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Kernel/PCI: Introduce a new ECAM access mechanism

Now the kernel supports 2 ECAM access methods.
MMIOAccess was renamed to WindowedMMIOAccess and is what we had until
now - each device that is detected on boot is assigned to a
memory-mapped window, so IO operations on multiple devices can occur
simultaneously due to creating multiple virtual mappings, hence the name
is a memory-mapped window.

This commit adds a new class called MMIOAccess (not to be confused with
the old MMIOAccess class). This class creates one memory-mapped window.
On each IO operation on a configuration space of a device, it maps the
requested PCI bus region to that window. Therefore it holds a SpinLock
during the operation to ensure that no other PCI bus region was mapped
during the call.

A user can choose to either use PCI ECAM with memory-mapped window
for each device, or for an entire bus. By default, the kernel prefers to
map the entire PCI bus region.
This commit is contained in:
Liav A 2021-04-03 16:46:04 +03:00 committed by Andreas Kling
parent 441e374396
commit 8abbb7e090
11 changed files with 320 additions and 100 deletions

View file

@ -50,6 +50,12 @@ enum class AcpiFeatureLevel {
Disabled,
};
enum class PCIAccessLevel {
IOAddressing,
MappingPerBus,
MappingPerDevice,
};
enum class AHCIResetMode {
ControllerOnly,
Complete,
@ -71,7 +77,7 @@ public:
[[nodiscard]] bool is_ide_enabled() const;
[[nodiscard]] bool is_smp_enabled() const;
[[nodiscard]] bool is_vmmouse_enabled() const;
[[nodiscard]] bool is_pci_ecam_enabled() const;
[[nodiscard]] PCIAccessLevel pci_access_level() const;
[[nodiscard]] bool is_legacy_time_enabled() const;
[[nodiscard]] bool is_text_mode() const;
[[nodiscard]] bool is_force_pio() const;