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pci: device enumeration with MCFG and legacy access

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Matheus
2023-07-13 22:52:44 -03:00
parent 854eaf4b1c
commit 14d6b4249d
4 changed files with 207 additions and 0 deletions
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kernel-src/arch/x86-64/main.c
+2
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@@ -25,6 +25,7 @@
#include <kernel/dpc.h>
#include <kernel/pipefs.h>
#include <kernel/fb.h>
#include <kernel/pci.h>
static cpu_t bsp_cpu;
@@ -65,6 +66,7 @@ void kernel_entry() {
__assert(vfs_mount(NULL, vfsroot, "/dev", "devfs", NULL) == 0);
pseudodevices_init();
pci_init();
keyboard_init();
arch_ps2_init();
fb_init();
kernel-src/include/kernel/pci.h
+41
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@@ -0,0 +1,41 @@
#ifndef _PCI_H
#define _PCI_H
// 2 byte fields
#define PCI_CONFIG_VENDOR 0x0
#define PCI_CONFIG_DEVICEID 0x2
// 1 byte fields
#define PCI_CONFIG_REVISION 0x8
#define PCI_CONFIG_PROGIF 0x9
#define PCI_CONFIG_SUBCLASS 0xa
#define PCI_CONFIG_CLASS 0xb
#define PCI_CONFIG_HEADERTYPE 0xe
#define PCI_HEADERTYPE_MULTIFUNCTION_MASK 0x80
#define PCI_HEADERTYPE_MASK 0x7f
#define PCI_HEADERTYPE_STANDARD 0
typedef struct pcienum_t {
struct pcienum_t *next;
int bus;
int device;
int function;
int type;
int class;
int subclass;
int progif;
int vendor;
int deviceid;
int revision;
} pcienum_t;
uint8_t pci_read8(int bus, int device, int function, uint32_t offset);
uint16_t pci_read16(int bus, int device, int function, uint32_t offset);
uint32_t pci_read32(int bus, int device, int function, uint32_t offset);
void pci_write8(int bus, int device, int function, uint32_t offset, uint8_t v);
void pci_write16(int bus, int device, int function, uint32_t offset, uint16_t v);
void pci_write32(int bus, int device, int function, uint32_t offset, uint32_t value);
void pci_init();
#endif
kernel-src/include/x86-64/arch/pci.h
+84
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@@ -0,0 +1,84 @@
#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>
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)MAKE_HHDM(entry->address);
uint32_t *address = (uint32_t *)(base + ((bus - entry->startbus) << 20) + (device << 15) + (function << 12));
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)MAKE_HHDM(entry->address);
uint32_t *address = (uint32_t *)(base + ((bus - entry->startbus) << 20) + (device << 15) + (function << 12));
*address = value;
}
static void pci_archinit() {
mcfg_t *mcfg = arch_acpi_findtable("MCFG", 0);
if (mcfg) {
printf("pci: MCFG table found. Using extended configuration space\n");
mcfgentries = mcfg->entries;
pci_archread32 = mcfg_read32;
pci_archwrite32 = mcfg_write32;
mcfgentrycount = (mcfg->header.length - sizeof(sdtheader_t)) / sizeof(mcfgentry_t);
// TODO map mcfg entries as UC
} else {
printf("pci: MCFG table not found. Falling back to legacy access mechanism\n");
pci_archread32 = legacy_read32;
pci_archwrite32 = legacy_write32;
}
}
#endif
kernel-src/io/pci.c
+80
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@@ -0,0 +1,80 @@
#include <logging.h>
#include <arch/pci.h>
#include <kernel/pci.h>
#include <kernel/alloc.h>
uint8_t pci_read8(int bus, int device, int function, uint32_t offset) {
return (pci_archread32(bus, device, function, offset) >> ((offset & 0b11) * 8)) & 0xff;
}
uint16_t pci_read16(int bus, int device, int function, uint32_t offset) {
return (pci_archread32(bus, device, function, offset) >> ((offset & 0b11) * 8)) & 0xffff;
}
void pci_write8(int bus, int device, int function, uint32_t offset, uint8_t v) {
uint32_t old = pci_archread32(bus, device, function, offset);
int bitoffset = 8 * (offset & 0b11);
old &= ~(0xff << bitoffset);
old |= v << bitoffset;
pci_archwrite32(bus, device, function, offset, old);
}
void pci_write16(int bus, int device, int function, uint32_t offset, uint16_t v) {
uint32_t old = pci_archread32(bus, device, function, offset);
int bitoffset = 8 * (offset & 0b11);
old &= ~(0xffff << bitoffset);
old |= v << bitoffset;
pci_archwrite32(bus, device, function, offset, old);
}
uint32_t pci_read32(int bus, int device, int function, uint32_t offset) {
return pci_archread32(bus, device, function, offset);
}
void pci_write32(int bus, int device, int function, uint32_t offset, uint32_t value) {
return pci_archwrite32(bus, device, function, offset, value);
}
static pcienum_t *enums;
// reads all 1s if a function doesn't exist
#define DOESNTEXIST(bus, device, function) (pci_read32(bus, device, function, 0) == 0xffffffff)
static void enumeratefunction(int bus, int device, int function) {
pcienum_t *e = alloc(sizeof(pcienum_t));
__assert(e);
e->bus = bus;
e->device = device;
e->function = function;
e->next = enums;
e->class = pci_read8(bus, device, function, PCI_CONFIG_CLASS);
e->subclass = pci_read8(bus, device, function, PCI_CONFIG_SUBCLASS);
e->progif = pci_read8(bus, device, function, PCI_CONFIG_PROGIF);
e->vendor = pci_read16(bus, device, function, PCI_CONFIG_VENDOR);
e->deviceid = pci_read16(bus, device, function, PCI_CONFIG_DEVICEID);
e->revision = pci_read8(bus, device, function, PCI_CONFIG_REVISION);
enums = e;
printf("pci: found %02x:%02x.%x %02x%02x: %04x:%04x (rev %2x) \n", bus, device, function, e->class, e->subclass, e->vendor, e->device, e->revision);
}
static void enumeratedevice(int bus, int device) {
bool multifunction = pci_read32(bus, device, 0, PCI_CONFIG_HEADERTYPE) & PCI_HEADERTYPE_MULTIFUNCTION_MASK;
size_t testcount = multifunction ? 1 : 8;
for (int i = 0; i < testcount; ++i) {
if (DOESNTEXIST(bus, device, i))
continue;
enumeratefunction(bus, device, i);
}
}
void pci_init() {
pci_archinit();
for (size_t bus = 0; bus < 1; ++bus) {
for (size_t device = 0; device < 32; ++device) {
if (DOESNTEXIST(bus, device, 0))
continue;
enumeratedevice(bus, device);
}
}
}