From: Rebecca Schultz Zavin <rebecca@android.com>
Date: Tue, 12 Oct 2010 23:58:27 +0000 (-0700)
Subject: Revert "[ARM] mmu: add option to map lowmem with page mappings"
X-Git-Tag: firefly_0821_release~9833^2~157^2~4
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=3501c826b4db6f55d31cbb34460b5d51d4e9df52;p=firefly-linux-kernel-4.4.55.git

Revert "[ARM] mmu: add option to map lowmem with page mappings"

This reverts commit ac21b321048091bdbf45bbda87161cc9f312c393.
---

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index d7fd03bd80eb..da057fcd0491 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -857,12 +857,3 @@ config ARCH_HAS_BARRIERS
 	help
 	  This option allows the use of custom mandatory barriers
 	  included via the mach/barriers.h file.
-
-config ARCH_LOWMEM_IN_PTES
-	bool
-	help
-	  This option will map the kernel direct-mapped lowmem region
-	  using page table mappings rather than section mappings.
-
-config ARCH_USES_PG_UNCACHED
-	bool
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 6e65f186905c..6a3a2d0cd6db 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -251,7 +251,6 @@ static struct mem_type mem_types[] = {
 				L_PTE_USER | L_PTE_EXEC,
 		.prot_l1   = PMD_TYPE_TABLE,
 		.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
-		.prot_l1   = PMD_TYPE_TABLE,
 		.domain    = DOMAIN_KERNEL,
 	},
 	[MT_ROM] = {
@@ -556,30 +555,6 @@ static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr,
 	} while (pte++, addr += PAGE_SIZE, addr != end);
 }
 
-#ifdef CONFIG_ARCH_LOWMEM_IN_PTES
-static void __init realloc_init_pte(pmd_t *pmd, unsigned long addr,
-				    unsigned long end, unsigned long pfn,
-				    const struct mem_type *type)
-{
-	pte_t *pte, *ptep;
-
-	if ((pmd_val(*pmd) & PMD_TYPE_MASK) != PMD_TYPE_SECT)
-		return;
-
-	pte = early_alloc(2 * PTRS_PER_PTE * sizeof(pte_t));
-	if (WARN_ON(!pte))
-		return;
-
-	ptep = pte + PTRS_PER_PTE + __pte_index(addr);
-	do {
-		set_pte_ext(ptep, pfn_pte(pfn, __pgprot(type->prot_pte)), 0);
-		pfn++;
-	} while (ptep++, addr += PAGE_SIZE, addr != end);
-
-	__pmd_populate(pmd, __pa(pte) | type->prot_l1);
-}
-#endif
-
 static void __init alloc_init_section(pgd_t *pgd, unsigned long addr,
 				      unsigned long end, unsigned long phys,
 				      const struct mem_type *type)
@@ -1042,40 +1017,6 @@ static void __init map_lowmem(void)
 	}
 }
 
-static void __init remap_lowmem(void)
-{
-#ifdef CONFIG_ARCH_LOWMEM_IN_PTES
-	struct meminfo *mi = &meminfo;
-	const struct mem_type *type = &mem_types[MT_MEMORY];
-	int i;
-
-	for (i = 0; i < mi->nr_banks; i++) {
-		pgd_t *pgd;
-		unsigned long phys, addr, end;
-		struct membank *bank = &mi->bank[i];
-
-		if (bank->highmem)
-			continue;
-
-		phys = __pfn_to_phys(bank_pfn_start(bank));
-		addr = __phys_to_virt(bank_phys_start(bank));
-		end = addr + bank_phys_size(bank);
-
-		pgd = pgd_offset_k(addr);
-		do {
-			unsigned long next = pgd_addr_end(addr, end);
-			pmd_t *pmd = pmd_offset(pgd, addr);
-
-			realloc_init_pte(pmd, addr, next,
-					 __phys_to_pfn(phys), type);
-
-			phys += next - addr;
-			addr = next;
-		} while (pgd++, addr != end);
-	}
-#endif
-}
-
 static int __init meminfo_cmp(const void *_a, const void *_b)
 {
 	const struct membank *a = _a, *b = _b;
@@ -1097,7 +1038,6 @@ void __init paging_init(struct machine_desc *mdesc)
 	sanity_check_meminfo();
 	prepare_page_table();
 	map_lowmem();
-	remap_lowmem();
 	devicemaps_init(mdesc);
 	kmap_init();