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Astral/kernel-src/include/x86-64/arch/pci.h
T
2024-07-27 23:58:33 -03:00

107 lines
3.5 KiB
C

#ifdef _PCIARCH_H
#error this file should only be included ONCE and only in the io/pci.c file
#else
#define _PCIARCH_H
#include <stdint.h>
#include <stddef.h>
#include <arch/io.h>
#include <arch/acpi.h>
#include <kernel/pmm.h>
#include <kernel/alloc.h>
#include <arch/cpu.h>
static size_t mcfgentrycount;
static mcfgentry_t *mcfgentries;
static uint32_t (*pci_archread32)(int bus, int device, int function, uint32_t offset);
static void (*pci_archwrite32)(int bus, int device, int function, uint32_t offset, uint32_t value);
#define CONFADD 0xcf8
#define CONFDATA 0xcfc
static uint32_t legacy_read32(int bus, int device, int function, uint32_t offset) {
uint32_t confadd = 0x80000000 | (offset & ~0x3) | (function << 8) | (device << 11) | (bus << 16);
outd(CONFADD, confadd);
return ind(CONFDATA);
}
static void legacy_write32(int bus, int device, int function, uint32_t offset, uint32_t value) {
uint32_t confadd = 0x80000000 | (offset & ~0x3) | (function << 8) | (device << 11) | (bus << 16);
outd(CONFADD, confadd);
outd(CONFDATA, value);
}
static inline mcfgentry_t *getmcfgentry(int bus) {
mcfgentry_t *entry;
int i;
for (i = 0; i < mcfgentrycount; ++i) {
entry = &mcfgentries[i];
if (bus >= entry->startbus && bus <= entry->endbus)
break;
}
if (i == mcfgentrycount)
entry = NULL;
return entry;
}
static uint32_t mcfg_read32(int bus, int device, int function, uint32_t offset) {
mcfgentry_t *entry = getmcfgentry(bus);
if (entry == NULL)
return 0xffffffff;
uint64_t base = (uint64_t)entry->address;
volatile uint32_t *address = (uint32_t *)((uintptr_t)base + (((bus - entry->startbus) << 20) | (device << 15) | (function << 12) | (offset & ~0x3)));
return *address;
}
static void mcfg_write32(int bus, int device, int function, uint32_t offset, uint32_t value) {
mcfgentry_t *entry = getmcfgentry(bus);
uint64_t base = (uint64_t)entry->address;
volatile uint32_t *address = (uint32_t *)((uintptr_t)base + (((bus - entry->startbus) << 20) | (device << 15) | (function << 12) | (offset & ~0x3)));
*address = value;
}
static uint64_t msiformatmessage(uint32_t *data, int vector, int edgetrigger, int deassert) {
*data = (edgetrigger ? 0 : (1 << 15)) | (deassert ? 0 : (1 << 14)) | vector;
return 0xfee00000 | (_cpu()->id << 12);
}
// in PCIe, every function has 4096 bytes of config space for it.
// there are 8 functions per device and 32 devices per bus
#define MCFG_MAPPING_SIZE(buscount) (4096l * 8l * 32l * (buscount))
static void pci_archinit() {
mcfg_t *mcfg = arch_acpi_findtable("MCFG", 0);
if (mcfg) {
printf("pci: MCFG table found. Using extended configuration space\n");
pci_archread32 = mcfg_read32;
pci_archwrite32 = mcfg_write32;
mcfgentrycount = (mcfg->header.length - sizeof(sdtheader_t)) / sizeof(mcfgentry_t);
mcfgentries = alloc(sizeof(mcfgentry_t) * mcfgentrycount);
__assert(mcfgentries);
memcpy(mcfgentries, mcfg->entries, sizeof(mcfgentry_t) * mcfgentrycount);
for (int i = 0; i < mcfgentrycount; ++i) {
void *phys = (void *)mcfgentries[i].address;
uintmax_t pageoffset = (uintptr_t)phys % PAGE_SIZE;
size_t mappingsize = pageoffset + MCFG_MAPPING_SIZE(mcfgentries[i].endbus - mcfgentries[i].startbus + 1);
void *virt = vmm_map(NULL, mappingsize, VMM_FLAGS_PHYSICAL,
ARCH_MMU_FLAGS_READ | ARCH_MMU_FLAGS_WRITE | ARCH_MMU_FLAGS_NOEXEC | ARCH_MMU_FLAGS_UC, phys);
__assert(virt);
mcfgentries[i].address = (uintptr_t)virt + pageoffset;
}
} else {
printf("pci: MCFG table not found. Falling back to legacy access mechanism\n");
pci_archread32 = legacy_read32;
pci_archwrite32 = legacy_write32;
}
}
#endif