Commit 7004cc9d authored by Dan Williams's avatar Dan Williams
Browse files

cxl/core/port: Handle invalid decoders 



In case init_hdm_decoder() finds invalid settings, skip to the next
valid decoder. Only fail port enumeration if zero valid decoders are
found. This protects the driver init against broken hardware and / or
future interleave capabilities.

Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/164317464918.3438644.12371149695618136198.stgit@dwillia2-desk3.amr.corp.intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 0909b4e5

drivers/cxl/core/hdm.c

+30 −6
Original line number Diff line number Diff line
@@ -149,8 +149,8 @@ static int to_interleave_ways(u32 ctrl) 
	}

}



static void init_hdm_decoder(struct cxl_decoder *cxld, int *target_map,

			     void __iomem *hdm, int which)

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

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

{

	u64 size, base;

	u32 ctrl;
@@ -166,6 +166,11 @@ static void init_hdm_decoder(struct cxl_decoder *cxld, int *target_map, 


	if (!(ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED))

		size = 0;

	if (base == U64_MAX || size == U64_MAX) {

		dev_warn(&port->dev, "decoder%d.%d: Invalid resource range\n",

			 port->id, cxld->id);

		return -ENXIO;

	}



	cxld->decoder_range = (struct range) {

		.start = base,
@@ -179,6 +184,12 @@ static void init_hdm_decoder(struct cxl_decoder *cxld, int *target_map, 
			cxld->flags |= CXL_DECODER_F_LOCK;

	}

	cxld->interleave_ways = to_interleave_ways(ctrl);

	if (!cxld->interleave_ways) {

		dev_warn(&port->dev,

			 "decoder%d.%d: Invalid interleave ways (ctrl: %#x)\n",

			 port->id, cxld->id, ctrl);

		return -ENXIO;

	}

	cxld->interleave_granularity = to_interleave_granularity(ctrl);



	if (FIELD_GET(CXL_HDM_DECODER0_CTRL_TYPE, ctrl))
@@ -187,12 +198,14 @@ static void init_hdm_decoder(struct cxl_decoder *cxld, int *target_map, 
		cxld->target_type = CXL_DECODER_ACCELERATOR;



	if (is_cxl_endpoint(to_cxl_port(cxld->dev.parent)))

		return;

		return 0;



	target_list.value =

		ioread64_hi_lo(hdm + CXL_HDM_DECODER0_TL_LOW(which));

	for (i = 0; i < cxld->interleave_ways; i++)

		target_map[i] = target_list.target_id[i];



	return 0;

}



/**
@@ -203,7 +216,7 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm) 
{

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

	struct cxl_port *port = cxlhdm->port;

	int i, committed;

	int i, committed, failed;

	u32 ctrl;



	/*
@@ -223,7 +236,7 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm) 
	if (committed != cxlhdm->decoder_count)

		msleep(20);



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

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

		int target_map[CXL_DECODER_MAX_INTERLEAVE] = { 0 };

		int rc, target_count = cxlhdm->target_count;

		struct cxl_decoder *cxld;
@@ -238,7 +251,13 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm) 
			return PTR_ERR(cxld);

		}



		init_hdm_decoder(cxld, target_map, cxlhdm->regs.hdm_decoder, i);

		rc = init_hdm_decoder(port, cxld, target_map,

				      cxlhdm->regs.hdm_decoder, i);

		if (rc) {

			put_device(&cxld->dev);

			failed++;

			continue;

		}

		rc = add_hdm_decoder(port, cxld, target_map);

		if (rc) {

			dev_warn(&port->dev,
@@ -247,6 +266,11 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm) 
		}

	}



	if (failed == cxlhdm->decoder_count) {

		dev_err(&port->dev, "No valid decoders found\n");

		return -ENXIO;

	}



	return 0;

}

EXPORT_SYMBOL_NS_GPL(devm_cxl_enumerate_decoders, CXL);