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.

Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

diff --git a/arch/mips/include/asm/mach-ralink/kmalloc.h b/arch/mips/include/asm/mach-ralink/kmalloc.h
new file mode 100644 (file)
index 0000000..1693209
--- /dev/null
+++ b/arch/mips/include/asm/mach-ralink/kmalloc.h
@@ -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 */