arm64: Factor out fixmap initialization from ioremap

The fixmap API was originally added for arm64 for
early_ioremap purposes. It can be used for other purposes too
so move the initialization from ioremap to somewhere more
generic. This makes it obvious where the fixmap is being set
up and allows for a cleaner implementation of __set_fixmap.

Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c
index 4a07630..cbb99c8 100644
--- a/arch/arm64/mm/ioremap.c
+++ b/arch/arm64/mm/ioremap.c
@@ -103,97 +103,10 @@
 }
 EXPORT_SYMBOL(ioremap_cache);
 
-static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss;
-#if CONFIG_ARM64_PGTABLE_LEVELS > 2
-static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss;
-#endif
-#if CONFIG_ARM64_PGTABLE_LEVELS > 3
-static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss;
-#endif
-
-static inline pud_t * __init early_ioremap_pud(unsigned long addr)
-{
-	pgd_t *pgd;
-
-	pgd = pgd_offset_k(addr);
-	BUG_ON(pgd_none(*pgd) || pgd_bad(*pgd));
-
-	return pud_offset(pgd, addr);
-}
-
-static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
-{
-	pud_t *pud = early_ioremap_pud(addr);
-
-	BUG_ON(pud_none(*pud) || pud_bad(*pud));
-
-	return pmd_offset(pud, addr);
-}
-
-static inline pte_t * __init early_ioremap_pte(unsigned long addr)
-{
-	pmd_t *pmd = early_ioremap_pmd(addr);
-
-	BUG_ON(pmd_none(*pmd) || pmd_bad(*pmd));
-
-	return pte_offset_kernel(pmd, addr);
-}
-
+/*
+ * Must be called after early_fixmap_init
+ */
 void __init early_ioremap_init(void)
 {
-	pgd_t *pgd;
-	pud_t *pud;
-	pmd_t *pmd;
-	unsigned long addr = fix_to_virt(FIX_BTMAP_BEGIN);
-
-	pgd = pgd_offset_k(addr);
-	pgd_populate(&init_mm, pgd, bm_pud);
-	pud = pud_offset(pgd, addr);
-	pud_populate(&init_mm, pud, bm_pmd);
-	pmd = pmd_offset(pud, addr);
-	pmd_populate_kernel(&init_mm, pmd, bm_pte);
-
-	/*
-	 * The boot-ioremap range spans multiple pmds, for which
-	 * we are not prepared:
-	 */
-	BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
-		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
-
-	if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
-		WARN_ON(1);
-		pr_warn("pmd %p != %p\n",
-			pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END)));
-		pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
-			fix_to_virt(FIX_BTMAP_BEGIN));
-		pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
-			fix_to_virt(FIX_BTMAP_END));
-
-		pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
-		pr_warn("FIX_BTMAP_BEGIN:     %d\n",
-			FIX_BTMAP_BEGIN);
-	}
-
 	early_ioremap_setup();
 }
-
-void __init __early_set_fixmap(enum fixed_addresses idx,
-			       phys_addr_t phys, pgprot_t flags)
-{
-	unsigned long addr = __fix_to_virt(idx);
-	pte_t *pte;
-
-	if (idx >= __end_of_fixed_addresses) {
-		BUG();
-		return;
-	}
-
-	pte = early_ioremap_pte(addr);
-
-	if (pgprot_val(flags))
-		set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
-	else {
-		pte_clear(&init_mm, addr, pte);
-		flush_tlb_kernel_range(addr, addr+PAGE_SIZE);
-	}
-}