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author | 2023-04-03 15:13:37 -0700 | |
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committer | 2023-04-04 15:34:34 -0700 | |
commit | 52cc48ad2a76a5fe82d239044d67944bbb928de6 (patch) | |
tree | c7c925152ca0ccad9682a25ad07bf973bc91df20 /drivers/cxl | |
parent | cxl/region: Move coherence tracking into cxl_region_attach() (diff) | |
download | linux-52cc48ad2a76a5fe82d239044d67944bbb928de6.tar.gz linux-52cc48ad2a76a5fe82d239044d67944bbb928de6.tar.bz2 linux-52cc48ad2a76a5fe82d239044d67944bbb928de6.zip |
cxl/hdm: Limit emulation to the number of range registers
Recall that range register emulation seeks to treat the 2 potential
range registers as Linux CXL "decoder" objects. The number of range
registers can be 1 or 2, while HDM decoder ranges can include more than
2.
Be careful not to confuse DVSEC range count with HDM capability decoder
count. Commit to range register earlier in devm_cxl_setup_hdm().
Otherwise, a device with more HDM decoders than range registers can set
@cxlhdm->decoder_count to an invalid value.
Avoid introducing a forward declaration by just moving the definition of
should_emulate_decoders() earlier in the file. should_emulate_decoders()
is unchanged.
Tested-by: Dave Jiang <dave.jiang@intel.com>
Fixes: d7a2153762c7 ("cxl/hdm: Add emulation when HDM decoders are not committed")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168012574932.221280.15944705098679646436.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl')
-rw-r--r-- | drivers/cxl/core/hdm.c | 82 |
1 files changed, 46 insertions, 36 deletions
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c index cc123996b1a4..9884b6d4d930 100644 --- a/drivers/cxl/core/hdm.c +++ b/drivers/cxl/core/hdm.c @@ -101,6 +101,42 @@ static int map_hdm_decoder_regs(struct cxl_port *port, void __iomem *crb, BIT(CXL_CM_CAP_CAP_ID_HDM)); } +static bool should_emulate_decoders(struct cxl_endpoint_dvsec_info *info) +{ + struct cxl_hdm *cxlhdm; + void __iomem *hdm; + u32 ctrl; + int i; + + if (!info) + return false; + + cxlhdm = dev_get_drvdata(&info->port->dev); + hdm = cxlhdm->regs.hdm_decoder; + + if (!hdm) + return true; + + /* + * If HDM decoders are present and the driver is in control of + * Mem_Enable skip DVSEC based emulation + */ + if (!info->mem_enabled) + return false; + + /* + * 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; +} + /** * devm_cxl_setup_hdm - map HDM decoder component registers * @port: cxl_port to map @@ -140,6 +176,16 @@ struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port, return ERR_PTR(-ENXIO); } + /* + * Now that the hdm capability is parsed, decide if range + * register emulation is needed and fixup cxlhdm accordingly. + */ + if (should_emulate_decoders(info)) { + dev_dbg(dev, "Fallback map %d range register%s\n", info->ranges, + info->ranges > 1 ? "s" : ""); + cxlhdm->decoder_count = info->ranges; + } + return cxlhdm; } EXPORT_SYMBOL_NS_GPL(devm_cxl_setup_hdm, CXL); @@ -717,42 +763,6 @@ static int cxl_setup_hdm_decoder_from_dvsec(struct cxl_port *port, return 0; } -static bool should_emulate_decoders(struct cxl_endpoint_dvsec_info *info) -{ - struct cxl_hdm *cxlhdm; - void __iomem *hdm; - u32 ctrl; - int i; - - if (!info) - return false; - - cxlhdm = dev_get_drvdata(&info->port->dev); - hdm = cxlhdm->regs.hdm_decoder; - - if (!hdm) - return true; - - /* - * If HDM decoders are present and the driver is in control of - * Mem_Enable skip DVSEC based emulation - */ - if (!info->mem_enabled) - return false; - - /* - * 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) |