diff options
Diffstat (limited to 'src/include/device/pci_mmio_cfg.h')
| -rw-r--r-- | src/include/device/pci_mmio_cfg.h | 55 |
1 files changed, 37 insertions, 18 deletions
diff --git a/src/include/device/pci_mmio_cfg.h b/src/include/device/pci_mmio_cfg.h index e7019151aa..5567ed86ae 100644 --- a/src/include/device/pci_mmio_cfg.h +++ b/src/include/device/pci_mmio_cfg.h @@ -20,55 +20,74 @@ #include <device/mmio.h> #include <device/pci_type.h> +#if !defined(__ROMCC__) + +/* By not assigning this to CONFIG_MMCONF_BASE_ADDRESS here we + * prevent some sub-optimal constant folding. */ +extern u8 *const pci_mmconf; + +/* Using a unique datatype for MMIO writes makes the pointers to _not_ + * qualify for pointer aliasing with any other objects in memory. + * + * MMIO offset is a value originally derived from 'struct device *' + * in ramstage. For the compiler to not discard this MMIO offset value + * from CPU registers after any MMIO writes, -fstrict-aliasing has to + * be also set for the build. + * + * Bottom 12 bits (4 KiB) are reserved to address the registers of a + * single PCI function. Declare the bank as a union to avoid some casting + * in the functions below. + */ +union pci_bank { + uint8_t reg8[4096]; + uint16_t reg16[4096 / sizeof(uint16_t)]; + uint32_t reg32[4096 / sizeof(uint32_t)]; +}; + +static __always_inline +volatile union pci_bank *pcicfg(pci_devfn_t dev) +{ + return (void *)&pci_mmconf[PCI_DEVFN_OFFSET(dev)]; +} static __always_inline uint8_t pci_mmio_read_config8(pci_devfn_t dev, uint16_t reg) { - void *addr; - addr = (void *)(uintptr_t)(CONFIG_MMCONF_BASE_ADDRESS | dev | reg); - return read8(addr); + return pcicfg(dev)->reg8[reg]; } static __always_inline uint16_t pci_mmio_read_config16(pci_devfn_t dev, uint16_t reg) { - void *addr; - addr = (void *)(uintptr_t)(CONFIG_MMCONF_BASE_ADDRESS | dev | (reg & ~1)); - return read16(addr); + return pcicfg(dev)->reg16[reg / sizeof(uint16_t)]; } static __always_inline uint32_t pci_mmio_read_config32(pci_devfn_t dev, uint16_t reg) { - void *addr; - addr = (void *)(uintptr_t)(CONFIG_MMCONF_BASE_ADDRESS | dev | (reg & ~3)); - return read32(addr); + return pcicfg(dev)->reg32[reg / sizeof(uint32_t)]; } static __always_inline void pci_mmio_write_config8(pci_devfn_t dev, uint16_t reg, uint8_t value) { - void *addr; - addr = (void *)(uintptr_t)(CONFIG_MMCONF_BASE_ADDRESS | dev | reg); - write8(addr, value); + pcicfg(dev)->reg8[reg] = value; } static __always_inline void pci_mmio_write_config16(pci_devfn_t dev, uint16_t reg, uint16_t value) { - void *addr; - addr = (void *)(uintptr_t)(CONFIG_MMCONF_BASE_ADDRESS | dev | (reg & ~1)); - write16(addr, value); + pcicfg(dev)->reg16[reg / sizeof(uint16_t)] = value; } static __always_inline void pci_mmio_write_config32(pci_devfn_t dev, uint16_t reg, uint32_t value) { - void *addr; - addr = (void *)(uintptr_t)(CONFIG_MMCONF_BASE_ADDRESS | dev | (reg & ~3)); - write32(addr, value); + pcicfg(dev)->reg32[reg / sizeof(uint32_t)] = value; } +#endif /* !defined(__ROMCC__) */ + #if CONFIG(MMCONF_SUPPORT) /* Avoid name collisions as different stages have different signature |