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authorSamuel Holland <samuel.holland@sifive.com>2024-03-27 07:49:51 +0300
committerPalmer Dabbelt <palmer@rivosinc.com>2024-04-29 20:49:33 +0300
commitf58e5dc45fa93a2f2a0028381b2e06fe74ae9e2c (patch)
tree0102a9b57ed51756c9bb40dce62f8e4fd56cc3c0
parent74cd17792d28162fe692d5a25fe5cc081203ad19 (diff)
downloadlinux-f58e5dc45fa93a2f2a0028381b2e06fe74ae9e2c.tar.xz
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 <alexghiti@rivosinc.com> Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20240327045035.368512-11-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
-rw-r--r--arch/riscv/include/asm/mmu.h4
-rw-r--r--arch/riscv/include/asm/tlbflush.h2
-rw-r--r--arch/riscv/mm/context.c6
3 files changed, 4 insertions, 8 deletions
diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h
index a550fbf770be..dc0273f7905f 100644
--- a/arch/riscv/include/asm/mmu.h
+++ b/arch/riscv/include/asm/mmu.h
@@ -26,8 +26,8 @@ typedef struct {
#endif
} mm_context_t;
-#define cntx2asid(cntx) ((cntx) & asid_mask)
-#define cntx2version(cntx) ((cntx) & ~asid_mask)
+#define cntx2asid(cntx) ((cntx) & SATP_ASID_MASK)
+#define cntx2version(cntx) ((cntx) & ~SATP_ASID_MASK)
void __init create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa,
phys_addr_t sz, pgprot_t prot);
diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h
index 8e329721375b..72e559934952 100644
--- a/arch/riscv/include/asm/tlbflush.h
+++ b/arch/riscv/include/asm/tlbflush.h
@@ -15,8 +15,6 @@
#define FLUSH_TLB_NO_ASID ((unsigned long)-1)
#ifdef CONFIG_MMU
-extern unsigned long asid_mask;
-
static inline void local_flush_tlb_all(void)
{
__asm__ __volatile__ ("sfence.vma" : : : "memory");
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, &current_version);
+ ver = atomic_long_add_return_relaxed(BIT(SATP_ASID_BITS), &current_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(&current_version, num_asids);
+ atomic_long_set(&current_version, BIT(SATP_ASID_BITS));
context_asid_map = bitmap_zalloc(num_asids, GFP_KERNEL);
if (!context_asid_map)