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Kernel: Don't remap BochsGraphicsAdapter MMIO registers on every access

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We were creating a new memory mapping every time WindowServer performed
a buffer flip. This was very visible in whole-system profiles, as the
mapping and unmapping of MMIO registers caused quite a bit of kmalloc()
and kfree() churn.

Avoid this problem by simply keeping the MMIO registers mapped.
This commit is contained in:
Andreas Kling 2021-07-06 11:47:12 +02:00
parent eda5ab2d0f
commit 7e4bc04057
2 changed files with 18 additions and 19 deletions
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33
Kernel/Graphics/BochsGraphicsAdapter.cpp
View file

@ -55,6 +55,7 @@ UNMAP_AFTER_INIT NonnullRefPtr<BochsGraphicsAdapter> BochsGraphicsAdapter::initi
UNMAP_AFTER_INIT BochsGraphicsAdapter::BochsGraphicsAdapter(PCI::Address pci_address)
: PCI::DeviceController(pci_address)
, m_mmio_registers(PCI::get_BAR2(pci_address) & 0xfffffff0)
, m_registers(map_typed_writable<BochsDisplayMMIORegisters volatile>(m_mmio_registers))
{
// We assume safe resolutio is 1024x768x32
m_framebuffer_console = Graphics::ContiguousFramebufferConsole::initialize(PhysicalAddress(PCI::get_BAR0(pci_address) & 0xfffffff0), 1024, 768, 1024 * sizeof(u32));
@ -89,9 +90,8 @@ GraphicsDevice::Type BochsGraphicsAdapter::type() const
void BochsGraphicsAdapter::unblank()
{
auto registers = map_typed_writable<volatile BochsDisplayMMIORegisters>(m_mmio_registers);
full_memory_barrier();
registers->vga_ioports[0] = 0x20;
m_registers->vga_ioports[0] = 0x20;
full_memory_barrier();
}
@ -131,18 +131,17 @@ void BochsGraphicsAdapter::set_resolution_registers_via_io(size_t width, size_t
void BochsGraphicsAdapter::set_resolution_registers(size_t width, size_t height)
{
dbgln_if(BXVGA_DEBUG, "BochsGraphicsAdapter resolution registers set to - {}x{}", width, height);
auto registers = map_typed_writable<volatile BochsDisplayMMIORegisters>(m_mmio_registers);
registers->bochs_regs.enable = VBE_DISPI_DISABLED;
m_registers->bochs_regs.enable = VBE_DISPI_DISABLED;
full_memory_barrier();
registers->bochs_regs.xres = width;
registers->bochs_regs.yres = height;
registers->bochs_regs.virt_width = width;
registers->bochs_regs.virt_height = height * 2;
registers->bochs_regs.bpp = 32;
m_registers->bochs_regs.xres = width;
m_registers->bochs_regs.yres = height;
m_registers->bochs_regs.virt_width = width;
m_registers->bochs_regs.virt_height = height * 2;
m_registers->bochs_regs.bpp = 32;
full_memory_barrier();
registers->bochs_regs.enable = VBE_DISPI_ENABLED | VBE_DISPI_LFB_ENABLED;
m_registers->bochs_regs.enable = VBE_DISPI_ENABLED | VBE_DISPI_LFB_ENABLED;
full_memory_barrier();
registers->bochs_regs.bank = 0;
m_registers->bochs_regs.bank = 0;
}
bool BochsGraphicsAdapter::try_to_set_resolution(size_t output_port_index, size_t width, size_t height)
@ -181,8 +180,7 @@ bool BochsGraphicsAdapter::validate_setup_resolution_with_io(size_t width, size_
bool BochsGraphicsAdapter::validate_setup_resolution(size_t width, size_t height)
{
auto registers = map_typed_writable<volatile BochsDisplayMMIORegisters>(m_mmio_registers);
if ((u16)width != registers->bochs_regs.xres || (u16)height != registers->bochs_regs.yres) {
if ((u16)width != m_registers->bochs_regs.xres || (u16)height != m_registers->bochs_regs.yres) {
return false;
}
return true;
@ -193,8 +191,7 @@ bool BochsGraphicsAdapter::set_y_offset(size_t output_port_index, size_t y_offse
VERIFY(output_port_index == 0);
if (m_console_enabled)
return false;
auto registers = map_typed_writable<volatile BochsDisplayMMIORegisters>(m_mmio_registers);
registers->bochs_regs.y_offset = y_offset;
m_registers->bochs_regs.y_offset = y_offset;
return true;
}
@ -203,8 +200,7 @@ void BochsGraphicsAdapter::enable_consoles()
ScopedSpinLock lock(m_console_mode_switch_lock);
VERIFY(m_framebuffer_console);
m_console_enabled = true;
auto registers = map_typed_writable<volatile BochsDisplayMMIORegisters>(m_mmio_registers);
registers->bochs_regs.y_offset = 0;
m_registers->bochs_regs.y_offset = 0;
if (m_framebuffer_device)
m_framebuffer_device->deactivate_writes();
m_framebuffer_console->enable();
@ -215,8 +211,7 @@ void BochsGraphicsAdapter::disable_consoles()
VERIFY(m_framebuffer_console);
VERIFY(m_framebuffer_device);
m_console_enabled = false;
auto registers = map_typed_writable<volatile BochsDisplayMMIORegisters>(m_mmio_registers);
registers->bochs_regs.y_offset = 0;
m_registers->bochs_regs.y_offset = 0;
m_framebuffer_console->disable();
m_framebuffer_device->activate_writes();
}

4
Kernel/Graphics/BochsGraphicsAdapter.h
View file

@ -13,11 +13,14 @@
#include <Kernel/Graphics/FramebufferDevice.h>
#include <Kernel/Graphics/GraphicsDevice.h>
#include <Kernel/PhysicalAddress.h>
#include <Kernel/VM/TypedMapping.h>
namespace Kernel {
class BochsFramebufferDevice;
class GraphicsManagement;
struct BochsDisplayMMIORegisters;
class BochsGraphicsAdapter final : public GraphicsDevice
, public PCI::DeviceController {
AK_MAKE_ETERNAL
@ -56,6 +59,7 @@ private:
void set_y_offset(size_t);
PhysicalAddress m_mmio_registers;
TypedMapping<BochsDisplayMMIORegisters volatile> m_registers;
RefPtr<FramebufferDevice> m_framebuffer_device;
RefPtr<Graphics::GenericFramebufferConsole> m_framebuffer_console;
SpinLock<u8> m_console_mode_switch_lock;