While CXL Memory Device endpoints locate the CXL MMIO registers in a PCI BAR, CXL root bridges have their MMIO base address described by platform firmware. Refactor the existing register lookup into a generic facility for endpoints and bridges to share.
Reviewed-by: Ben Widawsky <[email protected]> Signed-off-by: Dan Williams <[email protected]> --- drivers/cxl/core.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++- drivers/cxl/cxl.h | 3 +++ drivers/cxl/mem.c | 50 +++++----------------------------------------- 3 files changed, 65 insertions(+), 45 deletions(-) diff --git a/drivers/cxl/core.c b/drivers/cxl/core.c index 7f8d2034038a..2ab467ef9909 100644 --- a/drivers/cxl/core.c +++ b/drivers/cxl/core.c @@ -1,7 +1,8 @@ // SPDX-License-Identifier: GPL-2.0-only -/* Copyright(c) 2020 Intel Corporation. All rights reserved. */ +/* Copyright(c) 2020-2021 Intel Corporation. All rights reserved. */ #include <linux/device.h> #include <linux/module.h> +#include "cxl.h" /** * DOC: cxl core @@ -10,6 +11,60 @@ * point for cross-device interleave coordination through cxl ports. */ +/* + * cxl_setup_device_regs() - Detect CXL Device register blocks + * @dev: Host device of the @base mapping + * @base: mapping of CXL 2.0 8.2.8 CXL Device Register Interface + */ +void cxl_setup_device_regs(struct device *dev, void __iomem *base, + struct cxl_device_regs *regs) +{ + int cap, cap_count; + u64 cap_array; + + *regs = (struct cxl_device_regs) { 0 }; + + cap_array = readq(base + CXLDEV_CAP_ARRAY_OFFSET); + if (FIELD_GET(CXLDEV_CAP_ARRAY_ID_MASK, cap_array) != + CXLDEV_CAP_ARRAY_CAP_ID) + return; + + cap_count = FIELD_GET(CXLDEV_CAP_ARRAY_COUNT_MASK, cap_array); + + for (cap = 1; cap <= cap_count; cap++) { + void __iomem *register_block; + u32 offset; + u16 cap_id; + + cap_id = FIELD_GET(CXLDEV_CAP_HDR_CAP_ID_MASK, + readl(base + cap * 0x10)); + offset = readl(base + cap * 0x10 + 0x4); + register_block = base + offset; + + switch (cap_id) { + case CXLDEV_CAP_CAP_ID_DEVICE_STATUS: + dev_dbg(dev, "found Status capability (0x%x)\n", offset); + regs->status = register_block; + break; + case CXLDEV_CAP_CAP_ID_PRIMARY_MAILBOX: + dev_dbg(dev, "found Mailbox capability (0x%x)\n", offset); + regs->mbox = register_block; + break; + case CXLDEV_CAP_CAP_ID_SECONDARY_MAILBOX: + dev_dbg(dev, "found Secondary Mailbox capability (0x%x)\n", offset); + break; + case CXLDEV_CAP_CAP_ID_MEMDEV: + dev_dbg(dev, "found Memory Device capability (0x%x)\n", offset); + regs->memdev = register_block; + break; + default: + dev_dbg(dev, "Unknown cap ID: %d (0x%x)\n", cap_id, offset); + break; + } + } +} +EXPORT_SYMBOL_GPL(cxl_setup_device_regs); + struct bus_type cxl_bus_type = { .name = "cxl", }; diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 37325e504fb7..cbd29650c4e2 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -67,5 +67,8 @@ struct cxl_regs { }; }; +void cxl_setup_device_regs(struct device *dev, void __iomem *base, + struct cxl_device_regs *regs); + extern struct bus_type cxl_bus_type; #endif /* __CXL_H__ */ diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 6951243d128e..ee55abfa147e 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -865,53 +865,15 @@ static int cxl_mem_mbox_send_cmd(struct cxl_mem *cxlm, u16 opcode, static int cxl_mem_setup_regs(struct cxl_mem *cxlm) { struct device *dev = &cxlm->pdev->dev; - int cap, cap_count; - u64 cap_array; + struct cxl_regs *regs = &cxlm->regs; - cap_array = readq(cxlm->base + CXLDEV_CAP_ARRAY_OFFSET); - if (FIELD_GET(CXLDEV_CAP_ARRAY_ID_MASK, cap_array) != - CXLDEV_CAP_ARRAY_CAP_ID) - return -ENODEV; - - cap_count = FIELD_GET(CXLDEV_CAP_ARRAY_COUNT_MASK, cap_array); - - for (cap = 1; cap <= cap_count; cap++) { - void __iomem *register_block; - u32 offset; - u16 cap_id; - - cap_id = FIELD_GET(CXLDEV_CAP_HDR_CAP_ID_MASK, - readl(cxlm->base + cap * 0x10)); - offset = readl(cxlm->base + cap * 0x10 + 0x4); - register_block = cxlm->base + offset; - - switch (cap_id) { - case CXLDEV_CAP_CAP_ID_DEVICE_STATUS: - dev_dbg(dev, "found Status capability (0x%x)\n", offset); - cxlm->regs.status = register_block; - break; - case CXLDEV_CAP_CAP_ID_PRIMARY_MAILBOX: - dev_dbg(dev, "found Mailbox capability (0x%x)\n", offset); - cxlm->regs.mbox = register_block; - break; - case CXLDEV_CAP_CAP_ID_SECONDARY_MAILBOX: - dev_dbg(dev, "found Secondary Mailbox capability (0x%x)\n", offset); - break; - case CXLDEV_CAP_CAP_ID_MEMDEV: - dev_dbg(dev, "found Memory Device capability (0x%x)\n", offset); - cxlm->regs.memdev = register_block; - break; - default: - dev_dbg(dev, "Unknown cap ID: %d (0x%x)\n", cap_id, offset); - break; - } - } + cxl_setup_device_regs(dev, cxlm->base, ®s->device_regs); - if (!cxlm->regs.status || !cxlm->regs.mbox || !cxlm->regs.memdev) { + if (!regs->status || !regs->mbox || !regs->memdev) { dev_err(dev, "registers not found: %s%s%s\n", - !cxlm->regs.status ? "status " : "", - !cxlm->regs.mbox ? "mbox " : "", - !cxlm->regs.memdev ? "memdev" : ""); + !regs->status ? "status " : "", + !regs->mbox ? "mbox " : "", + !regs->memdev ? "memdev" : ""); return -ENXIO; }
