Commit 79bae42d authored by Ben Hutchings's avatar Ben Hutchings Committed by Linus Torvalds
Browse files

dmi_scan: refactor dmi_scan_machine(), {smbios,dmi}_present() 



Move the calls to memcpy_fromio() up into the loop in
dmi_scan_machine(), and move the signature checks back down into
dmi_decode().  We need to check at 16-byte intervals but keep a 32-byte
buffer for an SMBIOS entry, so shift the buffer after each iteration.

Merge smbios_present() into dmi_present(), so we look for an SMBIOS
signature at the beginning of the given buffer and then for a DMI
signature at an offset of 16 bytes.

[artem.savkov@gmail.com: use proper buf type in dmi_present()]
Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
Reported-by: default avatarTim McGrath <tmhikaru@gmail.com>
Tested-by: default avatarTim Mcgrath <tmhikaru@gmail.com>
Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: default avatarArtem Savkov <artem.savkov@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c1d025e2

drivers/firmware/dmi_scan.c

+37 −43
Original line number Diff line number Diff line
@@ -419,22 +419,45 @@ static void __init dmi_format_ids(char *buf, size_t len) 
			    dmi_get_system_info(DMI_BIOS_DATE));

}



static int __init dmi_present(const char __iomem *p)

static int __init dmi_present(const u8 *buf)

{

	u8 buf[15];

	int smbios_ver;



	memcpy_fromio(buf, p, 15);

	if (dmi_checksum(buf, 15)) {

	if (memcmp(buf, "_SM_", 4) == 0 &&

	    buf[5] < 32 && dmi_checksum(buf, buf[5])) {

		smbios_ver = (buf[6] << 8) + buf[7];



		/* Some BIOS report weird SMBIOS version, fix that up */

		switch (smbios_ver) {

		case 0x021F:

		case 0x0221:

			pr_debug("SMBIOS version fixup(2.%d->2.%d)\n",

				 smbios_ver & 0xFF, 3);

			smbios_ver = 0x0203;

			break;

		case 0x0233:

			pr_debug("SMBIOS version fixup(2.%d->2.%d)\n", 51, 6);

			smbios_ver = 0x0206;

			break;

		}

	} else {

		smbios_ver = 0;

	}



	buf += 16;



	if (memcmp(buf, "_DMI_", 5) == 0 && dmi_checksum(buf, 15)) {

		dmi_num = (buf[13] << 8) | buf[12];

		dmi_len = (buf[7] << 8) | buf[6];

		dmi_base = (buf[11] << 24) | (buf[10] << 16) |

			(buf[9] << 8) | buf[8];



		if (dmi_walk_early(dmi_decode) == 0) {

			if (dmi_ver)

			if (smbios_ver) {

				dmi_ver = smbios_ver;

				pr_info("SMBIOS %d.%d present.\n",

				       dmi_ver >> 8, dmi_ver & 0xFF);

			else {

			} else {

				dmi_ver = (buf[14] & 0xF0) << 4 |

					   (buf[14] & 0x0F);

				pr_info("Legacy DMI %d.%d present.\n",
@@ -445,40 +468,14 @@ static int __init dmi_present(const char __iomem *p) 
			return 0;

		}

	}

	dmi_ver = 0;

	return 1;

}



static int __init smbios_present(const char __iomem *p)

{

	u8 buf[32];



	memcpy_fromio(buf, p, 32);

	if ((buf[5] < 32) && dmi_checksum(buf, buf[5])) {

		dmi_ver = (buf[6] << 8) + buf[7];



		/* Some BIOS report weird SMBIOS version, fix that up */

		switch (dmi_ver) {

		case 0x021F:

		case 0x0221:

			pr_debug("SMBIOS version fixup(2.%d->2.%d)\n",

			       dmi_ver & 0xFF, 3);

			dmi_ver = 0x0203;

			break;

		case 0x0233:

			pr_debug("SMBIOS version fixup(2.%d->2.%d)\n", 51, 6);

			dmi_ver = 0x0206;

			break;

		}

		return memcmp(p + 16, "_DMI_", 5) || dmi_present(p + 16);

	}

	return 1;

}



void __init dmi_scan_machine(void)

{

	char __iomem *p, *q;

	int rc;

	char buf[32];



	if (efi_enabled(EFI_CONFIG_TABLES)) {

		if (efi.smbios == EFI_INVALID_TABLE_ADDR)
@@ -491,10 +488,10 @@ void __init dmi_scan_machine(void) 
		p = dmi_ioremap(efi.smbios, 32);

		if (p == NULL)

			goto error;



		rc = smbios_present(p);

		memcpy_fromio(buf, p, 32);

		dmi_iounmap(p, 32);

		if (!rc) {



		if (!dmi_present(buf)) {

			dmi_available = 1;

			goto out;

		}
@@ -509,18 +506,15 @@ void __init dmi_scan_machine(void) 
		if (p == NULL)

			goto error;



		memset(buf, 0, 16);

		for (q = p; q < p + 0x10000; q += 16) {

			if (memcmp(q, "_SM_", 4) == 0 && q - p <= 0xFFE0)

				rc = smbios_present(q);

			else if (memcmp(q, "_DMI_", 5) == 0)

				rc = dmi_present(q);

			else

				continue;

			if (!rc) {

			memcpy_fromio(buf + 16, q, 16);

			if (!dmi_present(buf)) {

				dmi_available = 1;

				dmi_iounmap(p, 0x10000);

				goto out;

			}

			memcpy(buf, buf + 16, 16);

		}

		dmi_iounmap(p, 0x10000);

	}

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