Import sources from 2011-03-30 iso image

1 files changed, 496 insertions, 0 deletions

diff --git a/sys/src/9/omap/mmu.c b/sys/src/9/omap/mmu.c
new file mode 100755
index 000000000..05b4dc38c
--- /dev/null
+++ b/sys/src/9/omap/mmu.c
@@ -0,0 +1,496 @@
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+
+#include "arm.h"
+
+#define L1X(va)		FEXT((va), 20, 12)
+#define L2X(va)		FEXT((va), 12, 8)
+
+enum {
+	L1lo		= UZERO/MiB,		/* L1X(UZERO)? */
+	L1hi		= (USTKTOP+MiB-1)/MiB,	/* L1X(USTKTOP+MiB-1)? */
+};
+
+#define ISHOLE(pte)	((pte) == 0)
+
+/* dump level 1 page table at virtual addr l1 */
+void
+mmudump(PTE *l1)
+{
+	int i, type, rngtype;
+	uintptr pa, startva, startpa;
+	uvlong va, endva;
+	PTE pte;
+
+//	pa -= MACHSIZE+1024;	/* put level 2 entries below level 1 */
+//	l2 = KADDR(pa);
+
+	print("\n");
+	endva = startva = startpa = 0;
+	rngtype = 0;
+	/* dump first level of ptes */
+	for (va = i = 0; i < 4096; i++) {
+		pte = l1[i];
+		pa = pte & ~(MB - 1);
+		type = pte & (Fine|Section|Coarse);
+		if (ISHOLE(pte)) {
+			if (endva != 0) {	/* open range? close it */
+				print("l1 maps va (%#lux-%#llux) -> pa %#lux type %#ux\n",
+					startva, endva-1, startpa, rngtype);
+				endva = 0;
+			}
+		} else {
+			if (endva == 0) {	/* no open range? start one */
+				startva = va;
+				startpa = pa;
+				rngtype = type;
+			}
+			endva = va + MB;	/* continue the open range */
+//			if (type == Coarse) {
+//				// could dump the l2 table for this l1 entry
+//			}
+		}
+		va += MB;
+	}
+	if (endva != 0)			/* close an open range */
+		print("l1 maps va (%#lux-%#llux) -> pa %#lux type %#ux\n",
+			startva, endva-1, startpa, rngtype);
+}
+
+/* identity map the megabyte containing va, uncached */
+static void
+idmap(PTE *l1, ulong va)
+{
+	va &= ~(MB-1);
+	l1[L1X(va)] = va | Dom0 | L1AP(Krw) | Section;
+}
+
+/* map `mbs' megabytes from virt to phys */
+void
+mmumap(uintptr virt, uintptr phys, int mbs)
+{
+	uint off;
+	PTE *l1;
+
+	phys &= ~(MB-1);
+	virt &= ~(MB-1);
+	l1 = KADDR(ttbget());
+	for (off = 0; mbs-- > 0; off += MB)
+		l1[L1X(virt + off)] = (phys + off) | Dom0 | L1AP(Krw) | Section;
+	cacheuwbinv();
+	l2cacheuwbinv();
+	mmuinvalidate();
+}
+
+/* identity map `mbs' megabytes from phys */
+void
+mmuidmap(uintptr phys, int mbs)
+{
+	mmumap(phys, phys, mbs);
+}
+
+void
+mmuinit(void)
+{
+	uintptr pa;
+	PTE *l1, *l2;
+
+	pa = ttbget();
+	l1 = KADDR(pa);
+
+	/* redundant with l.s; only covers first MB of 17MB */
+	l1[L1X(VIRTIO)] = PHYSIO|Dom0|L1AP(Krw)|Section;
+
+	idmap(l1, PHYSETHER);		/* igep 9221 ethernet regs */
+	idmap(l1, PHYSL4PROT);
+	idmap(l1, PHYSL3);
+	idmap(l1, PHYSSMS);
+	idmap(l1, PHYSDRC);
+	idmap(l1, PHYSGPMC);
+
+	/* map high vectors to start of dram, but only 4K, not 1MB */
+	pa -= MACHSIZE+2*1024;
+	l2 = KADDR(pa);
+	memset(l2, 0, 1024);
+	/* vectors step on u-boot, but so do page tables */
+	l2[L2X(HVECTORS)] = PHYSDRAM|L2AP(Krw)|Small;
+	l1[L1X(HVECTORS)] = pa|Dom0|Coarse;	/* vectors -> ttb-machsize-2k */
+	coherence();
+
+	cacheuwbinv();
+	l2cacheuwbinv();
+	mmuinvalidate();
+
+	m->mmul1 = l1;
+//	mmudump(l1);			/* DEBUG */
+}
+
+static void
+mmul2empty(Proc* proc, int clear)
+{
+	PTE *l1;
+	Page **l2, *page;
+
+	l1 = m->mmul1;
+	l2 = &proc->mmul2;
+	for(page = *l2; page != nil; page = page->next){
+		if(clear)
+			memset(UINT2PTR(page->va), 0, BY2PG);
+		l1[page->daddr] = Fault;
+		l2 = &page->next;
+	}
+	*l2 = proc->mmul2cache;
+	proc->mmul2cache = proc->mmul2;
+	proc->mmul2 = nil;
+}
+
+static void
+mmul1empty(void)
+{
+#ifdef notdef
+/* there's a bug in here */
+	PTE *l1;
+
+	/* clean out any user mappings still in l1 */
+	if(m->mmul1lo > L1lo){
+		if(m->mmul1lo == 1)
+			m->mmul1[L1lo] = Fault;
+		else
+			memset(&m->mmul1[L1lo], 0, m->mmul1lo*sizeof(PTE));
+		m->mmul1lo = L1lo;
+	}
+	if(m->mmul1hi < L1hi){
+		l1 = &m->mmul1[m->mmul1hi];
+		if((L1hi - m->mmul1hi) == 1)
+			*l1 = Fault;
+		else
+			memset(l1, 0, (L1hi - m->mmul1hi)*sizeof(PTE));
+		m->mmul1hi = L1hi;
+	}
+#else
+	memset(&m->mmul1[L1lo], 0, (L1hi - L1lo)*sizeof(PTE));
+#endif /* notdef */
+}
+
+void
+mmuswitch(Proc* proc)
+{
+	int x;
+	PTE *l1;
+	Page *page;
+
+	/* do kprocs get here and if so, do they need to? */
+	if(m->mmupid == proc->pid && !proc->newtlb)
+		return;
+	m->mmupid = proc->pid;
+
+	/* write back dirty and invalidate l1 caches */
+	cacheuwbinv();
+
+	if(proc->newtlb){
+		mmul2empty(proc, 1);
+		proc->newtlb = 0;
+	}
+
+	mmul1empty();
+
+	/* move in new map */
+	l1 = m->mmul1;
+	for(page = proc->mmul2; page != nil; page = page->next){
+		x = page->daddr;
+		l1[x] = PPN(page->pa)|Dom0|Coarse;
+		/* know here that L1lo < x < L1hi */
+		if(x+1 - m->mmul1lo < m->mmul1hi - x)
+			m->mmul1lo = x+1;
+		else
+			m->mmul1hi = x;
+	}
+
+	/* make sure map is in memory */
+	/* could be smarter about how much? */
+	cachedwbse(&l1[L1X(UZERO)], (L1hi - L1lo)*sizeof(PTE));
+
+	/* lose any possible stale tlb entries */
+	mmuinvalidate();
+
+	//print("mmuswitch l1lo %d l1hi %d %d\n",
+	//	m->mmul1lo, m->mmul1hi, proc->kp);
+}
+
+void
+flushmmu(void)
+{
+	int s;
+
+	s = splhi();
+	up->newtlb = 1;
+	mmuswitch(up);
+	splx(s);
+}
+
+void
+mmurelease(Proc* proc)
+{
+	Page *page, *next;
+
+	/* write back dirty and invalidate l1 caches */
+	cacheuwbinv();
+
+	mmul2empty(proc, 0);
+	for(page = proc->mmul2cache; page != nil; page = next){
+		next = page->next;
+		if(--page->ref)
+			panic("mmurelease: page->ref %d", page->ref);
+		pagechainhead(page);
+	}
+	if(proc->mmul2cache && palloc.r.p)
+		wakeup(&palloc.r);
+	proc->mmul2cache = nil;
+
+	mmul1empty();
+
+	/* make sure map is in memory */
+	/* could be smarter about how much? */
+	cachedwbse(&m->mmul1[L1X(UZERO)], (L1hi - L1lo)*sizeof(PTE));
+
+	/* lose any possible stale tlb entries */
+	mmuinvalidate();
+}
+
+void
+putmmu(uintptr va, uintptr pa, Page* page)
+{
+	int x;
+	Page *pg;
+	PTE *l1, *pte;
+
+	x = L1X(va);
+	l1 = &m->mmul1[x];
+	//print("putmmu(%#p, %#p, %#p) ", va, pa, page->pa);
+	//print("mmul1 %#p l1 %#p *l1 %#ux x %d pid %d\n",
+	//	m->mmul1, l1, *l1, x, up->pid);
+	if(*l1 == Fault){
+		/* wasteful - l2 pages only have 256 entries - fix */
+		if(up->mmul2cache == nil){
+			/* auxpg since we don't need much? memset if so */
+			pg = newpage(1, 0, 0);
+			pg->va = VA(kmap(pg));
+		}
+		else{
+			pg = up->mmul2cache;
+			up->mmul2cache = pg->next;
+			memset(UINT2PTR(pg->va), 0, BY2PG);
+		}
+		pg->daddr = x;
+		pg->next = up->mmul2;
+		up->mmul2 = pg;
+
+		/* force l2 page to memory */
+		cachedwbse((void *)pg->va, BY2PG);
+
+		*l1 = PPN(pg->pa)|Dom0|Coarse;
+		cachedwbse(l1, sizeof *l1);
+		//print("l1 %#p *l1 %#ux x %d pid %d\n", l1, *l1, x, up->pid);
+
+		if(x >= m->mmul1lo && x < m->mmul1hi){
+			if(x+1 - m->mmul1lo < m->mmul1hi - x)
+				m->mmul1lo = x+1;
+			else
+				m->mmul1hi = x;
+		}
+	}
+	pte = UINT2PTR(KADDR(PPN(*l1)));
+	//print("pte %#p index %ld was %#ux\n", pte, L2X(va), *(pte+L2X(va)));
+
+	/* protection bits are
+	 *	PTERONLY|PTEVALID;
+	 *	PTEWRITE|PTEVALID;
+	 *	PTEWRITE|PTEUNCACHED|PTEVALID;
+	 */
+	x = Small;
+	if(!(pa & PTEUNCACHED))
+		x |= Cached|Buffered;
+	if(pa & PTEWRITE)
+		x |= L2AP(Urw);
+	else
+		x |= L2AP(Uro);
+	pte[L2X(va)] = PPN(pa)|x;
+	cachedwbse(&pte[L2X(va)], sizeof pte[0]);
+
+	/* clear out the current entry */
+	mmuinvalidateaddr(PPN(va));
+
+	/*  write back dirty entries - we need this because the pio() in
+	 *  fault.c is writing via a different virt addr and won't clean
+	 *  its changes out of the dcache.  Page coloring doesn't work
+	 *  on this mmu because the virtual cache is set associative
+	 *  rather than direct mapped.
+	 */
+	cachedwbinv();
+	if(page->cachectl[0] == PG_TXTFLUSH){
+		/* pio() sets PG_TXTFLUSH whenever a text pg has been written */
+		cacheiinv();
+		page->cachectl[0] = PG_NOFLUSH;
+	}
+	//print("putmmu %#p %#p %#p\n", va, pa, PPN(pa)|x);
+}
+
+void*
+mmuuncache(void* v, usize size)
+{
+	int x;
+	PTE *pte;
+	uintptr va;
+
+	/*
+	 * Simple helper for ucalloc().
+	 * Uncache a Section, must already be
+	 * valid in the MMU.
+	 */
+	va = PTR2UINT(v);
+	assert(!(va & (1*MiB-1)) && size == 1*MiB);
+
+	x = L1X(va);
+	pte = &m->mmul1[x];
+	if((*pte & (Fine|Section|Coarse)) != Section)
+		return nil;
+	*pte &= ~(Cached|Buffered);
+	mmuinvalidateaddr(va);
+	cachedwbinvse(pte, 4);
+
+	return v;
+}
+
+uintptr
+mmukmap(uintptr va, uintptr pa, usize size)
+{
+	int x;
+	PTE *pte;
+
+	/*
+	 * Stub.
+	 */
+	assert(!(va & (1*MiB-1)) && !(pa & (1*MiB-1)) && size == 1*MiB);
+
+	x = L1X(va);
+	pte = &m->mmul1[x];
+	if(*pte != Fault)
+		return 0;
+	*pte = pa|Dom0|L1AP(Krw)|Section;
+	mmuinvalidateaddr(va);
+	cachedwbinvse(pte, 4);
+
+	return va;
+}
+
+uintptr
+mmukunmap(uintptr va, uintptr pa, usize size)
+{
+	int x;
+	PTE *pte;
+
+	/*
+	 * Stub.
+	 */
+	assert(!(va & (1*MiB-1)) && !(pa & (1*MiB-1)) && size == 1*MiB);
+
+	x = L1X(va);
+	pte = &m->mmul1[x];
+	if(*pte != (pa|Dom0|L1AP(Krw)|Section))
+		return 0;
+	*pte = Fault;
+	mmuinvalidateaddr(va);
+	cachedwbinvse(pte, 4);
+
+	return va;
+}
+
+/*
+ * Return the number of bytes that can be accessed via KADDR(pa).
+ * If pa is not a valid argument to KADDR, return 0.
+ */
+uintptr
+cankaddr(uintptr pa)
+{
+	if(pa >= PHYSDRAM && pa < PHYSDRAM+memsize)
+		return PHYSDRAM+memsize - pa;
+	return 0;
+}
+
+/* from 386 */
+void*
+vmap(uintptr pa, usize size)
+{
+	uintptr pae, va;
+	usize o, osize;
+
+	/*
+	 * XXX - replace with new vm stuff.
+	 * Crock after crock - the first 4MB is mapped with 2MB pages
+	 * so catch that and return good values because the current mmukmap
+	 * will fail.
+	 */
+	if(pa+size < 4*MiB)
+		return UINT2PTR(kseg0|pa);
+
+	osize = size;
+	o = pa & (BY2PG-1);
+	pa -= o;
+	size += o;
+	size = ROUNDUP(size, BY2PG);
+
+	va = kseg0|pa;
+	pae = mmukmap(va, pa, size);
+	if(pae == 0 || pae-size != pa)
+		panic("vmap(%#p, %ld) called from %#p: mmukmap fails %#p",
+			pa+o, osize, getcallerpc(&pa), pae);
+
+	return UINT2PTR(va+o);
+}
+
+/* from 386 */
+void
+vunmap(void* v, usize size)
+{
+	/*
+	 * XXX - replace with new vm stuff.
+	 * Can't do this until do real vmap for all space that
+	 * might be used, e.g. stuff below 1MB which is currently
+	 * mapped automagically at boot but that isn't used (or
+	 * at least shouldn't be used) by the kernel.
+	upafree(PADDR(v), size);
+	 */
+	USED(v, size);
+}
+
+/*
+ * Notes.
+ * Everything is in domain 0;
+ * domain 0 access bits in the DAC register are set
+ * to Client, which means access is controlled by the
+ * permission values set in the PTE.
+ *
+ * L1 access control for the kernel is set to 1 (RW,
+ * no user mode access);
+ * L2 access control for the kernel is set to 1 (ditto)
+ * for all 4 AP sets;
+ * L1 user mode access is never set;
+ * L2 access control for user mode is set to either
+ * 2 (RO) or 3 (RW) depending on whether text or data,
+ * for all 4 AP sets.
+ * (To get kernel RO set AP to 0 and S bit in control
+ * register c1).
+ * Coarse L1 page-tables are used. They have 256 entries
+ * and so consume 1024 bytes per table.
+ * Small L2 page-tables are used. They have 1024 entries
+ * and so consume 4096 bytes per table.
+ *
+ * 4KiB. That's the size of 1) a page, 2) the
+ * size allocated for an L2 page-table page (note only 1KiB
+ * is needed per L2 page - to be dealt with later) and
+ * 3) the size of the area in L1 needed to hold the PTEs
+ * to map 1GiB of user space (0 -> 0x3fffffff, 1024 entries).
+ */