[07/11] backports: io.h: Add __ioread32_copy()
diff mbox series

Message ID 20191003155642.14909-8-hauke@hauke-m.de
State New
Headers show
Series
  • backports: Update to kernel 5.4-rc1
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Commit Message

Hauke Mehrtens Oct. 3, 2019, 3:56 p.m. UTC
Add __ioread32_copy() from usptream Linux commit a9aec5881b9d
("lib/iomap_copy.c: add __ioread32_copy()") which is used by mt76
driver.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
---
 backport/backport-include/linux/io.h |  5 +++++
 backport/compat/backport-4.5.c       | 22 ++++++++++++++++++++++
 2 files changed, 27 insertions(+)

Patch
diff mbox series

diff --git a/backport/backport-include/linux/io.h b/backport/backport-include/linux/io.h
index 78ae4650..f91085be 100644
--- a/backport/backport-include/linux/io.h
+++ b/backport/backport-include/linux/io.h
@@ -6,4 +6,9 @@ 
 #define IOMEM_ERR_PTR(err) (__force void __iomem *)ERR_PTR(err)
 #endif
 
+#if LINUX_VERSION_IS_LESS(4,5,0)
+#define __ioread32_copy LINUX_BACKPORT(__ioread32_copy)
+void __ioread32_copy(void *to, const void __iomem *from, size_t count);
+#endif
+
 #endif /* __BP_LINUX_IO_H */
diff --git a/backport/compat/backport-4.5.c b/backport/compat/backport-4.5.c
index 13764dc7..b4aae624 100644
--- a/backport/compat/backport-4.5.c
+++ b/backport/compat/backport-4.5.c
@@ -18,6 +18,7 @@ 
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <asm/uaccess.h>
+#include <linux/io.h>
 
 #if LINUX_VERSION_IS_GEQ(3,19,0)
 int led_set_brightness_sync(struct led_classdev *led_cdev,
@@ -150,3 +151,24 @@  int devm_led_trigger_register(struct device *dev,
 	return rc;
 }
 EXPORT_SYMBOL_GPL(devm_led_trigger_register);
+
+/**
+ * __ioread32_copy - copy data from MMIO space, in 32-bit units
+ * @to: destination (must be 32-bit aligned)
+ * @from: source, in MMIO space (must be 32-bit aligned)
+ * @count: number of 32-bit quantities to copy
+ *
+ * Copy data from MMIO space to kernel space, in units of 32 bits at a
+ * time.  Order of access is not guaranteed, nor is a memory barrier
+ * performed afterwards.
+ */
+void __ioread32_copy(void *to, const void __iomem *from, size_t count)
+{
+	u32 *dst = to;
+	const u32 __iomem *src = from;
+	const u32 __iomem *end = src + count;
+
+	while (src < end)
+		*dst++ = __raw_readl(src++);
+}
+EXPORT_SYMBOL_GPL(__ioread32_copy);