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Wysocki" , Len Brown , James Morse , Ben Horgan , Reinette Chatre , Fenghua Yu Cc: Jonathan Cameron , Srivathsa L Rao , Ganapatrao Kulkarni , Trilok Soni , Srinivas Ramana , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20260710144520.917375-1-andre.przywara@arm.com> <20260710144520.917375-15-andre.przywara@arm.com> Content-Language: en-US From: Niyas Sait In-Reply-To: <20260710144520.917375-15-andre.przywara@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: LO2P265CA0509.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:13b::16) To DB9PR08MB7626.eurprd08.prod.outlook.com (2603:10a6:10:30a::19) MIME-Version: 1.0 X-MS-TrafficTypeDiagnostic: DB9PR08MB7626:EE_|PAXPR08MB7393:EE_|AM4PEPF00027A5F:EE_|DB8PR08MB5436:EE_ X-MS-Office365-Filtering-Correlation-Id: 56ab3aca-1395-4f40-4bdb-08dee1a363bb X-LD-Processed: f34e5979-57d9-4aaa-ad4d-b122a662184d,ExtAddr,ExtAddr x-checkrecipientrouted: true NoDisclaimer: true X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam-Untrusted: BCL:0;ARA:13230040|1800799024|7416014|376014|23010399003|366016|921020|4143699003|56012099006|11063799006|18002099003|22082099003; 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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: SxVeDUvWwCG/XojfXcpXaCbFz5HwrNLl4MxqsQUESGbps6gyptDF6GLZRxw3pxdQl6Q1yuMxDxQAxlmu3maPPDr3DnvbMok/446YlS2hqzn9WfRG8zFQGhT+pV3BYlTTX7paBi0HeOL2yAkpxRV+j8dn+xrrAuxtaWgQKfD+AJDMzp8C1ECYEhySOsJUyTU0HcHnAVjIeIjL/sNROBTbUzCMmhzpVAw8ecJZN2ev03CWBX7qyTyJCXCZCbRvGp1Zdl/Bj9igvhQUgi30H2Bt3kGwTgV15jJCJP16rnf6Qf0+Q7Gt2vYq1NSIVDXNxC1cdQ/Hspf3P1681TKb/DKNLowiZYVWTbd6vxjgfqsRmGtQUMJ2QtmVSYOLbcUJDnA8rFFkwFHR60YjeqS3firYOe9p6pyP8WnfksyXWyOzalKm1W+UFyH7edVC6pvK+ZCR X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 Jul 2026 12:28:20.1367 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 56ab3aca-1395-4f40-4bdb-08dee1a363bb X-MS-Exchange-CrossTenant-Id: f34e5979-57d9-4aaa-ad4d-b122a662184d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=f34e5979-57d9-4aaa-ad4d-b122a662184d;Ip=[4.158.2.129];Helo=[outbound-uk1.az.dlp.m.darktrace.com] X-MS-Exchange-CrossTenant-AuthSource: AM4PEPF00027A5F.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DB8PR08MB5436 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260714_052827_902909_7092A23F X-CRM114-Status: GOOD ( 11.82 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 10/07/2026 15:45, Andre Przywara wrote: > +#define MPAM_VERSION_MSG_SIZE (PCC_TYPE3_MSG_PAYLOAD_OFS) > +#define MPAM_READ_MSG_SIZE (PCC_TYPE3_MSG_PAYLOAD_OFS + 3 * sizeof(u32)) > +#define MPAM_WRITE_MSG_SIZE (PCC_TYPE3_MSG_PAYLOAD_OFS + 4 * sizeof(u32)) I think these lengths are wrong for ACPI extended PCC shared memory. Length should be command + payload, and should not include the payload offset within the PCC shared memory region. I think this should be something like #define MPAM_VERSION_MSG_SIZE sizeof(u32) #define MPAM_READ_MSG_SIZE (sizeof(u32) + 3 * sizeof(u32)) #define MPAM_WRITE_MSG_SIZE (sizeof(u32) + 4 * sizeof(u32)) > + > +static int mpam_fb_build_version_message(unsigned int token, > + void __iomem *msg_buf) > +{ > + struct acpi_pcct_ext_pcc_shared_memory *pcc_shmem = msg_buf; > + > + writel_relaxed(0, &pcc_shmem->flags); Here the flags are always 0. If the PCCT advertises interrupt based completion, I think we need to set PCC_CMD_COMPLETION_NOTIFY here. Otherwise the platform can process the request without generating an interrupt back to the AP, and the PCC driver will time out waiting for completion. > + > +static int mpam_fb_send_request(struct mpam_pcc_chan *pcc_chan, u32 msc_id, > + u16 reg, u32 *result, int mpam_fb_command) > +{ > + unsigned int token = atomic_inc_return(&mpam_fb_token); MPAM-Fb token is a 10-bit field in the message header, so this needs to be masked before using it. Otherwise once the token exceeds 1023, the platform returns the wrapped 10-bit token but Linux compares it against the original value and will probably time out. May be something like: unsigned int token = atomic_inc_return(&mpam_fb_token) & FIELD_MAX(MPAM_MSC_TOKEN_MASK); Thanks, Niyas