[vmbase] Move SwiotlbInfo from pvmfw to vmbase

for reuse in both pvmfw and rialto to init shared memory.

Bug: 284462758
Test: m pvmfw_img
Change-Id: Ibe7b8b1bb8d10fbbdc4ec3348e801084c9a93bfd
diff --git a/pvmfw/src/crypto.rs b/pvmfw/src/crypto.rs
index d607bee..3d9c8d1 100644
--- a/pvmfw/src/crypto.rs
+++ b/pvmfw/src/crypto.rs
@@ -21,8 +21,6 @@
 use core::num::NonZeroU32;
 use core::ptr;
 
-use crate::cstr;
-
 use bssl_ffi::CRYPTO_library_init;
 use bssl_ffi::ERR_get_error_line;
 use bssl_ffi::ERR_lib_error_string;
@@ -37,6 +35,7 @@
 use bssl_ffi::EVP_AEAD;
 use bssl_ffi::EVP_AEAD_CTX;
 use bssl_ffi::HKDF;
+use vmbase::cstr;
 
 #[derive(Debug)]
 pub struct Error {
diff --git a/pvmfw/src/dice.rs b/pvmfw/src/dice.rs
index 3116456..fbab013 100644
--- a/pvmfw/src/dice.rs
+++ b/pvmfw/src/dice.rs
@@ -14,17 +14,16 @@
 
 //! Support for DICE derivation and BCC generation.
 
-use crate::cstr;
 use core::ffi::c_void;
 use core::mem::size_of;
 use core::slice;
-use vmbase::memory::flushed_zeroize;
-
 use diced_open_dice::{
     bcc_format_config_descriptor, bcc_handover_main_flow, hash, Config, DiceMode, Hash,
     InputValues, HIDDEN_SIZE,
 };
 use pvmfw_avb::{DebugLevel, Digest, VerifiedBootData};
+use vmbase::cstr;
+use vmbase::memory::flushed_zeroize;
 
 fn to_dice_mode(debug_level: DebugLevel) -> DiceMode {
     match debug_level {
diff --git a/pvmfw/src/fdt.rs b/pvmfw/src/fdt.rs
index d4c8385..b5b1958 100644
--- a/pvmfw/src/fdt.rs
+++ b/pvmfw/src/fdt.rs
@@ -15,7 +15,6 @@
 //! High-level FDT functions.
 
 use crate::bootargs::BootArgsIterator;
-use crate::cstr;
 use crate::helpers::GUEST_PAGE_SIZE;
 use crate::Box;
 use crate::RebootReason;
@@ -38,6 +37,8 @@
 use log::info;
 use log::warn;
 use tinyvec::ArrayVec;
+use vmbase::cstr;
+use vmbase::fdt::SwiotlbInfo;
 use vmbase::layout::{crosvm::MEM_START, MAX_VIRT_ADDR};
 use vmbase::memory::SIZE_4KB;
 use vmbase::util::flatten;
@@ -430,36 +431,6 @@
     Ok(())
 }
 
-#[derive(Debug)]
-pub struct SwiotlbInfo {
-    addr: Option<usize>,
-    size: usize,
-    align: Option<usize>,
-}
-
-impl SwiotlbInfo {
-    /// Creates a `SwiotlbInfo` struct from the given device tree.
-    pub fn new_from_fdt(fdt: &Fdt) -> libfdt::Result<SwiotlbInfo> {
-        let node =
-            fdt.compatible_nodes(cstr!("restricted-dma-pool"))?.next().ok_or(FdtError::NotFound)?;
-
-        let (addr, size, align) = if let Some(mut reg) = node.reg()? {
-            let reg = reg.next().ok_or(FdtError::NotFound)?;
-            let size = reg.size.ok_or(FdtError::NotFound)?;
-            (Some(reg.addr.try_into().unwrap()), size.try_into().unwrap(), None)
-        } else {
-            let size = node.getprop_u64(cstr!("size"))?.ok_or(FdtError::NotFound)?;
-            let align = node.getprop_u64(cstr!("alignment"))?.ok_or(FdtError::NotFound)?;
-            (None, size.try_into().unwrap(), Some(align.try_into().unwrap()))
-        };
-        Ok(Self { addr, size, align })
-    }
-
-    pub fn fixed_range(&self) -> Option<Range<usize>> {
-        self.addr.map(|addr| addr..addr + self.size)
-    }
-}
-
 fn validate_swiotlb_info(
     swiotlb_info: &SwiotlbInfo,
     memory: &Range<usize>,
diff --git a/pvmfw/src/helpers.rs b/pvmfw/src/helpers.rs
index 5ad721e..8981408 100644
--- a/pvmfw/src/helpers.rs
+++ b/pvmfw/src/helpers.rs
@@ -18,11 +18,3 @@
 
 pub const GUEST_PAGE_SIZE: usize = SIZE_4KB;
 pub const PVMFW_PAGE_SIZE: usize = PAGE_SIZE;
-
-/// Create &CStr out of &str literal
-#[macro_export]
-macro_rules! cstr {
-    ($str:literal) => {{
-        core::ffi::CStr::from_bytes_with_nul(concat!($str, "\0").as_bytes()).unwrap()
-    }};
-}
diff --git a/vmbase/Android.bp b/vmbase/Android.bp
index 6db9ff8..0ef47db 100644
--- a/vmbase/Android.bp
+++ b/vmbase/Android.bp
@@ -67,6 +67,7 @@
         "libbuddy_system_allocator",
         "libfdtpci",
         "libhyp",
+        "liblibfdt",
         "liblog_rust_nostd",
         "libonce_cell_nostd",
         "libsmccc",
diff --git a/vmbase/src/fdt.rs b/vmbase/src/fdt.rs
new file mode 100644
index 0000000..537ca03
--- /dev/null
+++ b/vmbase/src/fdt.rs
@@ -0,0 +1,54 @@
+// Copyright 2023, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! High-level FDT functions.
+
+use crate::cstr;
+use core::ops::Range;
+use libfdt::{self, Fdt, FdtError};
+
+/// Represents information about a SWIOTLB buffer.
+#[derive(Debug)]
+pub struct SwiotlbInfo {
+    /// The address of the SWIOTLB buffer, if available.
+    pub addr: Option<usize>,
+    /// The size of the SWIOTLB buffer.
+    pub size: usize,
+    /// The alignment of the SWIOTLB buffer, if available.
+    pub align: Option<usize>,
+}
+
+impl SwiotlbInfo {
+    /// Creates a `SwiotlbInfo` struct from the given device tree.
+    pub fn new_from_fdt(fdt: &Fdt) -> libfdt::Result<SwiotlbInfo> {
+        let node =
+            fdt.compatible_nodes(cstr!("restricted-dma-pool"))?.next().ok_or(FdtError::NotFound)?;
+
+        let (addr, size, align) = if let Some(mut reg) = node.reg()? {
+            let reg = reg.next().ok_or(FdtError::NotFound)?;
+            let size = reg.size.ok_or(FdtError::NotFound)?;
+            (Some(reg.addr.try_into().unwrap()), size.try_into().unwrap(), None)
+        } else {
+            let size = node.getprop_u64(cstr!("size"))?.ok_or(FdtError::NotFound)?;
+            let align = node.getprop_u64(cstr!("alignment"))?.ok_or(FdtError::NotFound)?;
+            (None, size.try_into().unwrap(), Some(align.try_into().unwrap()))
+        };
+        Ok(Self { addr, size, align })
+    }
+
+    /// Returns the fixed range of memory mapped by the SWIOTLB buffer, if available.
+    pub fn fixed_range(&self) -> Option<Range<usize>> {
+        self.addr.map(|addr| addr..addr + self.size)
+    }
+}
diff --git a/vmbase/src/lib.rs b/vmbase/src/lib.rs
index ebb3707..54f3384 100644
--- a/vmbase/src/lib.rs
+++ b/vmbase/src/lib.rs
@@ -22,6 +22,7 @@
 mod bionic;
 pub mod console;
 mod entry;
+pub mod fdt;
 pub mod layout;
 mod linker;
 pub mod logger;
diff --git a/vmbase/src/util.rs b/vmbase/src/util.rs
index 8c230a1..7fe6015 100644
--- a/vmbase/src/util.rs
+++ b/vmbase/src/util.rs
@@ -16,6 +16,14 @@
 
 use core::ops::Range;
 
+/// Create &CStr out of &str literal
+#[macro_export]
+macro_rules! cstr {
+    ($str:literal) => {{
+        core::ffi::CStr::from_bytes_with_nul(concat!($str, "\0").as_bytes()).unwrap()
+    }};
+}
+
 /// Flatten [[T; N]] into &[T]
 /// TODO: use slice::flatten when it graduates from experimental
 pub fn flatten<T, const N: usize>(original: &[[T; N]]) -> &[T] {