Unverified Commit 74cd1779 authored by Samuel Holland's avatar Samuel Holland Committed by Palmer Dabbelt
Browse files

riscv: mm: Introduce cntx2asid/cntx2version helper macros 



When using the ASID allocator, the MM context ID contains two values:
the ASID in the lower bits, and the allocator version number in the
remaining bits. Use macros to make this separation more obvious.

Reviewed-by: default avatarAlexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: default avatarSamuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20240327045035.368512-10-samuel.holland@sifive.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent d6dcdaba

arch/riscv/include/asm/mmu.h

+3 −0
Original line number Diff line number Diff line
@@ -26,6 +26,9 @@ typedef struct { 
#endif

} mm_context_t;



#define cntx2asid(cntx)		((cntx) & asid_mask)

#define cntx2version(cntx)	((cntx) & ~asid_mask)



void __init create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa,

			       phys_addr_t sz, pgprot_t prot);

#endif /* __ASSEMBLY__ */

arch/riscv/mm/context.c

+6 −6
Original line number Diff line number Diff line
@@ -81,7 +81,7 @@ static void __flush_context(void) 
		if (cntx == 0)

			cntx = per_cpu(reserved_context, i);



		__set_bit(cntx & asid_mask, context_asid_map);

		__set_bit(cntx2asid(cntx), context_asid_map);

		per_cpu(reserved_context, i) = cntx;

	}
@@ -102,7 +102,7 @@ static unsigned long __new_context(struct mm_struct *mm) 
	lockdep_assert_held(&context_lock);



	if (cntx != 0) {

		unsigned long newcntx = ver | (cntx & asid_mask);

		unsigned long newcntx = ver | cntx2asid(cntx);



		/*

		 * If our current CONTEXT was active during a rollover, we
@@ -115,7 +115,7 @@ static unsigned long __new_context(struct mm_struct *mm) 
		 * We had a valid CONTEXT in a previous life, so try to

		 * re-use it if possible.

		 */

		if (!__test_and_set_bit(cntx & asid_mask, context_asid_map))

		if (!__test_and_set_bit(cntx2asid(cntx), context_asid_map))

			return newcntx;

	}
@@ -168,7 +168,7 @@ static void set_mm_asid(struct mm_struct *mm, unsigned int cpu) 
	 */

	old_active_cntx = atomic_long_read(&per_cpu(active_context, cpu));

	if (old_active_cntx &&

	    ((cntx & ~asid_mask) == atomic_long_read(&current_version)) &&

	    (cntx2version(cntx) == atomic_long_read(&current_version)) &&

	    atomic_long_cmpxchg_relaxed(&per_cpu(active_context, cpu),

					old_active_cntx, cntx))

		goto switch_mm_fast;
@@ -177,7 +177,7 @@ static void set_mm_asid(struct mm_struct *mm, unsigned int cpu) 


	/* Check that our ASID belongs to the current_version. */

	cntx = atomic_long_read(&mm->context.id);

	if ((cntx & ~asid_mask) != atomic_long_read(&current_version)) {

	if (cntx2version(cntx) != atomic_long_read(&current_version)) {

		cntx = __new_context(mm);

		atomic_long_set(&mm->context.id, cntx);

	}
@@ -191,7 +191,7 @@ static void set_mm_asid(struct mm_struct *mm, unsigned int cpu) 


switch_mm_fast:

	csr_write(CSR_SATP, virt_to_pfn(mm->pgd) |

		  ((cntx & asid_mask) << SATP_ASID_SHIFT) |

		  (cntx2asid(cntx) << SATP_ASID_SHIFT) |

		  satp_mode);



	if (need_flush_tlb)

arch/riscv/mm/tlbflush.c

+1 −1
Original line number Diff line number Diff line
@@ -110,7 +110,7 @@ static void __flush_tlb_range(struct cpumask *cmask, unsigned long asid, 
static inline unsigned long get_mm_asid(struct mm_struct *mm)

{

	return static_branch_unlikely(&use_asid_allocator) ?

			atomic_long_read(&mm->context.id) & asid_mask : FLUSH_TLB_NO_ASID;

			cntx2asid(atomic_long_read(&mm->context.id)) : FLUSH_TLB_NO_ASID;

}



void flush_tlb_mm(struct mm_struct *mm)