From 4474ce565ee4490fb4e6d8443b617a9d98ae10ff Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Tue, 14 Feb 2023 11:41:30 -0800 Subject: cxl/hdm: Create emulated cxl_hdm for devices that do not have HDM decoders CXL rev3 spec 8.1.3 RCDs may not have HDM register blocks. Create a fake HDM with information from the CXL PCIe DVSEC registers. The decoder count will be set to the HDM count retrieved from the DVSEC cap register. Reviewed-by: Jonathan Cameron Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/167640368994.935665.15831225724059704620.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams --- drivers/cxl/core/hdm.c | 58 +++++++++++++++++++++++++++++++++++++++++--------- drivers/cxl/core/pci.c | 9 +++++--- drivers/cxl/cxl.h | 3 ++- drivers/cxl/port.c | 2 +- 4 files changed, 57 insertions(+), 15 deletions(-) (limited to 'drivers') diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c index c0f224454447..a49543f22dca 100644 --- a/drivers/cxl/core/hdm.c +++ b/drivers/cxl/core/hdm.c @@ -101,11 +101,34 @@ static int map_hdm_decoder_regs(struct cxl_port *port, void __iomem *crb, BIT(CXL_CM_CAP_CAP_ID_HDM)); } +static struct cxl_hdm *devm_cxl_setup_emulated_hdm(struct cxl_port *port, + struct cxl_endpoint_dvsec_info *info) +{ + struct device *dev = &port->dev; + struct cxl_hdm *cxlhdm; + + if (!info->mem_enabled) + return ERR_PTR(-ENODEV); + + cxlhdm = devm_kzalloc(dev, sizeof(*cxlhdm), GFP_KERNEL); + if (!cxlhdm) + return ERR_PTR(-ENOMEM); + + cxlhdm->port = port; + cxlhdm->decoder_count = info->ranges; + cxlhdm->target_count = info->ranges; + dev_set_drvdata(&port->dev, cxlhdm); + + return cxlhdm; +} + /** * devm_cxl_setup_hdm - map HDM decoder component registers * @port: cxl_port to map + * @info: cached DVSEC range register info */ -struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port) +struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port, + struct cxl_endpoint_dvsec_info *info) { struct device *dev = &port->dev; struct cxl_hdm *cxlhdm; @@ -119,6 +142,9 @@ struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port) cxlhdm->port = port; crb = ioremap(port->component_reg_phys, CXL_COMPONENT_REG_BLOCK_SIZE); if (!crb) { + if (info->mem_enabled) + return devm_cxl_setup_emulated_hdm(port, info); + dev_err(dev, "No component registers mapped\n"); return ERR_PTR(-ENXIO); } @@ -814,19 +840,15 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld, return 0; } -/** - * devm_cxl_enumerate_decoders - add decoder objects per HDM register set - * @cxlhdm: Structure to populate with HDM capabilities - */ -int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm, - struct cxl_endpoint_dvsec_info *info) +static void cxl_settle_decoders(struct cxl_hdm *cxlhdm) { void __iomem *hdm = cxlhdm->regs.hdm_decoder; - struct cxl_port *port = cxlhdm->port; - int i, committed; - u64 dpa_base = 0; + int committed, i; u32 ctrl; + if (!hdm) + return; + /* * Since the register resource was recently claimed via request_region() * be careful about trusting the "not-committed" status until the commit @@ -843,6 +865,22 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm, /* ensure that future checks of committed can be trusted */ if (committed != cxlhdm->decoder_count) msleep(20); +} + +/** + * devm_cxl_enumerate_decoders - add decoder objects per HDM register set + * @cxlhdm: Structure to populate with HDM capabilities + * @info: cached DVSEC range register info + */ +int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm, + struct cxl_endpoint_dvsec_info *info) +{ + void __iomem *hdm = cxlhdm->regs.hdm_decoder; + struct cxl_port *port = cxlhdm->port; + int i; + u64 dpa_base = 0; + + cxl_settle_decoders(cxlhdm); for (i = 0; i < cxlhdm->decoder_count; i++) { int target_map[CXL_DECODER_MAX_INTERLEAVE] = { 0 }; diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c index 4df0b35c9b1a..4eb34dee7c95 100644 --- a/drivers/cxl/core/pci.c +++ b/drivers/cxl/core/pci.c @@ -378,16 +378,19 @@ int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm, struct device *dev = cxlds->dev; struct cxl_port *root; int i, rc, allowed; - u32 global_ctrl; + u32 global_ctrl = 0; - global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET); + if (hdm) + global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET); /* * If the HDM Decoder Capability is already enabled then assume * that some other agent like platform firmware set it up. */ - if (global_ctrl & CXL_HDM_DECODER_ENABLE) + if (global_ctrl & CXL_HDM_DECODER_ENABLE || (!hdm && info->mem_enabled)) return devm_cxl_enable_mem(&port->dev, cxlds); + else if (!hdm) + return -ENODEV; root = to_cxl_port(port->dev.parent); while (!is_cxl_root(root) && is_cxl_port(root->dev.parent)) diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index fe9d75989c8a..f8cbc5275451 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -643,7 +643,8 @@ struct cxl_endpoint_dvsec_info { }; struct cxl_hdm; -struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port); +struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port, + struct cxl_endpoint_dvsec_info *info); int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm, struct cxl_endpoint_dvsec_info *info); int devm_cxl_add_passthrough_decoder(struct cxl_port *port); diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c index d3a708e32565..9f9cc268b597 100644 --- a/drivers/cxl/port.c +++ b/drivers/cxl/port.c @@ -54,7 +54,7 @@ static int cxl_port_probe(struct device *dev) return devm_cxl_add_passthrough_decoder(port); } - cxlhdm = devm_cxl_setup_hdm(port); + cxlhdm = devm_cxl_setup_hdm(port, &info); if (IS_ERR(cxlhdm)) return PTR_ERR(cxlhdm); 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