--- a/drivers/misc/cxl/file.c
+++ b/drivers/misc/cxl/file.c
@@ -173,7 +173,7 @@ static long afu_ioctl_start_work(struct cxl_context *ctx,
* flags are set it's invalid
*/
if (work.reserved1 || work.reserved2 || work.reserved3 ||
- work.reserved4 || work.reserved5 || work.reserved6 ||
+ work.reserved4 || work.reserved5 ||
(work.flags & ~CXL_START_WORK_ALL)) {
rc = -EINVAL;
goto out;
@@ -248,7 +248,19 @@ static long afu_ioctl_start_work(struct cxl_context *ctx,
*/
smp_mb();
- trace_cxl_attach(ctx, work.work_element_descriptor,
work.num_interrupts, amr);
+ /* Assign a unique TIDR (thread id) for the current thread */
+ if (work.flags & CXL_START_WORK_TID) {
+ rc = cxl_context_thread_tidr(ctx);
+ if (rc)
We're already pretty deep and have allocated quite a few resources, we
we'd need to unwind (see error path below when the attach fails).
However, we cannot clear the thread TIDR register, so we need to be
careful that a user process cannot exhaust our limited pool of TIDs by
calling the attach ioctl with bogus arguments. Which should be easy to
do: attach the max number of contexts, and keep calling attach!
So we're going to need to figure out something to prevent that (define a
max allocation per context? with a value of 1 for now?)
diff --git a/include/uapi/misc/cxl.h b/include/uapi/misc/cxl.h
index 49e8fd0..3ea2d4b4 100644
--- a/include/uapi/misc/cxl.h
+++ b/include/uapi/misc/cxl.h
@@ -20,20 +20,22 @@ struct cxl_ioctl_start_work {
__u64 work_element_descriptor;
__u64 amr;
__s16 num_interrupts;
- __s16 reserved1;
- __s32 reserved2;
+ __s16 tid;
Should probably be unsigned.
Fred
+ __s32 reserved1;
+ __u64 reserved2;
__u64 reserved3;
__u64 reserved4;
__u64 reserved5;
- __u64 reserved6;
};
#define CXL_START_WORK_AMR 0x0000000000000001ULL
#define CXL_START_WORK_NUM_IRQS 0x0000000000000002ULL
#define CXL_START_WORK_ERR_FF 0x0000000000000004ULL
+#define CXL_START_WORK_TID 0x0000000000000008ULL
#define CXL_START_WORK_ALL (CXL_START_WORK_AMR |\
CXL_START_WORK_NUM_IRQS |\
- CXL_START_WORK_ERR_FF)
+ CXL_START_WORK_ERR_FF |\
+ CXL_START_WORK_TID)
/* Possible modes that an afu can be in */
