Add El2Mpu implementation for PMSAv8-32 EL2 MPU support

Author: korken89

cortex-ar/src/pmsav8.rs

@@ -11,7 +11,9 @@ use arbitrary_int::{u26, u3};
 use crate::register;
 
 #[doc(inline)]
-pub use register::prbar::{AccessPerms, Shareability};
+pub use register::hprbar::{AccessPerms as El2AccessPerms, Shareability as El2Shareability};
+#[doc(inline)]
+pub use register::prbar::{AccessPerms as El1AccessPerms, Shareability as El1Shareability};
 
 /// Ways this API can fail
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -44,7 +46,7 @@ impl El1Mpu {
     }
 
     /// Access the current state of a region
-    pub fn get_region(&mut self, idx: u8) -> Option<Region> {
+    pub fn get_region(&mut self, idx: u8) -> Option<El1Region> {
         if idx >= self.num_regions() {
             return None;
         }
@@ -53,7 +55,7 @@ impl El1Mpu {
         let prlar = register::Prlar::read();
         let start_addr = (prbar.base().value() << 6) as *mut u8;
         let end_addr = ((prlar.limit().value() << 6) | 0x3F) as *mut u8;
-        Some(Region {
+        Some(El1Region {
             range: start_addr..=end_addr,
             shareability: prbar.shareability(),
             access: prbar.access_perms(),
@@ -76,7 +78,7 @@ impl El1Mpu {
     /// - [Error::UnalignedRegion] if the region's start address is not 64-byte aligned.
     /// - [Error::UnalignedRegion] if the region's end address is not 63-byte aligned.
     /// - [Error::InvalidMair] if the region's MAIR index is invalid (greater than 7).
-    pub fn set_region(&mut self, idx: u8, region: &Region) -> Result<(), Error> {
+    pub fn set_region(&mut self, idx: u8, region: &El1Region) -> Result<(), Error> {
         let start = *(region.range.start()) as usize as u32;
         // Check for 64-byte alignment (0x3F is six bits)
         if start & 0x3F != 0 {
@@ -118,7 +120,7 @@ impl El1Mpu {
     pub fn set_regions(
         &mut self,
         regions_starting_idx: u8,
-        regions: &[Region],
+        regions: &[El1Region],
     ) -> Result<(), Error> {
         if regions.len().saturating_add(regions_starting_idx as usize) > self.num_regions() as usize
         {
@@ -162,7 +164,7 @@ impl El1Mpu {
     /// Configure the EL1 MPU
     ///
     /// Write regions, attributes and enable/disable the background region with a single [Config] struct.
-    pub fn configure(&mut self, config: &Config) -> Result<(), Error> {
+    pub fn configure(&mut self, config: &El1Config) -> Result<(), Error> {
         self.set_regions(0, config.regions)?;
 
         self.set_attributes(config.memory_attributes);
@@ -187,17 +189,180 @@ impl El1Mpu {
     }
 }
 
-/// Configuration for the PMSAv8-32 MPU
+/// Represents our PMSAv8-32 EL2 MPU
+pub struct El2Mpu();
+
+impl El2Mpu {
+    /// Create an EL2 MPU handle
+    ///
+    /// # Safety
+    ///
+    /// Only create one of these at any given time, as they access shared
+    /// mutable state within the processor and do read-modify-writes on that state.
+    pub unsafe fn new() -> El2Mpu {
+        El2Mpu()
+    }
+
+    /// How many EL2 MPU regions are there?
+    pub fn num_regions(&self) -> u8 {
+        register::Hmpuir::read().region()
+    }
+
+    /// Access the current state of a region
+    pub fn get_region(&mut self, idx: u8) -> Option<El2Region> {
+        if idx >= self.num_regions() {
+            return None;
+        }
+        register::Hprselr::write(register::Hprselr(idx as u32));
+        let hprbar = register::Hprbar::read();
+        let hprlar = register::Hprlar::read();
+        let start_addr = (hprbar.base().value() << 6) as *mut u8;
+        let end_addr = ((hprlar.limit().value() << 6) | 0x3F) as *mut u8;
+        Some(El2Region {
+            range: start_addr..=end_addr,
+            shareability: hprbar.shareability(),
+            access: hprbar.access_perms(),
+            no_exec: hprbar.nx(),
+            mair: hprlar.mair().value(),
+            enable: hprlar.enabled(),
+        })
+    }
+
+    /// Write a single region to the EL2 MPU
+    ///
+    /// ## Arguments
+    ///
+    /// - `region`: The [El2Region] object containing the configuration for the MPU region.
+    /// - `idx`: The index of the region to be configured.
+    ///
+    /// ## Errors
+    ///
+    /// Returns:
+    /// - [Error::UnalignedRegion] if the region's start address is not 64-byte aligned.
+    /// - [Error::UnalignedRegion] if the region's end address is not 63-byte aligned.
+    /// - [Error::InvalidMair] if the region's MAIR index is invalid (greater than 7).
+    pub fn set_region(&mut self, idx: u8, region: &El2Region) -> Result<(), Error> {
+        let start = *(region.range.start()) as usize as u32;
+        // Check for 64-byte alignment (0x3F is six bits)
+        if start & 0x3F != 0 {
+            return Err(Error::UnalignedRegion(region.range.clone()));
+        }
+        let end = *(region.range.end()) as usize as u32;
+        if end & 0x3F != 0x3F {
+            return Err(Error::UnalignedRegion(region.range.clone()));
+        }
+        if region.mair > 7 {
+            return Err(Error::InvalidMair(region.mair));
+        }
+        register::Hprselr::write(register::Hprselr(idx as u32));
+        register::Hprbar::write({
+            let mut bar = register::Hprbar::new_with_raw_value(0);
+            bar.set_base(u26::from_u32(start >> 6));
+            bar.set_access_perms(region.access);
+            bar.set_nx(region.no_exec);
+            bar.set_shareability(region.shareability);
+            bar
+        });
+        register::Hprlar::write({
+            let mut lar = register::Hprlar::new_with_raw_value(0);
+            lar.set_limit(u26::from_u32(end >> 6));
+            lar.set_enabled(region.enable);
+            lar.set_mair(u3::from_u8(region.mair));
+            lar
+        });
+
+        Ok(())
+    }
+
+    /// Writes a subset of EL2 MPU regions starting from a specified index.
+    ///
+    /// ## Arguments
+    ///
+    /// - `regions_starting_idx`: The starting index for the regions to be reconfigured.
+    /// - `regions`: A slice of [El2Region] objects that will overwrite the previous regions starting from `regions_starting_idx`.
+    pub fn set_regions(
+        &mut self,
+        regions_starting_idx: u8,
+        regions: &[El2Region],
+    ) -> Result<(), Error> {
+        if regions.len().saturating_add(regions_starting_idx as usize) > self.num_regions() as usize
+        {
+            return Err(Error::TooManyRegions);
+        }
+
+        for (idx, region) in regions.iter().enumerate() {
+            self.set_region(idx as u8 + regions_starting_idx, region)?;
+        }
+
+        Ok(())
+    }
+
+    /// Set the memory attributes to HMAIR0 and HMAIR1
+    pub fn set_attributes(&mut self, memattrs: &[MemAttr]) {
+        let mem_attr0 = memattrs.get(0).map(|m| m.to_bits()).unwrap_or(0) as u32;
+        let mem_attr1 = memattrs.get(1).map(|m| m.to_bits()).unwrap_or(0) as u32;
+        let mem_attr2 = memattrs.get(2).map(|m| m.to_bits()).unwrap_or(0) as u32;
+        let mem_attr3 = memattrs.get(3).map(|m| m.to_bits()).unwrap_or(0) as u32;
+        let hmair0 = mem_attr3 << 24 | mem_attr2 << 16 | mem_attr1 << 8 | mem_attr0;
+        unsafe {
+            register::Hmair0::write(register::Hmair0(hmair0));
+        }
+        let mem_attr0 = memattrs.get(4).map(|m| m.to_bits()).unwrap_or(0) as u32;
+        let mem_attr1 = memattrs.get(5).map(|m| m.to_bits()).unwrap_or(0) as u32;
+        let mem_attr2 = memattrs.get(6).map(|m| m.to_bits()).unwrap_or(0) as u32;
+        let mem_attr3 = memattrs.get(7).map(|m| m.to_bits()).unwrap_or(0) as u32;
+        let hmair1 = mem_attr3 << 24 | mem_attr2 << 16 | mem_attr1 << 8 | mem_attr0;
+        unsafe {
+            register::Hmair1::write(register::Hmair1(hmair1));
+        }
+    }
+
+    /// Enable or disable the background region
+    pub fn background_region_enable(&mut self, enable: bool) {
+        register::Hsctlr::modify(|r| {
+            r.set_br(enable);
+        });
+    }
+
+    /// Configure the EL2 MPU
+    ///
+    /// Write regions, attributes and enable/disable the background region with a single [El2Config] struct.
+    pub fn configure(&mut self, config: &El2Config) -> Result<(), Error> {
+        self.set_regions(0, config.regions)?;
+
+        self.set_attributes(config.memory_attributes);
+
+        self.background_region_enable(config.background_config);
+
+        Ok(())
+    }
+
+    /// Enable the EL2 MPU
+    pub fn enable(&mut self) {
+        register::Hsctlr::modify(|r| {
+            r.set_m(true);
+        });
+    }
+
+    /// Disable the EL2 MPU
+    pub fn disable(&mut self) {
+        register::Hsctlr::modify(|r| {
+            r.set_m(false);
+        });
+    }
+}
+
+/// Configuration for the PMSAv8-32 EL1 MPU
 #[derive(Clone, Debug, PartialEq, Eq)]
-pub struct Config<'a> {
+pub struct El1Config<'a> {
     /// Background Config Enable
     ///
     /// If true, use the default MMU config if no other region matches an address
     pub background_config: bool,
     /// Information about each Region.
     ///
     /// If you pass more regions than the MPU supports, you get an error.
-    pub regions: &'a [Region],
+    pub regions: &'a [El1Region],
     /// Information about each Memory Attribute
     ///
     /// If you pass more MemAttrs than the MPU supports (8), you get an error.
@@ -206,16 +371,16 @@ pub struct Config<'a> {
 
 /// Configuration for the PMSAv8-32 MPU
 #[derive(Clone, Debug, PartialEq, Eq)]
-pub struct Region {
+pub struct El1Region {
     /// The range of the region
     ///
     /// * The first address must be a multiple of 32.
     /// * The length must be a multiple of 32.
     pub range: core::ops::RangeInclusive<*mut u8>,
     /// Shareability of the region
-    pub shareability: Shareability,
+    pub shareability: El1Shareability,
     /// Access for the region
-    pub access: AccessPerms,
+    pub access: El1AccessPerms,
     /// Is region no-exec?
     pub no_exec: bool,
     /// Which Memory Attribute applies here?
@@ -230,7 +395,52 @@ pub struct Region {
 
 // Creating a static Region is fine - the pointers within it
 // only go to the MPU and aren't accessed via Rust code
-unsafe impl Sync for Region {}
+unsafe impl Sync for El1Region {}
+
+/// Configuration for the PMSAv8-32 EL2 MPU
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct El2Config<'a> {
+    /// Background Config Enable
+    ///
+    /// If true, use the default MMU config if no other region matches an address
+    pub background_config: bool,
+    /// Information about each Region.
+    ///
+    /// If you pass more regions than the MPU supports, you get an error.
+    pub regions: &'a [El2Region],
+    /// Information about each Memory Attribute
+    ///
+    /// If you pass more MemAttrs than the MPU supports (8), you get an error.
+    pub memory_attributes: &'a [MemAttr],
+}
+
+/// Configuration for the PMSAv8-32 EL2 MPU
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct El2Region {
+    /// The range of the region
+    ///
+    /// * The first address must be a multiple of 32.
+    /// * The length must be a multiple of 32.
+    pub range: core::ops::RangeInclusive<*mut u8>,
+    /// Shareability of the region
+    pub shareability: El2Shareability,
+    /// Access for the region
+    pub access: El2AccessPerms,
+    /// Is region no-exec?
+    pub no_exec: bool,
+    /// Which Memory Attribute applies here?
+    ///
+    /// Selects from the eight attributes in {HMAIR0, HMAIR1}.
+    ///
+    /// Only values 0..=7 are valid here.
+    pub mair: u8,
+    /// Is this region enabled?
+    pub enable: bool,
+}
+
+// Creating a static El2Region is fine - the pointers within it
+// only go to the MPU and aren't accessed via Rust code
+unsafe impl Sync for El2Region {}
 
 /// Describes the memory ordering and cacheability of a region
 #[derive(Debug, Clone, PartialEq, Eq)]