Commit d7a21537 authored by Dave Jiang's avatar Dave Jiang Committed by Dan Williams
Browse files

cxl/hdm: Add emulation when HDM decoders are not committed 



For the case where DVSEC range register(s) are active and HDM decoders are
not committed, use RR to provide emulation. A first pass is done to note
whether any decoders are committed. If there are no committed endpoint
decoders, then DVSEC ranges will be used for emulation.

Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarDave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/167640369536.935665.611974113442400127.stgit@dwillia2-xfh.jf.intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 4474ce56

drivers/cxl/core/hdm.c

+29 −0
Original line number Diff line number Diff line
@@ -730,6 +730,32 @@ static int cxl_setup_hdm_decoder_from_dvsec(struct cxl_port *port, 
	return 0;

}



static bool should_emulate_decoders(struct cxl_port *port)

{

	struct cxl_hdm *cxlhdm = dev_get_drvdata(&port->dev);

	void __iomem *hdm = cxlhdm->regs.hdm_decoder;

	u32 ctrl;

	int i;



	if (!is_cxl_endpoint(cxlhdm->port))

		return false;



	if (!hdm)

		return true;



	/*

	 * If any decoders are committed already, there should not be any

	 * emulated DVSEC decoders.

	 */

	for (i = 0; i < cxlhdm->decoder_count; i++) {

		ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(i));

		if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl))

			return false;

	}



	return true;

}



static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,

			    int *target_map, void __iomem *hdm, int which,

			    u64 *dpa_base, struct cxl_endpoint_dvsec_info *info)
@@ -745,6 +771,9 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld, 
		unsigned char target_id[8];

	} target_list;



	if (should_emulate_decoders(port))

		return cxl_setup_hdm_decoder_from_dvsec(port, cxld, which, info);



	if (is_endpoint_decoder(&cxld->dev))

		cxled = to_cxl_endpoint_decoder(&cxld->dev);