first usable version of kernel and commands

After an year of hard work, this is a first "usable" version of Jehanne.

sys/src/kern/port/allocb.c

@@ -0,0 +1,205 @@
+#include	"u.h"
+#include	"../port/lib.h"
+#include	"mem.h"
+#include	"dat.h"
+#include	"fns.h"
+
+enum
+{
+	Hdrspc		= 64,		/* leave room for high-level headers */
+	Bdead		= 0x51494F42,	/* "QIOB" */
+};
+
+struct
+{
+	Lock;
+	uint32_t	bytes;
+	uint32_t	limit;
+
+} ialloc;
+
+static Block*
+_allocb(int size, int align)
+{
+	Block *b;
+	uint8_t *p;
+	int n;
+
+	if(align <= 0)
+		align = BLOCKALIGN;
+	n = align + ROUNDUP(size+Hdrspc, align) + sizeof(Block);
+	if((p = malloc(n)) == nil)
+		return nil;
+
+	b = (Block*)(p + n - sizeof(Block));	/* block at end of allocated space */
+	b->base = p;
+	b->next = nil;
+	b->list = nil;
+	b->free = 0;
+	b->flag = 0;
+
+	/* align base and bounds of data */
+	b->lim = (uint8_t*)(PTR2UINT(b) & ~(align-1));
+
+	/* align start of writable data, leaving space below for added headers */
+	b->rp = b->lim - ROUNDUP(size, align);
+	b->wp = b->rp;
+
+	if(b->rp < b->base || b->lim - b->rp < size)
+		panic("_allocb");
+
+	return b;
+}
+
+Block*
+allocb(int size)
+{
+	Block *b;
+
+	/*
+	 * Check in a process and wait until successful.
+	 * Can still error out of here, though.
+	 */
+	if(up == nil)
+		panic("allocb without up: %#p\n", getcallerpc());
+	if((b = _allocb(size, 0)) == nil){
+		mallocsummary();
+		panic("allocb: no memory for %d bytes\n", size);
+	}
+	setmalloctag(b->base, getcallerpc());
+
+	return b;
+}
+
+Block*
+allocbalign(int size, int align)
+{
+	Block *b;
+
+	/*
+	 * Check in a process and wait until successful.
+	 * Can still error out of here, though.
+	 */
+	if(up == nil)
+		panic("allocbalign without up: %#p\n", getcallerpc());
+	if((b = _allocb(size, align)) == nil){
+		mallocsummary();
+		panic("allocbalign: no memory for %d bytes\n", size);
+	}
+	setmalloctag(b->base, getcallerpc());
+
+	return b;
+}
+
+void
+ialloclimit(uint32_t limit)
+{
+	ialloc.limit = limit;
+}
+
+Block*
+iallocb(int size)
+{
+	Block *b;
+	static int m1, m2, mp;
+
+	if(ialloc.bytes > ialloc.limit){
+		if((m1++%10000)==0){
+			if(mp++ > 1000){
+				active.exiting = 1;
+				exit(0);
+			}
+			iprint("iallocb: limited %lud/%lud\n",
+				ialloc.bytes, ialloc.limit);
+		}
+		return nil;
+	}
+
+	if((b = _allocb(size, 0)) == nil){
+		if((m2++%10000)==0){
+			if(mp++ > 1000){
+				active.exiting = 1;
+				exit(0);
+			}
+			iprint("iallocb: no memory %lud/%lud\n",
+				ialloc.bytes, ialloc.limit);
+		}
+		return nil;
+	}
+	b->flag = BINTR;
+	setmalloctag(b->base, getcallerpc());
+
+	ilock(&ialloc);
+	ialloc.bytes += b->lim - b->base;
+	iunlock(&ialloc);
+
+	return b;
+}
+
+void
+freeb(Block *b)
+{
+	void *dead = (void*)Bdead;
+	uint8_t *p;
+
+	if(b == nil)
+		return;
+
+	/*
+	 * drivers which perform non cache coherent DMA manage their own buffer
+	 * pool of uncached buffers and provide their own free routine.
+	 */
+	if(b->free) {
+		b->free(b);
+		return;
+	}
+	if(b->flag & BINTR) {
+		ilock(&ialloc);
+		ialloc.bytes -= b->lim - b->base;
+		iunlock(&ialloc);
+	}
+
+	p = b->base;
+
+	/* poison the block in case someone is still holding onto it */
+	b->next = dead;
+	b->rp = dead;
+	b->wp = dead;
+	b->lim = dead;
+	b->base = dead;
+
+	free(p);
+}
+
+void
+checkb(Block *b, char *msg)
+{
+	void *dead = (void*)Bdead;
+
+	if(b == dead)
+		panic("checkb b %s %#p", msg, b);
+	if(b->base == dead || b->lim == dead || b->next == dead
+	  || b->rp == dead || b->wp == dead){
+		print("checkb: base %#p lim %#p next %#p\n",
+			b->base, b->lim, b->next);
+		print("checkb: rp %#p wp %#p\n", b->rp, b->wp);
+		panic("checkb dead: %s\n", msg);
+	}
+
+	if(b->base > b->lim)
+		panic("checkb 0 %s %#p %#p", msg, b->base, b->lim);
+	if(b->rp < b->base)
+		panic("checkb 1 %s %#p %#p", msg, b->base, b->rp);
+	if(b->wp < b->base)
+		panic("checkb 2 %s %#p %#p", msg, b->base, b->wp);
+	if(b->rp > b->lim)
+		panic("checkb 3 %s %#p %#p", msg, b->rp, b->lim);
+	if(b->wp > b->lim)
+		panic("checkb 4 %s %#p %#p", msg, b->wp, b->lim);
+}
+
+void
+iallocsummary(void)
+{
+	print("ialloc %lud/%lud\n", ialloc.bytes, ialloc.limit);
+}