linux-kernel - [PATCH RFC 05/14] arm64/mm: Remove dependency on MM in new

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Message-Id: <20190321163623.20219-6-julien.grall@arm.com>
Date:   Thu, 21 Mar 2019 16:36:14 +0000
From:   Julien Grall <julien.grall@....com>
To:     linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        kvmarm@...ts.cs.columbia.edu
Cc:     christoffer.dall@....com, james.morse@....com,
        marc.zyngier@....com, julien.thierry@....com,
        suzuki.poulose@....com, catalin.marinas@....com,
        will.deacon@....com, Julien Grall <julien.grall@....com>
Subject: [PATCH RFC 05/14] arm64/mm: Remove dependency on MM in new_context

The function new_context will be part of a generic ASID allocator. At
the moment, the MM structure is only used to fetch the ASID.

To remove the dependency on MM, it is possible to just pass a pointer to
the current ASID.

Signed-off-by: Julien Grall <julien.grall@....com>
---
 arch/arm64/mm/context.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
index e98ab348b9cb..488845c39c39 100644
--- a/arch/arm64/mm/context.c
+++ b/arch/arm64/mm/context.c
@@ -151,10 +151,10 @@ static bool check_update_reserved_asid(struct asid_info *info, u64 asid,
 	return hit;
 }
 
-static u64 new_context(struct asid_info *info, struct mm_struct *mm)
+static u64 new_context(struct asid_info *info, atomic64_t *pasid)
 {
 	static u32 cur_idx = 1;
-	u64 asid = atomic64_read(&mm->context.id);
+	u64 asid = atomic64_read(pasid);
 	u64 generation = atomic64_read(&info->generation);
 
 	if (asid != 0) {
@@ -236,7 +236,7 @@ void check_and_switch_context(struct mm_struct *mm, unsigned int cpu)
 	/* Check that our ASID belongs to the current generation. */
 	asid = atomic64_read(&mm->context.id);
 	if ((asid ^ atomic64_read(&info->generation)) >> info->bits) {
-		asid = new_context(info, mm);
+		asid = new_context(info, &mm->context.id);
 		atomic64_set(&mm->context.id, asid);
 	}
 
-- 
2.11.0