Kernel/USB: Adjust USB Pipe buffer

Allocate DMA buffer pages for use within the USBD Pipe class, and allow
for the user to specify the size of this buffer, rounding up to the
next page boundary.

Kernel/Bus/USB/USBPipe.cpp

@@ -12,9 +12,9 @@
 
 namespace Kernel::USB {
 
-ErrorOr<NonnullOwnPtr<Pipe>> Pipe::try_create_pipe(USBController const& controller, Type type, Direction direction, u8 endpoint_address, u16 max_packet_size, i8 device_address, u8 poll_interval)
+ErrorOr<NonnullOwnPtr<Pipe>> Pipe::try_create_pipe(USBController const& controller, Type type, Direction direction, u8 endpoint_address, u16 max_packet_size, i8 device_address, size_t buffer_size, u8 poll_interval)
 {
-    auto dma_region = TRY(MM.allocate_kernel_region(PAGE_SIZE, "USB device DMA buffer"sv, Memory::Region::Access::ReadWrite));
+    auto dma_region = TRY(MM.allocate_dma_buffer_pages(TRY(Memory::page_round_up(buffer_size)), "USB device DMA buffer"sv, Memory::Region::Access::ReadWrite));
     return adopt_nonnull_own_or_enomem(new (nothrow) Pipe(controller, type, direction, endpoint_address, max_packet_size, poll_interval, device_address, move(dma_region)));
 }
 

Kernel/Bus/USB/USBPipe.h

@@ -41,7 +41,7 @@ public:
         FullSpeed
     };
 
-    static ErrorOr<NonnullOwnPtr<Pipe>> try_create_pipe(USBController const& controller, Type type, Direction direction, u8 endpoint_address, u16 max_packet_size, i8 device_address, u8 poll_interval = 0);
+    static ErrorOr<NonnullOwnPtr<Pipe>> try_create_pipe(USBController const& controller, Type type, Direction direction, u8 endpoint_address, u16 max_packet_size, i8 device_address, size_t buffer_size = PAGE_SIZE, u8 poll_interval = 0);
 
     Type type() const { return m_type; }
     Direction direction() const { return m_direction; }