[Tracking/Asahi] Upstream-ready Rust changes

Documentation/rust/arch-support.rst

@@ -15,5 +15,6 @@ support corresponds to ``S`` values in the ``MAINTAINERS`` file.
 ============  ================  ==============================================
 Architecture  Level of support  Constraints
 ============  ================  ==============================================
+``arm64``     Maintained        None.
 ``x86``       Maintained        ``x86_64`` only.
 ============  ================  ==============================================

arch/arm64/Kconfig

@@ -207,6 +207,7 @@ config ARM64
 	select HAVE_FUNCTION_ARG_ACCESS_API
 	select MMU_GATHER_RCU_TABLE_FREE
 	select HAVE_RSEQ
+	select HAVE_RUST
 	select HAVE_STACKPROTECTOR
 	select HAVE_SYSCALL_TRACEPOINTS
 	select HAVE_KPROBES

arch/arm64/Makefile

@@ -41,6 +41,8 @@ KBUILD_CFLAGS	+= -mgeneral-regs-only	\
 KBUILD_CFLAGS	+= $(call cc-disable-warning, psabi)
 KBUILD_AFLAGS	+= $(compat_vdso)
 
+KBUILD_RUSTFLAGS += -C target-feature="-neon,-fp-armv8"
+
 KBUILD_CFLAGS	+= $(call cc-option,-mabi=lp64)
 KBUILD_AFLAGS	+= $(call cc-option,-mabi=lp64)
 
@@ -85,8 +87,10 @@ PACRET-$(CONFIG_UNWIND_PATCH_PAC_INTO_SCS) := pac-ret
 
 ifeq ($(CONFIG_ARM64_BTI_KERNEL),y)
 branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET_BTI) := -mbranch-protection=$(PACRET-y)+bti
+KBUILD_RUSTFLAGS += -Z branch-protection=bti,pac-ret,leaf
 else
 branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=$(PACRET-y)
+KBUILD_RUSTFLAGS += -Z branch-protection=pac-ret,leaf
 endif
 # -march=armv8.3-a enables the non-nops instructions for PAC, to avoid the
 # compiler to generate them and consequently to break the single image contract

drivers/gpu/drm/drm_gem_shmem_helper.c

@@ -681,23 +681,7 @@ struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_shmem_object *shmem)
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_get_sg_table);
 
-/**
- * drm_gem_shmem_get_pages_sgt - Pin pages, dma map them, and return a
- *				 scatter/gather table for a shmem GEM object.
- * @shmem: shmem GEM object
- *
- * This function returns a scatter/gather table suitable for driver usage. If
- * the sg table doesn't exist, the pages are pinned, dma-mapped, and a sg
- * table created.
- *
- * This is the main function for drivers to get at backing storage, and it hides
- * and difference between dma-buf imported and natively allocated objects.
- * drm_gem_shmem_get_sg_table() should not be directly called by drivers.
- *
- * Returns:
- * A pointer to the scatter/gather table of pinned pages or errno on failure.
- */
-struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem)
+static struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
 	int ret;
@@ -706,9 +690,9 @@ struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem)
 	if (shmem->sgt)
 		return shmem->sgt;
 
-	WARN_ON(obj->import_attach);
+	WARN_ON(shmem->base.import_attach);
 
-	ret = drm_gem_shmem_get_pages(shmem);
+	ret = drm_gem_shmem_get_pages_locked(shmem);
 	if (ret)
 		return ERR_PTR(ret);
 
@@ -730,10 +714,40 @@ struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem)
 	sg_free_table(sgt);
 	kfree(sgt);
 err_put_pages:
-	drm_gem_shmem_put_pages(shmem);
+	drm_gem_shmem_put_pages_locked(shmem);
 	return ERR_PTR(ret);
 }
-EXPORT_SYMBOL_GPL(drm_gem_shmem_get_pages_sgt);
+
+/**
+ * drm_gem_shmem_get_pages_sgt - Pin pages, dma map them, and return a
+ *				 scatter/gather table for a shmem GEM object.
+ * @shmem: shmem GEM object
+ *
+ * This function returns a scatter/gather table suitable for driver usage. If
+ * the sg table doesn't exist, the pages are pinned, dma-mapped, and a sg
+ * table created.
+ *
+ * This is the main function for drivers to get at backing storage, and it hides
+ * and difference between dma-buf imported and natively allocated objects.
+ * drm_gem_shmem_get_sg_table() should not be directly called by drivers.
+ *
+ * Returns:
+ * A pointer to the scatter/gather table of pinned pages or errno on failure.
+ */
+struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem)
+{
+	int ret;
+	struct sg_table *sgt;
+
+	ret = mutex_lock_interruptible(&shmem->pages_lock);
+	if (ret)
+		return ERR_PTR(ret);
+	sgt = drm_gem_shmem_get_pages_sgt_locked(shmem);
+	mutex_unlock(&shmem->pages_lock);
+
+	return sgt;
+}
+EXPORT_SYMBOL(drm_gem_shmem_get_pages_sgt);
 
 /**
  * drm_gem_shmem_prime_import_sg_table - Produce a shmem GEM object from

drivers/soc/apple/rtkit.c

@@ -698,7 +698,7 @@ static int apple_rtkit_request_mbox_chan(struct apple_rtkit *rtk)
 	return 0;
 }
 
-static struct apple_rtkit *apple_rtkit_init(struct device *dev, void *cookie,
+struct apple_rtkit *apple_rtkit_init(struct device *dev, void *cookie,
 					    const char *mbox_name, int mbox_idx,
 					    const struct apple_rtkit_ops *ops)
 {
@@ -750,6 +750,7 @@ static struct apple_rtkit *apple_rtkit_init(struct device *dev, void *cookie,
 	kfree(rtk);
 	return ERR_PTR(ret);
 }
+EXPORT_SYMBOL_GPL(apple_rtkit_init);
 
 static int apple_rtkit_wait_for_completion(struct completion *c)
 {
@@ -926,10 +927,8 @@ int apple_rtkit_wake(struct apple_rtkit *rtk)
 }
 EXPORT_SYMBOL_GPL(apple_rtkit_wake);
 
-static void apple_rtkit_free(void *data)
+void apple_rtkit_free(struct apple_rtkit *rtk)
 {
-	struct apple_rtkit *rtk = data;
-
 	mbox_free_channel(rtk->mbox_chan);
 	destroy_workqueue(rtk->wq);
 
@@ -940,6 +939,12 @@ static void apple_rtkit_free(void *data)
 	kfree(rtk->syslog_msg_buffer);
 	kfree(rtk);
 }
+EXPORT_SYMBOL_GPL(apple_rtkit_free);
+
+static void apple_rtkit_free_wrapper(void *data)
+{
+	apple_rtkit_free(data);
+}
 
 struct apple_rtkit *devm_apple_rtkit_init(struct device *dev, void *cookie,
 					  const char *mbox_name, int mbox_idx,
@@ -952,7 +957,7 @@ struct apple_rtkit *devm_apple_rtkit_init(struct device *dev, void *cookie,
 	if (IS_ERR(rtk))
 		return rtk;
 
-	ret = devm_add_action_or_reset(dev, apple_rtkit_free, rtk);
+	ret = devm_add_action_or_reset(dev, apple_rtkit_free_wrapper, rtk);
 	if (ret)
 		return ERR_PTR(ret);
 

include/linux/soc/apple/rtkit.h

@@ -22,6 +22,7 @@
  * @size:      Size of the shared memory buffer.
  * @iova:      Device VA of shared memory buffer.
  * @is_mapped: Shared memory buffer is managed by the co-processor.
+ * @private:   Private data pointer for the parent driver.
  */
 
 struct apple_rtkit_shmem {
@@ -30,6 +31,7 @@ struct apple_rtkit_shmem {
 	size_t size;
 	dma_addr_t iova;
 	bool is_mapped;
+	void *private;
 };
 
 /*
@@ -77,6 +79,25 @@ struct apple_rtkit *devm_apple_rtkit_init(struct device *dev, void *cookie,
 					  const char *mbox_name, int mbox_idx,
 					  const struct apple_rtkit_ops *ops);
 
+/*
+ * Non-devm version of devm_apple_rtkit_init. Must be freed with
+ * apple_rtkit_free.
+ *
+ * @dev:         Pointer to the device node this coprocessor is assocated with
+ * @cookie:      opaque cookie passed to all functions defined in rtkit_ops
+ * @mbox_name:   mailbox name used to communicate with the co-processor
+ * @mbox_idx:    mailbox index to be used if mbox_name is NULL
+ * @ops:         pointer to rtkit_ops to be used for this co-processor
+ */
+struct apple_rtkit *apple_rtkit_init(struct device *dev, void *cookie,
+					  const char *mbox_name, int mbox_idx,
+					  const struct apple_rtkit_ops *ops);
+
+/*
+ * Free an instance of apple_rtkit.
+ */
+void apple_rtkit_free(struct apple_rtkit *rtk);
+
 /*
  * Reinitialize internal structures. Must only be called with the co-processor
  * is held in reset.

rust/alloc/vec/mod.rs

@@ -122,10 +122,8 @@ use self::spec_from_elem::SpecFromElem;
 #[cfg(not(no_global_oom_handling))]
 mod spec_from_elem;
 
-#[cfg(not(no_global_oom_handling))]
 use self::set_len_on_drop::SetLenOnDrop;
 
-#[cfg(not(no_global_oom_handling))]
 mod set_len_on_drop;
 
 #[cfg(not(no_global_oom_handling))]
@@ -149,7 +147,8 @@ mod spec_from_iter;
 #[cfg(not(no_global_oom_handling))]
 use self::spec_extend::SpecExtend;
 
-#[cfg(not(no_global_oom_handling))]
+use self::spec_extend::TrySpecExtend;
+
 mod spec_extend;
 
 /// A contiguous growable array type, written as `Vec<T>`, short for 'vector'.
@@ -1919,6 +1918,17 @@ impl<T, A: Allocator> Vec<T, A> {
         self.len += count;
     }
 
+    /// Tries to append elements to `self` from other buffer.
+    #[inline]
+    unsafe fn try_append_elements(&mut self, other: *const [T]) -> Result<(), TryReserveError> {
+        let count = unsafe { (*other).len() };
+        self.try_reserve(count)?;
+        let len = self.len();
+        unsafe { ptr::copy_nonoverlapping(other as *const T, self.as_mut_ptr().add(len), count) };
+        self.len += count;
+        Ok(())
+    }
+
     /// Removes the specified range from the vector in bulk, returning all
     /// removed elements as an iterator. If the iterator is dropped before
     /// being fully consumed, it drops the remaining removed elements.
@@ -2340,6 +2350,45 @@ impl<T: Clone, A: Allocator> Vec<T, A> {
         }
     }
 
+    /// Tries to resize the `Vec` in-place so that `len` is equal to `new_len`.
+    ///
+    /// If `new_len` is greater than `len`, the `Vec` is extended by the
+    /// difference, with each additional slot filled with `value`.
+    /// If `new_len` is less than `len`, the `Vec` is simply truncated.
+    ///
+    /// This method requires `T` to implement [`Clone`],
+    /// in order to be able to clone the passed value.
+    /// If you need more flexibility (or want to rely on [`Default`] instead of
+    /// [`Clone`]), use [`Vec::resize_with`].
+    /// If you only need to resize to a smaller size, use [`Vec::truncate`].
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let mut vec = vec!["hello"];
+    /// vec.try_resize(3, "world").unwrap();
+    /// assert_eq!(vec, ["hello", "world", "world"]);
+    ///
+    /// let mut vec = vec![1, 2, 3, 4];
+    /// vec.try_resize(2, 0).unwrap();
+    /// assert_eq!(vec, [1, 2]);
+    ///
+    /// let mut vec = vec![42];
+    /// let result = vec.try_resize(usize::MAX, 0);
+    /// assert!(result.is_err());
+    /// ```
+    #[stable(feature = "kernel", since = "1.0.0")]
+    pub fn try_resize(&mut self, new_len: usize, value: T) -> Result<(), TryReserveError> {
+        let len = self.len();
+
+        if new_len > len {
+            self.try_extend_with(new_len - len, ExtendElement(value))
+        } else {
+            self.truncate(new_len);
+            Ok(())
+        }
+    }
+
     /// Clones and appends all elements in a slice to the `Vec`.
     ///
     /// Iterates over the slice `other`, clones each element, and then appends
@@ -2365,6 +2414,30 @@ impl<T: Clone, A: Allocator> Vec<T, A> {
         self.spec_extend(other.iter())
     }
 
+    /// Tries to clone and append all elements in a slice to the `Vec`.
+    ///
+    /// Iterates over the slice `other`, clones each element, and then appends
+    /// it to this `Vec`. The `other` slice is traversed in-order.
+    ///
+    /// Note that this function is same as [`extend`] except that it is
+    /// specialized to work with slices instead. If and when Rust gets
+    /// specialization this function will likely be deprecated (but still
+    /// available).
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let mut vec = vec![1];
+    /// vec.try_extend_from_slice(&[2, 3, 4]).unwrap();
+    /// assert_eq!(vec, [1, 2, 3, 4]);
+    /// ```
+    ///
+    /// [`extend`]: Vec::extend
+    #[stable(feature = "kernel", since = "1.0.0")]
+    pub fn try_extend_from_slice(&mut self, other: &[T]) -> Result<(), TryReserveError> {
+        self.try_spec_extend(other.iter())
+    }
+
     /// Copies elements from `src` range to the end of the vector.
     ///
     /// # Panics
@@ -2504,6 +2577,36 @@ impl<T, A: Allocator> Vec<T, A> {
             // len set by scope guard
         }
     }
+
+    /// Try to extend the vector by `n` values, using the given generator.
+    fn try_extend_with<E: ExtendWith<T>>(&mut self, n: usize, mut value: E) -> Result<(), TryReserveError> {
+        self.try_reserve(n)?;
+
+        unsafe {
+            let mut ptr = self.as_mut_ptr().add(self.len());
+            // Use SetLenOnDrop to work around bug where compiler
+            // might not realize the store through `ptr` through self.set_len()
+            // don't alias.
+            let mut local_len = SetLenOnDrop::new(&mut self.len);
+
+            // Write all elements except the last one
+            for _ in 1..n {
+                ptr::write(ptr, value.next());
+                ptr = ptr.add(1);
+                // Increment the length in every step in case next() panics
+                local_len.increment_len(1);
+            }
+
+            if n > 0 {
+                // We can write the last element directly without cloning needlessly
+                ptr::write(ptr, value.last());
+                local_len.increment_len(1);
+            }
+
+            // len set by scope guard
+            Ok(())
+        }
+    }
 }
 
 impl<T: PartialEq, A: Allocator> Vec<T, A> {
@@ -2838,6 +2941,34 @@ impl<T, A: Allocator> Vec<T, A> {
         }
     }
 
+    // leaf method to which various SpecFrom/SpecExtend implementations delegate when
+    // they have no further optimizations to apply
+    fn try_extend_desugared<I: Iterator<Item = T>>(&mut self, mut iterator: I) -> Result<(), TryReserveError> {
+        // This is the case for a general iterator.
+        //
+        // This function should be the moral equivalent of:
+        //
+        //      for item in iterator {
+        //          self.push(item);
+        //      }
+        while let Some(element) = iterator.next() {
+            let len = self.len();
+            if len == self.capacity() {
+                let (lower, _) = iterator.size_hint();
+                self.try_reserve(lower.saturating_add(1))?;
+            }
+            unsafe {
+                ptr::write(self.as_mut_ptr().add(len), element);
+                // Since next() executes user code which can panic we have to bump the length
+                // after each step.
+                // NB can't overflow since we would have had to alloc the address space
+                self.set_len(len + 1);
+            }
+        }
+
+        Ok(())
+    }
+
     /// Creates a splicing iterator that replaces the specified range in the vector
     /// with the given `replace_with` iterator and yields the removed items.
     /// `replace_with` does not need to be the same length as `range`.