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Thu, 6 Mar 2025 10:19:29 +0100 Date: Thu, 6 Mar 2025 17:19:25 +0800 From: Jonathan Cameron To: CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH v2 2/3] ACPI:RAS2: Add ACPI RAS2 driver Message-ID: <20250306171925.00002721@huawei.com> In-Reply-To: <20250305180225.1226-3-shiju.jose@huawei.com> References: <20250305180225.1226-1-shiju.jose@huawei.com> <20250305180225.1226-3-shiju.jose@huawei.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.96.237.92] X-ClientProxiedBy: lhrpeml500005.china.huawei.com (7.191.163.240) To frapeml500008.china.huawei.com (7.182.85.71) X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: D1136A0017 X-Rspam-User: X-Stat-Signature: r6c1yjg4n76eixaixtpzqepo4qj6mtxj X-HE-Tag: 1741252786-553029 X-HE-Meta: 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 DPnuAUQA SGL7ScmA/SyLZ/0ZUfm73LO4SQYTfAbAy1KBDv+yysNXYGsLZOEy7UKSSJrqR5GEnS8v4kk7mpe3e/nDIYR6TNDkoozgyrz2QREX67IlFFXNkgJyfjVeKgqqZpfi5UkepbJyBbqRXunWE5wN3ZqPebmoBGAMATpdmAUXIKRt1OrLKmS8jw0In7iBJldxhiNSpsaTqzByFz8ckV0764c+27fgMVdwjzaszGKaD46kVY61bZ+YcJSKN9mFul1UV89UyhBCJ58g/uL9Yz2dAu5YRjBKstnV6Q/O+6wAjyViXFyKuBlM0GjHqkDiHoHflIGEB3wmq8B1GsMkxpes7IGb4DZ97w668QWlHFiNhfgNYkO2ju8S7DuYviyWxow== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, 5 Mar 2025 18:02:23 +0000 wrote: > From: Shiju Jose > > Add support for ACPI RAS2 feature table (RAS2) defined in the > ACPI 6.5 Specification, section 5.2.21. > Driver defines RAS2 Init, which extracts the RAS2 table and driver > adds auxiliary device for each memory feature which binds to the > RAS2 memory driver. > > Driver uses PCC mailbox to communicate with the ACPI HW and the > driver adds OSPM interfaces to send RAS2 commands. > > Acked-by: Rafael J. Wysocki > Co-developed-by: A Somasundaram > Signed-off-by: A Somasundaram > Co-developed-by: Jonathan Cameron > Signed-off-by: Jonathan Cameron > Tested-by: Daniel Ferguson > Signed-off-by: Shiju Jose Hi Shiju, I took another look through as it's been a while and I've pretty much forgotten this code :( Anyhow, a few minor comments inline. Thanks, Jonathan > diff --git a/drivers/acpi/ras2.c b/drivers/acpi/ras2.c > new file mode 100755 > index 000000000000..8831a2bd5fab > --- /dev/null > +++ b/drivers/acpi/ras2.c > +static int ras2_register_pcc_channel(struct ras2_mem_ctx *ras2_ctx, int pcc_id) > +{ > + struct ras2_pcc_subspace *pcc_subspace; > + struct pcc_mbox_chan *pcc_chan; > + struct mbox_client *mbox_cl; > + > + if (pcc_id < 0) > + return -EINVAL; > + > + mutex_lock(&ras2_pcc_lock); > + list_for_each_entry(pcc_subspace, &ras2_pcc_subspaces, elem) { > + if (pcc_subspace->pcc_id != pcc_id) > + continue; > + ras2_ctx->pcc_subspace = pcc_subspace; > + pcc_subspace->ref_count++; > + mutex_unlock(&ras2_pcc_lock); > + return 0; > + } > + mutex_unlock(&ras2_pcc_lock); > + > + pcc_subspace = kcalloc(1, sizeof(*pcc_subspace), GFP_KERNEL); if allocating a count of 1, why not kzalloc? > + if (!pcc_subspace) > + return -ENOMEM; > +static int acpi_ras2_parse(void) > +{ > + struct acpi_ras2_pcc_desc *pcc_desc_list; > + int pcc_id; > + u8 count = 0; > + int rc, i; > + > + if (ras2_tab->header.length < sizeof(struct acpi_table_ras2)) { extra space before < Maybe sizeof(*ras2_tab) is cleaner. > + pr_warn(FW_WARN "ACPI RAS2 table present but broken (too short #1)\n"); > + return -EINVAL; > + } > + > + if (!ras2_tab->num_pcc_descs) { > + pr_warn(FW_WARN "No PCC descs in ACPI RAS2 table\n"); > + return -EINVAL; > + } > + > + pcc_desc_list = (struct acpi_ras2_pcc_desc *)(ras2_tab + 1); > + /* Double scan for the case of only one actual controller */ > + pcc_id = -1; > + count = 0; Already set above, so no need to do it again. I'd do it just here. Can put it in the loop init though. > + for (i = 0; i < ras2_tab->num_pcc_descs; i++, pcc_desc_list++) { > + if (pcc_desc_list->feature_type != RAS2_FEAT_TYPE_MEMORY) > + continue; > + if (pcc_id == -1) { > + pcc_id = pcc_desc_list->channel_id; > + count++; > + } > + if (pcc_desc_list->channel_id != pcc_id) > + count++; > + } > + > + /* > + * Workaround for the client platform with multiple scrub devices > + * but uses single PCC subspace for communication. > + */ > + if (count == 1) { > + /* Add auxiliary device and bind ACPI RAS2 memory driver */ > + rc = ras2_add_aux_device(RAS2_MEM_DEV_ID_NAME, pcc_id); > + if (rc) > + return rc; > + > + return 0; > + } > + > + pcc_desc_list = (struct acpi_ras2_pcc_desc *)(ras2_tab + 1); > + count = 0; Maybe set in loop init. > + for (i = 0; i < ras2_tab->num_pcc_descs; i++, pcc_desc_list++) { > + if (pcc_desc_list->feature_type != RAS2_FEAT_TYPE_MEMORY) > + continue; > + pcc_id = pcc_desc_list->channel_id; > + /* Add auxiliary device and bind ACPI RAS2 memory driver */ obvious enough to drop the comment I think. > + rc = ras2_add_aux_device(RAS2_MEM_DEV_ID_NAME, pcc_id); pcc_desc_list->channel_id); and no local variable. > + if (rc) > + return rc; > + } > + > + return 0; > +} > + > +void __init acpi_ras2_init(void) > +{ > + acpi_status status; > + int rc; > + > + status = acpi_get_table(ACPI_SIG_RAS2, 0, > + (struct acpi_table_header **)&ras2_tab); > + if (ACPI_FAILURE(status) || !ras2_tab) { > + const char *msg = acpi_format_exception(status); > + > + pr_err("Failed to get table, %s\n", msg); If only going to use it here maybe pr_err("Failed to get table, %s\n", acpi_format_exception(status)); and save on the local variable. > + return; > + } > + > + rc = acpi_ras2_parse(); > + if (rc) { > + acpi_put_table((struct acpi_table_header *)ras2_tab); > + pr_err("Failed to parse RAS2 table\n"); > + } > +} > diff --git a/include/acpi/ras2.h b/include/acpi/ras2.h > new file mode 100644 > index 000000000000..5b27c1f30096 > --- /dev/null > +++ b/include/acpi/ras2.h > @@ -0,0 +1,48 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * ACPI RAS2 driver header file > + * > + * Copyright (c) 2024-2025 HiSilicon Limited > + */ > + > +#ifndef _ACPI_RAS2_H > +#define _ACPI_RAS2_H > + > +#include > +#include > +#include > +#include > +#include > + > +#define RAS2_PCC_CMD_COMPLETE BIT(0) > +#define RAS2_PCC_CMD_ERROR BIT(2) > + I think these bits are from table 14.11 and generic to all PCC status registers? Should these have more generic names rather than ras2 specific ones? > +/* RAS2 specific PCC commands */ > +#define RAS2_PCC_CMD_EXEC 0x01 Are we mixing commands and field definitions both with prefix RAS2_PCC_CMD_ ? That is somewhat confusing. > + > +#define RAS2_AUX_DEV_NAME "ras2" > +#define RAS2_MEM_DEV_ID_NAME "acpi_ras2_mem" > + I would add a forwards def struct device; whilst it is really unlikely that headers would ever be reorganized such that auxiliary_bus.h would not include device.h given the embedded device we shouldn't rely on that here. > +/* Data structure RAS2 table */ > +struct ras2_mem_ctx { > + struct auxiliary_device adev; > + /* Lock to provide mutually exclusive access to PCC channel */ > + struct mutex lock; > + struct device *dev; > + struct acpi_ras2_shmem __iomem *comm_addr; > + void *pcc_subspace; > + int id; > +}; > + > +#ifdef CONFIG_ACPI_RAS2 > +void __init acpi_ras2_init(void); > +int ras2_send_pcc_cmd(struct ras2_mem_ctx *ras2_ctx, u16 cmd); > +#else > +static inline void acpi_ras2_init(void) { } > + > +static inline int ras2_send_pcc_cmd(struct ras2_mem_ctx *ras2_ctx, u16 cmd) Is this stub ever needed? To me it seems unlikely we would have a user that is built without a dependency on CONFIG_ACPI_RAS2. This is different from acpi_ras2_init() which makes much more sense to me. > +{ > + return -EOPNOTSUPP; > +} > +#endif > +#endif /* _ACPI_RAS2_H */