mtip32xx: add trim support

TRIM support added through vendor unique command.

Signed-off-by: Sam Bradshaw < sbradshaw@micron.com>
Signed-off-by: Asai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 96 insertions, 0 deletions

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 99c2cf461be3..b7579b76b4a1 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -1519,6 +1519,12 @@ static int mtip_get_identify(struct mtip_port *port, void __user *user_buffer)
         }
 #endif
 
+        /* Demux ID.DRAT & ID.RZAT to determine trim support */
+        if (port->identify[69] & (1 << 14) && port->identify[69] & (1 << 5))
+                port->dd->trim_supp = true;
+        else
+                port->dd->trim_supp = false;
+
         /* Set the identify buffer as valid. */
         port->identify_valid = 1;
 
@@ -1706,6 +1712,81 @@ static int mtip_get_smart_attr(struct mtip_port *port, unsigned int id,
 }
 
 /*
+ * Trim unused sectors
+ *
+ * @dd          pointer to driver_data structure
+ * @lba         starting lba
+ * @len         # of 512b sectors to trim
+ *
+ * return value
+ *      -ENOMEM         Out of dma memory
+ *      -EINVAL         Invalid parameters passed in, trim not supported
+ *      -EIO            Error submitting trim request to hw
+ */
+int mtip_send_trim(struct driver_data *dd, unsigned int lba, unsigned int len)
+{
+        int i, rv = 0;
+        u64 tlba, tlen, sect_left;
+        struct mtip_trim_entry *buf;
+        dma_addr_t dma_addr;
+        struct host_to_dev_fis fis;
+
+        if (!len || dd->trim_supp == false)
+                return -EINVAL;
+
+        /* Trim request too big */
+        WARN_ON(len > (MTIP_MAX_TRIM_ENTRY_LEN * MTIP_MAX_TRIM_ENTRIES));
+
+        /* Trim request not aligned on 4k boundary */
+        WARN_ON(len % 8 != 0);
+
+        /* Warn if vu_trim structure is too big */
+        WARN_ON(sizeof(struct mtip_trim) > ATA_SECT_SIZE);
+
+        /* Allocate a DMA buffer for the trim structure */
+        buf = dmam_alloc_coherent(&dd->pdev->dev, ATA_SECT_SIZE, &dma_addr,
+                                                                GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+        memset(buf, 0, ATA_SECT_SIZE);
+
+        for (i = 0, sect_left = len, tlba = lba;
+                        i < MTIP_MAX_TRIM_ENTRIES && sect_left;
+                        i++) {
+                tlen = (sect_left >= MTIP_MAX_TRIM_ENTRY_LEN ?
+                                        MTIP_MAX_TRIM_ENTRY_LEN :
+                                        sect_left);
+                buf[i].lba = __force_bit2int cpu_to_le32(tlba);
+                buf[i].range = __force_bit2int cpu_to_le16(tlen);
+                tlba += tlen;
+                sect_left -= tlen;
+        }
+        WARN_ON(sect_left != 0);
+
+        /* Build the fis */
+        memset(&fis, 0, sizeof(struct host_to_dev_fis));
+        fis.type       = 0x27;
+        fis.opts       = 1 << 7;
+        fis.command    = 0xfb;
+        fis.features   = 0x60;
+        fis.sect_count = 1;
+        fis.device     = ATA_DEVICE_OBS;
+
+        if (mtip_exec_internal_command(dd->port,
+                                        &fis,
+                                        5,
+                                        dma_addr,
+                                        ATA_SECT_SIZE,
+                                        0,
+                                        GFP_KERNEL,
+                                        MTIP_TRIM_TIMEOUT_MS) < 0)
+                rv = -EIO;
+
+        dmam_free_coherent(&dd->pdev->dev, ATA_SECT_SIZE, buf, dma_addr);
+        return rv;
+}
+
+/*
  * Get the drive capacity.
  *
  * @dd      Pointer to the device data structure.
@@ -3675,6 +3756,12 @@ static void mtip_make_request(struct request_queue *queue, struct bio *bio)
                 }
         }
 
+        if (unlikely(bio->bi_rw & REQ_DISCARD)) {
+                bio_endio(bio, mtip_send_trim(dd, bio->bi_sector,
+                                                bio_sectors(bio)));
+                return;
+        }
+
         if (unlikely(!bio_has_data(bio))) {
                 blk_queue_flush(queue, 0);
                 bio_endio(bio, 0);
@@ -3817,6 +3904,15 @@ skip_create_disk:
          */
         blk_queue_flush(dd->queue, 0);
 
+        /* Signal trim support */
+        if (dd->trim_supp == true) {
+                set_bit(QUEUE_FLAG_DISCARD, &dd->queue->queue_flags);
+                dd->queue->limits.discard_granularity = 4096;
+                blk_queue_max_discard_sectors(dd->queue,
+                        MTIP_MAX_TRIM_ENTRY_LEN * MTIP_MAX_TRIM_ENTRIES);
+                dd->queue->limits.discard_zeroes_data = 0;
+        }
+
         /* Set the capacity of the device in 512 byte sectors. */
         if (!(mtip_hw_get_capacity(dd, &capacity))) {
                 dev_warn(&dd->pdev->dev,