Merge pull request #964 from cagatay-y/cast-elimination

Minimize casts to pointers

src/arch/aarch64/kernel/interrupts.rs

@@ -1,6 +1,7 @@
 use alloc::collections::BTreeMap;
 use alloc::vec::Vec;
 use core::arch::asm;
+use core::ptr;
 use core::sync::atomic::{AtomicU64, Ordering};
 
 use aarch64::regs::*;
@@ -190,7 +191,7 @@ pub(crate) extern "C" fn do_sync(state: &State) {
 
 			// add page fault handler
 
-			error!("Current stack pointer {:#x}", state as *const _ as u64);
+			error!("Current stack pointer {state:p}");
 			error!("Unable to handle page fault at {:#x}", far);
 			error!("Exception return address {:#x}", ELR_EL1.get());
 			error!("Thread ID register {:#x}", TPIDR_EL0.get());
@@ -231,8 +232,10 @@ pub(crate) fn init() {
 	info!("Intialize generic interrupt controller");
 
 	let dtb = unsafe {
-		Dtb::from_raw(boot_info().hardware_info.device_tree.unwrap().get() as *const u8)
-			.expect(".dtb file has invalid header")
+		Dtb::from_raw(ptr::from_exposed_addr(
+			boot_info().hardware_info.device_tree.unwrap().get() as usize,
+		))
+		.expect(".dtb file has invalid header")
 	};
 
 	let reg = dtb.get_property("/intc", "reg").unwrap();

src/arch/aarch64/kernel/mod.rs

@@ -13,8 +13,8 @@ pub mod switch;
 pub mod systemtime;
 
 use core::arch::global_asm;
-use core::str;
 use core::sync::atomic::{AtomicU32, AtomicU64, Ordering};
+use core::{ptr, str};
 
 use hermit_entry::boot_info::{BootInfo, RawBootInfo};
 
@@ -52,7 +52,7 @@ pub fn raw_boot_info() -> &'static RawBootInfo {
 }
 
 pub fn get_boot_info_address() -> VirtAddr {
-	VirtAddr(raw_boot_info() as *const _ as u64)
+	VirtAddr(ptr::from_ref(raw_boot_info()).addr() as u64)
 }
 
 pub fn is_uhyve_with_pci() -> bool {
@@ -93,8 +93,10 @@ pub fn get_processor_count() -> u32 {
 
 pub fn args() -> Option<&'static str> {
 	let dtb = unsafe {
-		hermit_dtb::Dtb::from_raw(boot_info().hardware_info.device_tree.unwrap().get() as *const u8)
-			.expect(".dtb file has invalid header")
+		hermit_dtb::Dtb::from_raw(ptr::from_exposed_addr(
+			boot_info().hardware_info.device_tree.unwrap().get() as usize,
+		))
+		.expect(".dtb file has invalid header")
 	};
 
 	dtb.get_property("/chosen", "bootargs")

src/arch/aarch64/kernel/pci.rs

@@ -22,9 +22,19 @@ pub(crate) struct PciConfigRegion(VirtAddr);
 
 impl PciConfigRegion {
 	pub const fn new(addr: VirtAddr) -> Self {
-		assert!(addr.as_u64() & 0xFFFFFFF == 0, "Unaligend PCI Config Space");
+		assert!(addr.as_u64() & 0xFFFFFFF == 0, "Unaligned PCI Config Space");
 		Self(addr)
 	}
+
+	#[inline]
+	fn addr_from_offset(&self, pci_addr: PciAddress, offset: u16) -> usize {
+		assert!(offset & 0xF000 == 0, "Invalid offset");
+		(u64::from(pci_addr.bus()) << 20
+			| u64::from(pci_addr.device()) << 15
+			| u64::from(pci_addr.function()) << 12
+			| (u64::from(offset) & 0xFFF)
+			| self.0.as_u64()) as usize
+	}
 }
 
 impl ConfigRegionAccess for PciConfigRegion {
@@ -36,27 +46,15 @@ impl ConfigRegionAccess for PciConfigRegion {
 
 	#[inline]
 	unsafe fn read(&self, pci_addr: PciAddress, offset: u16) -> u32 {
-		assert!(offset & 0xF000 == 0, "Inavlid offset");
-		let addr = u64::from(pci_addr.bus()) << 20
-			| u64::from(pci_addr.device()) << 15
-			| u64::from(pci_addr.function()) << 12
-			| (u64::from(offset) & 0xFFF)
-			| self.0.as_u64();
-		unsafe {
-			crate::drivers::pci::from_pci_endian(core::ptr::read_volatile(addr as *const u32))
-		}
+		let ptr = core::ptr::from_exposed_addr(self.addr_from_offset(pci_addr, offset));
+		unsafe { crate::drivers::pci::from_pci_endian(core::ptr::read_volatile(ptr)) }
 	}
 
 	#[inline]
 	unsafe fn write(&self, pci_addr: PciAddress, offset: u16, value: u32) {
-		assert!(offset & 0xF000 == 0, "Inavlid offset");
-		let addr = u64::from(pci_addr.bus()) << 20
-			| u64::from(pci_addr.device()) << 15
-			| u64::from(pci_addr.function()) << 12
-			| (u64::from(offset) & 0xFFF)
-			| self.0.as_u64();
+		let ptr = core::ptr::from_exposed_addr_mut(self.addr_from_offset(pci_addr, offset));
 		unsafe {
-			core::ptr::write_volatile(addr as *mut u32, value.to_le());
+			core::ptr::write_volatile(ptr, value.to_le());
 		}
 	}
 }
@@ -230,8 +228,10 @@ fn detect_interrupt(
 
 pub fn init() {
 	let dtb = unsafe {
-		Dtb::from_raw(boot_info().hardware_info.device_tree.unwrap().get() as *const u8)
-			.expect(".dtb file has invalid header")
+		Dtb::from_raw(core::ptr::from_exposed_addr(
+			boot_info().hardware_info.device_tree.unwrap().get() as usize,
+		))
+		.expect(".dtb file has invalid header")
 	};
 
 	for node in dtb.enum_subnodes("/") {

src/arch/aarch64/kernel/processor.rs

@@ -244,8 +244,10 @@ pub fn set_oneshot_timer(wakeup_time: Option<u64>) {
 
 pub fn print_information() {
 	let dtb = unsafe {
-		Dtb::from_raw(boot_info().hardware_info.device_tree.unwrap().get() as *const u8)
-			.expect(".dtb file has invalid header")
+		Dtb::from_raw(core::ptr::from_exposed_addr(
+			boot_info().hardware_info.device_tree.unwrap().get() as usize,
+		))
+		.expect(".dtb file has invalid header")
 	};
 
 	let reg = dtb

src/arch/aarch64/kernel/serial.rs

@@ -10,7 +10,7 @@ impl SerialPort {
 	}
 
 	pub fn write_byte(&self, byte: u8) {
-		let port = self.port_address as *mut u8;
+		let port = core::ptr::from_exposed_addr_mut::<u8>(self.port_address as usize);
 
 		// LF newline characters need to be extended to CRLF over a real serial port.
 		if byte == b'\n' {

src/arch/aarch64/kernel/switch.rs

@@ -15,7 +15,7 @@ macro_rules! kernel_function_impl {
 						let mut reg = 0_usize;
 						// SAFETY: $A is smaller than usize and directly fits in a register
 						// Since f takes $A as argument via C calling convention, any opper bytes do not matter.
-						ptr::write(&mut reg as *mut _ as _, $arg);
+						ptr::write(ptr::from_mut(&mut reg) as _, $arg);
 						reg
 					};
 				)*

src/arch/aarch64/kernel/systemtime.rs

@@ -50,8 +50,10 @@ pub fn get_boot_time() -> u64 {
 
 pub fn init() {
 	let dtb = unsafe {
-		Dtb::from_raw(boot_info().hardware_info.device_tree.unwrap().get() as *const u8)
-			.expect(".dtb file has invalid header")
+		Dtb::from_raw(core::ptr::from_exposed_addr(
+			boot_info().hardware_info.device_tree.unwrap().get() as usize,
+		))
+		.expect(".dtb file has invalid header")
 	};
 
 	for node in dtb.enum_subnodes("/") {

src/arch/aarch64/mm/paging.rs

@@ -517,10 +517,10 @@ where
 
 		// Calculate the address of the subtable.
 		let index = page.table_index::<L>();
-		let table_address = self as *const PageTable<L> as usize;
+		let table_address = core::ptr::from_ref(self).addr();
 		let subtable_address =
 			(table_address << PAGE_MAP_BITS) & !(usize::MAX << 48) | (index << PAGE_BITS);
-		unsafe { &mut *(subtable_address as *mut PageTable<L::SubtableLevel>) }
+		unsafe { &mut *(ptr::from_exposed_addr_mut(subtable_address)) }
 	}
 
 	/// Maps a continuous range of pages.

src/arch/x86_64/kernel/acpi.rs

@@ -140,7 +140,7 @@ impl<'a> AcpiTable<'a> {
 	}
 
 	pub fn header_start_address(&self) -> usize {
-		self.header as *const _ as usize
+		ptr::from_ref(self.header).addr()
 	}
 
 	pub fn table_start_address(&self) -> usize {
@@ -237,7 +237,7 @@ struct AcpiFadt {
 /// (wrapping) sum over all table fields equals zero.
 fn verify_checksum(start_address: usize, length: usize) -> Result<(), ()> {
 	// Get a slice over all bytes of the structure that are considered for the checksum.
-	let slice = unsafe { slice::from_raw_parts(start_address as *const u8, length) };
+	let slice = unsafe { slice::from_raw_parts(ptr::from_exposed_addr(start_address), length) };
 
 	// Perform a wrapping sum over these bytes.
 	let checksum = slice.iter().fold(0, |acc: u8, x| acc.wrapping_add(*x));
@@ -269,7 +269,7 @@ fn detect_rsdp(start_address: PhysAddr, end_address: PhysAddr) -> Result<&'stati
 		}
 
 		// Verify the signature to find out if this is really an ACPI RSDP.
-		let rsdp = unsafe { &*(current_address as *const AcpiRsdp) };
+		let rsdp = unsafe { &*(ptr::from_exposed_addr::<AcpiRsdp>(current_address)) };
 		if &rsdp.signature != b"RSD PTR " {
 			continue;
 		}
@@ -338,9 +338,9 @@ fn search_s5_in_table(table: AcpiTable<'_>) {
 	// Get the AML code.
 	// As we do not implement an AML interpreter, we search through the bytecode.
 	let aml = unsafe {
-		slice::from_raw_parts(
-			table.table_start_address() as *const u8,
-			table.table_end_address() - table.table_start_address(),
+		slice::from_ptr_range(
+			ptr::from_exposed_addr(table.table_start_address())
+				..ptr::from_exposed_addr(table.table_end_address()),
 		)
 	};
 
@@ -389,13 +389,13 @@ fn parse_fadt(fadt: AcpiTable<'_>) {
 	// Get us a reference to the actual fields of the FADT table.
 	// Note that not all fields may be accessible depending on the ACPI revision of the computer.
 	// Always check fadt.table_end_address() when accessing an optional field!
-	let fadt_table = unsafe { &*(fadt.table_start_address() as *const AcpiFadt) };
+	let fadt_table = unsafe { &*ptr::from_exposed_addr::<AcpiFadt>(fadt.table_start_address()) };
 
 	// Check if the FADT is large enough to hold an x_pm1a_cnt_blk field and if this field is non-zero.
 	// In that case, it shall be preferred over the I/O port specified in pm1a_cnt_blk.
 	// As all PM1 control registers are supposed to be in I/O space, we can simply check the address_space field
 	// of x_pm1a_cnt_blk to determine the validity of x_pm1a_cnt_blk.
-	let x_pm1a_cnt_blk_field_address = &fadt_table.x_pm1a_cnt_blk as *const _ as usize;
+	let x_pm1a_cnt_blk_field_address = ptr::from_ref(&fadt_table.x_pm1a_cnt_blk).addr();
 	let pm1a_cnt_blk = if x_pm1a_cnt_blk_field_address < fadt.table_end_address()
 		&& fadt_table.x_pm1a_cnt_blk.address_space == GENERIC_ADDRESS_IO_SPACE
 	{
@@ -485,12 +485,16 @@ pub fn init() {
 		// Depending on the RSDP revision, either an XSDT or an RSDT has been chosen above.
 		// The XSDT contains 64-bit pointers whereas the RSDT has 32-bit pointers.
 		let table_physical_address = if rsdp.revision >= 2 {
-			let address = PhysAddr(unsafe { ptr::read_unaligned(current_address as *const u64) });
+			let address = PhysAddr(unsafe {
+				ptr::read_unaligned(ptr::from_exposed_addr::<u64>(current_address))
+			});
 			current_address += mem::size_of::<u64>();
 			address
 		} else {
-			let address =
-				PhysAddr((unsafe { ptr::read_unaligned(current_address as *const u32) }).into());
+			let address = PhysAddr(
+				(unsafe { ptr::read_unaligned(ptr::from_exposed_addr::<u32>(current_address)) })
+					.into(),
+			);
 			current_address += mem::size_of::<u32>();
 			address
 		};

src/arch/x86_64/kernel/apic.rs

@@ -2,10 +2,8 @@ use alloc::vec::Vec;
 #[cfg(feature = "smp")]
 use core::arch::x86_64::_mm_mfence;
 use core::hint::spin_loop;
-#[cfg(feature = "smp")]
-use core::ptr;
 use core::sync::atomic::Ordering;
-use core::{cmp, fmt, mem, u32};
+use core::{cmp, fmt, mem, ptr, u32};
 
 use align_address::Align;
 #[cfg(feature = "smp")]
@@ -267,21 +265,23 @@ fn detect_from_acpi() -> Result<PhysAddr, ()> {
 fn detect_from_acpi() -> Result<PhysAddr, ()> {
 	// Get the Multiple APIC Description Table (MADT) from the ACPI information and its specific table header.
 	let madt = acpi::get_madt().ok_or(())?;
-	let madt_header = unsafe { &*(madt.table_start_address() as *const AcpiMadtHeader) };
+	let madt_header =
+		unsafe { &*(ptr::from_exposed_addr::<AcpiMadtHeader>(madt.table_start_address())) };
 
 	// Jump to the actual table entries (after the table header).
 	let mut current_address = madt.table_start_address() + mem::size_of::<AcpiMadtHeader>();
 
 	// Loop through all table entries.
 	while current_address < madt.table_end_address() {
-		let record = unsafe { &*(current_address as *const AcpiMadtRecordHeader) };
+		let record = unsafe { &*(ptr::from_exposed_addr::<AcpiMadtRecordHeader>(current_address)) };
 		current_address += mem::size_of::<AcpiMadtRecordHeader>();
 
 		match record.entry_type {
 			0 => {
 				// Processor Local APIC
-				let processor_local_apic_record =
-					unsafe { &*(current_address as *const ProcessorLocalApicRecord) };
+				let processor_local_apic_record = unsafe {
+					&*(ptr::from_exposed_addr::<ProcessorLocalApicRecord>(current_address))
+				};
 				debug!(
 					"Found Processor Local APIC record: {}",
 					processor_local_apic_record
@@ -293,7 +293,8 @@ fn detect_from_acpi() -> Result<PhysAddr, ()> {
 			}
 			1 => {
 				// I/O APIC
-				let ioapic_record = unsafe { &*(current_address as *const IoApicRecord) };
+				let ioapic_record =
+					unsafe { &*(ptr::from_exposed_addr::<IoApicRecord>(current_address)) };
 				debug!("Found I/O APIC record: {}", ioapic_record);
 
 				init_ioapic_address(PhysAddr(ioapic_record.address.into()));
@@ -379,7 +380,7 @@ fn detect_from_mp() -> Result<PhysAddr, ()> {
 
 	let mut addr: usize = virtual_address.as_usize()
 		| (mp_float.mp_config as usize & (BasePageSize::SIZE as usize - 1));
-	let mp_config: &ApicConfigTable = unsafe { &*(addr as *const ApicConfigTable) };
+	let mp_config: &ApicConfigTable = unsafe { &*(ptr::from_exposed_addr(addr)) };
 	if mp_config.signature != MP_CONFIG_SIGNATURE {
 		warn!("Invalid MP config table");
 		virtualmem::deallocate(virtual_address, BasePageSize::SIZE as usize);
@@ -395,19 +396,19 @@ fn detect_from_mp() -> Result<PhysAddr, ()> {
 		// entries starts directly after the config table
 		addr += mem::size_of::<ApicConfigTable>();
 		for _i in 0..mp_config.entry_count {
-			match unsafe { *(addr as *const u8) } {
+			match unsafe { *(ptr::from_exposed_addr(addr)) } {
 				// CPU entry
 				0 => {
 					let cpu_entry: &ApicProcessorEntry =
-						unsafe { &*(addr as *const ApicProcessorEntry) };
+						unsafe { &*(ptr::from_exposed_addr(addr)) };
 					if cpu_entry.cpu_flags & 0x01 == 0x01 {
 						add_local_apic_id(cpu_entry.id);
 					}
 					addr += mem::size_of::<ApicProcessorEntry>();
 				}
 				// IO-APIC entry
 				2 => {
-					let io_entry: &ApicIoEntry = unsafe { &*(addr as *const ApicIoEntry) };
+					let io_entry: &ApicIoEntry = unsafe { &*(ptr::from_exposed_addr(addr)) };
 					let ioapic = PhysAddr(io_entry.addr.into());
 					info!("Found IOAPIC at 0x{:p}", ioapic);
 
@@ -729,7 +730,7 @@ pub fn boot_application_processors() {
 		);
 		ptr::write_unaligned(
 			(SMP_BOOT_CODE_ADDRESS + SMP_BOOT_CODE_OFFSET_BOOTINFO).as_mut_ptr(),
-			raw_boot_info() as *const _ as u64,
+			ptr::from_ref(raw_boot_info()).addr() as u64,
 		);
 	}