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Kernel/PCI + CPU: Allow to access unaligned data

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This commit is contained in:
Liav A 2021-04-04 22:13:20 +03:00 • committed by Andreas Kling
parent 543c29377b
commit 210754a93a
3 changed files with 62 additions and 8 deletions
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44
Kernel/Arch/x86/CPU.h
View file

@ -195,6 +195,50 @@ public:
class GenericInterruptHandler;
struct RegisterState;
template<typename T>
void read_possibly_unaligned_data(u8* where, T& data)
{
// FIXME: Implement 64 bit unaligned data access
VERIFY(sizeof(T) == 8 || sizeof(T) == 4 || sizeof(T) == 2);
if (((FlatPtr)where % sizeof(T)) == 0) {
data = *(T*)where;
return;
}
if (sizeof(T) == 2) {
data = *(u8*)where | ((u16)(*(where + 1)) << 8);
return;
}
if (sizeof(T) == 4) {
data = *(u8*)where | (((u32) * (where + 1)) << 8) | (((u32) * (where + 2)) << 16) | (((u32) * (u8*)(where + 3)) << 24);
return;
}
VERIFY_NOT_REACHED();
}
template<typename T>
void write_possibly_unaligned_data(u8* where, T data)
{
// FIXME: Implement 64 bit unaligned data access
VERIFY(sizeof(T) == 8 || sizeof(T) == 4 || sizeof(T) == 2);
if (((FlatPtr)where % sizeof(T)) == 0) {
*(T*)where = data;
return;
}
if (sizeof(T) == 2) {
where[0] = (u8)(data & 0xFF);
where[1] = (u8)((data >> 8) & 0xFF);
return;
}
if (sizeof(T) == 4) {
where[0] = (u8)(data & 0xFF);
where[1] = (u8)((data >> 8) & 0xFF);
where[2] = (u8)((data >> 16) & 0xFF);
where[3] = (u8)((data >> 24) & 0xFF);
return;
}
VERIFY_NOT_REACHED();
}
const DescriptorTablePointer& get_gdtr();
const DescriptorTablePointer& get_idtr();
void register_interrupt_handler(u8 number, void (*handler)());

13
Kernel/PCI/MMIOAccess.cpp
View file

@ -26,6 +26,7 @@
#include <AK/Optional.h>
#include <AK/StringView.h>
#include <Kernel/Arch/x86/CPU.h>
#include <Kernel/Debug.h>
#include <Kernel/PCI/MMIOAccess.h>
#include <Kernel/VM/MemoryManager.h>
@ -142,7 +143,9 @@ u16 MMIOAccess::read16_field(Address address, u32 field)
ScopedSpinLock lock(m_access_lock);
VERIFY(field < 0xfff);
dbgln_if(PCI_DEBUG, "PCI: MMIO Reading 16-bit field {:#08x} for {}", field, address);
return *((volatile u16*)(get_device_configuration_space(address).get() + (field & 0xfff)));
u16 data = 0;
read_possibly_unaligned_data<u16>(get_device_configuration_space(address).offset(field & 0xfff).as_ptr(), data);
return data;
}
u32 MMIOAccess::read32_field(Address address, u32 field)
@ -150,7 +153,9 @@ u32 MMIOAccess::read32_field(Address address, u32 field)
ScopedSpinLock lock(m_access_lock);
VERIFY(field <= 0xffc);
dbgln_if(PCI_DEBUG, "PCI: MMIO Reading 32-bit field {:#08x} for {}", field, address);
return *((volatile u32*)(get_device_configuration_space(address).get() + (field & 0xfff)));
u32 data = 0;
read_possibly_unaligned_data<u32>(get_device_configuration_space(address).offset(field & 0xfff).as_ptr(), data);
return data;
}
void MMIOAccess::write8_field(Address address, u32 field, u8 value)
@ -165,14 +170,14 @@ void MMIOAccess::write16_field(Address address, u32 field, u16 value)
ScopedSpinLock lock(m_access_lock);
VERIFY(field < 0xfff);
dbgln_if(PCI_DEBUG, "PCI: MMIO Writing 16-bit field {:#08x}, value={:#02x} for {}", field, value, address);
*((volatile u16*)(get_device_configuration_space(address).get() + (field & 0xfff))) = value;
write_possibly_unaligned_data<u16>(get_device_configuration_space(address).offset(field & 0xfff).as_ptr(), value);
}
void MMIOAccess::write32_field(Address address, u32 field, u32 value)
{
ScopedSpinLock lock(m_access_lock);
VERIFY(field <= 0xffc);
dbgln_if(PCI_DEBUG, "PCI: MMIO Writing 32-bit field {:#08x}, value={:#02x} for {}", field, value, address);
*((volatile u32*)(get_device_configuration_space(address).get() + (field & 0xfff))) = value;
write_possibly_unaligned_data<u32>(get_device_configuration_space(address).offset(field & 0xfff).as_ptr(), value);
}
void MMIOAccess::enumerate_hardware(Function<void(Address, ID)> callback)

13
Kernel/PCI/WindowedMMIOAccess.cpp
View file

@ -26,6 +26,7 @@
#include <AK/Optional.h>
#include <AK/StringView.h>
#include <Kernel/Arch/x86/CPU.h>
#include <Kernel/Debug.h>
#include <Kernel/PCI/WindowedMMIOAccess.h>
#include <Kernel/VM/MemoryManager.h>
@ -96,7 +97,9 @@ u16 WindowedMMIOAccess::read16_field(Address address, u32 field)
InterruptDisabler disabler;
VERIFY(field < 0xfff);
dbgln_if(PCI_DEBUG, "PCI: MMIO Reading 16-bit field {:#08x} for {}", field, address);
return *((u16*)(get_device_configuration_space(address).value().get() + (field & 0xfff)));
u16 data = 0;
read_possibly_unaligned_data<u16>(get_device_configuration_space(address).value().offset(field & 0xfff).as_ptr(), data);
return data;
}
u32 WindowedMMIOAccess::read32_field(Address address, u32 field)
@ -104,7 +107,9 @@ u32 WindowedMMIOAccess::read32_field(Address address, u32 field)
InterruptDisabler disabler;
VERIFY(field <= 0xffc);
dbgln_if(PCI_DEBUG, "PCI: MMIO Reading 32-bit field {:#08x} for {}", field, address);
return *((u32*)(get_device_configuration_space(address).value().get() + (field & 0xfff)));
u32 data = 0;
read_possibly_unaligned_data<u32>(get_device_configuration_space(address).value().offset(field & 0xfff).as_ptr(), data);
return data;
}
void WindowedMMIOAccess::write8_field(Address address, u32 field, u8 value)
@ -119,14 +124,14 @@ void WindowedMMIOAccess::write16_field(Address address, u32 field, u16 value)
InterruptDisabler disabler;
VERIFY(field < 0xfff);
dbgln_if(PCI_DEBUG, "PCI: MMIO Writing 16-bit field {:#08x}, value={:#02x} for {}", field, value, address);
*((u16*)(get_device_configuration_space(address).value().get() + (field & 0xfff))) = value;
write_possibly_unaligned_data<u16>(get_device_configuration_space(address).value().offset(field & 0xfff).as_ptr(), value);
}
void WindowedMMIOAccess::write32_field(Address address, u32 field, u32 value)
{
InterruptDisabler disabler;
VERIFY(field <= 0xffc);
dbgln_if(PCI_DEBUG, "PCI: MMIO Writing 32-bit field {:#08x}, value={:#02x} for {}", field, value, address);
*((u32*)(get_device_configuration_space(address).value().get() + (field & 0xfff))) = value;
write_possibly_unaligned_data<u32>(get_device_configuration_space(address).value().offset(field & 0xfff).as_ptr(), value);
}
}