Allow non-standard access sizes in Generic Address Structures

This is required for various special address space types (e.g. the PCC)

Author: IsaacWoods

src/address.rs

@@ -49,25 +49,27 @@ pub enum AddressSpace {
     OemDefined(u8),
 }
 
+/// Specifies a standard access size. The access size of a GAS can be non-standard, and is defined
+/// by the Address Space ID in such cases.
 #[derive(PartialEq, Eq, Clone, Copy, Debug)]
-pub enum AccessSize {
+pub enum StandardAccessSize {
     Undefined,
     ByteAccess,
     WordAccess,
     DWordAccess,
     QWordAccess,
 }
 
-impl TryFrom<u8> for AccessSize {
+impl TryFrom<u8> for StandardAccessSize {
     type Error = AcpiError;
 
     fn try_from(size: u8) -> Result<Self, Self::Error> {
         match size {
-            0 => Ok(AccessSize::Undefined),
-            1 => Ok(AccessSize::ByteAccess),
-            2 => Ok(AccessSize::WordAccess),
-            3 => Ok(AccessSize::DWordAccess),
-            4 => Ok(AccessSize::QWordAccess),
+            0 => Ok(StandardAccessSize::Undefined),
+            1 => Ok(StandardAccessSize::ByteAccess),
+            2 => Ok(StandardAccessSize::WordAccess),
+            3 => Ok(StandardAccessSize::DWordAccess),
+            4 => Ok(StandardAccessSize::QWordAccess),
             _ => Err(AcpiError::InvalidGenericAddress),
         }
     }
@@ -78,7 +80,7 @@ pub struct GenericAddress {
     pub address_space: AddressSpace,
     pub bit_width: u8,
     pub bit_offset: u8,
-    pub access_size: AccessSize,
+    pub access_size: u8,
     pub address: u64,
 }
 
@@ -106,8 +108,12 @@ impl GenericAddress {
             address_space,
             bit_width: raw.bit_width,
             bit_offset: raw.bit_offset,
-            access_size: AccessSize::try_from(raw.access_size)?,
+            access_size: raw.access_size,
             address: raw.address,
         })
     }
+
+    pub fn standard_access_size(&self) -> Result<StandardAccessSize, AcpiError> {
+        StandardAccessSize::try_from(self.access_size)
+    }
 }

src/sdt/fadt.rs

@@ -1,7 +1,7 @@
 use crate::{
     AcpiError,
     AcpiTable,
-    address::{AccessSize, AddressSpace, GenericAddress, RawGenericAddress},
+    address::{AddressSpace, GenericAddress, RawGenericAddress, StandardAccessSize},
     sdt::{ExtendedField, SdtHeader, Signature},
 };
 use bit_field::BitField;
@@ -179,7 +179,7 @@ impl Fadt {
             address_space: AddressSpace::SystemIo,
             bit_width: self.pm1_event_length * 8,
             bit_offset: 0,
-            access_size: AccessSize::Undefined,
+            access_size: 0,
             address: self.pm1a_event_block.into(),
         })
     }
@@ -196,7 +196,7 @@ impl Fadt {
                 address_space: AddressSpace::SystemIo,
                 bit_width: self.pm1_event_length * 8,
                 bit_offset: 0,
-                access_size: AccessSize::Undefined,
+                access_size: 0,
                 address: self.pm1b_event_block.into(),
             }))
         } else {
@@ -215,7 +215,7 @@ impl Fadt {
             address_space: AddressSpace::SystemIo,
             bit_width: self.pm1_control_length * 8,
             bit_offset: 0,
-            access_size: AccessSize::Undefined,
+            access_size: 0,
             address: self.pm1a_control_block.into(),
         })
     }
@@ -232,7 +232,7 @@ impl Fadt {
                 address_space: AddressSpace::SystemIo,
                 bit_width: self.pm1_control_length * 8,
                 bit_offset: 0,
-                access_size: AccessSize::Undefined,
+                access_size: 0,
                 address: self.pm1b_control_block.into(),
             }))
         } else {
@@ -252,7 +252,7 @@ impl Fadt {
                 address_space: AddressSpace::SystemIo,
                 bit_width: self.pm2_control_length * 8,
                 bit_offset: 0,
-                access_size: AccessSize::Undefined,
+                access_size: 0,
                 address: self.pm2_control_block.into(),
             }))
         } else {
@@ -279,7 +279,7 @@ impl Fadt {
                 address_space: AddressSpace::SystemIo,
                 bit_width: 32,
                 bit_offset: 0,
-                access_size: AccessSize::Undefined,
+                access_size: 0,
                 address: self.pm_timer_block.into(),
             }))
         } else {
@@ -299,7 +299,7 @@ impl Fadt {
                 address_space: AddressSpace::SystemIo,
                 bit_width: self.gpe0_block_length * 8,
                 bit_offset: 0,
-                access_size: AccessSize::Undefined,
+                access_size: 0,
                 address: self.gpe0_block.into(),
             }))
         } else {
@@ -319,7 +319,7 @@ impl Fadt {
                 address_space: AddressSpace::SystemIo,
                 bit_width: self.gpe1_block_length * 8,
                 bit_offset: 0,
-                access_size: AccessSize::Undefined,
+                access_size: 0,
                 address: self.gpe1_block.into(),
             }))
         } else {