mips32/drivers/soclib_tty.c

@@ -272 +272 @@
     xptr_t       parent_main_xp;    // local pointer on parent process main thread
 
-    // get TXT chdev channel, direction and server thread
+    // get TXT chdev channel, direction, server thread, and server core
     channel    = chdev->channel;
     is_rx      = chdev->is_rx;
@@ -455 +455 @@
                 thread_unblock( XPTR( local_cxy , server ) , THREAD_BLOCKED_ISR );
 
-                // send IPI to core running server thread
-                dev_pic_send_ipi( local_cxy , server_lid );
+                // send IPI to core running server thread if required
+                if( server_lid != CURRENT_THREAD->core->lid )
+                {
+                    dev_pic_send_ipi( local_cxy , server_lid );
+                }
             }
             else
@@ -501 +504 @@
         thread_unblock( XPTR( local_cxy , server ) , THREAD_BLOCKED_ISR );
 
-        // send IPI to core running server thread
-        dev_pic_send_ipi( local_cxy , server_lid );
+        // send IPI to core running server thread if required
+        if( server_lid != CURRENT_THREAD->core->lid )
+        {
+            dev_pic_send_ipi( local_cxy , server_lid );
+        }
 
     }  // end TX

trunk/hal/tsar_mips32/drivers/soclib_tty.h

@@ -2 +2 @@
  * soclib_tty.c - soclib tty driver definition.
  *
- * Author  Alain Greiner (2016)
+ * Author  Alain Greiner (2016,2017,2018)
  *
  * Copyright (c)  UPMC Sorbonne Universites
@@ -29 +29 @@
 /****************************************************************************************
  * This driver supports the vci_tty_tsar component.
- * It implements the generic TXT device API:
+ * Regarding read/write request, it implements the generic TXT device API:
  * - transfer one single character from TTY to command "buffer" if to_mem is non-zero.
  * - transfer "count" characters from command "buffer" to TTY if "to_mem is zero.
+ * It handles asynchronous control characters (^C / ^Z), that are translated to signals
+ * transmited to the TXT owner process (foreground process).
  ***************************************************************************************/
 
@@ -101 +103 @@
 /****************************************************************************************
  * This ISR is executed to handle both the TTY_TX_IRQ and the TTY_RX_IRQ, even if
- *   The RX_IRQ is activated as soon as the TTY_STATUS_RX_FULL bit is 1 in the
+ * there is two different channel devices for TX and RX transfers.
+ *
+ * As the <chdev> argument is a local pointer, this ISR is always executed by a core
+ * that is in the same cluster as the core running the DEV server thread.
+ *
+ * - The RX_IRQ is activated as soon as the TTY_STATUS_RX_FULL bit is 1 in the
  *   TTY_STATUS register, when the TTY_RX_IRQ_ENABLE is non zero, indicating that
  *   the TTY_READ buffer is full and can be read.
- *   The TX_IRQ is activated as soon as the TTY_STATUS_TX_FULL bit is 0 in the
+ * - The TX_IRQ is activated as soon as the TTY_STATUS_TX_FULL bit is 0 in the
  *   TTY_STATUS register, when the TTY_TX_IRQ_ENABLE is non zero, indicating that
  *   the TTY_WRITE buffer is empty, and can be written.
- * WARNING : In ALMOS-MKH, the RX_IRQ is always enabled to catch the control signals,
+ *
+ * The RX_IRQ is always enabled to catch the control characters (^Z / ^C),
  * but the TX_IRQ is dynamically enabled by the TXT_WRITE command, and disabled when
  * the command is completed.
  *
- * 1) The ISR first read the TTY_STATUS to get the current state of the TTY_READ and
- *   the TTY_WRITE buffers.
+ * For normal characters The ISR uses two private TTY_RX and TTY_TX software FIFOs
+ * (two FIFOs per channel) to communicates with the DEV server thread executing the 
+ * soclib_tty_cmd() function.
+
+ * For an RX transfer, this ISR executes a while loop moving bytes until the source
+ * TTY_READ buffer is empty:
+ *   1) The ISR read one byte from the TTY_READ register and acknowledge the RX_IRQ.
+ *   2) if the byte is a ^Z character, it uses a multicast RPC to block all treads of
+ *      the TXT owner process, and transfer TXT ownership to another process of the group.
+ *   3) if the byte is a ^C character, it removes the process from the TXT group, and send
+ *      a multicast RPC to delete all threads of the TXT owner process.
+ *   4) if the byte is a normal character and the destination TTY_RX_FIFO is not full,
+ *      it writes the byte to this FIFO, unblock the TXT_RX server thread, and send an IPI
+ *      to this server thread (only if it is running on another core than the ISR). 
+ *   5) It discards the byte if the TTY_RX_FIFO is full, with a warning message on TXT0.
  *
- * 2) It try to read the first command registered in the server thread queue associated 
- *    to the TTY channel
- *
- * 2) The ISR handles the RX when the TTY_READ buffer is full :
- *   . it read the available character from the TTY_READ buffer, and this
- *     acknowledges the RX_IRQ.
- *   . if it is a control character ( ^C / ^D / ^Z ) it translate it to the proper
- *     signal and execute the relevant sigaction for the foreground process.
- *   . if it is a normal character, it try to get the first command registered in the 
- *     server thread queue. If it is a TXT_READ, it returns this character to the 
- *     command buffer in the client thread.
- * 
- * 3) The ISR handles the TX when the TTY_WRITE buffer is empty and a TXT_WRITE
- *   . it try to get it copies the
- *     character to the command buffer, acknowledges the TTY_RX_IRQ, and unblock the 
- *     associated server thread.
-     
- *   . the control characters ^C / ^D / ^Z  are directly handled by the ISR and
- *     translated to the foreground process.
-
- * - the 
- the TXT_READ and TXT_WRITE commands.
- * It gets the command arguments from the first client thread in the TXT chdev queue:
- * - if TXT_READ, it transfers one byte from the TTY_READ_REG to the command buffer.
- *   It simply returns for retry if TTY_READ_REG is empty.
- * - if TXT_WRITE, it tries to transfer several bytes from the command buffer to the
- *   TTY_WRITE_REG. If the TTY_WRITE_REG is full, it updates the "count" and "buffer"
- *   command arguments and returns for retry.
- * When the I/O operation is completed, it sets the status field in the command, unblocks
- * the server thread, and unblocks the client thread.
+ * For a TX transfer, this ISR executes a while loop moving bytes until the source
+ * TTY_TX_FIFO is empty:
+ *   1) if the destination TTY_WRITE register is not full, it moves the byte from the
+ *      TTY_TX_FIFO to the TTY_WRITE register.
+ *   2) if the TTY_WRITE register is full, it polls (busy waiting) the TTY_STATUS register,
+ *      until the TTY_WRITE register is empty.
+ *   3) when the source TTY_TX_FIFO is empty, this ISR disable the TTY_TX_IRQ, unblock
+ *      the TXT_TX server thread, and send an IPI to this server thread (only if it is
+ *      running on another core than the ISR). 
  ****************************************************************************************
  * @ chdev     : local pointer on TXT chdev descriptor.