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Currently the shared memory communication address was mapped by the mailbox client drivers leading to all sorts of inconsistencies. It also has resulted in the inconsistent attributes used while mapping the shared memory regions. In order to remove/eliminate any issues, let us ensures the shared memory address is always mapped and unmapped when the PCC channels are requested and release. We need to map them as the ACPI PCCT associates these shared memory with each channel subspace and may need use the status or the flags in the headers of those shared memory communication address regions to manage the transport/channel. Note, until all the drivers using PCC start using this mapped shmem, there might be double mapping of the shared memory address. This shouldn't have any impact on existing mbox client drivers. Since there are no users of pcc_chan_ioremap() and also it is mapped by default, we can stop exporting it and merge the functionality into pcc_mbox_request_channel(). Acked-by: Huisong Li <lihuisong@huawei.com> Tested-by: Huisong Li <lihuisong@huawei.com> Tested-by: Adam Young <admiyo@os.amperecomputing.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
50 lines
1.3 KiB
C
50 lines
1.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* PCC (Platform Communications Channel) methods
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*/
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#ifndef _PCC_H
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#define _PCC_H
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#include <linux/mailbox_controller.h>
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#include <linux/mailbox_client.h>
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struct pcc_mbox_chan {
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struct mbox_chan *mchan;
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u64 shmem_base_addr;
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void __iomem *shmem;
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u64 shmem_size;
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u32 latency;
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u32 max_access_rate;
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u16 min_turnaround_time;
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};
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/* Generic Communications Channel Shared Memory Region */
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#define PCC_SIGNATURE 0x50434300
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/* Generic Communications Channel Command Field */
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#define PCC_CMD_GENERATE_DB_INTR BIT(15)
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/* Generic Communications Channel Status Field */
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#define PCC_STATUS_CMD_COMPLETE BIT(0)
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#define PCC_STATUS_SCI_DOORBELL BIT(1)
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#define PCC_STATUS_ERROR BIT(2)
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#define PCC_STATUS_PLATFORM_NOTIFY BIT(3)
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/* Initiator Responder Communications Channel Flags */
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#define PCC_CMD_COMPLETION_NOTIFY BIT(0)
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#define MAX_PCC_SUBSPACES 256
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#ifdef CONFIG_PCC
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extern struct pcc_mbox_chan *
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pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id);
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extern void pcc_mbox_free_channel(struct pcc_mbox_chan *chan);
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#else
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static inline struct pcc_mbox_chan *
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pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id)
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{
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return ERR_PTR(-ENODEV);
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}
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static inline void pcc_mbox_free_channel(struct pcc_mbox_chan *chan) { }
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#endif
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#endif /* _PCC_H */
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