ringbuffer: Make ring buffer access irq-save

We have to temporarily disable nterrupts when performing rinbuffer
operations, as the ring buffer is used both from IRQ as well as process
context.

firmware/src_simtrace/card_emu.c

@@ -17,6 +17,8 @@
  *
  */
 
+#define TRACE_LEVEL 6
+
 #include <assert.h>
 #include <errno.h>
 #include <string.h>

firmware/src_simtrace/host_communication.c

@@ -1,3 +1,5 @@
+//#define TRACE_LEVEL 6
+
 #include "board.h"
 #include "req_ctx.h"
 #include "linuxlist.h"

firmware/src_simtrace/mode_cardemu.c

@@ -1,3 +1,5 @@
+#define TRACE_LEVEL 6
+
 #include "board.h"
 #include "simtrace.h"
 #include "ringbuffer.h"
@@ -250,6 +252,9 @@ void mode_cardemu_exit(void)
 {
 	TRACE_ENTRY();
 
+	/* FIXME: stop tc_fdt */
+	/* FIXME: release all rctx, unlink them from any queue */
+
 	PIO_DisableIt(&pin_usim1_rst);
 	PIO_DisableIt(&pin_usim1_vcc);
 

firmware/src_simtrace/ringbuffer.c

@@ -1,16 +1,27 @@
 #include "ringbuffer.h"
 #include "trace.h"
+#include "utils.h"
 
 void rbuf_reset(volatile ringbuf * rb)
 {
+	unsigned long state;
+
+	local_irq_save(state);
 	rb->ird = 0;
 	rb->iwr = 0;
+	local_irq_restore(state);
 }
 
 uint8_t rbuf_read(volatile ringbuf * rb)
 {
-	uint8_t val = rb->buf[rb->ird];
+	unsigned long state;
+	uint8_t val;
+
+	local_irq_save(state);
+	val = rb->buf[rb->ird];
 	rb->ird = (rb->ird + 1) % RING_BUFLEN;
+	local_irq_restore(state);
+
 	return val;
 }
 
@@ -19,22 +30,41 @@ uint8_t rbuf_peek(volatile ringbuf * rb)
 	return rb->buf[rb->ird];
 }
 
-void rbuf_write(volatile volatile ringbuf * rb, uint8_t item)
-{
-	if (!rbuf_is_full(rb)) {
-		rb->buf[rb->iwr] = item;
-		rb->iwr = (rb->iwr + 1) % RING_BUFLEN;
-	} else {
-		TRACE_ERROR("Ringbuffer full, losing bytes!");
-	}
-}
-
 bool rbuf_is_empty(volatile ringbuf * rb)
 {
 	return rb->ird == rb->iwr;
 }
 
-bool rbuf_is_full(volatile ringbuf * rb)
+static bool __rbuf_is_full(volatile ringbuf * rb)
 {
 	return rb->ird == (rb->iwr + 1) % RING_BUFLEN;
 }
+
+bool rbuf_is_full(volatile ringbuf * rb)
+{
+	unsigned long state;
+	bool rc;
+
+	local_irq_save(state);
+	rc = rb->ird == (rb->iwr + 1) % RING_BUFLEN;
+	local_irq_restore(state);
+
+	return rc;
+}
+
+void rbuf_write(volatile volatile ringbuf * rb, uint8_t item)
+{
+	unsigned long state;
+
+	local_irq_save(state);
+	if (!__rbuf_is_full(rb)) {
+		rb->buf[rb->iwr] = item;
+		rb->iwr = (rb->iwr + 1) % RING_BUFLEN;
+		local_irq_restore(state);
+	} else {
+		local_irq_restore(state);
+		TRACE_ERROR("Ringbuffer full, losing bytes!");
+	}
+}
+
+