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-rw-r--r--arch/i386/Kconfig.cpu22
-rw-r--r--arch/i386/boot/setup.S17
-rw-r--r--arch/i386/kernel/verify_cpu.S65
3 files changed, 102 insertions, 2 deletions
diff --git a/arch/i386/Kconfig.cpu b/arch/i386/Kconfig.cpu
index b1af9f5..dce6124 100644
--- a/arch/i386/Kconfig.cpu
+++ b/arch/i386/Kconfig.cpu
@@ -240,14 +240,19 @@ config X86_L1_CACHE_SHIFT
default "5" if MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCRUSOE || MEFFICEON || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M586 || MVIAC3_2 || MGEODE_LX
default "6" if MK7 || MK8 || MPENTIUMM || MCORE2 || MVIAC7
+config X86_XADD
+ bool
+ depends on !M386
+ default y
+
config RWSEM_GENERIC_SPINLOCK
bool
- depends on M386
+ depends on !X86_XADD
default y
config RWSEM_XCHGADD_ALGORITHM
bool
- depends on !M386
+ depends on X86_XADD
default y
config ARCH_HAS_ILOG2_U32
@@ -331,3 +336,16 @@ config X86_TSC
bool
depends on (MWINCHIP3D || MWINCHIP2 || MCRUSOE || MEFFICEON || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || MK8 || MVIAC3_2 || MVIAC7 || MGEODEGX1 || MGEODE_LX || MCORE2) && !X86_NUMAQ
default y
+
+# this should be set for all -march=.. options where the compiler
+# generates cmov.
+config X86_CMOV
+ bool
+ depends on (MK7 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MVIAC3_2 || MVIAC7)
+ default y
+
+config X86_MINIMUM_CPU_MODEL
+ int
+ default "4" if X86_XADD || X86_CMPXCHG || X86_BSWAP
+ default "0"
+
diff --git a/arch/i386/boot/setup.S b/arch/i386/boot/setup.S
index b74b7f4..f8b3b9c 100644
--- a/arch/i386/boot/setup.S
+++ b/arch/i386/boot/setup.S
@@ -302,7 +302,24 @@ good_sig:
loader_panic_mess: .string "Wrong loader, giving up..."
+# check minimum cpuid
+# we do this here because it is the last place we can actually
+# show a user visible error message. Later the video modus
+# might be already messed up.
loader_ok:
+ call verify_cpu
+ testl %eax,%eax
+ jz cpu_ok
+ lea cpu_panic_mess,%si
+ call prtstr
+1: jmp 1b
+
+cpu_panic_mess:
+ .asciz "PANIC: CPU too old for this kernel."
+
+#include "../kernel/verify_cpu.S"
+
+cpu_ok:
# Get memory size (extended mem, kB)
xorl %eax, %eax
diff --git a/arch/i386/kernel/verify_cpu.S b/arch/i386/kernel/verify_cpu.S
new file mode 100644
index 0000000..e51a869
--- /dev/null
+++ b/arch/i386/kernel/verify_cpu.S
@@ -0,0 +1,65 @@
+/* Check if CPU has some minimum CPUID bits
+ This runs in 16bit mode so that the caller can still use the BIOS
+ to output errors on the screen */
+#include <asm/cpufeature.h>
+
+verify_cpu:
+ pushfl # Save caller passed flags
+ pushl $0 # Kill any dangerous flags
+ popfl
+
+#if CONFIG_X86_MINIMUM_CPU_MODEL >= 4
+ pushfl
+ orl $(1<<18),(%esp) # try setting AC
+ popfl
+ pushfl
+ popl %eax
+ testl $(1<<18),%eax
+ jz bad
+#endif
+#if REQUIRED_MASK1 != 0
+ pushfl # standard way to check for cpuid
+ popl %eax
+ movl %eax,%ebx
+ xorl $0x200000,%eax
+ pushl %eax
+ popfl
+ pushfl
+ popl %eax
+ cmpl %eax,%ebx
+ pushfl # standard way to check for cpuid
+ popl %eax
+ movl %eax,%ebx
+ xorl $0x200000,%eax
+ pushl %eax
+ popfl
+ pushfl
+ popl %eax
+ cmpl %eax,%ebx
+ jz bad # REQUIRED_MASK1 != 0 requires CPUID
+
+ movl $0x0,%eax # See if cpuid 1 is implemented
+ cpuid
+ cmpl $0x1,%eax
+ jb bad # no cpuid 1
+
+ movl $0x1,%eax # Does the cpu have what it takes
+ cpuid
+
+#if CONFIG_X86_MINIMUM_CPU_MODEL > 4
+#error add proper model checking here
+#endif
+
+ andl $REQUIRED_MASK1,%edx
+ xorl $REQUIRED_MASK1,%edx
+ jnz bad
+#endif /* REQUIRED_MASK1 */
+
+ popfl
+ xor %eax,%eax
+ ret
+
+bad:
+ popfl
+ movl $1,%eax
+ ret