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Matthew R. OchsJames Bottomley
Matthew R. Ochs
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James Bottomley
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cxlflash: Base support for IBM CXL Flash Adapter
SCSI device driver to support filesystem access on the IBM CXL Flash adapter. Supported-by: Stephen Bates <stephen.bates@pmcs.com> Reviewed-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
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‎drivers/scsi/Kconfig

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@@ -345,6 +345,7 @@ source "drivers/scsi/cxgbi/Kconfig"
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source "drivers/scsi/bnx2i/Kconfig"
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source "drivers/scsi/bnx2fc/Kconfig"
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source "drivers/scsi/be2iscsi/Kconfig"
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source "drivers/scsi/cxlflash/Kconfig"
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config SGIWD93_SCSI
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tristate "SGI WD93C93 SCSI Driver"

‎drivers/scsi/Makefile

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@@ -102,6 +102,7 @@ obj-$(CONFIG_SCSI_7000FASST) += wd7000.o
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obj-$(CONFIG_SCSI_EATA) += eata.o
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obj-$(CONFIG_SCSI_DC395x) += dc395x.o
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obj-$(CONFIG_SCSI_AM53C974) += esp_scsi.o am53c974.o
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obj-$(CONFIG_CXLFLASH) += cxlflash/
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obj-$(CONFIG_MEGARAID_LEGACY) += megaraid.o
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obj-$(CONFIG_MEGARAID_NEWGEN) += megaraid/
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obj-$(CONFIG_MEGARAID_SAS) += megaraid/

‎drivers/scsi/cxlflash/Kconfig

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#
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# IBM CXL-attached Flash Accelerator SCSI Driver
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#
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config CXLFLASH
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tristate "Support for IBM CAPI Flash"
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depends on PCI && SCSI && CXL
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default m
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help
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Allows CAPI Accelerated IO to Flash
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If unsure, say N.

‎drivers/scsi/cxlflash/Makefile

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obj-$(CONFIG_CXLFLASH) += cxlflash.o
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cxlflash-y += main.o

‎drivers/scsi/cxlflash/common.h

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/*
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* CXL Flash Device Driver
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*
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* Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
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* Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
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*
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* Copyright (C) 2015 IBM Corporation
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _CXLFLASH_COMMON_H
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#define _CXLFLASH_COMMON_H
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#include <linux/list.h>
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#include <linux/types.h>
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#include <scsi/scsi.h>
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#include <scsi/scsi_device.h>
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#define MAX_CONTEXT CXLFLASH_MAX_CONTEXT /* num contexts per afu */
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#define CXLFLASH_BLOCK_SIZE 4096 /* 4K blocks */
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#define CXLFLASH_MAX_XFER_SIZE 16777216 /* 16MB transfer */
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#define CXLFLASH_MAX_SECTORS (CXLFLASH_MAX_XFER_SIZE/512) /* SCSI wants
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max_sectors
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in units of
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512 byte
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sectors
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*/
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#define NUM_RRQ_ENTRY 16 /* for master issued cmds */
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#define MAX_RHT_PER_CONTEXT (PAGE_SIZE / sizeof(struct sisl_rht_entry))
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/* AFU command retry limit */
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#define MC_RETRY_CNT 5 /* sufficient for SCSI check and
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certain AFU errors */
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/* Command management definitions */
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#define CXLFLASH_NUM_CMDS (2 * CXLFLASH_MAX_CMDS) /* Must be a pow2 for
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alignment and more
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efficient array
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index derivation
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*/
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#define CXLFLASH_MAX_CMDS 16
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#define CXLFLASH_MAX_CMDS_PER_LUN CXLFLASH_MAX_CMDS
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static inline void check_sizes(void)
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{
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BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_NUM_CMDS);
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}
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/* AFU defines a fixed size of 4K for command buffers (borrow 4K page define) */
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#define CMD_BUFSIZE SIZE_4K
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/* flags in IOA status area for host use */
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#define B_DONE 0x01
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#define B_ERROR 0x02 /* set with B_DONE */
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#define B_TIMEOUT 0x04 /* set with B_DONE & B_ERROR */
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enum cxlflash_lr_state {
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LINK_RESET_INVALID,
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LINK_RESET_REQUIRED,
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LINK_RESET_COMPLETE
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};
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enum cxlflash_init_state {
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INIT_STATE_NONE,
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INIT_STATE_PCI,
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INIT_STATE_AFU,
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INIT_STATE_SCSI
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};
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/*
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* Each context has its own set of resource handles that is visible
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* only from that context.
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*/
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struct cxlflash_cfg {
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struct afu *afu;
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struct cxl_context *mcctx;
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struct pci_dev *dev;
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struct pci_device_id *dev_id;
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struct Scsi_Host *host;
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ulong cxlflash_regs_pci;
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wait_queue_head_t eeh_waitq;
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struct work_struct work_q;
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enum cxlflash_init_state init_state;
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enum cxlflash_lr_state lr_state;
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int lr_port;
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struct cxl_afu *cxl_afu;
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struct pci_pool *cxlflash_cmd_pool;
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struct pci_dev *parent_dev;
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wait_queue_head_t tmf_waitq;
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bool tmf_active;
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u8 err_recovery_active:1;
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};
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struct afu_cmd {
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struct sisl_ioarcb rcb; /* IOARCB (cache line aligned) */
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struct sisl_ioasa sa; /* IOASA must follow IOARCB */
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spinlock_t slock;
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struct completion cevent;
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char *buf; /* per command buffer */
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struct afu *parent;
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int slot;
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atomic_t free;
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u8 cmd_tmf:1;
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/* As per the SISLITE spec the IOARCB EA has to be 16-byte aligned.
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* However for performance reasons the IOARCB/IOASA should be
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* cache line aligned.
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*/
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} __aligned(cache_line_size());
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struct afu {
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/* Stuff requiring alignment go first. */
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u64 rrq_entry[NUM_RRQ_ENTRY]; /* 128B RRQ */
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/*
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* Command & data for AFU commands.
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*/
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struct afu_cmd cmd[CXLFLASH_NUM_CMDS];
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/* Beware of alignment till here. Preferably introduce new
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* fields after this point
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*/
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/* AFU HW */
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struct cxl_ioctl_start_work work;
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struct cxlflash_afu_map *afu_map; /* entire MMIO map */
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struct sisl_host_map *host_map; /* MC host map */
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struct sisl_ctrl_map *ctrl_map; /* MC control map */
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ctx_hndl_t ctx_hndl; /* master's context handle */
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u64 *hrrq_start;
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u64 *hrrq_end;
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u64 *hrrq_curr;
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bool toggle;
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bool read_room;
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atomic64_t room;
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u64 hb;
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u32 cmd_couts; /* Number of command checkouts */
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u32 internal_lun; /* User-desired LUN mode for this AFU */
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char version[8];
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u64 interface_version;
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struct cxlflash_cfg *parent; /* Pointer back to parent cxlflash_cfg */
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};
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static inline u64 lun_to_lunid(u64 lun)
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{
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u64 lun_id;
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int_to_scsilun(lun, (struct scsi_lun *)&lun_id);
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return swab64(lun_id);
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}
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int cxlflash_send_cmd(struct afu *, struct afu_cmd *);
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void cxlflash_wait_resp(struct afu *, struct afu_cmd *);
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int cxlflash_afu_reset(struct cxlflash_cfg *);
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struct afu_cmd *cxlflash_cmd_checkout(struct afu *);
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void cxlflash_cmd_checkin(struct afu_cmd *);
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int cxlflash_afu_sync(struct afu *, ctx_hndl_t, res_hndl_t, u8);
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#endif /* ifndef _CXLFLASH_COMMON_H */

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