Revert "cxl: Add kernel API to allow a context to operate with relocate disabled"

Remove abandonned capi support for the Mellanox CX4.
The symbol 'cxl_set_translation_mode' is never called, so
ctx->real_mode is always false.

This reverts commit 7a0d85d3.
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

drivers/misc/cxl/api.c

@@ -324,7 +324,6 @@ int cxl_start_context(struct cxl_context *ctx, u64 wed,
 	if (task) {
 		ctx->pid = get_task_pid(task, PIDTYPE_PID);
 		kernel = false;
-		ctx->real_mode = false;
 
 		/* acquire a reference to the task's mm */
 		ctx->mm = get_task_mm(current);
@@ -388,24 +387,6 @@ void cxl_set_master(struct cxl_context *ctx)
 }
 EXPORT_SYMBOL_GPL(cxl_set_master);
 
-int cxl_set_translation_mode(struct cxl_context *ctx, bool real_mode)
-{
-	if (ctx->status == STARTED) {
-		/*
-		 * We could potentially update the PE and issue an update LLCMD
-		 * to support this, but it doesn't seem to have a good use case
-		 * since it's trivial to just create a second kernel context
-		 * with different translation modes, so until someone convinces
-		 * me otherwise:
-		 */
-		return -EBUSY;
-	}
-
-	ctx->real_mode = real_mode;
-	return 0;
-}
-EXPORT_SYMBOL_GPL(cxl_set_translation_mode);
-
 /* wrappers around afu_* file ops which are EXPORTED */
 int cxl_fd_open(struct inode *inode, struct file *file)
 {

drivers/misc/cxl/cxl.h

@@ -613,7 +613,6 @@ struct cxl_context {
 	bool pe_inserted;
 	bool master;
 	bool kernel;
-	bool real_mode;
 	bool pending_irq;
 	bool pending_fault;
 	bool pending_afu_err;

drivers/misc/cxl/guest.c

@@ -623,9 +623,6 @@ static int guest_attach_process(struct cxl_context *ctx, bool kernel, u64 wed, u
 {
 	pr_devel("in %s\n", __func__);
 
-	if (ctx->real_mode)
-		return -EPERM;
-
 	ctx->kernel = kernel;
 	if (ctx->afu->current_mode == CXL_MODE_DIRECTED)
 		return attach_afu_directed(ctx, wed, amr);

drivers/misc/cxl/native.c

@@ -605,6 +605,7 @@ u64 cxl_calculate_sr(bool master, bool kernel, bool real_mode, bool p9)
 		sr |= CXL_PSL_SR_An_MP;
 	if (mfspr(SPRN_LPCR) & LPCR_TC)
 		sr |= CXL_PSL_SR_An_TC;
+
 	if (kernel) {
 		if (!real_mode)
 			sr |= CXL_PSL_SR_An_R;
@@ -629,7 +630,7 @@ u64 cxl_calculate_sr(bool master, bool kernel, bool real_mode, bool p9)
 
 static u64 calculate_sr(struct cxl_context *ctx)
 {
-	return cxl_calculate_sr(ctx->master, ctx->kernel, ctx->real_mode,
+	return cxl_calculate_sr(ctx->master, ctx->kernel, false,
 				cxl_is_power9());
 }
 

include/misc/cxl.h

@@ -173,14 +173,6 @@ int cxl_afu_reset(struct cxl_context *ctx);
  */
 void cxl_set_master(struct cxl_context *ctx);
 
-/*
- * Sets the context to use real mode memory accesses to operate with
- * translation disabled. Note that this only makes sense for kernel contexts
- * under bare metal, and will not work with virtualisation. May only be
- * performed on stopped contexts.
- */
-int cxl_set_translation_mode(struct cxl_context *ctx, bool real_mode);
-
 /*
  * Map and unmap the AFU Problem Space area. The amount and location mapped
  * depends on if this context is a master or slave.