From 0c8a32eed1625a65798286fb73fea8710a908545 Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Mon, 7 Sep 2020 06:20:18 +0000 Subject: csky: Add memory layout 2.5G(user):1.5G(kernel) There are two ways for translating va to pa for csky: - Use TLB(Translate Lookup Buffer) and PTW (Page Table Walk) - Use SSEG0/1 (Simple Segment Mapping) We use tlb mapping 0-2G and 3G-4G virtual address area and SSEG0/1 are for 2G-2.5G and 2.5G-3G translation. We could disable SSEG0 to use 2G-2.5G as TLB user mapping. Signed-off-by: Guo Ren --- arch/csky/kernel/setup.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) (limited to 'arch/csky/kernel/setup.c') diff --git a/arch/csky/kernel/setup.c b/arch/csky/kernel/setup.c index e4cab16056d6..e93bc6f74432 100644 --- a/arch/csky/kernel/setup.c +++ b/arch/csky/kernel/setup.c @@ -45,13 +45,17 @@ static void __init csky_memblock_init(void) if (size >= lowmem_size) { max_low_pfn = min_low_pfn + lowmem_size; +#ifdef CONFIG_PAGE_OFFSET_80000000 write_mmu_msa1(read_mmu_msa0() + SSEG_SIZE); +#endif } else if (size > sseg_size) { max_low_pfn = min_low_pfn + sseg_size; } max_zone_pfn[ZONE_NORMAL] = max_low_pfn; + mmu_init(min_low_pfn, max_low_pfn); + #ifdef CONFIG_HIGHMEM max_zone_pfn[ZONE_HIGHMEM] = max_pfn; @@ -101,16 +105,26 @@ void __init setup_arch(char **cmdline_p) unsigned long va_pa_offset; EXPORT_SYMBOL(va_pa_offset); +static inline unsigned long read_mmu_msa(void) +{ +#ifdef CONFIG_PAGE_OFFSET_80000000 + return read_mmu_msa0(); +#endif + +#ifdef CONFIG_PAGE_OFFSET_A0000000 + return read_mmu_msa1(); +#endif +} + asmlinkage __visible void __init csky_start(unsigned int unused, void *dtb_start) { /* Clean up bss section */ memset(__bss_start, 0, __bss_stop - __bss_start); - va_pa_offset = read_mmu_msa0() & ~(SSEG_SIZE - 1); + va_pa_offset = read_mmu_msa() & ~(SSEG_SIZE - 1); pre_trap_init(); - pre_mmu_init(); if (dtb_start == NULL) early_init_dt_scan(__dtb_start); -- cgit v1.2.3