IB/ipath: Fix port sharing on powerpc

The port sharing feature mixed kernel virtual addresses as well as
physical addresses for the offset used to describe the mmap address to
map the InfiniPath hardware into user space.  This had a conflict on
powerpc.  The new scheme converts it to a physical address so it
doesn't conflict with chip addresses and yet still fits in 40/44 bits
so it isn't truncated by 32-bit applications calling mmap64().
Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ipath/ipath_file_ops.c

@@ -41,12 +41,6 @@
 #include "ipath_kernel.h"
 #include "ipath_common.h"
 
-/*
- * mmap64 doesn't allow all 64 bits for 32-bit applications
- * so only use the low 43 bits.
- */
-#define MMAP64_MASK	0x7FFFFFFFFFFUL
-
 static int ipath_open(struct inode *, struct file *);
 static int ipath_close(struct inode *, struct file *);
 static ssize_t ipath_write(struct file *, const char __user *, size_t,
@@ -63,6 +57,24 @@ static const struct file_operations ipath_file_ops = {
 	.mmap = ipath_mmap
 };
 
+/*
+ * Convert kernel virtual addresses to physical addresses so they don't
+ * potentially conflict with the chip addresses used as mmap offsets.
+ * It doesn't really matter what mmap offset we use as long as we can
+ * interpret it correctly.
+ */
+static u64 cvt_kvaddr(void *p)
+{
+	struct page *page;
+	u64 paddr = 0;
+
+	page = vmalloc_to_page(p);
+	if (page)
+		paddr = page_to_pfn(page) << PAGE_SHIFT;
+
+	return paddr;
+}
+
 static int ipath_get_base_info(struct file *fp,
 			       void __user *ubase, size_t ubase_size)
 {
@@ -173,15 +185,14 @@ static int ipath_get_base_info(struct file *fp,
 		kinfo->spi_piocnt = dd->ipath_pbufsport / subport_cnt;
 		kinfo->spi_piobufbase = (u64) pd->port_piobufs +
 			dd->ipath_palign * kinfo->spi_piocnt * slave;
-		kinfo->__spi_uregbase = ((u64) pd->subport_uregbase +
-			PAGE_SIZE * slave) & MMAP64_MASK;
+		kinfo->__spi_uregbase = cvt_kvaddr(pd->subport_uregbase +
+			PAGE_SIZE * slave);
 
-		kinfo->spi_rcvhdr_base = ((u64) pd->subport_rcvhdr_base +
-			pd->port_rcvhdrq_size * slave) & MMAP64_MASK;
+		kinfo->spi_rcvhdr_base = cvt_kvaddr(pd->subport_rcvhdr_base +
+			pd->port_rcvhdrq_size * slave);
 		kinfo->spi_rcvhdr_tailaddr = 0;
-		kinfo->spi_rcv_egrbufs = ((u64) pd->subport_rcvegrbuf +
-			dd->ipath_rcvegrcnt * dd->ipath_rcvegrbufsize * slave) &
-			MMAP64_MASK;
+		kinfo->spi_rcv_egrbufs = cvt_kvaddr(pd->subport_rcvegrbuf +
+			dd->ipath_rcvegrcnt * dd->ipath_rcvegrbufsize * slave);
 	}
 
 	kinfo->spi_pioindex = (kinfo->spi_piobufbase - dd->ipath_piobufbase) /
@@ -199,11 +210,11 @@ static int ipath_get_base_info(struct file *fp,
 	if (master) {
 		kinfo->spi_runtime_flags |= IPATH_RUNTIME_MASTER;
 		kinfo->spi_subport_uregbase =
-			(u64) pd->subport_uregbase & MMAP64_MASK;
+			cvt_kvaddr(pd->subport_uregbase);
 		kinfo->spi_subport_rcvegrbuf =
-			(u64) pd->subport_rcvegrbuf & MMAP64_MASK;
+			cvt_kvaddr(pd->subport_rcvegrbuf);
 		kinfo->spi_subport_rcvhdr_base =
-			(u64) pd->subport_rcvhdr_base & MMAP64_MASK;
+			cvt_kvaddr(pd->subport_rcvhdr_base);
 		ipath_cdbg(PROC, "port %u flags %x %llx %llx %llx\n",
 			kinfo->spi_port, kinfo->spi_runtime_flags,
 			(unsigned long long) kinfo->spi_subport_uregbase,
@@ -1131,13 +1142,11 @@ static int mmap_kvaddr(struct vm_area_struct *vma, u64 pgaddr,
 	struct ipath_devdata *dd;
 	void *addr;
 	size_t size;
-	int ret;
+	int ret = 0;
 
 	/* If the port is not shared, all addresses should be physical */
-	if (!pd->port_subport_cnt) {
-		ret = -EINVAL;
+	if (!pd->port_subport_cnt)
 		goto bail;
-	}
 
 	dd = pd->port_dd;
 	size = pd->port_rcvegrbuf_chunks * pd->port_rcvegrbuf_size;
@@ -1149,33 +1158,28 @@ static int mmap_kvaddr(struct vm_area_struct *vma, u64 pgaddr,
 	if (subport == 0) {
 		unsigned num_slaves = pd->port_subport_cnt - 1;
 
-		if (pgaddr == ((u64) pd->subport_uregbase & MMAP64_MASK)) {
+		if (pgaddr == cvt_kvaddr(pd->subport_uregbase)) {
 			addr = pd->subport_uregbase;
 			size = PAGE_SIZE * num_slaves;
-		} else if (pgaddr == ((u64) pd->subport_rcvhdr_base &
-				      MMAP64_MASK)) {
+		} else if (pgaddr == cvt_kvaddr(pd->subport_rcvhdr_base)) {
 			addr = pd->subport_rcvhdr_base;
 			size = pd->port_rcvhdrq_size * num_slaves;
-		} else if (pgaddr == ((u64) pd->subport_rcvegrbuf &
-				      MMAP64_MASK)) {
+		} else if (pgaddr == cvt_kvaddr(pd->subport_rcvegrbuf)) {
 			addr = pd->subport_rcvegrbuf;
 			size *= num_slaves;
-		} else {
-			ret = -EINVAL;
+		} else
 			goto bail;
-		}
-	} else if (pgaddr == (((u64) pd->subport_uregbase +
-			       PAGE_SIZE * (subport - 1)) & MMAP64_MASK)) {
+	} else if (pgaddr == cvt_kvaddr(pd->subport_uregbase +
+					PAGE_SIZE * (subport - 1))) {
 		addr = pd->subport_uregbase + PAGE_SIZE * (subport - 1);
 		size = PAGE_SIZE;
-	} else if (pgaddr == (((u64) pd->subport_rcvhdr_base +
-			       pd->port_rcvhdrq_size * (subport - 1)) &
-			      MMAP64_MASK)) {
+	} else if (pgaddr == cvt_kvaddr(pd->subport_rcvhdr_base +
+				pd->port_rcvhdrq_size * (subport - 1))) {
 		addr = pd->subport_rcvhdr_base +
 			pd->port_rcvhdrq_size * (subport - 1);
 		size = pd->port_rcvhdrq_size;
-	} else if (pgaddr == (((u64) pd->subport_rcvegrbuf +
-			       size * (subport - 1)) & MMAP64_MASK)) {
+	} else if (pgaddr == cvt_kvaddr(pd->subport_rcvegrbuf +
+			       size * (subport - 1))) {
 		addr = pd->subport_rcvegrbuf + size * (subport - 1);
 		/* rcvegrbufs are read-only on the slave */
 		if (vma->vm_flags & VM_WRITE) {
@@ -1190,10 +1194,8 @@ static int mmap_kvaddr(struct vm_area_struct *vma, u64 pgaddr,
 		 * with mprotect.
 		 */
 		vma->vm_flags &= ~VM_MAYWRITE;
-	} else {
-		ret = -EINVAL;
+	} else
 		goto bail;
-	}
 	len = vma->vm_end - vma->vm_start;
 	if (len > size) {
 		ipath_cdbg(MM, "FAIL: reqlen %lx > %zx\n", len, size);
@@ -1204,7 +1206,7 @@ static int mmap_kvaddr(struct vm_area_struct *vma, u64 pgaddr,
 	vma->vm_pgoff = (unsigned long) addr >> PAGE_SHIFT;
 	vma->vm_ops = &ipath_file_vm_ops;
 	vma->vm_flags |= VM_RESERVED | VM_DONTEXPAND;
-	ret = 0;
+	ret = 1;
 
 bail:
 	return ret;
@@ -1264,8 +1266,10 @@ static int ipath_mmap(struct file *fp, struct vm_area_struct *vma)
 	 * Check for kernel virtual addresses first, anything else must
 	 * match a HW or memory address.
 	 */
-	if (pgaddr >= (1ULL<<40)) {
-		ret = mmap_kvaddr(vma, pgaddr, pd, subport_fp(fp));
+	ret = mmap_kvaddr(vma, pgaddr, pd, subport_fp(fp));
+	if (ret) {
+		if (ret > 0)
+			ret = 0;
 		goto bail;
 	}
 
@@ -1411,7 +1415,7 @@ static int init_subports(struct ipath_devdata *dd,
 	 */
 	if (uinfo->spu_subport_cnt <= 1)
 		goto bail;
-	if (uinfo->spu_subport_cnt > 4) {
+	if (uinfo->spu_subport_cnt > INFINIPATH_MAX_SUBPORT) {
 		ret = -EINVAL;
 		goto bail;
 	}