diff options
Diffstat (limited to 'drivers/cxl/core/region.c')
-rw-r--r-- | drivers/cxl/core/region.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 5c186e0a39b9..45eb9c560fd6 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -2679,6 +2679,141 @@ int cxl_get_poison_by_endpoint(struct cxl_port *port) return rc; } +struct cxl_dpa_to_region_context { + struct cxl_region *cxlr; + u64 dpa; +}; + +static int __cxl_dpa_to_region(struct device *dev, void *arg) +{ + struct cxl_dpa_to_region_context *ctx = arg; + struct cxl_endpoint_decoder *cxled; + u64 dpa = ctx->dpa; + + if (!is_endpoint_decoder(dev)) + return 0; + + cxled = to_cxl_endpoint_decoder(dev); + if (!cxled->dpa_res || !resource_size(cxled->dpa_res)) + return 0; + + if (dpa > cxled->dpa_res->end || dpa < cxled->dpa_res->start) + return 0; + + dev_dbg(dev, "dpa:0x%llx mapped in region:%s\n", dpa, + dev_name(&cxled->cxld.region->dev)); + + ctx->cxlr = cxled->cxld.region; + + return 1; +} + +struct cxl_region *cxl_dpa_to_region(const struct cxl_memdev *cxlmd, u64 dpa) +{ + struct cxl_dpa_to_region_context ctx; + struct cxl_port *port; + + ctx = (struct cxl_dpa_to_region_context) { + .dpa = dpa, + }; + port = cxlmd->endpoint; + if (port && is_cxl_endpoint(port) && cxl_num_decoders_committed(port)) + device_for_each_child(&port->dev, &ctx, __cxl_dpa_to_region); + + return ctx.cxlr; +} + +static bool cxl_is_hpa_in_range(u64 hpa, struct cxl_region *cxlr, int pos) +{ + struct cxl_region_params *p = &cxlr->params; + int gran = p->interleave_granularity; + int ways = p->interleave_ways; + u64 offset; + + /* Is the hpa within this region at all */ + if (hpa < p->res->start || hpa > p->res->end) { + dev_dbg(&cxlr->dev, + "Addr trans fail: hpa 0x%llx not in region\n", hpa); + return false; + } + + /* Is the hpa in an expected chunk for its pos(-ition) */ + offset = hpa - p->res->start; + offset = do_div(offset, gran * ways); + if ((offset >= pos * gran) && (offset < (pos + 1) * gran)) + return true; + + dev_dbg(&cxlr->dev, + "Addr trans fail: hpa 0x%llx not in expected chunk\n", hpa); + + return false; +} + +static u64 cxl_dpa_to_hpa(u64 dpa, struct cxl_region *cxlr, + struct cxl_endpoint_decoder *cxled) +{ + u64 dpa_offset, hpa_offset, bits_upper, mask_upper, hpa; + struct cxl_region_params *p = &cxlr->params; + int pos = cxled->pos; + u16 eig = 0; + u8 eiw = 0; + + ways_to_eiw(p->interleave_ways, &eiw); + granularity_to_eig(p->interleave_granularity, &eig); + + /* + * The device position in the region interleave set was removed + * from the offset at HPA->DPA translation. To reconstruct the + * HPA, place the 'pos' in the offset. + * + * The placement of 'pos' in the HPA is determined by interleave + * ways and granularity and is defined in the CXL Spec 3.0 Section + * 8.2.4.19.13 Implementation Note: Device Decode Logic + */ + + /* Remove the dpa base */ + dpa_offset = dpa - cxl_dpa_resource_start(cxled); + + mask_upper = GENMASK_ULL(51, eig + 8); + + if (eiw < 8) { + hpa_offset = (dpa_offset & mask_upper) << eiw; + hpa_offset |= pos << (eig + 8); + } else { + bits_upper = (dpa_offset & mask_upper) >> (eig + 8); + bits_upper = bits_upper * 3; + hpa_offset = ((bits_upper << (eiw - 8)) + pos) << (eig + 8); + } + + /* The lower bits remain unchanged */ + hpa_offset |= dpa_offset & GENMASK_ULL(eig + 7, 0); + + /* Apply the hpa_offset to the region base address */ + hpa = hpa_offset + p->res->start; + + if (!cxl_is_hpa_in_range(hpa, cxlr, cxled->pos)) + return ULLONG_MAX; + + return hpa; +} + +u64 cxl_trace_hpa(struct cxl_region *cxlr, const struct cxl_memdev *cxlmd, + u64 dpa) +{ + struct cxl_region_params *p = &cxlr->params; + struct cxl_endpoint_decoder *cxled = NULL; + + for (int i = 0; i < p->nr_targets; i++) { + cxled = p->targets[i]; + if (cxlmd == cxled_to_memdev(cxled)) + break; + } + if (!cxled || cxlmd != cxled_to_memdev(cxled)) + return ULLONG_MAX; + + return cxl_dpa_to_hpa(dpa, cxlr, cxled); +} + static struct lock_class_key cxl_pmem_region_key; static struct cxl_pmem_region *cxl_pmem_region_alloc(struct cxl_region *cxlr) |