diff options
Diffstat (limited to 'arch/x86/kernel/cpu/mtrr/legacy.c')
-rw-r--r-- | arch/x86/kernel/cpu/mtrr/legacy.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/legacy.c b/arch/x86/kernel/cpu/mtrr/legacy.c new file mode 100644 index 0000000000..d25882fcf1 --- /dev/null +++ b/arch/x86/kernel/cpu/mtrr/legacy.c @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/syscore_ops.h> +#include <asm/cpufeature.h> +#include <asm/mtrr.h> +#include <asm/processor.h> +#include "mtrr.h" + +void mtrr_set_if(void) +{ + switch (boot_cpu_data.x86_vendor) { + case X86_VENDOR_AMD: + /* Pre-Athlon (K6) AMD CPU MTRRs */ + if (cpu_feature_enabled(X86_FEATURE_K6_MTRR)) + mtrr_if = &amd_mtrr_ops; + break; + case X86_VENDOR_CENTAUR: + if (cpu_feature_enabled(X86_FEATURE_CENTAUR_MCR)) + mtrr_if = ¢aur_mtrr_ops; + break; + case X86_VENDOR_CYRIX: + if (cpu_feature_enabled(X86_FEATURE_CYRIX_ARR)) + mtrr_if = &cyrix_mtrr_ops; + break; + default: + break; + } +} + +/* + * The suspend/resume methods are only for CPUs without MTRR. CPUs using generic + * MTRR driver don't require this. + */ +struct mtrr_value { + mtrr_type ltype; + unsigned long lbase; + unsigned long lsize; +}; + +static struct mtrr_value *mtrr_value; + +static int mtrr_save(void) +{ + int i; + + if (!mtrr_value) + return -ENOMEM; + + for (i = 0; i < num_var_ranges; i++) { + mtrr_if->get(i, &mtrr_value[i].lbase, + &mtrr_value[i].lsize, + &mtrr_value[i].ltype); + } + return 0; +} + +static void mtrr_restore(void) +{ + int i; + + for (i = 0; i < num_var_ranges; i++) { + if (mtrr_value[i].lsize) { + mtrr_if->set(i, mtrr_value[i].lbase, + mtrr_value[i].lsize, + mtrr_value[i].ltype); + } + } +} + +static struct syscore_ops mtrr_syscore_ops = { + .suspend = mtrr_save, + .resume = mtrr_restore, +}; + +void mtrr_register_syscore(void) +{ + mtrr_value = kcalloc(num_var_ranges, sizeof(*mtrr_value), GFP_KERNEL); + + /* + * The CPU has no MTRR and seems to not support SMP. They have + * specific drivers, we use a tricky method to support + * suspend/resume for them. + * + * TBD: is there any system with such CPU which supports + * suspend/resume? If no, we should remove the code. + */ + register_syscore_ops(&mtrr_syscore_ops); +} |