From 13b40a1a065824d2d4e55c8b48ea9f3f9d162929 Mon Sep 17 00:00:00 2001 From: Zhao Yakui Date: Sun, 4 Jan 2009 12:04:21 +0800 Subject: ACPI: Avoid array address overflow when _CST MWAIT hint bits are set The Cx Register address obtained from the _CST object is used as the MWAIT hints if the register type is FFixedHW. And it is used to check whether the Cx type is supported or not. On some boxes the following Cx state package is obtained from _CST object: >{ ResourceTemplate () { Register (FFixedHW, 0x01, // Bit Width 0x02, // Bit Offset 0x0000000000889759, // Address 0x03, // Access Size ) }, 0x03, 0xF5, 0x015E } In such case we should use the bit[7:4] of Cx address to check whether the Cx type is supported or not. mask the MWAIT hint to avoid array address overflow Signed-off-by: Zhao Yakui Acked-by:Venki Pallipadi Signed-off-by: Len Brown --- arch/x86/kernel/acpi/cstate.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c index c2502eb9aa8..a4805b3b409 100644 --- a/arch/x86/kernel/acpi/cstate.c +++ b/arch/x86/kernel/acpi/cstate.c @@ -56,6 +56,7 @@ static struct cstate_entry *cpu_cstate_entry; /* per CPU ptr */ static short mwait_supported[ACPI_PROCESSOR_MAX_POWER]; #define MWAIT_SUBSTATE_MASK (0xf) +#define MWAIT_CSTATE_MASK (0xf) #define MWAIT_SUBSTATE_SIZE (4) #define CPUID_MWAIT_LEAF (5) @@ -98,7 +99,8 @@ int acpi_processor_ffh_cstate_probe(unsigned int cpu, cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx); /* Check whether this particular cx_type (in CST) is supported or not */ - cstate_type = (cx->address >> MWAIT_SUBSTATE_SIZE) + 1; + cstate_type = ((cx->address >> MWAIT_SUBSTATE_SIZE) & + MWAIT_CSTATE_MASK) + 1; edx_part = edx >> (cstate_type * MWAIT_SUBSTATE_SIZE); num_cstate_subtype = edx_part & MWAIT_SUBSTATE_MASK; -- cgit v1.2.3 From 237889bf0a62f1399fb2ba0c2a259e6a96597131 Mon Sep 17 00:00:00 2001 From: Zhao Yakui Date: Wed, 17 Dec 2008 16:55:18 +0800 Subject: ACPI : Use RSDT instead of XSDT by adding boot option of "acpi=rsdt" On some boxes there exist both RSDT and XSDT table. But unfortunately sometimes there exists the following error when XSDT table is used: a. 32/64X address mismatch b. The 32/64X FACS address mismatch In such case the boot option of "acpi=rsdt" is provided so that RSDT is tried instead of XSDT table when the system can't work well. http://bugzilla.kernel.org/show_bug.cgi?id=8246 Signed-off-by: Zhao Yakui cc:Thomas Renninger Signed-off-by: Len Brown --- arch/x86/kernel/acpi/boot.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 4c51a2f8fd3..db1a90a76b3 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -47,7 +47,7 @@ #endif static int __initdata acpi_force = 0; - +u32 acpi_rsdt_forced; #ifdef CONFIG_ACPI int acpi_disabled = 0; #else @@ -1783,6 +1783,10 @@ static int __init parse_acpi(char *arg) disable_acpi(); acpi_ht = 1; } + /* acpi=rsdt use RSDT instead of XSDT */ + else if (strcmp(arg, "rsdt") == 0) { + acpi_rsdt_forced = 1; + } /* "acpi=noirq" disables ACPI interrupt routing */ else if (strcmp(arg, "noirq") == 0) { acpi_noirq_set(); -- cgit v1.2.3