From 5017b2851373ee15c7035151853bb1448800cae2 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Wed, 3 Jul 2013 15:05:02 -0700 Subject: dmi: add support for exact DMI matches in addition to substring matching dmi_match() considers a substring match to be a successful match. This is not always sufficient to distinguish between DMI data for different systems. Add support for exact string matching using strcmp() in addition to the substring matching using strstr(). The specific use case in the i915 driver is to allow us to use an exact match for D510MO, without also incorrectly matching D510MOV: { .ident = "Intel D510MO", .matches = { DMI_MATCH(DMI_BOARD_VENDOR, "Intel"), DMI_EXACT_MATCH(DMI_BOARD_NAME, "D510MO"), }, } Signed-off-by: Jani Nikula Cc: Cc: Chris Wilson Cc: Cornel Panceac Acked-by: Daniel Vetter Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/firmware/dmi_scan.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'drivers/firmware/dmi_scan.c') diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index b95159b33c39..eb760a218da4 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -551,9 +551,15 @@ static bool dmi_matches(const struct dmi_system_id *dmi) int s = dmi->matches[i].slot; if (s == DMI_NONE) break; - if (dmi_ident[s] - && strstr(dmi_ident[s], dmi->matches[i].substr)) - continue; + if (dmi_ident[s]) { + if (!dmi->matches[i].exact_match && + strstr(dmi_ident[s], dmi->matches[i].substr)) + continue; + else if (dmi->matches[i].exact_match && + !strcmp(dmi_ident[s], dmi->matches[i].substr)) + continue; + } + /* No match */ return false; } -- cgit v1.2.3 From d39de28c95876f8becb559d242eefe718ea1f747 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Wed, 31 Jul 2013 13:53:30 -0700 Subject: dmi_scan: add comments on dmi_present() and the loop in dmi_scan_machine() My previous refactoring in commit 79bae42d51a5 ("dmi_scan: refactor dmi_scan_machine(), {smbios,dmi}_present()") resulted in slightly tricky code (though I think it's more elegant). Explain what it's doing. Signed-off-by: Ben Hutchings Cc: Zhenzhong Duan Cc: Jean Delvare Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/firmware/dmi_scan.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'drivers/firmware/dmi_scan.c') diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index eb760a218da4..232fa8fce26a 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -419,6 +419,13 @@ static void __init dmi_format_ids(char *buf, size_t len) dmi_get_system_info(DMI_BIOS_DATE)); } +/* + * Check for DMI/SMBIOS headers in the system firmware image. Any + * SMBIOS header must start 16 bytes before the DMI header, so take a + * 32 byte buffer and check for DMI at offset 16 and SMBIOS at offset + * 0. If the DMI header is present, set dmi_ver accordingly (SMBIOS + * takes precedence) and return 0. Otherwise return 1. + */ static int __init dmi_present(const u8 *buf) { int smbios_ver; @@ -506,6 +513,13 @@ void __init dmi_scan_machine(void) if (p == NULL) goto error; + /* + * Iterate over all possible DMI header addresses q. + * Maintain the 32 bytes around q in buf. On the + * first iteration, substitute zero for the + * out-of-range bytes so there is no chance of falsely + * detecting an SMBIOS header. + */ memset(buf, 0, 16); for (q = p; q < p + 0x10000; q += 16) { memcpy_fromio(buf + 16, q, 16); -- cgit v1.2.3