NVMe: Implement doorbell stride capability
[linux-2.6-block.git] / drivers / block / nvme.c
index a7f82fbdaf87a4f75605e4ecb3942148b5f4b2f6..a17f80fa3881fc54a4bd849219baa4d540c1d40d 100644 (file)
@@ -70,6 +70,7 @@ struct nvme_dev {
        struct dma_pool *prp_small_pool;
        int instance;
        int queue_count;
+       int db_stride;
        u32 ctrl_config;
        struct msix_entry *entry;
        struct nvme_bar __iomem *bar;
@@ -265,7 +266,7 @@ static int nvme_submit_cmd(struct nvme_queue *nvmeq, struct nvme_command *cmd)
 }
 
 struct nvme_prps {
-       int npages;
+       int npages;             /* 0 means small pool in use */
        dma_addr_t first_dma;
        __le64 *list[0];
 };
@@ -347,7 +348,7 @@ static struct nvme_prps *nvme_setup_prps(struct nvme_dev *dev,
        int offset = offset_in_page(dma_addr);
        __le64 *prp_list;
        dma_addr_t prp_dma;
-       int nprps, npages, i, prp_page;
+       int nprps, npages, i;
        struct nvme_prps *prps = NULL;
 
        cmd->prp1 = cpu_to_le64(dma_addr);
@@ -370,20 +371,20 @@ static struct nvme_prps *nvme_setup_prps(struct nvme_dev *dev,
        }
 
        nprps = DIV_ROUND_UP(length, PAGE_SIZE);
-       npages = DIV_ROUND_UP(8 * nprps, PAGE_SIZE);
+       npages = DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
        prps = kmalloc(sizeof(*prps) + sizeof(__le64 *) * npages, gfp);
        if (!prps) {
                cmd->prp2 = cpu_to_le64(dma_addr);
                *len = (*len - length) + PAGE_SIZE;
                return prps;
        }
-       prp_page = 0;
+
        if (nprps <= (256 / 8)) {
                pool = dev->prp_small_pool;
                prps->npages = 0;
        } else {
                pool = dev->prp_page_pool;
-               prps->npages = npages;
+               prps->npages = 1;
        }
 
        prp_list = dma_pool_alloc(pool, gfp, &prp_dma);
@@ -393,7 +394,7 @@ static struct nvme_prps *nvme_setup_prps(struct nvme_dev *dev,
                kfree(prps);
                return NULL;
        }
-       prps->list[prp_page++] = prp_list;
+       prps->list[0] = prp_list;
        prps->first_dma = prp_dma;
        cmd->prp2 = cpu_to_le64(prp_dma);
        i = 0;
@@ -405,7 +406,7 @@ static struct nvme_prps *nvme_setup_prps(struct nvme_dev *dev,
                                *len = (*len - length);
                                return prps;
                        }
-                       prps->list[prp_page++] = prp_list;
+                       prps->list[prps->npages++] = prp_list;
                        prp_list[0] = old_prp_list[i - 1];
                        old_prp_list[i - 1] = cpu_to_le64(prp_dma);
                        i = 1;
@@ -672,7 +673,7 @@ static irqreturn_t nvme_process_cq(struct nvme_queue *nvmeq)
        if (head == nvmeq->cq_head && phase == nvmeq->cq_phase)
                return IRQ_NONE;
 
-       writel(head, nvmeq->q_db + 1);
+       writel(head, nvmeq->q_db + (1 << nvmeq->dev->db_stride));
        nvmeq->cq_head = head;
        nvmeq->cq_phase = phase;
 
@@ -812,6 +813,34 @@ static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
        return adapter_delete_queue(dev, nvme_admin_delete_sq, sqid);
 }
 
+static int nvme_identify(struct nvme_dev *dev, unsigned nsid, unsigned cns,
+                                                       dma_addr_t dma_addr)
+{
+       struct nvme_command c;
+
+       memset(&c, 0, sizeof(c));
+       c.identify.opcode = nvme_admin_identify;
+       c.identify.nsid = cpu_to_le32(nsid);
+       c.identify.prp1 = cpu_to_le64(dma_addr);
+       c.identify.cns = cpu_to_le32(cns);
+
+       return nvme_submit_admin_cmd(dev, &c, NULL);
+}
+
+static int nvme_get_features(struct nvme_dev *dev, unsigned fid,
+                       unsigned dword11, dma_addr_t dma_addr, u32 *result)
+{
+       struct nvme_command c;
+
+       memset(&c, 0, sizeof(c));
+       c.features.opcode = nvme_admin_get_features;
+       c.features.prp1 = cpu_to_le64(dma_addr);
+       c.features.fid = cpu_to_le32(fid);
+       c.features.dword11 = cpu_to_le32(dword11);
+
+       return nvme_submit_admin_cmd(dev, &c, result);
+}
+
 static void nvme_free_queue(struct nvme_dev *dev, int qid)
 {
        struct nvme_queue *nvmeq = dev->queues[qid];
@@ -861,7 +890,7 @@ static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
        init_waitqueue_head(&nvmeq->sq_full);
        init_waitqueue_entry(&nvmeq->sq_cong_wait, nvme_thread);
        bio_list_init(&nvmeq->sq_cong);
-       nvmeq->q_db = &dev->dbs[qid * 2];
+       nvmeq->q_db = &dev->dbs[qid << (dev->db_stride + 1)];
        nvmeq->q_depth = depth;
        nvmeq->cq_vector = vector;
 
@@ -953,6 +982,7 @@ static int __devinit nvme_configure_admin_queue(struct nvme_dev *dev)
 
        cap = readq(&dev->bar->cap);
        timeout = ((NVME_CAP_TIMEOUT(cap) + 1) * HZ / 2) + jiffies;
+       dev->db_stride = NVME_CAP_STRIDE(cap);
 
        while (!(readl(&dev->bar->csts) & NVME_CSTS_RDY)) {
                msleep(100);
@@ -1318,15 +1348,10 @@ static int set_queue_count(struct nvme_dev *dev, int count)
 {
        int status;
        u32 result;
-       struct nvme_command c;
        u32 q_count = (count - 1) | ((count - 1) << 16);
 
-       memset(&c, 0, sizeof(c));
-       c.features.opcode = nvme_admin_get_features;
-       c.features.fid = cpu_to_le32(NVME_FEAT_NUM_QUEUES);
-       c.features.dword11 = cpu_to_le32(q_count);
-
-       status = nvme_submit_admin_cmd(dev, &c, &result);
+       status = nvme_get_features(dev, NVME_FEAT_NUM_QUEUES, q_count, 0,
+                                                               &result);
        if (status)
                return -EIO;
        return min(result & 0xffff, result >> 16) + 1;
@@ -1334,7 +1359,7 @@ static int set_queue_count(struct nvme_dev *dev, int count)
 
 static int __devinit nvme_setup_io_queues(struct nvme_dev *dev)
 {
-       int result, cpu, i, nr_io_queues;
+       int result, cpu, i, nr_io_queues, db_bar_size;
 
        nr_io_queues = num_online_cpus();
        result = set_queue_count(dev, nr_io_queues);
@@ -1346,6 +1371,15 @@ static int __devinit nvme_setup_io_queues(struct nvme_dev *dev)
        /* Deregister the admin queue's interrupt */
        free_irq(dev->entry[0].vector, dev->queues[0]);
 
+       db_bar_size = 4096 + ((nr_io_queues + 1) << (dev->db_stride + 3));
+       if (db_bar_size > 8192) {
+               iounmap(dev->bar);
+               dev->bar = ioremap(pci_resource_start(dev->pci_dev, 0),
+                                                               db_bar_size);
+               dev->dbs = ((void __iomem *)dev->bar) + 4096;
+               dev->queues[0]->q_db = dev->dbs;
+       }
+
        for (i = 0; i < nr_io_queues; i++)
                dev->entry[i].entry = i;
        for (;;) {
@@ -1400,65 +1434,51 @@ static int __devinit nvme_dev_add(struct nvme_dev *dev)
        int res, nn, i;
        struct nvme_ns *ns, *next;
        struct nvme_id_ctrl *ctrl;
-       void *id;
+       struct nvme_id_ns *id_ns;
+       void *mem;
        dma_addr_t dma_addr;
-       struct nvme_command cid, crt;
 
        res = nvme_setup_io_queues(dev);
        if (res)
                return res;
 
-       /* XXX: Switch to a SG list once prp2 works */
-       id = dma_alloc_coherent(&dev->pci_dev->dev, 8192, &dma_addr,
+       mem = dma_alloc_coherent(&dev->pci_dev->dev, 8192, &dma_addr,
                                                                GFP_KERNEL);
 
-       memset(&cid, 0, sizeof(cid));
-       cid.identify.opcode = nvme_admin_identify;
-       cid.identify.nsid = 0;
-       cid.identify.prp1 = cpu_to_le64(dma_addr);
-       cid.identify.cns = cpu_to_le32(1);
-
-       res = nvme_submit_admin_cmd(dev, &cid, NULL);
+       res = nvme_identify(dev, 0, 1, dma_addr);
        if (res) {
                res = -EIO;
                goto out_free;
        }
 
-       ctrl = id;
+       ctrl = mem;
        nn = le32_to_cpup(&ctrl->nn);
        memcpy(dev->serial, ctrl->sn, sizeof(ctrl->sn));
        memcpy(dev->model, ctrl->mn, sizeof(ctrl->mn));
        memcpy(dev->firmware_rev, ctrl->fr, sizeof(ctrl->fr));
 
-       cid.identify.cns = 0;
-       memset(&crt, 0, sizeof(crt));
-       crt.features.opcode = nvme_admin_get_features;
-       crt.features.prp1 = cpu_to_le64(dma_addr + 4096);
-       crt.features.fid = cpu_to_le32(NVME_FEAT_LBA_RANGE);
-
-       for (i = 0; i <= nn; i++) {
-               cid.identify.nsid = cpu_to_le32(i);
-               res = nvme_submit_admin_cmd(dev, &cid, NULL);
+       id_ns = mem;
+       for (i = 1; i <= nn; i++) {
+               res = nvme_identify(dev, i, 0, dma_addr);
                if (res)
                        continue;
 
-               if (((struct nvme_id_ns *)id)->ncap == 0)
+               if (id_ns->ncap == 0)
                        continue;
 
-               crt.features.nsid = cpu_to_le32(i);
-               res = nvme_submit_admin_cmd(dev, &crt, NULL);
+               res = nvme_get_features(dev, NVME_FEAT_LBA_RANGE, i,
+                                                       dma_addr + 4096, NULL);
                if (res)
                        continue;
 
-               ns = nvme_alloc_ns(dev, i, id, id + 4096);
+               ns = nvme_alloc_ns(dev, i, mem, mem + 4096);
                if (ns)
                        list_add_tail(&ns->list, &dev->namespaces);
        }
        list_for_each_entry(ns, &dev->namespaces, list)
                add_disk(ns->disk);
 
-       dma_free_coherent(&dev->pci_dev->dev, 4096, id, dma_addr);
-       return 0;
+       goto out;
 
  out_free:
        list_for_each_entry_safe(ns, next, &dev->namespaces, list) {
@@ -1466,7 +1486,8 @@ static int __devinit nvme_dev_add(struct nvme_dev *dev)
                nvme_ns_free(ns);
        }
 
-       dma_free_coherent(&dev->pci_dev->dev, 4096, id, dma_addr);
+ out:
+       dma_free_coherent(&dev->pci_dev->dev, 8192, mem, dma_addr);
        return res;
 }
 
@@ -1690,6 +1711,6 @@ static void __exit nvme_exit(void)
 
 MODULE_AUTHOR("Matthew Wilcox <willy@linux.intel.com>");
 MODULE_LICENSE("GPL");
-MODULE_VERSION("0.6");
+MODULE_VERSION("0.7");
 module_init(nvme_init);
 module_exit(nvme_exit);