svn commit: r352446 - head/stand/efi/libefi

Toomas Soome tsoome at FreeBSD.org
Tue Sep 17 13:50:25 UTC 2019


Author: tsoome
Date: Tue Sep 17 13:50:25 2019
New Revision: 352446
URL: https://svnweb.freebsd.org/changeset/base/352446

Log:
  loader.efi: efipart needs to use ioalign
  
  UEFI specification 2.7A, EFI_BLOCK_IO_PROTOCOL, page 566.
  
  The ioalign property does define the alignment of data buffer.
  
  If the alignment is required and our buffer is not aligned, or if
  the data buffer is not multiple of Blocksize, we need to use bounce buffer
  to perform the block IO. This is much like with BIOS version, except
  there the INT13 needs buffer to be located in low memory.
  
  Additionally, we need to handle disk writes properly.

Modified:
  head/stand/efi/libefi/efipart.c

Modified: head/stand/efi/libefi/efipart.c
==============================================================================
--- head/stand/efi/libefi/efipart.c	Tue Sep 17 13:15:27 2019	(r352445)
+++ head/stand/efi/libefi/efipart.c	Tue Sep 17 13:50:25 2019	(r352446)
@@ -64,6 +64,9 @@ static int efipart_printhd(int);
 #define	PNP0700	0x700
 #define	PNP0701	0x701
 
+/* Bounce buffer max size */
+#define	BIO_BUFFER_SIZE	0x4000
+
 struct devsw efipart_fddev = {
 	.dv_name = "fd",
 	.dv_type = DEVT_FD,
@@ -266,6 +269,12 @@ efipart_inithandles(void)
 			continue;
 		}
 
+		/* Allowed values are 0, 1 and power of 2. */
+		if (blkio->Media->IoAlign > 1 &&
+		    !powerof2(blkio->Media->IoAlign)) {
+			continue;
+		}
+
 		/* This is bad. */
 		if ((pd = calloc(1, sizeof(*pd))) == NULL) {
 			printf("efipart_inithandles: Out of memory.\n");
@@ -979,8 +988,10 @@ efipart_realstrategy(void *devdata, int rw, daddr_t bl
 	EFI_BLOCK_IO *blkio;
 	uint64_t off, disk_blocks, d_offset = 0;
 	char *blkbuf;
-	size_t blkoff, blksz;
-	int error;
+	size_t blkoff, blksz, bio_size;
+	unsigned ioalign;
+	bool need_buf;
+	int rc;
 	uint64_t diskend, readstart;
 
 	if (dev == NULL || blk < 0)
@@ -1028,40 +1039,118 @@ efipart_realstrategy(void *devdata, int rw, daddr_t bl
 		size = size * blkio->Media->BlockSize;
 	}
 
-	if (rsize != NULL)
-		*rsize = size;
-
+	need_buf = true;
+	/* Do we need bounce buffer? */
 	if ((size % blkio->Media->BlockSize == 0) &&
 	    (off % blkio->Media->BlockSize == 0))
-		return (efipart_readwrite(blkio, rw,
-		    off / blkio->Media->BlockSize,
-		    size / blkio->Media->BlockSize, buf));
+		need_buf = false;
 
-	/*
-	 * The buffer size is not a multiple of the media block size.
-	 */
-	blkbuf = malloc(blkio->Media->BlockSize);
+	/* Do we have IO alignment requirement? */
+	ioalign = blkio->Media->IoAlign;
+	if (ioalign == 0)
+		ioalign++;
+
+	if (ioalign > 1 && (uintptr_t)buf != roundup2((uintptr_t)buf, ioalign))
+		need_buf = true;
+
+	if (need_buf) {
+		for (bio_size = BIO_BUFFER_SIZE; bio_size > 0;
+		    bio_size -= blkio->Media->BlockSize) {
+			blkbuf = memalign(ioalign, bio_size);
+			if (blkbuf != NULL)
+				break;
+		}
+	} else {
+		blkbuf = buf;
+		bio_size = size;
+	}
+
 	if (blkbuf == NULL)
 		return (ENOMEM);
 
-	error = 0;
+	if (rsize != NULL)
+		*rsize = size;
+
+	rc = 0;
 	blk = off / blkio->Media->BlockSize;
 	blkoff = off % blkio->Media->BlockSize;
-	blksz = blkio->Media->BlockSize - blkoff;
+
 	while (size > 0) {
-		error = efipart_readwrite(blkio, rw, blk, 1, blkbuf);
-		if (error)
+		size_t x = min(size, bio_size);
+
+		if (x < blkio->Media->BlockSize)
+			x = 1;
+		else
+			x /= blkio->Media->BlockSize;
+
+		switch (rw & F_MASK) {
+		case F_READ:
+			blksz = blkio->Media->BlockSize * x - blkoff;
+			if (size < blksz)
+				blksz = size;
+
+			rc = efipart_readwrite(blkio, rw, blk, x, blkbuf);
+			if (rc != 0)
+				goto error;
+
+			if (need_buf)
+				bcopy(blkbuf + blkoff, buf, blksz);
 			break;
-		if (size < blksz)
-			blksz = size;
-		bcopy(blkbuf + blkoff, buf, blksz);
+		case F_WRITE:
+			rc = 0;
+			if (blkoff != 0) {
+				/*
+				 * We got offset to sector, read 1 sector to
+				 * blkbuf.
+				 */
+				x = 1;
+				blksz = blkio->Media->BlockSize - blkoff;
+				blksz = min(blksz, size);
+				rc = efipart_readwrite(blkio, F_READ, blk, x,
+				    blkbuf);
+			} else if (size < blkio->Media->BlockSize) {
+				/*
+				 * The remaining block is not full
+				 * sector. Read 1 sector to blkbuf.
+				 */
+				x = 1;
+				blksz = size;
+				rc = efipart_readwrite(blkio, F_READ, blk, x,
+				    blkbuf);
+			} else {
+				/* We can write full sector(s). */
+				blksz = blkio->Media->BlockSize * x;
+			}
+
+			if (rc != 0)
+				goto error;
+			/*
+			 * Put your Data In, Put your Data out,
+			 * Put your Data In, and shake it all about
+			 */
+			if (need_buf)
+				bcopy(buf, blkbuf + blkoff, blksz);
+			rc = efipart_readwrite(blkio, F_WRITE, blk, x, blkbuf);
+			if (rc != 0)
+				goto error;
+			break;
+		default:
+			/* DO NOTHING */
+			rc = EROFS;
+			goto error;
+		}
+
+		blkoff = 0;
 		buf += blksz;
 		size -= blksz;
-		blk++;
-		blkoff = 0;
-		blksz = blkio->Media->BlockSize;
+		blk += x;
 	}
 
-	free(blkbuf);
-	return (error);
+error:
+	if (rsize != NULL)
+		*rsize -= size;
+
+	if (need_buf)
+		free(blkbuf);
+	return (rc);
 }


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