From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1780C15ACE for ; Tue, 6 Jun 2023 12:10:31 +0000 (UTC) Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-56536dd5f79so97926517b3.3 for ; Tue, 06 Jun 2023 05:10:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1686053430; x=1688645430; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=83dlZFDhtSz2rg2AR6ggZ2Mh/ASzqdpRvSd02rbzaCk=; b=IoFA55ulrjtnJDTW5pbuUTS9XeM0qmUYpaAJ3OnF3fjh404oOtNySp8WzgeTzaaiiO mVRlBZ2obwVwh4OUFmiQJt7UUnDxoDMkllhaIBQAmBhFfw48M+MKZQjL4e//71A1xQ+M ZQe0Lx0j/uNjanZ997DNS7XHK7FjkoWOzElSxea08x+rZug6VZyihB4gEnokoKygwiFy oohF6tU936F+ATOKuIyJj4FuSck9QyYVTKPs6mJWVCMGD4SJTG4PI7zHHboXxVFaZsG2 nDS7Gx45dkGyCy6J2pqiwfXPIBXnbTfVR9nkfcP+mnZCb8QJyIFTWcKIELfCjtVWDZgK oB0A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686053430; x=1688645430; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=83dlZFDhtSz2rg2AR6ggZ2Mh/ASzqdpRvSd02rbzaCk=; b=YcYWOnNS/vft2+YCQ3HC8y/uwS03rnbN4QbnRvZTQnewt/r4j154+kguQq75LcC/CU bApLZxgo0/eIDKIJxTMA4KUZ1OBZQLg+oKrfYInNL/QKzR5APENv9m69bG/rEr/lr94r PGftj6e4bs22fEg2nduYqYiZOUwCtKmWSjHGMBQobkqaC18tLsXeXP9jg79afnhGfyyo HKZsiTMTiiA/oWuGbGhQ1WQ0LbdQ0BrJfORyhyCaPNENXf3k2CdfYMM85k/LCyYmBl+0 3tOg7G3qo9x2zYGTagP34OspuauSqWy9D0WQZnZwDV+iMe0CI2BmX2D/9Hg0X550YXYS +qnA== X-Gm-Message-State: AC+VfDx49ctP4UAXdnA+xlV/J8xNWhgTGmi8ZqS7qEVJE6b0tde5tQ1v LulyqgIXGjKpcyXB+qAHLqPop0E4bBX5 X-Google-Smtp-Source: ACHHUZ64pvQvCxVufeRzNt0VKrbwAwJNjh5MfrOYdfJtgOmahfaQ951Oi+PY3aJvHU4m52siOi/iL4Zbsjnl X-Received: from mshavit.ntc.corp.google.com ([2401:fa00:95:20c:a615:63d5:b54e:6919]) (user=mshavit job=sendgmr) by 2002:a81:b289:0:b0:562:837:122f with SMTP id q131-20020a81b289000000b005620837122fmr942001ywh.9.1686053430214; Tue, 06 Jun 2023 05:10:30 -0700 (PDT) Date: Tue, 6 Jun 2023 20:07:46 +0800 In-Reply-To: <20230606120854.4170244-1-mshavit@google.com> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20230606120854.4170244-1-mshavit@google.com> X-Mailer: git-send-email 2.41.0.rc0.172.g3f132b7071-goog Message-ID: <20230606120854.4170244-11-mshavit@google.com> Subject: [PATCH v2 10/18] iommu/arm-smmu-v3-sva: Remove bond refcount From: Michael Shavit To: Will Deacon , Robin Murphy , Joerg Roedel Cc: Michael Shavit , jean-philippe@linaro.org, nicolinc@nvidia.com, jgg@nvidia.com, baolu.lu@linux.intel.com, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" The iommu-sva framework checks if a bond between a device and mm already exists and handles refcounting at the iommu_domain level. __arm_smmu_sva_bind is therefore only called once for a device/mm pair. Signed-off-by: Michael Shavit --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-) diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c index d07c08b53c5cf..20301d0a2c0b0 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c @@ -29,7 +29,6 @@ struct arm_smmu_bond { struct mm_struct *mm; struct arm_smmu_mmu_notifier *smmu_mn; struct list_head list; - refcount_t refs; }; #define sva_to_bond(handle) \ @@ -377,21 +376,12 @@ __arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm) if (!master || !master->sva_enabled) return ERR_PTR(-ENODEV); - /* If bind() was already called for this {dev, mm} pair, reuse it. */ - list_for_each_entry(bond, &master->bonds, list) { - if (bond->mm == mm) { - refcount_inc(&bond->refs); - return &bond->sva; - } - } - bond = kzalloc(sizeof(*bond), GFP_KERNEL); if (!bond) return ERR_PTR(-ENOMEM); bond->mm = mm; bond->sva.dev = dev; - refcount_set(&bond->refs, 1); bond->smmu_mn = arm_smmu_mmu_notifier_get(smmu_domain, mm); if (IS_ERR(bond->smmu_mn)) { @@ -570,7 +560,7 @@ void arm_smmu_sva_remove_dev_pasid(struct iommu_domain *domain, } } - if (!WARN_ON(!bond) && refcount_dec_and_test(&bond->refs)) { + if (!WARN_ON(!bond)) { list_del(&bond->list); arm_smmu_mmu_notifier_put(bond->smmu_mn); kfree(bond); -- 2.41.0.rc0.172.g3f132b7071-goog