path: root/include/uapi
diff options
authorVaibhav Jain <vaibhav@linux.vnet.ibm.com>2015-04-29 15:47:23 +0530
committerMichael Ellerman <mpe@ellerman.id.au>2015-06-03 13:27:15 +1000
commit27d4dc7116eed98775902627ba61b70e9045e321 (patch)
tree1fd00dbdc54706726c892cb2fe22e699f2809ce3 /include/uapi
parent989898b707f74716ec27a4ae2b57e404ca54cbd2 (diff)
cxl: Implement an ioctl to fetch afu card-id, offset-id and mode
Given a file descriptor on an afu device, libcxl currently uses the major/minor number obtained from fstat on the fd to construct path to the afu's sysfs directory. However it is possible that rather than using one of the device in /dev/cxl, a kernel driver creates its own device which export generic cxl interface to the userspace. This causes problems with libcxl as it tries to use a wrong major/minor number to construct the sysfs path and fail. So this patch introduces a new ioctl called CXL_IOCTL_GET_AFU_ID on the afu file descriptor to fetch the cxl_afu_id struct that holds the card/offset-id and mode information. These info is then used by libcxl to construct the correct path to the afu sysfs directory. Testing: - Build against pseries be/le configs - Testing with corresponding libcxl changes to verify that it constructs right sysfs path to the afu. Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'include/uapi')
1 files changed, 22 insertions, 0 deletions
diff --git a/include/uapi/misc/cxl.h b/include/uapi/misc/cxl.h
index cd6d789b73ec..99a8ca15fe64 100644
--- a/include/uapi/misc/cxl.h
+++ b/include/uapi/misc/cxl.h
@@ -32,10 +32,32 @@ struct cxl_ioctl_start_work {
+/* Possible modes that an afu can be in */
+#define CXL_MODE_DIRECTED 0x2
+/* possible flags for the cxl_afu_id flags field */
+#define CXL_AFUID_FLAG_SLAVE 0x1 /* In directed-mode afu is in slave mode */
+struct cxl_afu_id {
+ __u64 flags; /* One of CXL_AFUID_FLAG_X */
+ __u32 card_id;
+ __u32 afu_offset;
+ __u32 afu_mode; /* one of the CXL_MODE_X */
+ __u32 reserved1;
+ __u64 reserved2;
+ __u64 reserved3;
+ __u64 reserved4;
+ __u64 reserved5;
+ __u64 reserved6;
/* ioctl numbers */
#define CXL_MAGIC 0xCA
#define CXL_IOCTL_START_WORK _IOW(CXL_MAGIC, 0x00, struct cxl_ioctl_start_work)
+#define CXL_IOCTL_GET_AFU_ID _IOR(CXL_MAGIC, 0x02, struct cxl_afu_id)
#define CXL_READ_MIN_SIZE 0x1000 /* 4K */

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