Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
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>
Subject: [PATCH v5 37/70] cxl: Remove vma linked list walk
Thread-Topic: [PATCH v5 37/70] cxl: Remove vma linked list walk
Thread-Index: AQHYF958sDuevQ8VU0qak8xnCl2NRw==
Date:   Wed, 2 Feb 2022 02:42:13 +0000
Message-ID: <20220202024137.2516438-38-Liam.Howlett@oracle.com>
References: <20220202024137.2516438-1-Liam.Howlett@oracle.com>
In-Reply-To: <20220202024137.2516438-1-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?MpGeTvVt/JCN2SNnaU3R0pASKGkLJJHmupQALe8oO5oISRT0RrxP3m8b9j?=
 =?iso-8859-1?Q?KbGmiB/Pa2NqY6MD6h4OVDeTZuKK8St4aU0a26szl6OGjYEPRvmxWc4gfG?=
 =?iso-8859-1?Q?BLvzOy4K5dQU6FqmCZn3tZivqzLpePtrLd/AH1hxZ8bO3b/4B69NRSd0EQ?=
 =?iso-8859-1?Q?q9Od/qih3ldeItzxaCARzi9bpTn9hnQwi2vW5up6Xa+aMOuSm86uKXSZ/V?=
 =?iso-8859-1?Q?7xA4QVjz/auvDkUUdoiMB5kw5Kzwm2CxbOXdD7r8NFvhMl0/PVde1kfIg+?=
 =?iso-8859-1?Q?BxMjYMRYP1hbp2zYs+6lnR6o13RfS6axzQzskpu/fA1AlmABvjoEqk9oGu?=
 =?iso-8859-1?Q?Yu3eeSV5Sk9wlrzreTg/bYp6lrZF8sNwZPhIL8vED021J7idTN8D8j1FrH?=
 =?iso-8859-1?Q?RQnMBbEVLKm3E1N5EpDuYhobSXe71KhOnoQpuNGyPCLyEmulib3a13M8w7?=
 =?iso-8859-1?Q?z6LjKyspeQ6Co/zY4XZniOPBXP96O2Siw3TIp6IEKjI3reJH/zL40u/3mM?=
 =?iso-8859-1?Q?d/MibY7xzB2YyaWV+I2Okn7pQVx4KIWtAl8w42vDC0Bz/BvtLWhDgnha3Y?=
 =?iso-8859-1?Q?//+VK2uTC626k+i0dfdkUxhPjUWKpA94/gGIFp2xsK6WY7FUh0/pR9sfCa?=
 =?iso-8859-1?Q?XQqSCl88hEFvuTmte5fXbU9kpl4xN/ECmjLSoDM8LKqk3gmvXcOHrNyjJw?=
 =?iso-8859-1?Q?5MFNNrt+zgcGBloYYRQjU469Dm57ogUM7LG5mJEqw5est+1DcisLcCaUZ9?=
 =?iso-8859-1?Q?3deMI+lx/+lFDfPFUAw60fit66wUPPCmAwDMs2u1h887Lz/t8hotId7/nN?=
 =?iso-8859-1?Q?D28cxyImj/n/UeZpHkJaC5bI2vgTn8kPb5Iz0NQoSZ++52nhIdu9wEQ7VA?=
 =?iso-8859-1?Q?2O+QFwNkw+e9hyYyUCd2qll68K1xnzwfyNrd95O2aPBi+oeV7cHPhbnjsx?=
 =?iso-8859-1?Q?7tDXdlQ7L9UYWdHM0jABHUuTwnQj7euCTzJ4Y8hffWwSKvgMwepU+jxxki?=
 =?iso-8859-1?Q?0J+Wcc8zk7LEW6aYLrnSAOTz9rf323vYKP6tKrpUcU8tmZwwSk+hw4Xx2d?=
 =?iso-8859-1?Q?ysqDxmJGSHI/wobr8Lgy9ZQLHV3loQmbcBjEbJaZmon3IZuHmWyWrNqJsC?=
 =?iso-8859-1?Q?czPXFqRcj/USZUJWOCoyt7ZnfKQKOYIgIxEVkNywCkEn6/pSnlBAI1h8g5?=
 =?iso-8859-1?Q?i7bNgu9+47SKqbZ99863jcyLiOWtYVJY3MUTdjvttB/0pA3xUocIdYJC9H?=
 =?iso-8859-1?Q?2sAFvcETToPtRWSEk4LtPLI3xG+gvSQo2/rRzohJ/Aq6xwzNCPgtaCiLh2?=
 =?iso-8859-1?Q?Sn5aakCbReUZ4EQvRMOW1bllOewFVpZlCynY0SJGwvfI5CEuN3vWKJJCiR?=
 =?iso-8859-1?Q?eBppdTWXmfI4clMxGHnLd/1o4mVkq1NSG1SOJFF7wBSBm5zp6Tx6L2QaVh?=
 =?iso-8859-1?Q?FsWii9sR20Dy4rAzaad+Ku2q9vqiQsMH1fLryK0CZpedolwDDgpl6yf1Ly?=
 =?iso-8859-1?Q?ID5f/nhoY7igctbfS2rzMNU61wJFAXLdgv755nYzvUrCVmcnwytvRgTksr?=
 =?iso-8859-1?Q?Yf4StIVYalQoWOUgOowSWxrY55yJ5CshF7Fun56iEW29w5fjswEjbt5Dqd?=
 =?iso-8859-1?Q?3L0kGz8Ei3dsEhFsbZjjBCO/7HPLNPtyIaLxsHA91x1GfWjq817kmwcDIA?=
 =?iso-8859-1?Q?T/WxGh0g8KIni4akucI=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: ec986db7-c481-4009-3f38-08d9e5f5b299
X-MS-Exchange-CrossTenant-originalarrivaltime: 02 Feb 2022 02:42:13.9544
 (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: lHHqp0Dgj+tB2IHv5BGgpdQaKOpsNIqI/n0CFhpSgzoHAmdBlVWiFVLeIpd2UCoj1RX9n6YY4uZkwg/DGvv+SA==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY5PR10MB4129
X-Proofpoint-Virus-Version: vendor=nai engine=6300 definitions=10245 signatures=673430
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 malwarescore=0 phishscore=0
 mlxscore=0 adultscore=0 suspectscore=0 mlxlogscore=999 bulkscore=0
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2201110000
 definitions=main-2202020010
X-Proofpoint-ORIG-GUID: gW7XFMaytIb9SpCtKZiabwhJoBn8B2wa
X-Proofpoint-GUID: gW7XFMaytIb9SpCtKZiabwhJoBn8B2wa
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>

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
2.34.1