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Kernel: Map PCI devices only once during boot

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Instead of mapping a 4KB region to access device configuration space
each time we call one of the PCI helpers, just map them once during
the boot process.
Then, if we request to access one of those devices, we can ask the
PCI subsystem to give us the virtual address where the device's
configuration space is mapped.
This commit is contained in:
Liav A 2020-10-31 22:24:01 +02:00 • committed by Andreas Kling
parent 0aeef47abd
commit 6131048a5f
4 changed files with 95 additions and 60 deletions
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37
Kernel/PCI/Access.cpp
View file

@ -24,6 +24,7 @@
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <Kernel/IO.h>
#include <Kernel/PCI/Access.h>
#include <Kernel/PCI/IOAccess.h>
@ -57,18 +58,36 @@ Access::Access()
s_access = this;
}
static u16 read_type(Address address)
u8 Access::early_read8_field(Address address, u32 field)
{
return (read8(address, PCI_CLASS) << 8u) | read8(address, PCI_SUBCLASS);
IO::out32(PCI_ADDRESS_PORT, address.io_address_for_field(field));
return IO::in8(PCI_VALUE_PORT + (field & 3));
}
u16 Access::early_read16_field(Address address, u32 field)
{
IO::out32(PCI_ADDRESS_PORT, address.io_address_for_field(field));
return IO::in16(PCI_VALUE_PORT + (field & 2));
}
u32 Access::early_read32_field(Address address, u32 field)
{
IO::out32(PCI_ADDRESS_PORT, address.io_address_for_field(field));
return IO::in32(PCI_VALUE_PORT);
}
u16 Access::early_read_type(Address address)
{
return (early_read8_field(address, PCI_CLASS) << 8u) | early_read8_field(address, PCI_SUBCLASS);
}
void Access::enumerate_functions(int type, u8 bus, u8 slot, u8 function, Function<void(Address, ID)>& callback)
{
Address address(0, bus, slot, function);
if (type == -1 || type == read_type(address))
callback(address, { read16_field(address, PCI_VENDOR_ID), read16_field(address, PCI_DEVICE_ID) });
if (read_type(address) == PCI_TYPE_BRIDGE) {
u8 secondary_bus = read8_field(address, PCI_SECONDARY_BUS);
if (type == -1 || type == early_read_type(address))
callback(address, { early_read16_field(address, PCI_VENDOR_ID), early_read16_field(address, PCI_DEVICE_ID) });
if (early_read_type(address) == PCI_TYPE_BRIDGE) {
u8 secondary_bus = early_read8_field(address, PCI_SECONDARY_BUS);
#ifdef PCI_DEBUG
klog() << "PCI: Found secondary bus: " << secondary_bus;
#endif
@ -80,14 +99,14 @@ void Access::enumerate_functions(int type, u8 bus, u8 slot, u8 function, Functio
void Access::enumerate_slot(int type, u8 bus, u8 slot, Function<void(Address, ID)>& callback)
{
Address address(0, bus, slot, 0);
if (read16_field(address, PCI_VENDOR_ID) == PCI_NONE)
if (early_read16_field(address, PCI_VENDOR_ID) == PCI_NONE)
return;
enumerate_functions(type, bus, slot, 0, callback);
if (!(read8_field(address, PCI_HEADER_TYPE) & 0x80))
if (!(early_read8_field(address, PCI_HEADER_TYPE) & 0x80))
return;
for (u8 function = 1; function < 8; ++function) {
Address address(0, bus, slot, function);
if (read16_field(address, PCI_VENDOR_ID) != PCI_NONE)
if (early_read16_field(address, PCI_VENDOR_ID) != PCI_NONE)
enumerate_functions(type, bus, slot, function, callback);
}
}