We currently have __ioread32_copy, __iowrite32_copy & __iowrite64_copy
helpers in lib/iomap_copy.c. This patch adds __ioread64_copy to round
out the set, allowing copies from I/O memory using 32 or 64 bit reads.
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
---
include/linux/io.h | 1 +
lib/iomap_copy.c | 25 +++++++++++++++++++++++++
2 files changed, 26 insertions(+)
diff --git a/include/linux/io.h b/include/linux/io.h
index 2195d9ea4aaa..29a602a6ee0a 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -31,6 +31,7 @@ struct resource;
__visible void __iowrite32_copy(void __iomem *to, const void *from, size_t count);
void __ioread32_copy(void *to, const void __iomem *from, size_t count);
void __iowrite64_copy(void __iomem *to, const void *from, size_t count);
+void __ioread64_copy(void *to, const void __iomem *from, size_t count);
#ifdef CONFIG_MMU
int ioremap_page_range(unsigned long addr, unsigned long end,
diff --git a/lib/iomap_copy.c b/lib/iomap_copy.c
index b8f1d6cbb200..2efdf4baf9d4 100644
--- a/lib/iomap_copy.c
+++ b/lib/iomap_copy.c
@@ -89,3 +89,28 @@ void __attribute__((weak)) __iowrite64_copy(void __iomem *to,
}
EXPORT_SYMBOL_GPL(__iowrite64_copy);
+
+/**
+ * __ioread64_copy - copy data from MMIO space, in 64-bit units
+ * @to: destination (must be 64-bit aligned)
+ * @from: source, in MMIO space (must be 64-bit aligned)
+ * @count: number of 64-bit quantities to copy
+ *
+ * Copy data from MMIO space to kernel space, in units of 32 or 64 bits at a
+ * time. Order of access is not guaranteed, nor is a memory barrier
+ * performed afterwards.
+ */
+void __ioread64_copy(void *to, const void __iomem *from, size_t count)
+{
+#ifdef CONFIG_64BIT
+ u64 *dst = to;
+ const u64 __iomem *src = from;
+ const u64 __iomem *end = src + count;
+
+ while (src < end)
+ *dst++ = __raw_readq(src++);
+#else
+ __ioread32_copy(to, from, count * 2);
+#endif
+}
+EXPORT_SYMBOL_GPL(__ioread64_copy);
--
2.14.0
