From 6152e4b1c99a3689fc318d092cd144597f7dbd14 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Tue, 29 Jul 2008 17:23:16 -0700 Subject: x86, xsave: keep the XSAVE feature mask as an u64 The XSAVE feature mask is a 64-bit number; keep it that way, in order to avoid the mistake done with rdmsr/wrmsr. Use the xsetbv() function provided in the previous patch. Signed-off-by: H. Peter Anvin Signed-off-by: Ingo Molnar --- arch/x86/kernel/xsave.c | 45 +++++++++++++++++---------------------------- 1 file changed, 17 insertions(+), 28 deletions(-) (limited to 'arch/x86/kernel/xsave.c') diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c index dd66d0714c1..7415f3e38a5 100644 --- a/arch/x86/kernel/xsave.c +++ b/arch/x86/kernel/xsave.c @@ -9,11 +9,12 @@ #ifdef CONFIG_IA32_EMULATION #include #endif +#include /* * Supported feature mask by the CPU and the kernel. */ -unsigned int pcntxt_hmask, pcntxt_lmask; +u64 pcntxt_mask; struct _fpx_sw_bytes fx_sw_reserved; #ifdef CONFIG_IA32_EMULATION @@ -127,30 +128,28 @@ int save_i387_xstate(void __user *buf) int restore_user_xstate(void __user *buf) { struct _fpx_sw_bytes fx_sw_user; - unsigned int lmask, hmask; + u64 mask; int err; if (((unsigned long)buf % 64) || check_for_xstate(buf, buf, &fx_sw_user)) goto fx_only; - lmask = fx_sw_user.xstate_bv; - hmask = fx_sw_user.xstate_bv >> 32; + mask = fx_sw_user.xstate_bv; /* * restore the state passed by the user. */ - err = xrestore_user(buf, lmask, hmask); + err = xrestore_user(buf, mask); if (err) return err; /* * init the state skipped by the user. */ - lmask = pcntxt_lmask & ~lmask; - hmask = pcntxt_hmask & ~hmask; + mask = pcntxt_mask & ~mask; - xrstor_state(init_xstate_buf, lmask, hmask); + xrstor_state(init_xstate_buf, mask); return 0; @@ -160,8 +159,7 @@ fx_only: * memory layout. Restore just the FP/SSE and init all * the other extended state. */ - xrstor_state(init_xstate_buf, pcntxt_lmask & ~XSTATE_FPSSE, - pcntxt_hmask); + xrstor_state(init_xstate_buf, pcntxt_mask & ~XSTATE_FPSSE); return fxrstor_checking((__force struct i387_fxsave_struct *)buf); } @@ -231,8 +229,7 @@ void prepare_fx_sw_frame(void) fx_sw_reserved.magic1 = FP_XSTATE_MAGIC1; fx_sw_reserved.extended_size = sig_xstate_size; - fx_sw_reserved.xstate_bv = pcntxt_lmask | - (((u64) (pcntxt_hmask)) << 32); + fx_sw_reserved.xstate_bv = pcntxt_mask; fx_sw_reserved.xstate_size = xstate_size; #ifdef CONFIG_IA32_EMULATION memcpy(&fx_sw_reserved_ia32, &fx_sw_reserved, @@ -263,11 +260,8 @@ void __cpuinit xsave_init(void) /* * Enable all the features that the HW is capable of * and the Linux kernel is aware of. - * - * xsetbv(); */ - asm volatile(".byte 0x0f,0x01,0xd1" : : "c" (0), - "a" (pcntxt_lmask), "d" (pcntxt_hmask)); + xsetbv(XCR_XFEATURE_ENABLED_MASK, pcntxt_mask); } /* @@ -287,36 +281,31 @@ void __init xsave_cntxt_init(void) unsigned int eax, ebx, ecx, edx; cpuid_count(0xd, 0, &eax, &ebx, &ecx, &edx); + pcntxt_mask = eax + ((u64)edx << 32); - pcntxt_lmask = eax; - pcntxt_hmask = edx; - - if ((pcntxt_lmask & XSTATE_FPSSE) != XSTATE_FPSSE) { - printk(KERN_ERR "FP/SSE not shown under xsave features %x\n", - pcntxt_lmask); + if ((pcntxt_mask & XSTATE_FPSSE) != XSTATE_FPSSE) { + printk(KERN_ERR "FP/SSE not shown under xsave features 0x%llx\n", + pcntxt_mask); BUG(); } /* * for now OS knows only about FP/SSE */ - pcntxt_lmask = pcntxt_lmask & XCNTXT_LMASK; - pcntxt_hmask = pcntxt_hmask & XCNTXT_HMASK; - + pcntxt_mask = pcntxt_mask & XCNTXT_MASK; xsave_init(); /* * Recompute the context size for enabled features */ cpuid_count(0xd, 0, &eax, &ebx, &ecx, &edx); - xstate_size = ebx; prepare_fx_sw_frame(); setup_xstate_init(); - printk(KERN_INFO "xsave/xrstor: enabled xstate_bv 0x%Lx, " + printk(KERN_INFO "xsave/xrstor: enabled xstate_bv 0x%llx, " "cntxt size 0x%x\n", - (pcntxt_lmask | ((u64) pcntxt_hmask << 32)), xstate_size); + pcntxt_mask, xstate_size); } -- cgit v1.2.3