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 <[email protected]>
Reviewed-by: Marcelo Tosatti <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
Signed-off-by: Christoffer Dall <[email protected]>
diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c
index 99db769..2dffc01 100644
--- a/arch/arm/mm/idmap.c
+++ b/arch/arm/mm/idmap.c
@@ -1,4 +1,6 @@
+#include <linux/module.h>
#include <linux/kernel.h>
+#include <linux/slab.h>
#include <asm/cputype.h>
#include <asm/idmap.h>
@@ -6,6 +8,7 @@
#include <asm/pgtable.h>
#include <asm/sections.h>
#include <asm/system_info.h>
+#include <asm/virt.h>
pgd_t *idmap_pgd;
@@ -59,11 +62,17 @@
} while (pud++, addr = next, addr != end);
}
-static void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end)
+static void identity_mapping_add(pgd_t *pgd, const char *text_start,
+ const char *text_end, unsigned long prot)
{
- unsigned long prot, next;
+ unsigned long addr, end;
+ unsigned long next;
- prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AF;
+ addr = virt_to_phys(text_start);
+ end = virt_to_phys(text_end);
+
+ prot |= PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AF;
+
if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())
prot |= PMD_BIT4;
@@ -74,28 +83,52 @@
} while (pgd++, addr = next, addr != end);
}
+#if defined(CONFIG_ARM_VIRT_EXT) && defined(CONFIG_ARM_LPAE)
+pgd_t *hyp_pgd;
+
+extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[];
+
+static int __init init_static_idmap_hyp(void)
+{
+ hyp_pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL);
+ if (!hyp_pgd)
+ return -ENOMEM;
+
+ pr_info("Setting up static HYP identity map for 0x%p - 0x%p\n",
+ __hyp_idmap_text_start, __hyp_idmap_text_end);
+ identity_mapping_add(hyp_pgd, __hyp_idmap_text_start,
+ __hyp_idmap_text_end, PMD_SECT_AP1);
+
+ return 0;
+}
+#else
+static int __init init_static_idmap_hyp(void)
+{
+ return 0;
+}
+#endif
+
extern char __idmap_text_start[], __idmap_text_end[];
static int __init init_static_idmap(void)
{
- phys_addr_t idmap_start, idmap_end;
+ int ret;
idmap_pgd = pgd_alloc(&init_mm);
if (!idmap_pgd)
return -ENOMEM;
- /* Add an identity mapping for the physical address of the section. */
- idmap_start = virt_to_phys((void *)__idmap_text_start);
- idmap_end = virt_to_phys((void *)__idmap_text_end);
+ pr_info("Setting up static identity map for 0x%p - 0x%p\n",
+ __idmap_text_start, __idmap_text_end);
+ identity_mapping_add(idmap_pgd, __idmap_text_start,
+ __idmap_text_end, 0);
- pr_info("Setting up static identity map for 0x%llx - 0x%llx\n",
- (long long)idmap_start, (long long)idmap_end);
- identity_mapping_add(idmap_pgd, idmap_start, idmap_end);
+ ret = init_static_idmap_hyp();
/* Flush L1 for the hardware to see this page table content */
flush_cache_louis();
- return 0;
+ return ret;
}
early_initcall(init_static_idmap);
