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cxl/hdm: Extend DVSEC range register emulation for region enumeration

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One motivation for mapping range registers to decoder objects is
to use those settings for region autodiscovery.

The need to map a region for devices programmed to use range registers
is especially urgent now that the kernel no longer routes "Soft
Reserved" ranges in the memory map to device-dax by default. The CXL
memory range loses all access mechanisms.

Complete the implementation by marking the DPA reservation and setting
the endpoint-decoder state to signal autodiscovery. Note that the
default settings of ways=1 and granularity=4096 set in cxl_decode_init()
do not need to be updated.

Fixes: 09d09e04d2 ("cxl/dax: Create dax devices for CXL RAM regions")
Tested-by: Dave Jiang <dave.jiang@intel.com>
Tested-by: Gregory Price <gregory.price@memverge.com>
Link: https://lore.kernel.org/r/168012575521.221280.14177293493678527326.stgit@dwillia2-xfh.jf.intel.com
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams 2023-04-03 16:01:32 -07:00
parent 52cc48ad2a
commit 24b1819718
1 changed files with 22 additions and 5 deletions
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27
drivers/cxl/core/hdm.c
View file

@ -738,14 +738,20 @@ static int cxl_decoder_reset(struct cxl_decoder *cxld)
return 0;
}
static int cxl_setup_hdm_decoder_from_dvsec(struct cxl_port *port,
struct cxl_decoder *cxld, int which,
struct cxl_endpoint_dvsec_info *info)
static int cxl_setup_hdm_decoder_from_dvsec(
struct cxl_port *port, struct cxl_decoder *cxld, u64 *dpa_base,
int which, struct cxl_endpoint_dvsec_info *info)
{
struct cxl_endpoint_decoder *cxled;
u64 len;
int rc;
if (!is_cxl_endpoint(port))
return -EOPNOTSUPP;
if (!range_len(&info->dvsec_range[which]))
cxled = to_cxl_endpoint_decoder(&cxld->dev);
len = range_len(&info->dvsec_range[which]);
if (!len)
return -ENOENT;
cxld->target_type = CXL_DECODER_EXPANDER;
@ -760,6 +766,16 @@ static int cxl_setup_hdm_decoder_from_dvsec(struct cxl_port *port,
cxld->flags |= CXL_DECODER_F_ENABLE | CXL_DECODER_F_LOCK;
port->commit_end = cxld->id;
rc = devm_cxl_dpa_reserve(cxled, *dpa_base, len, 0);
if (rc) {
dev_err(&port->dev,
"decoder%d.%d: Failed to reserve DPA range %#llx - %#llx\n (%d)",
port->id, cxld->id, *dpa_base, *dpa_base + len - 1, rc);
return rc;
}
*dpa_base += len;
cxled->state = CXL_DECODER_STATE_AUTO;
return 0;
}
@ -779,7 +795,8 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
} target_list;
if (should_emulate_decoders(info))
return cxl_setup_hdm_decoder_from_dvsec(port, cxld, which, info);
return cxl_setup_hdm_decoder_from_dvsec(port, cxld, dpa_base,
which, info);
ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(which));
base = ioread64_hi_lo(hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(which));