Commit a3a5b763 authored by Yunfeng Ye's avatar Yunfeng Ye Committed by Catalin Marinas
Browse files

arm64: mm: Rename asid2idx() to ctxid2asid() 



The commit 0c8ea531 ("arm64: mm: Allocate ASIDs in pairs") introduce
the asid2idx and idx2asid macro, but these macros are not really useful
after the commit f88f42f8 ("arm64: context: Free up kernel ASIDs if
KPTI is not in use").

The code "(asid & ~ASID_MASK)" can be instead by a macro, which is the
same code with asid2idx(). So rename it to ctxid2asid() for a better
understanding.

Also we add asid2ctxid() macro, the contextid can be generated based on
the asid and generation through this macro.

Signed-off-by: default avatarYunfeng Ye <yeyunfeng@huawei.com>
Reviewed-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Link: https://lore.kernel.org/r/c31516eb-6d15-94e0-421c-305fc010ea79@huawei.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 7afccde3

arch/arm64/mm/context.c

+9 −9
Original line number Diff line number Diff line
@@ -35,8 +35,8 @@ static unsigned long *pinned_asid_map; 
#define ASID_FIRST_VERSION	(1UL << asid_bits)



#define NUM_USER_ASIDS		ASID_FIRST_VERSION

#define asid2idx(asid)		((asid) & ~ASID_MASK)

#define idx2asid(idx)		asid2idx(idx)

#define ctxid2asid(asid)	((asid) & ~ASID_MASK)

#define asid2ctxid(asid, genid)	((asid) | (genid))



/* Get the ASIDBits supported by the current CPU */

static u32 get_cpu_asid_bits(void)
@@ -120,7 +120,7 @@ static void flush_context(void) 
		 */

		if (asid == 0)

			asid = per_cpu(reserved_asids, i);

		__set_bit(asid2idx(asid), asid_map);

		__set_bit(ctxid2asid(asid), asid_map);

		per_cpu(reserved_asids, i) = asid;

	}
@@ -162,7 +162,7 @@ static u64 new_context(struct mm_struct *mm) 
	u64 generation = atomic64_read(&asid_generation);



	if (asid != 0) {

		u64 newasid = generation | (asid & ~ASID_MASK);

		u64 newasid = asid2ctxid(ctxid2asid(asid), generation);



		/*

		 * If our current ASID was active during a rollover, we
@@ -183,7 +183,7 @@ static u64 new_context(struct mm_struct *mm) 
		 * We had a valid ASID in a previous life, so try to re-use

		 * it if possible.

		 */

		if (!__test_and_set_bit(asid2idx(asid), asid_map))

		if (!__test_and_set_bit(ctxid2asid(asid), asid_map))

			return newasid;

	}
@@ -209,7 +209,7 @@ static u64 new_context(struct mm_struct *mm) 
set_asid:

	__set_bit(asid, asid_map);

	cur_idx = asid;

	return idx2asid(asid) | generation;

	return asid2ctxid(asid, generation);

}



void check_and_switch_context(struct mm_struct *mm)
@@ -300,13 +300,13 @@ unsigned long arm64_mm_context_get(struct mm_struct *mm) 
	}



	nr_pinned_asids++;

	__set_bit(asid2idx(asid), pinned_asid_map);

	__set_bit(ctxid2asid(asid), pinned_asid_map);

	refcount_set(&mm->context.pinned, 1);



out_unlock:

	raw_spin_unlock_irqrestore(&cpu_asid_lock, flags);



	asid &= ~ASID_MASK;

	asid = ctxid2asid(asid);



	/* Set the equivalent of USER_ASID_BIT */

	if (asid && arm64_kernel_unmapped_at_el0())
@@ -327,7 +327,7 @@ void arm64_mm_context_put(struct mm_struct *mm) 
	raw_spin_lock_irqsave(&cpu_asid_lock, flags);



	if (refcount_dec_and_test(&mm->context.pinned)) {

		__clear_bit(asid2idx(asid), pinned_asid_map);

		__clear_bit(ctxid2asid(asid), pinned_asid_map);

		nr_pinned_asids--;

	}