i386: fix PGE mask

cr4 is a 32-bit register, so casting the mask to an unsigned char is wrong, as it clears more than the PGE bit. Signed-off-by: Brian Gerst <bgerst@didntduck.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
git-mirror · May 21, 2007 · 1730438 · 1730438
1 parent d0aff6e
commit 1730438
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diff --git a/arch/i386/kernel/cpu/mtrr/cyrix.c b/arch/i386/kernel/cpu/mtrr/cyrix.c
@@ -136,7 +136,7 @@ static void prepare_set(void)
 	/*  Save value of CR4 and clear Page Global Enable (bit 7)  */
 	if ( cpu_has_pge ) {
 		cr4 = read_cr4();
-		write_cr4(cr4 & (unsigned char) ~(1 << 7));
+		write_cr4(cr4 & ~X86_CR4_PGE);
 	}
 
 	/*  Disable and flush caches. Note that wbinvd flushes the TLBs as

diff --git a/arch/i386/kernel/cpu/mtrr/state.c b/arch/i386/kernel/cpu/mtrr/state.c
@@ -19,7 +19,7 @@ void set_mtrr_prepare_save(struct set_mtrr_context *ctxt)
 		/*  Save value of CR4 and clear Page Global Enable (bit 7)  */
 		if ( cpu_has_pge ) {
 			ctxt->cr4val = read_cr4();
-			write_cr4(ctxt->cr4val & (unsigned char) ~(1 << 7));
+			write_cr4(ctxt->cr4val & ~X86_CR4_PGE);
 		}
 
 		/*  Disable and flush caches. Note that wbinvd flushes the TLBs as