MIPS: ralink: reduce ARCH_DMA_MINALIGN

Currently, Ralink SoCs use the default ARCH_DMA_MINALIGN value of 128 bytes defined in mach-generic. This is excessive for these platforms and leads to significant memory waste in kmalloc.

Override ARCH_DMA_MINALIGN to use L1_CACHE_BYTES, which is 16 bytes for RT288X and 32 bytes for other Ralink SoCs.

---
 arch/mips/include/asm/mach-ralink/kmalloc.h | 9 +++++++++
 1 file changed, 9 insertions(+)
 create mode 100644 arch/mips/include/asm/mach-ralink/kmalloc.h

new file mode 100644
index 000000000000..1693209d3f37
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_MACH_RALINK_KMALLOC_H
+#define __ASM_MACH_RALINK_KMALLOC_H
+
+#ifdef CONFIG_DMA_NONCOHERENT
+#define ARCH_DMA_MINALIGN	L1_CACHE_BYTES
+#endif
+
+#endif /* __ASM_MACH_RALINK_KMALLOC_H */

2.43.0

applied to mips-next

Thomas.

Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]