ARM: mm: Recreate kernel mappings in early_paging_init() (a77e0c7b) · Commits · 戴 / test

arch/arm/include/asm/mach/arch.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -49,6 +49,7 @@ struct machine_desc {
		bool (*smp_init)(void);
		void (fixup)(struct tag , char **,
		struct meminfo *);
		void (*init_meminfo)(void);
		void (reserve)(void);/ reserve mem blocks */
		void (map_io)(void);/ IO mapping function */
		void (*init_early)(void);

arch/arm/kernel/setup.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -73,6 +73,8 @@ __setup("fpe=", fpe_setup);
		#endif

		extern void paging_init(const struct machine_desc *desc);
		extern void early_paging_init(const struct machine_desc *,
		struct proc_info_list *);
		extern void sanity_check_meminfo(void);
		extern enum reboot_mode reboot_mode;
		extern void setup_dma_zone(const struct machine_desc *desc);
		@@ -878,6 +880,8 @@ void __init setup_arch(char **cmdline_p)
		parse_early_param();

		sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL);

		early_paging_init(mdesc, lookup_processor_type(read_cpuid_id()));
		sanity_check_meminfo();
		arm_memblock_init(&meminfo, mdesc);

arch/arm/mm/mmu.c

+82 −0

Original line number	Diff line number	Diff line
		@@ -28,6 +28,8 @@
		#include <asm/highmem.h>
		#include <asm/system_info.h>
		#include <asm/traps.h>
		#include <asm/procinfo.h>
		#include <asm/memory.h>

		#include <asm/mach/arch.h>
		#include <asm/mach/map.h>
		@@ -1315,6 +1317,86 @@ static void __init map_lowmem(void)
		}
		}

		#ifdef CONFIG_ARM_LPAE
		/*
		* early_paging_init() recreates boot time page table setup, allowing machines
		* to switch over to a high (>4G) address space on LPAE systems
		*/
		void __init early_paging_init(const struct machine_desc *mdesc,
		struct proc_info_list *procinfo)
		{
		pmdval_t pmdprot = procinfo->__cpu_mm_mmu_flags;
		unsigned long map_start, map_end;
		pgd_t pgd0, pgdk;
		pud_t pud0, pudk, *pud_start;
		pmd_t pmd0, pmdk;
		phys_addr_t phys;
		int i;

		if (!(mdesc->init_meminfo))
		return;

		/* remap kernel code and data */
		map_start = init_mm.start_code;
		map_end = init_mm.brk;

		/* get a handle on things... */
		pgd0 = pgd_offset_k(0);
		pud_start = pud0 = pud_offset(pgd0, 0);
		pmd0 = pmd_offset(pud0, 0);

		pgdk = pgd_offset_k(map_start);
		pudk = pud_offset(pgdk, map_start);
		pmdk = pmd_offset(pudk, map_start);

		mdesc->init_meminfo();

		/* Run the patch stub to update the constants */
		fixup_pv_table(&__pv_table_begin,
		(&__pv_table_end - &__pv_table_begin) << 2);

		/*
		* Cache cleaning operations for self-modifying code
		* We should clean the entries by MVA but running a
		* for loop over every pv_table entry pointer would
		* just complicate the code.
		*/
		flush_cache_louis();
		dsb();
		isb();

		/* remap level 1 table */
		for (i = 0; i < PTRS_PER_PGD; pud0++, i++) {
		set_pud(pud0,
		__pud(__pa(pmd0) \| PMD_TYPE_TABLE \| L_PGD_SWAPPER));
		pmd0 += PTRS_PER_PMD;
		}

		/* remap pmds for kernel mapping */
		phys = __pa(map_start) & PMD_MASK;
		do {
		*pmdk++ = __pmd(phys \| pmdprot);
		phys += PMD_SIZE;
		} while (phys < map_end);

		flush_cache_all();
		cpu_switch_mm(pgd0, &init_mm);
		cpu_set_ttbr(1, __pa(pgd0) + TTBR1_OFFSET);
		local_flush_bp_all();
		local_flush_tlb_all();
		}

		#else

		void __init early_paging_init(const struct machine_desc *mdesc,
		struct proc_info_list *procinfo)
		{
		if (mdesc->init_meminfo)
		mdesc->init_meminfo();
		}

		#endif

		/*
		* paging_init() sets up the page tables, initialises the zone memory
		* maps, and sets up the zero page, bad page and bad page tables.

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