X-Git-Url: http://sraa.de/git/?a=blobdiff_plain;f=dol%2Fsrc%2Fdol%2Fvisitor%2Fcell%2Flib%2Fppu%2FFifo.cpp;fp=dol%2Fsrc%2Fdol%2Fvisitor%2Fcell%2Flib%2Fppu%2FFifo.cpp;h=6198d3c3759f3b79b71e98f59e82679376a79ad2;hb=8c411cf24ed0eb889191aaeafd8fa1e69081df42;hp=0000000000000000000000000000000000000000;hpb=dea7a4fb1ed110d3ce6e6d9255103d724bd66c0e;p=jump.git

diff --git a/dol/src/dol/visitor/cell/lib/ppu/Fifo.cpp b/dol/src/dol/visitor/cell/lib/ppu/Fifo.cpp
new file mode 100644
index 0000000..6198d3c
--- /dev/null
+++ b/dol/src/dol/visitor/cell/lib/ppu/Fifo.cpp
@@ -0,0 +1,142 @@
+#include "Fifo.h"
+
+/**
+ *
+ */
+Fifo::Fifo(unsigned size = 18) {
+	//except at the beginning, _head and _tail must never overlap,
+	//otherwise one does not know whether the buffer is full or
+	//empty. To have nevertheless a buffer with the given capacity,
+	//a buffer with one more element is allocated.
+	_size = size;
+	_buffer = (char *) _malloc_align(_size, ALIGNMENT_FACTOR);
+        if(!_buffer) {
+	    fprintf(stderr,"[FIFO] Memory allocation failure\n");
+	    exit(-1);
+	}
+        
+	_tail = 0;
+	_pos = 0;
+	_blocked = 0;
+
+	_inTail = 0;
+	_activeDMA = false;
+}
+
+/**
+ *
+ */
+Fifo::~Fifo() {
+	if (_buffer) {
+		_free_align(_buffer);
+	}
+	_buffer = 0;
+	_tail = 0;
+	_pos = 0;
+}
+
+/**
+ *
+ */
+unsigned Fifo::read(void *destination, unsigned len) {
+	char* buffer = (char*) destination;
+	unsigned read = (len <= used() ? len : used());
+
+	if (_tail + read < _size) {
+		memcpy(buffer, _buffer + _tail, read);
+	} else {
+		memcpy(buffer, _buffer + _tail, _size - _tail);
+		memcpy(buffer + _size - _tail, _buffer, read - _size + _tail);
+	}
+
+	_tail = ((unsigned) (_tail + read) % _size);
+	_pos -= read;
+	return read;
+}
+
+/**
+ *
+ */
+unsigned Fifo::write(const void *source, unsigned len) {
+
+	char* buffer = (char*) source;
+	unsigned write = (len <= unused() ? len : unused());
+	unsigned head = (_tail + _pos) % _size;
+
+	if (head + write < _size) {
+		memcpy(_buffer + head, buffer, write);
+	} else {
+		memcpy(_buffer + head, buffer, _size - head);
+		memcpy(_buffer, buffer + _size - head, write - _size + head);
+	}
+
+	_pos += write;
+	return write;
+}
+
+/**
+ * Size of this fifo
+ */
+unsigned Fifo::size() const {
+	return (_size);
+}
+
+/**
+ * How many bytes are currently free in the buffer
+ */
+unsigned Fifo::unused() const {
+	return (_size) - used();
+}
+
+/**
+ * How many data are currently stored in the fifo
+ */
+unsigned Fifo::used() const {
+	return _pos;
+}
+
+/*
+ * Get the pointer to the start of the queue
+ */
+char *Fifo::getQueuePointer() {
+	return _buffer;
+}
+
+/*
+ * Has completed a dma read process, i.e. has read out of the queue
+ */
+void Fifo::dmaRead(unsigned len) {
+	_activeDMA = false;
+
+	if (len == 0) {
+		_blocked = BLOCKED_MAX_NR;
+	} else {
+		_tail = ((unsigned) (_tail + len) % _size);
+		_pos -= len;
+	}
+}
+
+/*
+ * Start a DMA request, returns the current space one have
+ */
+unsigned Fifo::dmaStart() {
+	_activeDMA = true;
+
+	if (_tail + _pos > _size) {
+		return _size - _tail;
+	} else {
+		return _pos;
+	}
+}
+
+/*
+ * Is allowed to start a dma request
+ */
+bool Fifo::dmaAllowed() {
+	if (_blocked > 0) {
+		_blocked--;
+		return false;
+	} else {
+		return !_activeDMA;
+	}
+}