diff --git a/arch/powerpc/include/asm/book3s/64/mmu-hash.h b/arch/powerpc/include/asm/book3s/64/mmu-hash.h index 5961b0d65a79..6d56974adf28 100644 --- a/arch/powerpc/include/asm/book3s/64/mmu-hash.h +++ b/arch/powerpc/include/asm/book3s/64/mmu-hash.h @@ -589,11 +589,18 @@ extern void slb_set_size(u16 size); #define VSID_MULTIPLIER_256M ASM_CONST(12538073) /* 24-bit prime */ #define VSID_BITS_256M (VA_BITS - SID_SHIFT) #define VSID_BITS_65_256M (65 - SID_SHIFT) +/* + * Modular multiplicative inverse of VSID_MULTIPLIER under modulo VSID_MODULUS + */ +#define VSID_MULINV_256M ASM_CONST(665548017062) #define VSID_MULTIPLIER_1T ASM_CONST(12538073) /* 24-bit prime */ #define VSID_BITS_1T (VA_BITS - SID_SHIFT_1T) #define VSID_BITS_65_1T (65 - SID_SHIFT_1T) +#define VSID_MULINV_1T ASM_CONST(209034062) +/* 1TB VSID reserved for VRMA */ +#define VRMA_VSID 0x1ffffffUL #define USER_VSID_RANGE (1UL << (ESID_BITS + SID_SHIFT)) /* 4 bits per slice and we have one slice per 1TB */ diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h index d9b48f5bb606..d55c7f881ce7 100644 --- a/arch/powerpc/include/asm/kvm_book3s_64.h +++ b/arch/powerpc/include/asm/kvm_book3s_64.h @@ -49,8 +49,6 @@ static inline bool kvm_is_radix(struct kvm *kvm) #define KVM_DEFAULT_HPT_ORDER 24 /* 16MB HPT by default */ #endif -#define VRMA_VSID 0x1ffffffUL /* 1TB VSID reserved for VRMA */ - /* * We use a lock bit in HPTE dword 0 to synchronize updates and * accesses to each HPTE, and another bit to indicate non-present diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h index 7d721101ec78..78803a7ebdd9 100644 --- a/arch/powerpc/include/asm/mmu_context.h +++ b/arch/powerpc/include/asm/mmu_context.h @@ -52,6 +52,7 @@ static inline void switch_mmu_context(struct mm_struct *prev, } extern int hash__alloc_context_id(void); +extern void hash__reserve_context_id(int id); extern void __destroy_context(int context_id); static inline void mmu_context_init(void) { } #else diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index 716255f88bbd..8848fec51ce9 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -1868,5 +1868,4 @@ static int __init hash64_debugfs(void) return 0; } machine_device_initcall(pseries, hash64_debugfs); - #endif /* CONFIG_DEBUG_FS */ diff --git a/arch/powerpc/mm/mmu_context_book3s64.c b/arch/powerpc/mm/mmu_context_book3s64.c index fd0bc6db2dcd..7bc5b63034db 100644 --- a/arch/powerpc/mm/mmu_context_book3s64.c +++ b/arch/powerpc/mm/mmu_context_book3s64.c @@ -57,6 +57,22 @@ again: return index; } +void hash__reserve_context_id(int id) +{ + int rc, result = 0; + + do { + if (!ida_pre_get(&mmu_context_ida, GFP_KERNEL)) + break; + + spin_lock(&mmu_context_lock); + rc = ida_get_new_above(&mmu_context_ida, id, &result); + spin_unlock(&mmu_context_lock); + } while (rc == -EAGAIN); + + WARN(result != id, "mmu: Failed to reserve context id %d (rc %d)\n", id, result); +} + int hash__alloc_context_id(void) { unsigned long max; diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c index 8b1fe895daa3..6541d0b03e4c 100644 --- a/arch/powerpc/platforms/pseries/lpar.c +++ b/arch/powerpc/platforms/pseries/lpar.c @@ -958,3 +958,64 @@ int h_get_mpp_x(struct hvcall_mpp_x_data *mpp_x_data) return rc; } + +static unsigned long vsid_unscramble(unsigned long vsid, int ssize) +{ + unsigned long protovsid; + unsigned long va_bits = VA_BITS; + unsigned long modinv, vsid_modulus; + unsigned long max_mod_inv, tmp_modinv; + + if (!mmu_has_feature(MMU_FTR_68_BIT_VA)) + va_bits = 65; + + if (ssize == MMU_SEGSIZE_256M) { + modinv = VSID_MULINV_256M; + vsid_modulus = ((1UL << (va_bits - SID_SHIFT)) - 1); + } else { + modinv = VSID_MULINV_1T; + vsid_modulus = ((1UL << (va_bits - SID_SHIFT_1T)) - 1); + } + + /* + * vsid outside our range. + */ + if (vsid >= vsid_modulus) + return 0; + + /* + * If modinv is the modular multiplicate inverse of (x % vsid_modulus) + * and vsid = (protovsid * x) % vsid_modulus, then we say: + * protovsid = (vsid * modinv) % vsid_modulus + */ + + /* Check if (vsid * modinv) overflow (63 bits) */ + max_mod_inv = 0x7fffffffffffffffull / vsid; + if (modinv < max_mod_inv) + return (vsid * modinv) % vsid_modulus; + + tmp_modinv = modinv/max_mod_inv; + modinv %= max_mod_inv; + + protovsid = (((vsid * max_mod_inv) % vsid_modulus) * tmp_modinv) % vsid_modulus; + protovsid = (protovsid + vsid * modinv) % vsid_modulus; + + return protovsid; +} + +static int __init reserve_vrma_context_id(void) +{ + unsigned long protovsid; + + /* + * Reserve context ids which map to reserved virtual addresses. For now + * we only reserve the context id which maps to the VRMA VSID. We ignore + * the addresses in "ibm,adjunct-virtual-addresses" because we don't + * enable adjunct support via the "ibm,client-architecture-support" + * interface. + */ + protovsid = vsid_unscramble(VRMA_VSID, MMU_SEGSIZE_1T); + hash__reserve_context_id(protovsid >> ESID_BITS_1T); + return 0; +} +machine_device_initcall(pseries, reserve_vrma_context_id);