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authorGuo Ren <guoren@linux.alibaba.com>2020-09-07 06:20:18 +0000
committerGuo Ren <guoren@linux.alibaba.com>2021-01-12 09:52:40 +0800
commit0c8a32eed1625a65798286fb73fea8710a908545 (patch)
tree69992b6e217f5e985ebbf1f739b2af336d89138c /arch/csky/mm
parent7c53f6b671f4aba70ff15e1b05148b10d58c2837 (diff)
downloadlinux-0c8a32eed1625a65798286fb73fea8710a908545.tar.gz
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 <guoren@linux.alibaba.com>
Diffstat (limited to 'arch/csky/mm')
-rw-r--r--arch/csky/mm/fault.c7
-rw-r--r--arch/csky/mm/init.c29
2 files changed, 23 insertions, 13 deletions
diff --git a/arch/csky/mm/fault.c b/arch/csky/mm/fault.c
index 081b178b41b1..94eac13b9c97 100644
--- a/arch/csky/mm/fault.c
+++ b/arch/csky/mm/fault.c
@@ -59,7 +59,6 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
 
 	si_code = SEGV_MAPERR;
 
-#ifndef CONFIG_CPU_HAS_TLBI
 	/*
 	 * We fault-in kernel-space virtual memory on-demand. The
 	 * 'reference' page table is init_mm.pgd.
@@ -84,10 +83,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
 		pmd_t *pmd, *pmd_k;
 		pte_t *pte_k;
 
-		unsigned long pgd_base;
-
-		pgd_base = (unsigned long)__va(get_pgd());
-		pgd = (pgd_t *)pgd_base + offset;
+		pgd = get_pgd() + offset;
 		pgd_k = init_mm.pgd + offset;
 
 		if (!pgd_present(*pgd_k))
@@ -110,7 +106,6 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
 			goto no_context;
 		return;
 	}
-#endif
 
 	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
 	/*
diff --git a/arch/csky/mm/init.c b/arch/csky/mm/init.c
index af627128314f..7742f1441a67 100644
--- a/arch/csky/mm/init.c
+++ b/arch/csky/mm/init.c
@@ -28,9 +28,12 @@
 #include <asm/mmu_context.h>
 #include <asm/sections.h>
 #include <asm/tlb.h>
+#include <asm/cacheflush.h>
 
 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
+pte_t kernel_pte_tables[(PTRS_PER_PGD - USER_PTRS_PER_PGD)*PTRS_PER_PTE] __page_aligned_bss;
+
 EXPORT_SYMBOL(invalid_pte_table);
 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
 						__page_aligned_bss;
@@ -130,20 +133,32 @@ void pgd_init(unsigned long *p)
 
 	for (i = 0; i < PTRS_PER_PGD; i++)
 		p[i] = __pa(invalid_pte_table);
+
+	flush_tlb_all();
+	local_icache_inv_all(NULL);
 }
 
-void __init pre_mmu_init(void)
+void __init mmu_init(unsigned long min_pfn, unsigned long max_pfn)
 {
-	/*
-	 * Setup page-table and enable TLB-hardrefill
-	 */
+	int i;
+
+	for (i = 0; i < USER_PTRS_PER_PGD; i++)
+		swapper_pg_dir[i].pgd = __pa(invalid_pte_table);
+
+	for (i = USER_PTRS_PER_PGD; i < PTRS_PER_PGD; i++)
+		swapper_pg_dir[i].pgd =
+			__pa(kernel_pte_tables + (PTRS_PER_PTE * (i - USER_PTRS_PER_PGD)));
+
+	for (i = min_pfn; i < max_pfn; i++)
+		set_pte(&kernel_pte_tables[i - PFN_DOWN(va_pa_offset)], pfn_pte(i, PAGE_KERNEL));
+
 	flush_tlb_all();
-	pgd_init((unsigned long *)swapper_pg_dir);
-	TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);
-	TLBMISS_HANDLER_SETUP_PGD_KERNEL(swapper_pg_dir);
+	local_icache_inv_all(NULL);
 
 	/* Setup page mask to 4k */
 	write_mmu_pagemask(0);
+
+	setup_pgd(swapper_pg_dir);
 }
 
 void __init fixrange_init(unsigned long start, unsigned long end,