On Tue, Jul 6, 2021 at 6:18 AM Huacai Chen <chenhuacai@xxxxxxxxxxx> wrote:
> diff --git a/arch/loongarch/include/asm/kmalloc.h b/arch/loongarch/include/asm/kmalloc.h
> new file mode 100644
> index 000000000000..b318c41520d8
> --- /dev/null
> +++ b/arch/loongarch/include/asm/kmalloc.h
> @@ -0,0 +1,10 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
> + */
> +#ifndef __ASM_KMALLOC_H
> +#define __ASM_KMALLOC_H
> +
> +#define ARCH_DMA_MINALIGN L1_CACHE_BYTES
> +
> +#endif /* __ASM_KMALLOC_H */
You wrote elsewhere that DMA is cache-coherent, so this should not
be needed at all.
> diff --git a/arch/loongarch/include/asm/shmparam.h b/arch/loongarch/include/asm/shmparam.h
> new file mode 100644
> index 000000000000..f726ac537710
> --- /dev/null
> +++ b/arch/loongarch/include/asm/shmparam.h
> @@ -0,0 +1,12 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
> + */
> +#ifndef _ASM_SHMPARAM_H
> +#define _ASM_SHMPARAM_H
> +
> +#define __ARCH_FORCE_SHMLBA 1
> +
> +#define SHMLBA (4 * PAGE_SIZE) /* attach addr a multiple of this */
> +
> +#endif /* _ASM_SHMPARAM_H */
I think this needs to be defined in a way that is independent of the configured
page size to minimize the differences between kernel configuration visible to
user space.
Maybe make it always 64KB?
> diff --git a/arch/loongarch/include/asm/sparsemem.h b/arch/loongarch/include/asm/sparsemem.h
> new file mode 100644
> index 000000000000..9b57dc69f523
> --- /dev/null
> +++ b/arch/loongarch/include/asm/sparsemem.h
> @@ -0,0 +1,21 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _LOONGARCH_SPARSEMEM_H
> +#define _LOONGARCH_SPARSEMEM_H
> +
> +#ifdef CONFIG_SPARSEMEM
> +
> +/*
> + * SECTION_SIZE_BITS 2^N: how big each section will be
> + * MAX_PHYSMEM_BITS 2^N: how much memory we can have in that space
> + */
> +#define SECTION_SIZE_BITS 29
> +#define MAX_PHYSMEM_BITS 48
Maybe add a comment to explain how you got to '29'?
> +
> +#ifdef CONFIG_PAGE_SIZE_4KB
> +#define PAGE_SHIFT 12
> +#endif
> +#ifdef CONFIG_PAGE_SIZE_16KB
> +#define PAGE_SHIFT 14
> +#endif
> +#ifdef CONFIG_PAGE_SIZE_64KB
> +#define PAGE_SHIFT 16
> +#endif
Shouldn't these be defined in some header?
Arnd
