Kernel: Create support for PCI ECAM

The new PCI subsystem is initialized during runtime.
PCI::Initializer is supposed to be called during early boot, to
perform a few tests, and initialize the proper configuration space
access mechanism. Kernel boot parameters can be specified by a user to
determine what tests will occur, to aid debugging on problematic
machines.
After that, PCI::Initializer should be dismissed.

PCI::IOAccess is a class that is derived from PCI::Access
class and implements PCI configuration space access mechanism via x86
IO ports.
PCI::MMIOAccess is a class that is derived from PCI::Access
and implements PCI configurtaion space access mechanism via memory
access.

The new PCI subsystem also supports determination of IO/MMIO space
needed by a device by checking a given BAR.
In addition, Every device or component that use the PCI subsystem has
changed to match the last changes.

1 files changed, 62 insertions, 0 deletions

diff --git a/Kernel/PCI/Access.h b/Kernel/PCI/Access.h
new file mode 100644
index 0000000000..d2f7cdc053
--- /dev/null
+++ b/Kernel/PCI/Access.h
@@ -0,0 +1,62 @@
+#pragma once
+
+#include <AK/String.h>
+#include <Kernel/PCI/Definitions.h>
+
+class PCI::Access {
+public:
+    virtual void enumerate_all(Function<void(Address, ID)>&) = 0;
+    virtual u8 get_interrupt_line(Address address) { return read8_field(address, PCI_INTERRUPT_LINE); }
+    virtual u32 get_BAR0(Address address) { return read32_field(address, PCI_BAR0); }
+    virtual u32 get_BAR1(Address address) { return read32_field(address, PCI_BAR1); }
+    virtual u32 get_BAR2(Address address) { return read32_field(address, PCI_BAR2); }
+    virtual u32 get_BAR3(Address address) { return read32_field(address, PCI_BAR3); }
+    virtual u32 get_BAR4(Address address) { return read32_field(address, PCI_BAR4); }
+    virtual u32 get_BAR5(Address address) { return read32_field(address, PCI_BAR5); }
+
+    virtual u32 get_BAR_Space_Size(Address address, u8 bar_number)
+    {
+        // See PCI Spec 2.3, Page 222
+        ASSERT(bar_number < 6);
+        u8 field = (PCI_BAR0 + (bar_number << 2));
+        u32 bar_reserved = read32_field(address, field);
+        write32_field(address, field, 0xFFFFFFFF);
+        u32 space_size = read32_field(address, field);
+        write32_field(address, field, bar_reserved);
+        space_size &= 0xfffffff0;
+        space_size = (~space_size) + 1;
+        return space_size;
+    }
+
+    virtual u8 get_revision_id(Address address) { return read8_field(address, PCI_REVISION_ID); }
+    virtual u8 get_subclass(Address address) { return read8_field(address, PCI_SUBCLASS); }
+    virtual u8 get_class(Address address) { return read8_field(address, PCI_CLASS); }
+    virtual u16 get_subsystem_id(Address address) { return read16_field(address, PCI_SUBSYSTEM_ID); }
+    virtual u16 get_subsystem_vendor_id(Address address) { return read16_field(address, PCI_SUBSYSTEM_VENDOR_ID); }
+    virtual u16 read_type(Address address) { return (read8_field(address, PCI_CLASS) << 8u) | read8_field(address, PCI_SUBCLASS); }
+
+    virtual void enable_bus_mastering(Address) final;
+    virtual void disable_bus_mastering(Address) final;
+
+    virtual void enumerate_bus(int type, u8 bus, Function<void(Address, ID)>&) final;
+    virtual void enumerate_functions(int type, u8 bus, u8 slot, u8 function, Function<void(Address, ID)>& callback) final;
+    virtual void enumerate_slot(int type, u8 bus, u8 slot, Function<void(Address, ID)>& callback) final;
+
+    static Access& the();
+    static bool is_initialized();
+    virtual uint32_t get_segments_count() = 0;
+    virtual uint8_t get_segment_start_bus(u32 segment) = 0;
+    virtual uint8_t get_segment_end_bus(u32 segment) = 0;
+    virtual String get_access_type() = 0;
+
+protected:
+    Access();
+
+    virtual u8 read8_field(Address address, u32 field) = 0;
+    virtual u16 read16_field(Address address, u32 field) = 0;
+    virtual u32 read32_field(Address address, u32 field) = 0;
+
+    virtual void write8_field(Address address, u32 field, u8 value) = 0;
+    virtual void write16_field(Address address, u32 field, u16 value) = 0;
+    virtual void write32_field(Address address, u32 field, u32 value) = 0;
+};