diff options
Diffstat (limited to 'drivers/cxl/core/pci.c')
| -rw-r--r-- | drivers/cxl/core/pci.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c index c9a494d6976a..603945f49174 100644 --- a/drivers/cxl/core/pci.c +++ b/drivers/cxl/core/pci.c @@ -1,8 +1,11 @@ // SPDX-License-Identifier: GPL-2.0-only /* Copyright(c) 2021 Intel Corporation. All rights reserved. */ +#include <linux/io-64-nonatomic-lo-hi.h> #include <linux/device.h> +#include <linux/delay.h> #include <linux/pci.h> #include <cxlpci.h> +#include <cxlmem.h> #include <cxl.h> #include "core.h" @@ -13,6 +16,10 @@ * a set of helpers for CXL interactions which occur via PCIe. */ +static unsigned short media_ready_timeout = 60; +module_param(media_ready_timeout, ushort, 0644); +MODULE_PARM_DESC(media_ready_timeout, "seconds to wait for media ready"); + struct cxl_walk_context { struct pci_bus *bus; struct cxl_port *port; @@ -94,3 +101,44 @@ int devm_cxl_port_enumerate_dports(struct cxl_port *port) return ctx.count; } EXPORT_SYMBOL_NS_GPL(devm_cxl_port_enumerate_dports, CXL); + +/* + * Wait up to @media_ready_timeout for the device to report memory + * active. + */ +int cxl_await_media_ready(struct cxl_dev_state *cxlds) +{ + struct pci_dev *pdev = to_pci_dev(cxlds->dev); + int d = cxlds->cxl_dvsec; + bool active = false; + u64 md_status; + int rc, i; + + for (i = media_ready_timeout; i; i--) { + u32 temp; + + rc = pci_read_config_dword( + pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(0), &temp); + if (rc) + return rc; + + active = FIELD_GET(CXL_DVSEC_MEM_ACTIVE, temp); + if (active) + break; + msleep(1000); + } + + if (!active) { + dev_err(&pdev->dev, + "timeout awaiting memory active after %d seconds\n", + media_ready_timeout); + return -ETIMEDOUT; + } + + md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET); + if (!CXLMDEV_READY(md_status)) + return -EIO; + + return 0; +} +EXPORT_SYMBOL_NS_GPL(cxl_await_media_ready, CXL); |