diff options
Diffstat (limited to 'drivers/cxl/core/regs.c')
| -rw-r--r-- | drivers/cxl/core/regs.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c index b10f8b79ec40..dfce37d11df1 100644 --- a/drivers/cxl/core/regs.c +++ b/drivers/cxl/core/regs.c @@ -7,6 +7,8 @@ #include <cxlmem.h> #include <cxlpci.h> +#include "core.h" + /** * DOC: cxl registers * @@ -179,6 +181,9 @@ void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr, void __iomem *ret_val; struct resource *res; + if (WARN_ON_ONCE(addr == CXL_RESOURCE_NONE)) + return NULL; + res = devm_request_mem_region(dev, addr, length, dev_name(dev)); if (!res) { resource_size_t end = addr + length - 1; @@ -326,3 +331,68 @@ int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type, return -ENODEV; } EXPORT_SYMBOL_NS_GPL(cxl_find_regblock, CXL); + +resource_size_t cxl_rcrb_to_component(struct device *dev, + resource_size_t rcrb, + enum cxl_rcrb which) +{ + resource_size_t component_reg_phys; + u32 bar0, bar1; + void *addr; + u16 cmd; + u32 id; + + if (which == CXL_RCRB_UPSTREAM) + rcrb += SZ_4K; + + /* + * RCRB's BAR[0..1] point to component block containing CXL + * subsystem component registers. MEMBAR extraction follows + * the PCI Base spec here, esp. 64 bit extraction and memory + * ranges alignment (6.0, 7.5.1.2.1). + */ + if (!request_mem_region(rcrb, SZ_4K, "CXL RCRB")) + return CXL_RESOURCE_NONE; + addr = ioremap(rcrb, SZ_4K); + if (!addr) { + dev_err(dev, "Failed to map region %pr\n", addr); + release_mem_region(rcrb, SZ_4K); + return CXL_RESOURCE_NONE; + } + + id = readl(addr + PCI_VENDOR_ID); + cmd = readw(addr + PCI_COMMAND); + bar0 = readl(addr + PCI_BASE_ADDRESS_0); + bar1 = readl(addr + PCI_BASE_ADDRESS_1); + iounmap(addr); + release_mem_region(rcrb, SZ_4K); + + /* + * Sanity check, see CXL 3.0 Figure 9-8 CXL Device that Does Not + * Remap Upstream Port and Component Registers + */ + if (id == U32_MAX) { + if (which == CXL_RCRB_DOWNSTREAM) + dev_err(dev, "Failed to access Downstream Port RCRB\n"); + return CXL_RESOURCE_NONE; + } + if (!(cmd & PCI_COMMAND_MEMORY)) + return CXL_RESOURCE_NONE; + /* The RCRB is a Memory Window, and the MEM_TYPE_1M bit is obsolete */ + if (bar0 & (PCI_BASE_ADDRESS_MEM_TYPE_1M | PCI_BASE_ADDRESS_SPACE_IO)) + return CXL_RESOURCE_NONE; + + component_reg_phys = bar0 & PCI_BASE_ADDRESS_MEM_MASK; + if (bar0 & PCI_BASE_ADDRESS_MEM_TYPE_64) + component_reg_phys |= ((u64)bar1) << 32; + + if (!component_reg_phys) + return CXL_RESOURCE_NONE; + + /* MEMBAR is block size (64k) aligned. */ + if (!IS_ALIGNED(component_reg_phys, CXL_COMPONENT_REG_BLOCK_SIZE)) + return CXL_RESOURCE_NONE; + + return component_reg_phys; +} +EXPORT_SYMBOL_NS_GPL(cxl_rcrb_to_component, CXL); |