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--- sata_port_multipliers [2019/04/24 10:41] – [Build files] rpjday
+++ sata_port_multipliers [2019/04/24 12:30] (current) – [struct ata_device] rpjday
@@ Line 14: / Line 14: @@
       * Makefile
       * libata-pmp.c
+      * libata-eh.c
 ===== Build files [drivers/ata] =====
@@ Line 111: / Line 112: @@
 </code>
-===== libata-pmp.c =====
+<code>
+struct ata_port_operations {
+        ...
+        void (*pmp_attach)(struct ata_port *ap);
+        void (*pmp_detach)(struct ata_port *ap);
+        ...
+</code>
+<code>
+#ifdef CONFIG_SATA_PMP
+static inline bool sata_pmp_supported(struct ata_port *ap)
+{
+        return ap->flags & ATA_FLAG_PMP;
+}
+static inline bool sata_pmp_attached(struct ata_port *ap)
+{
+        return ap->nr_pmp_links != 0;
+}
+static inline bool ata_is_host_link(const struct ata_link *link)
+{
+        return link == &link->ap->link || link == link->ap->slave_link;
+}
+#else /* CONFIG_SATA_PMP */
+static inline bool sata_pmp_supported(struct ata_port *ap)
+{
+        return false;
+}
+static inline bool sata_pmp_attached(struct ata_port *ap)
+{
+        return false;
+}
+static inline bool ata_is_host_link(const struct ata_link *link)
+{
+        return 1;
+}
+#endif /* CONFIG_SATA_PMP */
+</code>
+===== Structures [libata.h] =====
+==== struct ata_device ====
+''ata_device'' %%->%% ''ata_link'':
+<code>
+struct ata_device {
+        struct ata_link         *link;
+        unsigned int            devno;          /* 0 or 1 */
+        unsigned int            horkage;        /* List of broken features */
+        unsigned long           flags;          /* ATA_DFLAG_xxx */
+        struct scsi_device      *sdev;          /* attached SCSI device */
+        void                    *private_data;
+#ifdef CONFIG_ATA_ACPI
+        union acpi_object       *gtf_cache;
+        unsigned int            gtf_filter;
+#endif
+#ifdef CONFIG_SATA_ZPODD
+        void                    *zpodd;
+#endif
+        struct device           tdev;
+        /* n_sector is CLEAR_BEGIN, read comment above CLEAR_BEGIN */
+        u64                     n_sectors;      /* size of device, if ATA */
+        u64                     n_native_sectors; /* native size, if ATA */
+        unsigned int            class;          /* ATA_DEV_xxx */
+        ...
+        union {
+                u16             id[ATA_ID_WORDS]; /* IDENTIFY xxx DEVICE data */
+                u32             gscr[SATA_PMP_GSCR_DWORDS]; /* PMP GSCR block */
+        } ____cacheline_aligned;
+</code>
+''class'' should be ''DEV_ATA_PMP''.
+==== struct ata_link ====
+''ata_link'' %%->%% ''ata_port'':
+<code>
+struct ata_link {
+        struct ata_port         *ap;
+        int                     pmp;            /* port multiplier port # */
+        ...
+        struct ata_device       device[ATA_MAX_DEVICES];
+</code>
+==== struct ata_port ====
+<code>
+struct ata_port {
+        struct Scsi_Host        *scsi_host; /* our co-allocated scsi host */
+        struct ata_port_operations *ops;
+        spinlock_t              *lock;
+        /* Flags owned by the EH context. Only EH should touch these once the
+           port is active */
+        unsigned long           flags;  /* ATA_FLAG_xxx */
+        ...
+        struct ata_link         link;           /* host default link */
+        struct ata_link         *slave_link;    /* see ata_slave_link_init() */
+        int                     nr_pmp_links;   /* nr of available PMP links */
+        struct ata_link         *pmp_link;      /* array of PMP links */
+        ...
+        struct ata_host         *host;
+        struct device           *dev;
+        ...
+</code>
+===== drivers/ata/ =====
+==== libata-eh.c ====
+<code>
+static int ata_eh_revalidate_and_attach(struct ata_link *link,
+					struct ata_device **r_failed_dev)
+{
+	struct ata_port *ap = link->ap;
+	struct ata_eh_context *ehc = &link->eh_context;
+	struct ata_device *dev;
+        ...
+        ata_for_each_dev(dev, link, ALL_REVERSE) {
+                ...
+                dev->class = ehc->classes[dev->devno];
+                if (dev->class == ATA_DEV_PMP)
+                        rc = sata_pmp_attach(dev);
+                else
+                        ...
+</code>
+==== libata-pmp.c ====
+=== sata_pmp_configure() ===