Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
From:   Liam Howlett <liam.howlett@oracle.com>
To:     "maple-tree@lists.infradead.org" <maple-tree@lists.infradead.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Yu Zhao <yuzhao@google.com>
Subject: [PATCH v8 38/70] cxl: remove vma linked list walk
Thread-Topic: [PATCH v8 38/70] cxl: remove vma linked list walk
Thread-Index: AQHYWX88ztObwv+hQ0eO2Qkr4L0vgg==
Date:   Tue, 26 Apr 2022 15:06:41 +0000
Message-ID: <20220426150616.3937571-39-Liam.Howlett@oracle.com>
References: <20220426150616.3937571-1-Liam.Howlett@oracle.com>
In-Reply-To: <20220426150616.3937571-1-Liam.Howlett@oracle.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?iso-8859-1?Q?JUCB2uLy2q5ETB2eiP9kY88aLBtaJoQvEkg9z8yMKfnCcmiUbD1oVWSTVs?=
 =?iso-8859-1?Q?jTYi4WxexsN2D2NtoVD3ELi7/W1MRZyeAuv8EgYG7jr2rFqZwZu1UJ8vLm?=
 =?iso-8859-1?Q?3QOwZl/VdC3SC5pUlBbrA5VzHdo1xmiWBINCBop8ONn/jouDT1UZnpserP?=
 =?iso-8859-1?Q?InL0QRiCPgDD3H9g+Va1k7Uwoe6UZf1pn3vkpsByP6HbqRS1ZDy0wbzbub?=
 =?iso-8859-1?Q?V33LD9y0hSNmFwu68IZGmjW+UYOfV2pJxV+Bk3KWe+DiMlJxzfqaqMdK5+?=
 =?iso-8859-1?Q?TnhqOkbLCEowoLmBLvkrszC8k3bBhcg3ceJcaKcaWO6TTiik9ADWXZycfh?=
 =?iso-8859-1?Q?hskZqA/YRqm9b4ZoFgPzTcfQKDCZpR/k3sddFziAOofafTu+t+h/9Axxlo?=
 =?iso-8859-1?Q?FX56Xi+V5C1PYnfLvgWm6TKUldXzHK49BmMV8yqbVP+I6NhZ79yc0nevfc?=
 =?iso-8859-1?Q?wzm466zq9D5yIShpUWqIC6Puemaia0KVNaFrhXRK6vPu7/KbkrUpMNtuTg?=
 =?iso-8859-1?Q?x7g8IzG7FVcidZIbG/Pwh60yFwz+84iK3pmbJ/CttNaHzNAFUKU7P4qUCP?=
 =?iso-8859-1?Q?zoA5Akpo+YJNyo2+XAfvkL/DFmfl3WBTlSFC9Ab+fAXiZ/3uheiWSQ31DS?=
 =?iso-8859-1?Q?AAp4+cT2xq3jikSETgeXuJ0WtiFmWHvX9tl68L8kE/2IFp9JN4PxcLvWse?=
 =?iso-8859-1?Q?SAdUP7uft7XMaFsrrUtqPCc2KbAoudlR/eoFa9PILHiBDXxS4OC9t0dPKn?=
 =?iso-8859-1?Q?qpDZeK5ghVRwEvqNoml0OlIJIPOU6IzsSHMWueNLpPQbL+SfCvmH9Fl5yt?=
 =?iso-8859-1?Q?hCr735/N3WuVOaQfDa3oSc938+XP3gwvC9cLXmQ8HgpETI2HV5r9ygBu+p?=
 =?iso-8859-1?Q?dJC75hmGb9db1S6kvRLIOzGKoxpwYgIdwSoHb5/31EYYGjyJTUs/OqW/A7?=
 =?iso-8859-1?Q?aPCKmabtuEQQB8D3o29JUlPdPP/ptqTFwt3ykpOLMXfbuZmkyfwANUS94D?=
 =?iso-8859-1?Q?plt23O6zXiK9hiiusrx5jgXD/J1ccLqRyn+fr97yUzGOXSClprqHSpe92N?=
 =?iso-8859-1?Q?I4u0LssO5eeAowW+sjwmLu/f0h1SgmqvrcQG71vGfAObP4FjqUf8d94Mic?=
 =?iso-8859-1?Q?aU527e4vRZxJXybOIL2Zpj5wAN8NbNOUl8PXmuYH0HGHHfAajWKD2h7nLq?=
 =?iso-8859-1?Q?qyEgk6wYUvjOX/pC2dYKhjBJ7476ilETGk7X/ruqeoZLtM2Ykb2ppG/4Nt?=
 =?iso-8859-1?Q?6Ib7HmcG71xSZp59iNxczYMm7k6SRlBX06tK7g7MRiwpDK8Uxi7e2j1L9w?=
 =?iso-8859-1?Q?jL0ilaJQFFzb+Cvyrdg0mbLPfbTlSd4c06CWRptcvlEALnB4387ffXNdUe?=
 =?iso-8859-1?Q?ApcRAn3KA8u8Y0XopI/uanOKlTgLN8lZ8MhpEJEdmffdcc5kLDhlVi6xTM?=
 =?iso-8859-1?Q?tQPwCOt7IdLprWA/+uxtaPN3dewv4T7xCFXpmICS9hBAR+iMhRMiUUCGeo?=
 =?iso-8859-1?Q?nzffS3btHsX8ynEMGYuUDSDj4JhSylJlHDqXS8hPFW2H41IJGrU8jfvZWF?=
 =?iso-8859-1?Q?S7uC55Y5qyoxKX+d2oSSOKkYatAs437W6hd/0bBxLdPtxd2rNfUtujYk1r?=
 =?iso-8859-1?Q?dC8oZYIlywliLl29PbPKYe+c6eUVsZmjiv0MbopJnTgYW36uAPb/wGQSNg?=
 =?iso-8859-1?Q?p9tOxrozIf0Jw5/szcbldoysdqZJxnw6AZagxRoIbp5ySTZWcNkjgON58Q?=
 =?iso-8859-1?Q?RUeV85npf6TlBBGKL+diAtf+bpdcWvVPGuZ95g0y+nmd4/Gh6W5Yy/tnDF?=
 =?iso-8859-1?Q?T5p0C1uljbOHUuhe7DC361G3uZwkHn0=3D?=
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: SN6PR10MB3022.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 4fc6798b-3c7e-4279-fbf2-08da27967373
X-MS-Exchange-CrossTenant-originalarrivaltime: 26 Apr 2022 15:06:41.9272
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: wu2IP8vagaqvGlzZw8XvsIbOO99l7xu6v5TT8nRwlbhVbBLkoJ9+09P0nIoWBAXSiHbX1A/ENjj0b/mRSerl7g==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL0PR10MB2929
X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.486,18.0.858
 definitions=2022-04-26_04:2022-04-26,2022-04-26 signatures=0
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 spamscore=0 adultscore=0
 mlxscore=0 bulkscore=0 suspectscore=0 malwarescore=0 mlxlogscore=999
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2202240000
 definitions=main-2204260096
X-Proofpoint-ORIG-GUID: MOjTYr0weEQst9udW3RwcEo3xTHRL8L5
X-Proofpoint-GUID: MOjTYr0weEQst9udW3RwcEo3xTHRL8L5
X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,RDNS_NONE,SPF_HELO_NONE autolearn=no
	autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
	lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

Use the VMA iterator instead.  This requires a little restructuring of the
surrounding code to hoist the mm to the caller.  That turns
cxl_prefault_one() into a trivial function, so call cxl_fault_segment()
directly.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
---
 drivers/misc/cxl/fault.c | 45 ++++++++++++++--------------------------
 1 file changed, 15 insertions(+), 30 deletions(-)

diff --git a/drivers/misc/cxl/fault.c b/drivers/misc/cxl/fault.c
index 60c829113299..2c64f55cf01f 100644
--- a/drivers/misc/cxl/fault.c
+++ b/drivers/misc/cxl/fault.c
@@ -280,22 +280,6 @@ void cxl_handle_fault(struct work_struct *fault_work)
 		mmput(mm);
 }
=20
-static void cxl_prefault_one(struct cxl_context *ctx, u64 ea)
-{
-	struct mm_struct *mm;
-
-	mm =3D get_mem_context(ctx);
-	if (mm =3D=3D NULL) {
-		pr_devel("cxl_prefault_one unable to get mm %i\n",
-			 pid_nr(ctx->pid));
-		return;
-	}
-
-	cxl_fault_segment(ctx, mm, ea);
-
-	mmput(mm);
-}
-
 static u64 next_segment(u64 ea, u64 vsid)
 {
 	if (vsid & SLB_VSID_B_1T)
@@ -306,23 +290,16 @@ static u64 next_segment(u64 ea, u64 vsid)
 	return ea + 1;
 }
=20
-static void cxl_prefault_vma(struct cxl_context *ctx)
+static void cxl_prefault_vma(struct cxl_context *ctx, struct mm_struct *mm=
)
 {
 	u64 ea, last_esid =3D 0;
 	struct copro_slb slb;
+	VMA_ITERATOR(vmi, mm, 0);
 	struct vm_area_struct *vma;
 	int rc;
-	struct mm_struct *mm;
-
-	mm =3D get_mem_context(ctx);
-	if (mm =3D=3D NULL) {
-		pr_devel("cxl_prefault_vm unable to get mm %i\n",
-			 pid_nr(ctx->pid));
-		return;
-	}
=20
 	mmap_read_lock(mm);
-	for (vma =3D mm->mmap; vma; vma =3D vma->vm_next) {
+	for_each_vma(vmi, vma) {
 		for (ea =3D vma->vm_start; ea < vma->vm_end;
 				ea =3D next_segment(ea, slb.vsid)) {
 			rc =3D copro_calculate_slb(mm, ea, &slb);
@@ -337,20 +314,28 @@ static void cxl_prefault_vma(struct cxl_context *ctx)
 		}
 	}
 	mmap_read_unlock(mm);
-
-	mmput(mm);
 }
=20
 void cxl_prefault(struct cxl_context *ctx, u64 wed)
 {
+	struct mm_struct *mm =3D get_mem_context(ctx);
+
+	if (mm =3D=3D NULL) {
+		pr_devel("cxl_prefault unable to get mm %i\n",
+			 pid_nr(ctx->pid));
+		return;
+	}
+
 	switch (ctx->afu->prefault_mode) {
 	case CXL_PREFAULT_WED:
-		cxl_prefault_one(ctx, wed);
+		cxl_fault_segment(ctx, mm, wed);
 		break;
 	case CXL_PREFAULT_ALL:
-		cxl_prefault_vma(ctx);
+		cxl_prefault_vma(ctx, mm);
 		break;
 	default:
 		break;
 	}
+
+	mmput(mm);
 }
--=20
2.35.1