ARM: Section based HYP idmap

Add a method (hyp_idmap_setup) to populate a hyp pgd with an
identity mapping of the code contained in the .hyp.idmap.text
section.

Offer a method to drop this identity mapping through
hyp_idmap_teardown.

Make all the above depend on CONFIG_ARM_VIRT_EXT and CONFIG_ARM_LPAE.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>

2 files changed, 2 insertions, 0 deletions

diff --git a/arch/arm/include/asm/idmap.h b/arch/arm/include/asm/idmap.h
index bf863edb517d..1a66f907e5cc 100644
--- a/arch/arm/include/asm/idmap.h
+++ b/arch/arm/include/asm/idmap.h
@@ -8,6 +8,7 @@
 #define __idmap __section(.idmap.text) noinline notrace
 
 extern pgd_t *idmap_pgd;
+extern pgd_t *hyp_pgd;
 
 void setup_mm_for_reboot(void);
 
diff --git a/arch/arm/include/asm/pgtable-3level-hwdef.h b/arch/arm/include/asm/pgtable-3level-hwdef.h
index d7952824c5c4..a2d404ed1ade 100644
--- a/arch/arm/include/asm/pgtable-3level-hwdef.h
+++ b/arch/arm/include/asm/pgtable-3level-hwdef.h
@@ -44,6 +44,7 @@
 #define PMD_SECT_XN             (_AT(pmdval_t, 1) << 54)
 #define PMD_SECT_AP_WRITE       (_AT(pmdval_t, 0))
 #define PMD_SECT_AP_READ        (_AT(pmdval_t, 0))
+#define PMD_SECT_AP1            (_AT(pmdval_t, 1) << 6)
 #define PMD_SECT_TEX(x)         (_AT(pmdval_t, 0))
 
 /*