Hi Jia, Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on v4.15-rc5] [also build test WARNING on next-20171222] [cannot apply to tip/x86/core] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Jia-Zhang/x86-clean-up-confusing-x86_mask/20171231-182946 reproduce: # apt-get install sparse make ARCH=x86_64 allmodconfig make C=1 CF=-D__CHECK_ENDIAN__ sparse warnings: (new ones prefixed by >>) vim +165 drivers/char/hw_random/via-rng.c 135233635 Michael Buesch 2006-06-26 128 135233635 Michael Buesch 2006-06-26 129 static int via_rng_init(struct hwrng *rng) 135233635 Michael Buesch 2006-06-26 130 { 11025e855 Dave Jones 2008-02-06 131 struct cpuinfo_x86 *c = &cpu_data(0); 135233635 Michael Buesch 2006-06-26 132 u32 lo, hi, old_lo; 135233635 Michael Buesch 2006-06-26 133 858576bdc Harald Welte 2009-05-15 134 /* VIA Nano CPUs don't have the MSR_VIA_RNG anymore. The RNG 858576bdc Harald Welte 2009-05-15 135 * is always enabled if CPUID rng_en is set. There is no 858576bdc Harald Welte 2009-05-15 136 * RNG configuration like it used to be the case in this 858576bdc Harald Welte 2009-05-15 137 * register */ 858576bdc Harald Welte 2009-05-15 138 if ((c->x86 == 6) && (c->x86_model >= 0x0f)) { 362f924b6 Borislav Petkov 2015-12-07 139 if (!boot_cpu_has(X86_FEATURE_XSTORE_EN)) { 7a1ae9c0c Sudip Mukherjee 2014-09-15 140 pr_err(PFX "can't enable hardware RNG " 858576bdc Harald Welte 2009-05-15 141 "if XSTORE is not enabled\n"); 858576bdc Harald Welte 2009-05-15 142 return -ENODEV; 858576bdc Harald Welte 2009-05-15 143 } 858576bdc Harald Welte 2009-05-15 144 return 0; 858576bdc Harald Welte 2009-05-15 145 } 858576bdc Harald Welte 2009-05-15 146 135233635 Michael Buesch 2006-06-26 147 /* Control the RNG via MSR. Tread lightly and pay very close 135233635 Michael Buesch 2006-06-26 148 * close attention to values written, as the reserved fields 135233635 Michael Buesch 2006-06-26 149 * are documented to be "undefined and unpredictable"; but it 135233635 Michael Buesch 2006-06-26 150 * does not say to write them as zero, so I make a guess that 135233635 Michael Buesch 2006-06-26 151 * we restore the values we find in the register. 135233635 Michael Buesch 2006-06-26 152 */ 135233635 Michael Buesch 2006-06-26 153 rdmsr(MSR_VIA_RNG, lo, hi); 135233635 Michael Buesch 2006-06-26 154 135233635 Michael Buesch 2006-06-26 155 old_lo = lo; 135233635 Michael Buesch 2006-06-26 156 lo &= ~(0x7f << VIA_STRFILT_CNT_SHIFT); 135233635 Michael Buesch 2006-06-26 157 lo &= ~VIA_XSTORE_CNT_MASK; 135233635 Michael Buesch 2006-06-26 158 lo &= ~(VIA_STRFILT_ENABLE | VIA_STRFILT_FAIL | VIA_RAWBITS_ENABLE); 135233635 Michael Buesch 2006-06-26 159 lo |= VIA_RNG_ENABLE; 11025e855 Dave Jones 2008-02-06 160 lo |= VIA_NOISESRC1; 11025e855 Dave Jones 2008-02-06 161 11025e855 Dave Jones 2008-02-06 162 /* Enable secondary noise source on CPUs where it is present. */ 11025e855 Dave Jones 2008-02-06 163 11025e855 Dave Jones 2008-02-06 164 /* Nehemiah stepping 8 and higher */ 11025e855 Dave Jones 2008-02-06 @165 if ((c->x86_model == 9) && (c->x86_mask > 7)) 11025e855 Dave Jones 2008-02-06 166 lo |= VIA_NOISESRC2; 11025e855 Dave Jones 2008-02-06 167 11025e855 Dave Jones 2008-02-06 168 /* Esther */ 11025e855 Dave Jones 2008-02-06 169 if (c->x86_model >= 10) 11025e855 Dave Jones 2008-02-06 170 lo |= VIA_NOISESRC2; 135233635 Michael Buesch 2006-06-26 171 135233635 Michael Buesch 2006-06-26 172 if (lo != old_lo) 135233635 Michael Buesch 2006-06-26 173 wrmsr(MSR_VIA_RNG, lo, hi); 135233635 Michael Buesch 2006-06-26 174 135233635 Michael Buesch 2006-06-26 175 /* perhaps-unnecessary sanity check; remove after testing if 135233635 Michael Buesch 2006-06-26 176 unneeded */ 135233635 Michael Buesch 2006-06-26 177 rdmsr(MSR_VIA_RNG, lo, hi); 135233635 Michael Buesch 2006-06-26 178 if ((lo & VIA_RNG_ENABLE) == 0) { 7a1ae9c0c Sudip Mukherjee 2014-09-15 179 pr_err(PFX "cannot enable VIA C3 RNG, aborting\n"); 135233635 Michael Buesch 2006-06-26 180 return -ENODEV; 135233635 Michael Buesch 2006-06-26 181 } 135233635 Michael Buesch 2006-06-26 182 135233635 Michael Buesch 2006-06-26 183 return 0; 135233635 Michael Buesch 2006-06-26 184 } 135233635 Michael Buesch 2006-06-26 185 :::::: The code at line 165 was first introduced by commit :::::: 11025e855235144271a0e447e3650b203f8215f4 via-rng: enable secondary noise source on CPUs where it is present :::::: TO: Dave Jones <da...@redhat.com> :::::: CC: Linus Torvalds <torva...@woody.linux-foundation.org> --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
