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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
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>
-rw-r--r--drivers/misc/cxl/cxl.h2
-rw-r--r--drivers/misc/cxl/file.c22
-rw-r--r--include/uapi/misc/cxl.h22
3 files changed, 44 insertions, 2 deletions
diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h
index a1cee4767ec6..9f280e3e742e 100644
--- a/drivers/misc/cxl/cxl.h
+++ b/drivers/misc/cxl/cxl.h
@@ -315,8 +315,6 @@ static const cxl_p2n_reg_t CXL_PSL_WED_An = {0x0A0};
#define CXL_MAX_SLICES 4
#define MAX_AFU_MMIO_REGS 3
-#define CXL_MODE_DEDICATED 0x1
-#define CXL_MODE_DIRECTED 0x2
#define CXL_MODE_TIME_SLICED 0x4
#define CXL_SUPPORTED_MODES (CXL_MODE_DEDICATED | CXL_MODE_DIRECTED)
diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c
index 2364bcadb9a9..985523443829 100644
--- a/drivers/misc/cxl/file.c
+++ b/drivers/misc/cxl/file.c
@@ -212,6 +212,25 @@ static long afu_ioctl_process_element(struct cxl_context *ctx,
return 0;
}
+static long afu_ioctl_get_afu_id(struct cxl_context *ctx,
+ struct cxl_afu_id __user *upafuid)
+{
+ struct cxl_afu_id afuid = { 0 };
+
+ afuid.card_id = ctx->afu->adapter->adapter_num;
+ afuid.afu_offset = ctx->afu->slice;
+ afuid.afu_mode = ctx->afu->current_mode;
+
+ /* set the flag bit in case the afu is a slave */
+ if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master)
+ afuid.flags |= CXL_AFUID_FLAG_SLAVE;
+
+ if (copy_to_user(upafuid, &afuid, sizeof(afuid)))
+ return -EFAULT;
+
+ return 0;
+}
+
static long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct cxl_context *ctx = file->private_data;
@@ -225,6 +244,9 @@ static long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg);
case CXL_IOCTL_GET_PROCESS_ELEMENT:
return afu_ioctl_process_element(ctx, (__u32 __user *)arg);
+ case CXL_IOCTL_GET_AFU_ID:
+ return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *)
+ arg);
}
return -EINVAL;
}
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 {
#define CXL_START_WORK_ALL (CXL_START_WORK_AMR |\
CXL_START_WORK_NUM_IRQS)
+
+/* Possible modes that an afu can be in */
+#define CXL_MODE_DEDICATED 0x1
+#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_PROCESS_ELEMENT _IOR(CXL_MAGIC, 0x01, __u32)
+#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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