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authorIra Weiny <[email protected]>2022-09-26 14:57:11 -0700
committerDan Williams <[email protected]>2022-11-14 10:07:22 -0800
commit487d828d751d90cf9ca594f45b02dd0e0d712b64 (patch)
treefb83694896b6a27fa0fc2448a6044e041b470269
parent278294798ac9118412c9624a801d3f20f2279363 (diff)
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: Ira Weiny <[email protected]> Reviewed-by: Jonathan Cameron <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Dan Williams <[email protected]>
-rw-r--r--drivers/cxl/pci.c5
-rw-r--r--include/uapi/linux/pci_regs.h1
2 files changed, 6 insertions, 0 deletions
diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index faeb5d9d7a7a..621a0522b554 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -418,6 +418,11 @@ static void devm_cxl_pci_create_doe(struct cxl_dev_state *cxlds)
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)) {
dev_err(dev, "xa_insert failed to insert MB @ %x\n",
off);
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index 57b8e2ffb1dd..82a03ea954af 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -1119,6 +1119,7 @@
#define PCI_DOE_STATUS_DATA_OBJECT_READY 0x80000000 /* Data Object Ready */
#define PCI_DOE_WRITE 0x10 /* DOE Write 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 */
#define PCI_DOE_DATA_OBJECT_HEADER_1_VID 0x0000ffff