From f58e5dc45fa93a2f2a0028381b2e06fe74ae9e2c Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Tue, 26 Mar 2024 21:49:51 -0700 Subject: riscv: mm: Use a fixed layout for the MM context ID Currently, the size of the ASID field in the MM context ID dynamically depends on the number of hardware-supported ASID bits. This requires reading a global variable to extract either field from the context ID. Instead, allocate the maximum possible number of bits to the ASID field, so the layout of the context ID is known at compile-time. Reviewed-by: Alexandre Ghiti Signed-off-by: Samuel Holland Link: https://lore.kernel.org/r/20240327045035.368512-11-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/context.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'arch/riscv/mm/context.c') diff --git a/arch/riscv/mm/context.c b/arch/riscv/mm/context.c index b562b3c44487..5315af06cd4d 100644 --- a/arch/riscv/mm/context.c +++ b/arch/riscv/mm/context.c @@ -22,7 +22,6 @@ DEFINE_STATIC_KEY_FALSE(use_asid_allocator); static unsigned long asid_bits; static unsigned long num_asids; -unsigned long asid_mask; static atomic_long_t current_version; @@ -128,7 +127,7 @@ static unsigned long __new_context(struct mm_struct *mm) goto set_asid; /* We're out of ASIDs, so increment current_version */ - ver = atomic_long_add_return_relaxed(num_asids, ¤t_version); + ver = atomic_long_add_return_relaxed(BIT(SATP_ASID_BITS), ¤t_version); /* Flush everything */ __flush_context(); @@ -247,7 +246,6 @@ static int __init asids_init(void) /* Pre-compute ASID details */ if (asid_bits) { num_asids = 1 << asid_bits; - asid_mask = num_asids - 1; } /* @@ -255,7 +253,7 @@ static int __init asids_init(void) * at-least twice more than CPUs */ if (num_asids > (2 * num_possible_cpus())) { - atomic_long_set(¤t_version, num_asids); + atomic_long_set(¤t_version, BIT(SATP_ASID_BITS)); context_asid_map = bitmap_zalloc(num_asids, GFP_KERNEL); if (!context_asid_map) -- cgit v1.2.3