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Commit fc5d1829 authored by Aaron Sierra's avatar Aaron Sierra Committed by Jon Mason
Browse files

NTB: transport: Try harder to alloc an aligned MW buffer 



Be a little wasteful if the (likely CMA) message window buffer is not
suitably aligned after our first attempt; allocate a buffer twice as big
as we need and manually align our MW buffer within it.

This was needed on Intel Broadwell DE platforms with intel_iommu=off

Signed-off-by: default avatarAaron Sierra <asierra@xes-inc.com>
Reviewed-by: default avatarDave Jiang <dave.jiang@intel.com>
Signed-off-by: default avatarJon Mason <jdmason@kudzu.us>
parent 846429bc

drivers/ntb/ntb_transport.c

+63 −23
Original line number Original line Diff line number Diff line
@@ -194,6 +194,8 @@ struct ntb_transport_mw { 
	void __iomem *vbase;

	void __iomem *vbase;

	size_t xlat_size;

	size_t xlat_size;

	size_t buff_size;

	size_t buff_size;

	size_t alloc_size;

	void *alloc_addr;

	void *virt_addr;

	void *virt_addr;

	dma_addr_t dma_addr;

	dma_addr_t dma_addr;

};

};
@@ -672,13 +674,59 @@ static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw) 
		return;

		return;





	ntb_mw_clear_trans(nt->ndev, PIDX, num_mw);

	ntb_mw_clear_trans(nt->ndev, PIDX, num_mw);

	dma_free_coherent(&pdev->dev, mw->buff_size,

	dma_free_coherent(&pdev->dev, mw->alloc_size,

			  mw->virt_addr, mw->dma_addr);

			  mw->alloc_addr, mw->dma_addr);

	mw->xlat_size = 0;

	mw->xlat_size = 0;

	mw->buff_size = 0;

	mw->buff_size = 0;

	mw->alloc_size = 0;

	mw->alloc_addr = NULL;

	mw->virt_addr = NULL;

	mw->virt_addr = NULL;

}

}





static int ntb_alloc_mw_buffer(struct ntb_transport_mw *mw,

			       struct device *dma_dev, size_t align)

{

	dma_addr_t dma_addr;

	void *alloc_addr, *virt_addr;

	int rc;



	alloc_addr = dma_alloc_coherent(dma_dev, mw->alloc_size,

					&dma_addr, GFP_KERNEL);

	if (!alloc_addr) {

		dev_err(dma_dev, "Unable to alloc MW buff of size %zu\n",

			mw->alloc_size);

		return -ENOMEM;

	}

	virt_addr = alloc_addr;



	/*

	 * we must ensure that the memory address allocated is BAR size

	 * aligned in order for the XLAT register to take the value. This

	 * is a requirement of the hardware. It is recommended to setup CMA

	 * for BAR sizes equal or greater than 4MB.

	 */

	if (!IS_ALIGNED(dma_addr, align)) {

		if (mw->alloc_size > mw->buff_size) {

			virt_addr = PTR_ALIGN(alloc_addr, align);

			dma_addr = ALIGN(dma_addr, align);

		} else {

			rc = -ENOMEM;

			goto err;

		}

	}



	mw->alloc_addr = alloc_addr;

	mw->virt_addr = virt_addr;

	mw->dma_addr = dma_addr;



	return 0;



err:

	dma_free_coherent(dma_dev, mw->alloc_size, alloc_addr, dma_addr);



	return rc;

}



static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,

static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,

		      resource_size_t size)

		      resource_size_t size)

{

{
@@ -710,28 +758,20 @@ static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw, 
	/* Alloc memory for receiving data.  Must be aligned */

	/* Alloc memory for receiving data.  Must be aligned */

	mw->xlat_size = xlat_size;

	mw->xlat_size = xlat_size;

	mw->buff_size = buff_size;

	mw->buff_size = buff_size;

	mw->alloc_size = buff_size;





	mw->virt_addr = dma_alloc_coherent(&pdev->dev, buff_size,

	rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align);

					   &mw->dma_addr, GFP_KERNEL);

	if (rc) {

	if (!mw->virt_addr) {

		mw->alloc_size *= 2;

		rc = ntb_alloc_mw_buffer(mw, &pdev->dev, xlat_align);

		if (rc) {

			dev_err(&pdev->dev,

				"Unable to alloc aligned MW buff\n");

			mw->xlat_size = 0;

			mw->xlat_size = 0;

			mw->buff_size = 0;

			mw->buff_size = 0;

		dev_err(&pdev->dev, "Unable to alloc MW buff of size %zu\n",

			mw->alloc_size = 0;

			buff_size);

			return rc;

		return -ENOMEM;

		}

		}



	/*

	 * we must ensure that the memory address allocated is BAR size

	 * aligned in order for the XLAT register to take the value. This

	 * is a requirement of the hardware. It is recommended to setup CMA

	 * for BAR sizes equal or greater than 4MB.

	 */

	if (!IS_ALIGNED(mw->dma_addr, xlat_align)) {

		dev_err(&pdev->dev, "DMA memory %pad is not aligned\n",

			&mw->dma_addr);

		ntb_free_mw(nt, num_mw);

		return -ENOMEM;

	}

	}





	/* Notify HW the memory location of the receive buffer */

	/* Notify HW the memory location of the receive buffer */