Commit 9e23897b authored by Jarkko Nikula's avatar Jarkko Nikula Committed by Alexandre Belloni
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i3c: mipi-i3c-hci: Use physical device pointer with DMA API 



DMA transfer faults on Intel hardware when the IOMMU is enabled and
driver initialization will fail when attempting to do the first transfer:

	DMAR: DRHD: handling fault status reg 2
	DMAR: [DMA Read NO_PASID] Request device [00:11.0] fault addr 0x676e3000 [fault reason 0x71] SM: Present bit in first-level paging entry is clear
 	i3c mipi-i3c-hci.0: ring 0: Transfer Aborted
	mipi-i3c-hci mipi-i3c-hci.0: probe with driver mipi-i3c-hci failed with error -62

Reason for this is that the IOMMU setup is done for the physical devices
only and not for the virtual I3C Controller device object.

Therefore use the pointer to a physical device object with the DMA API.

Due to a data corruption observation when the device DMA is IOMMU
mapped, a properly sized receive bounce buffer is required if transfer
length is not a multiple of DWORDs.

Reported-by:
Signed-off-by: default avatarJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: default avatarFrank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250822105630.2820009-4-jarkko.nikula@linux.intel.com


Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent 1c46bfc4

drivers/i3c/master/mipi-i3c-hci/dma.c

+33 −13
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/errno.h>

#include <linux/i3c/master.h>

#include <linux/io.h>

#include <linux/pci.h>



#include "hci.h"

#include "cmd.h"
@@ -138,6 +139,7 @@ struct hci_rh_data { 
};



struct hci_rings_data {

	struct device *sysdev;

	unsigned int total;

	struct hci_rh_data headers[] __counted_by(total);

};
@@ -165,20 +167,20 @@ static void hci_dma_cleanup(struct i3c_hci *hci) 
		rh_reg_write(IBI_SETUP, 0);



		if (rh->xfer)

			dma_free_coherent(&hci->master.dev,

			dma_free_coherent(rings->sysdev,

					  rh->xfer_struct_sz * rh->xfer_entries,

					  rh->xfer, rh->xfer_dma);

		if (rh->resp)

			dma_free_coherent(&hci->master.dev,

			dma_free_coherent(rings->sysdev,

					  rh->resp_struct_sz * rh->xfer_entries,

					  rh->resp, rh->resp_dma);

		kfree(rh->src_xfers);

		if (rh->ibi_status)

			dma_free_coherent(&hci->master.dev,

			dma_free_coherent(rings->sysdev,

					  rh->ibi_status_sz * rh->ibi_status_entries,

					  rh->ibi_status, rh->ibi_status_dma);

		if (rh->ibi_data_dma)

			dma_unmap_single(&hci->master.dev, rh->ibi_data_dma,

			dma_unmap_single(rings->sysdev, rh->ibi_data_dma,

					 rh->ibi_chunk_sz * rh->ibi_chunks_total,

					 DMA_FROM_DEVICE);

		kfree(rh->ibi_data);
@@ -194,11 +196,23 @@ static int hci_dma_init(struct i3c_hci *hci) 
{

	struct hci_rings_data *rings;

	struct hci_rh_data *rh;

	struct device *sysdev;

	u32 regval;

	unsigned int i, nr_rings, xfers_sz, resps_sz;

	unsigned int ibi_status_ring_sz, ibi_data_ring_sz;

	int ret;



	/*

	 * Set pointer to a physical device that does DMA and has IOMMU setup

	 * done for it in case of enabled IOMMU and use it with the DMA API.

	 * Here such device is either

	 * "mipi-i3c-hci" platform device (OF/ACPI enumeration) parent or

	 * grandparent (PCI enumeration).

	 */

	sysdev = hci->master.dev.parent;

	if (sysdev->parent && dev_is_pci(sysdev->parent))

		sysdev = sysdev->parent;



	regval = rhs_reg_read(CONTROL);

	nr_rings = FIELD_GET(MAX_HEADER_COUNT_CAP, regval);

	dev_info(&hci->master.dev, "%d DMA rings available\n", nr_rings);
@@ -213,6 +227,7 @@ static int hci_dma_init(struct i3c_hci *hci) 
		return -ENOMEM;

	hci->io_data = rings;

	rings->total = nr_rings;

	rings->sysdev = sysdev;



	regval = FIELD_PREP(MAX_HEADER_COUNT, rings->total);

	rhs_reg_write(CONTROL, regval);
@@ -239,9 +254,9 @@ static int hci_dma_init(struct i3c_hci *hci) 
		xfers_sz = rh->xfer_struct_sz * rh->xfer_entries;

		resps_sz = rh->resp_struct_sz * rh->xfer_entries;



		rh->xfer = dma_alloc_coherent(&hci->master.dev, xfers_sz,

		rh->xfer = dma_alloc_coherent(rings->sysdev, xfers_sz,

					      &rh->xfer_dma, GFP_KERNEL);

		rh->resp = dma_alloc_coherent(&hci->master.dev, resps_sz,

		rh->resp = dma_alloc_coherent(rings->sysdev, resps_sz,

					      &rh->resp_dma, GFP_KERNEL);

		rh->src_xfers =

			kmalloc_array(rh->xfer_entries, sizeof(*rh->src_xfers),
@@ -295,16 +310,16 @@ static int hci_dma_init(struct i3c_hci *hci) 
		ibi_data_ring_sz = rh->ibi_chunk_sz * rh->ibi_chunks_total;



		rh->ibi_status =

			dma_alloc_coherent(&hci->master.dev, ibi_status_ring_sz,

			dma_alloc_coherent(rings->sysdev, ibi_status_ring_sz,

					   &rh->ibi_status_dma, GFP_KERNEL);

		rh->ibi_data = kmalloc(ibi_data_ring_sz, GFP_KERNEL);

		ret = -ENOMEM;

		if (!rh->ibi_status || !rh->ibi_data)

			goto err_out;

		rh->ibi_data_dma =

			dma_map_single(&hci->master.dev, rh->ibi_data,

			dma_map_single(rings->sysdev, rh->ibi_data,

				       ibi_data_ring_sz, DMA_FROM_DEVICE);

		if (dma_mapping_error(&hci->master.dev, rh->ibi_data_dma)) {

		if (dma_mapping_error(rings->sysdev, rh->ibi_data_dma)) {

			rh->ibi_data_dma = 0;

			ret = -ENOMEM;

			goto err_out;
@@ -372,6 +387,7 @@ static int hci_dma_queue_xfer(struct i3c_hci *hci, 
		u32 *ring_data = rh->xfer + rh->xfer_struct_sz * enqueue_ptr;

		enum dma_data_direction dir = xfer->rnw ? DMA_FROM_DEVICE :

							  DMA_TO_DEVICE;

		bool need_bounce;



		/* store cmd descriptor */

		*ring_data++ = xfer->cmd_desc[0];
@@ -390,10 +406,13 @@ static int hci_dma_queue_xfer(struct i3c_hci *hci, 


		/* 2nd and 3rd words of Data Buffer Descriptor Structure */

		if (xfer->data) {

			xfer->dma = i3c_master_dma_map_single(&hci->master.dev,

			need_bounce = device_iommu_mapped(rings->sysdev) &&

				      xfer->rnw &&

				      xfer->data_len != ALIGN(xfer->data_len, 4);

			xfer->dma = i3c_master_dma_map_single(rings->sysdev,

							      xfer->data,

							      xfer->data_len,

							      false,

							      need_bounce,

							      dir);

			if (!xfer->dma) {

				hci_dma_unmap_xfer(hci, xfer_list, i);
@@ -581,6 +600,7 @@ static void hci_dma_recycle_ibi_slot(struct i3c_hci *hci, 


static void hci_dma_process_ibi(struct i3c_hci *hci, struct hci_rh_data *rh)

{

	struct hci_rings_data *rings = hci->io_data;

	struct i3c_dev_desc *dev;

	struct i3c_hci_dev_data *dev_data;

	struct hci_dma_dev_ibi_data *dev_ibi;
@@ -691,7 +711,7 @@ static void hci_dma_process_ibi(struct i3c_hci *hci, struct hci_rh_data *rh) 
			* rh->ibi_chunk_sz;

	if (first_part > ibi_size)

		first_part = ibi_size;

	dma_sync_single_for_cpu(&hci->master.dev, ring_ibi_data_dma,

	dma_sync_single_for_cpu(rings->sysdev, ring_ibi_data_dma,

				first_part, DMA_FROM_DEVICE);

	memcpy(slot->data, ring_ibi_data, first_part);
@@ -700,7 +720,7 @@ static void hci_dma_process_ibi(struct i3c_hci *hci, struct hci_rh_data *rh) 
		/* we wrap back to the start and copy remaining data */

		ring_ibi_data = rh->ibi_data;

		ring_ibi_data_dma = rh->ibi_data_dma;

		dma_sync_single_for_cpu(&hci->master.dev, ring_ibi_data_dma,

		dma_sync_single_for_cpu(rings->sysdev, ring_ibi_data_dma,

					ibi_size - first_part, DMA_FROM_DEVICE);

		memcpy(slot->data + first_part, ring_ibi_data,

		       ibi_size - first_part);