cxl/mbox: Convert 'enabled_cmds' to DECLARE_BITMAP

Define enabled_cmds as an embedded member of 'struct cxl_mem' rather
than a pointer to another dynamic allocation.

As this leaves only one user of cxl_cmd_count, just open code it and
delete the helper.

Acked-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/163116436415.2460985.10101824045493194813.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/cxl/core/mbox.c

@@ -315,8 +315,6 @@ static int cxl_validate_cmd_from_user(struct cxl_mem *cxlm,
 	return 0;
 }
 
-#define cxl_cmd_count ARRAY_SIZE(cxl_mem_commands)
-
 int cxl_query_cmd(struct cxl_memdev *cxlmd,
 		  struct cxl_mem_query_commands __user *q)
 {
@@ -332,7 +330,7 @@ int cxl_query_cmd(struct cxl_memdev *cxlmd,
 
 	/* returns the total number if 0 elements are requested. */
 	if (n_commands == 0)
-		return put_user(cxl_cmd_count, &q->n_commands);
+		return put_user(ARRAY_SIZE(cxl_mem_commands), &q->n_commands);
 
 	/*
 	 * otherwise, return max(n_commands, total commands) cxl_command_info
@@ -794,14 +792,6 @@ struct cxl_mem *cxl_mem_create(struct device *dev)
 
 	mutex_init(&cxlm->mbox_mutex);
 	cxlm->dev = dev;
-	cxlm->enabled_cmds =
-		devm_kmalloc_array(dev, BITS_TO_LONGS(cxl_cmd_count),
-				   sizeof(unsigned long),
-				   GFP_KERNEL | __GFP_ZERO);
-	if (!cxlm->enabled_cmds) {
-		dev_err(dev, "No memory available for bitmap\n");
-		return ERR_PTR(-ENOMEM);
-	}
 
 	return cxlm;
 }

drivers/cxl/cxlmem.h

@@ -126,7 +126,7 @@ struct cxl_mem {
 	size_t lsa_size;
 	struct mutex mbox_mutex; /* Protects device mailbox and firmware */
 	char firmware_version[0x10];
-	unsigned long *enabled_cmds;
+	DECLARE_BITMAP(enabled_cmds, CXL_MEM_COMMAND_ID_MAX);
 
 	struct range pmem_range;
 	struct range ram_range;