Commit 487d828d authored by Ira Weiny's avatar Ira Weiny Committed by Dan Williams
Browse files

cxl/doe: Request exclusive DOE access 



The PCIE Data Object Exchange (DOE) mailbox is a protocol run over
configuration cycles.  It assumes one initiator at a time.  While the
kernel has control of the mailbox user space writes could interfere with
the kernel access.

Mark DOE mailbox config space exclusive when iterated by the CXL driver.

Signed-off-by: default avatarIra Weiny <ira.weiny@intel.com>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20220926215711.2893286-3-ira.weiny@intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 27829479

drivers/cxl/pci.c

+5 −0
Original line number Original line Diff line number Diff line
@@ -418,6 +418,11 @@ static void devm_cxl_pci_create_doe(struct cxl_dev_state *cxlds) 
			continue;

			continue;

		}

		}





		if (!pci_request_config_region_exclusive(pdev, off,

							 PCI_DOE_CAP_SIZEOF,

							 dev_name(dev)))

			pci_err(pdev, "Failed to exclude DOE registers\n");



		if (xa_insert(&cxlds->doe_mbs, off, doe_mb, GFP_KERNEL)) {

		if (xa_insert(&cxlds->doe_mbs, off, doe_mb, GFP_KERNEL)) {

			dev_err(dev, "xa_insert failed to insert MB @ %x\n",

			dev_err(dev, "xa_insert failed to insert MB @ %x\n",

				off);

				off);

include/uapi/linux/pci_regs.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -1119,6 +1119,7 @@ 
#define  PCI_DOE_STATUS_DATA_OBJECT_READY	0x80000000  /* Data Object Ready */

#define  PCI_DOE_STATUS_DATA_OBJECT_READY	0x80000000  /* Data Object Ready */

#define PCI_DOE_WRITE		0x10    /* DOE Write Data Mailbox Register */

#define PCI_DOE_WRITE		0x10    /* DOE Write Data Mailbox Register */

#define PCI_DOE_READ		0x14    /* DOE Read Data Mailbox Register */

#define PCI_DOE_READ		0x14    /* DOE Read Data Mailbox Register */

#define PCI_DOE_CAP_SIZEOF	0x18	/* Size of DOE register block */





/* DOE Data Object - note not actually registers */

/* DOE Data Object - note not actually registers */

#define PCI_DOE_DATA_OBJECT_HEADER_1_VID		0x0000ffff

#define PCI_DOE_DATA_OBJECT_HEADER_1_VID		0x0000ffff