[SCSI] libsas: add host SMP processing

This adds support for host side SMP processing, via a separate
SMP interpreter file.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

5 files changed, 301 insertions, 5 deletions

diff --git a/drivers/scsi/libsas/Kconfig b/drivers/scsi/libsas/Kconfig
index c01a40d321d4..18f33cd54411 100644
--- a/drivers/scsi/libsas/Kconfig
+++ b/drivers/scsi/libsas/Kconfig
@@ -38,6 +38,15 @@ config SCSI_SAS_ATA
                 Builds in ATA support into libsas.  Will necessitate
                 the loading of libata along with libsas.
 
+config SCSI_SAS_HOST_SMP
+        bool "Support for SMP interpretation for SAS hosts"
+        default y
+        depends on SCSI_SAS_LIBSAS
+        help
+                Allows sas hosts to receive SMP frames.  Selecting this
+                option builds an SMP interpreter into libsas.  Say
+                N here if you want to save the few kb this consumes.
+
 config SCSI_SAS_LIBSAS_DEBUG
         bool "Compile the SAS Domain Transport Attributes in debug mode"
         default y
diff --git a/drivers/scsi/libsas/Makefile b/drivers/scsi/libsas/Makefile
index fd387b91856e..60d6e93dd949 100644
--- a/drivers/scsi/libsas/Makefile
+++ b/drivers/scsi/libsas/Makefile
@@ -35,3 +35,4 @@ libsas-y +=  sas_init.o     \
                 sas_expander.o \
                 sas_scsi_host.o
 libsas-$(CONFIG_SCSI_SAS_ATA) +=        sas_ata.o
+libsas-$(CONFIG_SCSI_SAS_HOST_SMP) +=   sas_host_smp.o
\ No newline at end of file
diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 27674fe468f5..76555b1ddfd5 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -1896,11 +1896,9 @@ int sas_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
         }
 
         /* no rphy means no smp target support (ie aic94xx host) */
-        if (!rphy) {
-                printk("%s: can we send a smp request to a host?\n",
-                       __FUNCTION__);
-                return -EINVAL;
-        }
+        if (!rphy)
+                return sas_smp_host_handler(shost, req, rsp);
+
         type = rphy->identify.device_type;
 
         if (type != SAS_EDGE_EXPANDER_DEVICE &&
diff --git a/drivers/scsi/libsas/sas_host_smp.c b/drivers/scsi/libsas/sas_host_smp.c
new file mode 100644
index 000000000000..16f93123271e
--- /dev/null
+++ b/drivers/scsi/libsas/sas_host_smp.c
@@ -0,0 +1,274 @@
+/*
+ * Serial Attached SCSI (SAS) Expander discovery and configuration
+ *
+ * Copyright (C) 2007 James E.J. Bottomley
+ *              <James.Bottomley@HansenPartnership.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2 only.
+ */
+#include <linux/scatterlist.h>
+#include <linux/blkdev.h>
+
+#include "sas_internal.h"
+
+#include <scsi/scsi_transport.h>
+#include <scsi/scsi_transport_sas.h>
+#include "../scsi_sas_internal.h"
+
+static void sas_host_smp_discover(struct sas_ha_struct *sas_ha, u8 *resp_data,
+                                  u8 phy_id)
+{
+        struct sas_phy *phy;
+        struct sas_rphy *rphy;
+
+        if (phy_id >= sas_ha->num_phys) {
+                resp_data[2] = SMP_RESP_NO_PHY;
+                return;
+        }
+        resp_data[2] = SMP_RESP_FUNC_ACC;
+
+        phy = sas_ha->sas_phy[phy_id]->phy;
+        resp_data[9] = phy_id;
+        resp_data[13] = phy->negotiated_linkrate;
+        memcpy(resp_data + 16, sas_ha->sas_addr, SAS_ADDR_SIZE);
+        memcpy(resp_data + 24, sas_ha->sas_phy[phy_id]->attached_sas_addr,
+               SAS_ADDR_SIZE);
+        resp_data[40] = (phy->minimum_linkrate << 4) |
+                phy->minimum_linkrate_hw;
+        resp_data[41] = (phy->maximum_linkrate << 4) |
+                phy->maximum_linkrate_hw;
+
+        if (!sas_ha->sas_phy[phy_id]->port ||
+            !sas_ha->sas_phy[phy_id]->port->port_dev)
+                return;
+
+        rphy = sas_ha->sas_phy[phy_id]->port->port_dev->rphy;
+        resp_data[12] = rphy->identify.device_type << 4;
+        resp_data[14] = rphy->identify.initiator_port_protocols;
+        resp_data[15] = rphy->identify.target_port_protocols;
+}
+
+static void sas_report_phy_sata(struct sas_ha_struct *sas_ha, u8 *resp_data,
+                                u8 phy_id)
+{
+        struct sas_rphy *rphy;
+        struct dev_to_host_fis *fis;
+        int i;
+
+        if (phy_id >= sas_ha->num_phys) {
+                resp_data[2] = SMP_RESP_NO_PHY;
+                return;
+        }
+
+        resp_data[2] = SMP_RESP_PHY_NO_SATA;
+
+        if (!sas_ha->sas_phy[phy_id]->port)
+                return;
+
+        rphy = sas_ha->sas_phy[phy_id]->port->port_dev->rphy;
+        fis = (struct dev_to_host_fis *)
+                sas_ha->sas_phy[phy_id]->port->port_dev->frame_rcvd;
+        if (rphy->identify.target_port_protocols != SAS_PROTOCOL_SATA)
+                return;
+
+        resp_data[2] = SMP_RESP_FUNC_ACC;
+        resp_data[9] = phy_id;
+        memcpy(resp_data + 16, sas_ha->sas_phy[phy_id]->attached_sas_addr,
+               SAS_ADDR_SIZE);
+
+        /* check to see if we have a valid d2h fis */
+        if (fis->fis_type != 0x34)
+                return;
+
+        /* the d2h fis is required by the standard to be in LE format */
+        for (i = 0; i < 20; i += 4) {
+                u8 *dst = resp_data + 24 + i, *src =
+                        &sas_ha->sas_phy[phy_id]->port->port_dev->frame_rcvd[i];
+                dst[0] = src[3];
+                dst[1] = src[2];
+                dst[2] = src[1];
+                dst[3] = src[0];
+        }
+}
+
+static void sas_phy_control(struct sas_ha_struct *sas_ha, u8 phy_id,
+                            u8 phy_op, enum sas_linkrate min,
+                            enum sas_linkrate max, u8 *resp_data)
+{
+        struct sas_internal *i =
+                to_sas_internal(sas_ha->core.shost->transportt);
+        struct sas_phy_linkrates rates;
+
+        if (phy_id >= sas_ha->num_phys) {
+                resp_data[2] = SMP_RESP_NO_PHY;
+                return;
+        }
+        switch (phy_op) {
+        case PHY_FUNC_NOP:
+        case PHY_FUNC_LINK_RESET:
+        case PHY_FUNC_HARD_RESET:
+        case PHY_FUNC_DISABLE:
+        case PHY_FUNC_CLEAR_ERROR_LOG:
+        case PHY_FUNC_CLEAR_AFFIL:
+        case PHY_FUNC_TX_SATA_PS_SIGNAL:
+                break;
+
+        default:
+                resp_data[2] = SMP_RESP_PHY_UNK_OP;
+                return;
+        }
+
+        rates.minimum_linkrate = min;
+        rates.maximum_linkrate = max;
+
+        if (i->dft->lldd_control_phy(sas_ha->sas_phy[phy_id], phy_op, &rates))
+                resp_data[2] = SMP_RESP_FUNC_FAILED;
+        else
+                resp_data[2] = SMP_RESP_FUNC_ACC;
+}
+
+int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req,
+                         struct request *rsp)
+{
+        u8 *req_data = NULL, *resp_data = NULL, *buf;
+        struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
+        int error = -EINVAL, resp_data_len = rsp->data_len;
+
+        /* eight is the minimum size for request and response frames */
+        if (req->data_len < 8 || rsp->data_len < 8)
+                goto out;
+
+        if (bio_offset(req->bio) + req->data_len > PAGE_SIZE ||
+            bio_offset(rsp->bio) + rsp->data_len > PAGE_SIZE) {
+                shost_printk(KERN_ERR, shost,
+                        "SMP request/response frame crosses page boundary");
+                goto out;
+        }
+
+        req_data = kzalloc(req->data_len, GFP_KERNEL);
+
+        /* make sure frame can always be built ... we copy
+         * back only the requested length */
+        resp_data = kzalloc(max(rsp->data_len, 128U), GFP_KERNEL);
+
+        if (!req_data || !resp_data) {
+                error = -ENOMEM;
+                goto out;
+        }
+
+        local_irq_disable();
+        buf = kmap_atomic(bio_page(req->bio), KM_USER0) + bio_offset(req->bio);
+        memcpy(req_data, buf, req->data_len);
+        kunmap_atomic(buf - bio_offset(req->bio), KM_USER0);
+        local_irq_enable();
+
+        if (req_data[0] != SMP_REQUEST)
+                goto out;
+
+        /* always succeeds ... even if we can't process the request
+         * the result is in the response frame */
+        error = 0;
+
+        /* set up default don't know response */
+        resp_data[0] = SMP_RESPONSE;
+        resp_data[1] = req_data[1];
+        resp_data[2] = SMP_RESP_FUNC_UNK;
+
+        switch (req_data[1]) {
+        case SMP_REPORT_GENERAL:
+                req->data_len -= 8;
+                resp_data_len -= 32;
+                resp_data[2] = SMP_RESP_FUNC_ACC;
+                resp_data[9] = sas_ha->num_phys;
+                break;
+
+        case SMP_REPORT_MANUF_INFO:
+                req->data_len -= 8;
+                resp_data_len -= 64;
+                resp_data[2] = SMP_RESP_FUNC_ACC;
+                memcpy(resp_data + 12, shost->hostt->name,
+                       SAS_EXPANDER_VENDOR_ID_LEN);
+                memcpy(resp_data + 20, "libsas virt phy",
+                       SAS_EXPANDER_PRODUCT_ID_LEN);
+                break;
+
+        case SMP_READ_GPIO_REG:
+                /* FIXME: need GPIO support in the transport class */
+                break;
+
+        case SMP_DISCOVER:
+                req->data_len =- 16;
+                if (req->data_len < 0) {
+                        req->data_len = 0;
+                        error = -EINVAL;
+                        goto out;
+                }
+                resp_data_len -= 56;
+                sas_host_smp_discover(sas_ha, resp_data, req_data[9]);
+                break;
+
+        case SMP_REPORT_PHY_ERR_LOG:
+                /* FIXME: could implement this with additional
+                 * libsas callbacks providing the HW supports it */
+                break;
+
+        case SMP_REPORT_PHY_SATA:
+                req->data_len =- 16;
+                if (req->data_len < 0) {
+                        req->data_len = 0;
+                        error = -EINVAL;
+                        goto out;
+                }
+                resp_data_len -= 60;
+                sas_report_phy_sata(sas_ha, resp_data, req_data[9]);
+                break;
+
+        case SMP_REPORT_ROUTE_INFO:
+                /* Can't implement; hosts have no routes */
+                break;
+
+        case SMP_WRITE_GPIO_REG:
+                /* FIXME: need GPIO support in the transport class */
+                break;
+
+        case SMP_CONF_ROUTE_INFO:
+                /* Can't implement; hosts have no routes */
+                break;
+
+        case SMP_PHY_CONTROL:
+                req->data_len =- 44;
+                if (req->data_len < 0) {
+                        req->data_len = 0;
+                        error = -EINVAL;
+                        goto out;
+                }
+                resp_data_len -= 8;
+                sas_phy_control(sas_ha, req_data[9], req_data[10],
+                                req_data[32] >> 4, req_data[33] >> 4,
+                                resp_data);
+                break;
+
+        case SMP_PHY_TEST_FUNCTION:
+                /* FIXME: should this be implemented? */
+                break;
+
+        default:
+                /* probably a 2.0 function */
+                break;
+        }
+
+        local_irq_disable();
+        buf = kmap_atomic(bio_page(rsp->bio), KM_USER0) + bio_offset(rsp->bio);
+        memcpy(buf, resp_data, rsp->data_len);
+        flush_kernel_dcache_page(bio_page(rsp->bio));
+        kunmap_atomic(buf - bio_offset(rsp->bio), KM_USER0);
+        local_irq_enable();
+        rsp->data_len = resp_data_len;
+
+ out:
+        kfree(req_data);
+        kfree(resp_data);
+        return error;
+}
diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
index baa0666ffa80..b4f9368f116a 100644
--- a/drivers/scsi/libsas/sas_internal.h
+++ b/drivers/scsi/libsas/sas_internal.h
@@ -80,6 +80,20 @@ struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy);
 
 void sas_hae_reset(struct work_struct *work);
 
+#ifdef CONFIG_SCSI_SAS_HOST_SMP
+extern int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req,
+                                struct request *rsp);
+#else
+static inline int sas_smp_host_handler(struct Scsi_Host *shost,
+                                       struct request *req,
+                                       struct request *rsp)
+{
+        shost_printk(KERN_ERR, shost,
+                "Cannot send SMP to a sas host (not enabled in CONFIG)\n");
+        return -EINVAL;
+}
+#endif
+
 static inline void sas_queue_event(int event, spinlock_t *lock,
                                    unsigned long *pending,
                                    struct work_struct *work,