arm64: add support for ioremap() block mappings

This wires up the existing generic huge-vmap feature, which allows
ioremap() to use PMD or PUD sized block mappings. It also adds support
to the unmap path for dealing with block mappings, which will allow us
to unmap the __init region using unmap_kernel_range() in a subsequent
patch.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 324420bf91f60582bb481133db9547111768ef17)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

1 files changed, 41 insertions, 0 deletions

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index d1fa678355c9..b4afa9fbb00f 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -745,3 +745,44 @@ void *__init fixmap_remap_fdt(phys_addr_t dt_phys)
 
 	return dt_virt;
 }
+
+int __init arch_ioremap_pud_supported(void)
+{
+	/* only 4k granule supports level 1 block mappings */
+	return IS_ENABLED(CONFIG_ARM64_4K_PAGES);
+}
+
+int __init arch_ioremap_pmd_supported(void)
+{
+	return 1;
+}
+
+int pud_set_huge(pud_t *pud, phys_addr_t phys, pgprot_t prot)
+{
+	BUG_ON(phys & ~PUD_MASK);
+	set_pud(pud, __pud(phys | PUD_TYPE_SECT | pgprot_val(mk_sect_prot(prot))));
+	return 1;
+}
+
+int pmd_set_huge(pmd_t *pmd, phys_addr_t phys, pgprot_t prot)
+{
+	BUG_ON(phys & ~PMD_MASK);
+	set_pmd(pmd, __pmd(phys | PMD_TYPE_SECT | pgprot_val(mk_sect_prot(prot))));
+	return 1;
+}
+
+int pud_clear_huge(pud_t *pud)
+{
+	if (!pud_sect(*pud))
+		return 0;
+	pud_clear(pud);
+	return 1;
+}
+
+int pmd_clear_huge(pmd_t *pmd)
+{
+	if (!pmd_sect(*pmd))
+		return 0;
+	pmd_clear(pmd);
+	return 1;
+}