dmaengine: ioat: Support in-use unbind

Don't allocate memory using the devm infrastructure and instead call
kfree with the new dmaengine device_release call back. This ensures
the structures are available until the last reference is dropped.

We also need to ensure we call ioat_shutdown() in ioat_remove() so
that all the channels are quiesced and further transaction fails.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20191216190120.21374-6-logang@deltatee.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/ioat/init.c b/drivers/dma/ioat/init.c
index a6a6dc4..60e9afb 100644 (file)
--- a/drivers/dma/ioat/init.c
+++ b/drivers/dma/ioat/init.c
@@ -556,10 +556,6 @@ static void ioat_dma_remove(struct ioatdma_device *ioat_dma)
        ioat_kobject_del(ioat_dma);
 
        dma_async_device_unregister(dma);
-
-       dma_pool_destroy(ioat_dma->completion_pool);
-
-       INIT_LIST_HEAD(&dma->channels);
 }
 
 /**
@@ -589,7 +585,7 @@ static void ioat_enumerate_channels(struct ioatdma_device *ioat_dma)
        dev_dbg(dev, "%s: xfercap = %d\n", __func__, 1 << xfercap_log);
 
        for (i = 0; i < dma->chancnt; i++) {
-               ioat_chan = devm_kzalloc(dev, sizeof(*ioat_chan), GFP_KERNEL);
+               ioat_chan = kzalloc(sizeof(*ioat_chan), GFP_KERNEL);
                if (!ioat_chan)
                        break;
 
@@ -624,12 +620,16 @@ static void ioat_free_chan_resources(struct dma_chan *c)
                return;
 
        ioat_stop(ioat_chan);
-       ioat_reset_hw(ioat_chan);
 
-       /* Put LTR to idle */
-       if (ioat_dma->version >= IOAT_VER_3_4)
-               writeb(IOAT_CHAN_LTR_SWSEL_IDLE,
-                       ioat_chan->reg_base + IOAT_CHAN_LTR_SWSEL_OFFSET);
+       if (!test_bit(IOAT_CHAN_DOWN, &ioat_chan->state)) {
+               ioat_reset_hw(ioat_chan);
+
+               /* Put LTR to idle */
+               if (ioat_dma->version >= IOAT_VER_3_4)
+                       writeb(IOAT_CHAN_LTR_SWSEL_IDLE,
+                              ioat_chan->reg_base +
+                              IOAT_CHAN_LTR_SWSEL_OFFSET);
+       }
 
        spin_lock_bh(&ioat_chan->cleanup_lock);
        spin_lock_bh(&ioat_chan->prep_lock);
@@ -1322,16 +1322,28 @@ static struct pci_driver ioat_pci_driver = {
        .err_handler    = &ioat_err_handler,
 };
 
+static void release_ioatdma(struct dma_device *device)
+{
+       struct ioatdma_device *d = to_ioatdma_device(device);
+       int i;
+
+       for (i = 0; i < IOAT_MAX_CHANS; i++)
+               kfree(d->idx[i]);
+
+       dma_pool_destroy(d->completion_pool);
+       kfree(d);
+}
+
 static struct ioatdma_device *
 alloc_ioatdma(struct pci_dev *pdev, void __iomem *iobase)
 {
-       struct device *dev = &pdev->dev;
-       struct ioatdma_device *d = devm_kzalloc(dev, sizeof(*d), GFP_KERNEL);
+       struct ioatdma_device *d = kzalloc(sizeof(*d), GFP_KERNEL);
 
        if (!d)
                return NULL;
        d->pdev = pdev;
        d->reg_base = iobase;
+       d->dma_dev.device_release = release_ioatdma;
        return d;
 }
 
@@ -1400,6 +1412,8 @@ static void ioat_remove(struct pci_dev *pdev)
        if (!device)
                return;
 
+       ioat_shutdown(pdev);
+
        dev_err(&pdev->dev, "Removing dma and dca services\n");
        if (device->dca) {
                unregister_dca_provider(device->dca, &pdev->dev);