[PATCH stable 5.4 v2 1/4] ARM: 9011/1: centralize phys-to-virt conversion of DT/ATAGS address

From: Florian Fainelli
Date: Mon May 10 2021 - 09:57:45 EST


From: Ard Biesheuvel <ardb@xxxxxxxxxx>

commit e9a2f8b599d0bc22a1b13e69527246ac39c697b4 upstream

Before moving the DT mapping out of the linear region, let's prepare
for this change by removing all the phys-to-virt translations of the
__atags_pointer variable, and perform this translation only once at
setup time.

Tested-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Acked-by: Nicolas Pitre <nico@xxxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
arch/arm/include/asm/prom.h | 4 ++--
arch/arm/kernel/atags.h | 4 ++--
arch/arm/kernel/atags_parse.c | 6 +++---
arch/arm/kernel/devtree.c | 6 +++---
arch/arm/kernel/setup.c | 14 +++++++++-----
arch/arm/mm/mmu.c | 4 ++--
6 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/arch/arm/include/asm/prom.h b/arch/arm/include/asm/prom.h
index 1e36c40533c1..402e3f34c7ed 100644
--- a/arch/arm/include/asm/prom.h
+++ b/arch/arm/include/asm/prom.h
@@ -9,12 +9,12 @@

#ifdef CONFIG_OF

-extern const struct machine_desc *setup_machine_fdt(unsigned int dt_phys);
+extern const struct machine_desc *setup_machine_fdt(void *dt_virt);
extern void __init arm_dt_init_cpu_maps(void);

#else /* CONFIG_OF */

-static inline const struct machine_desc *setup_machine_fdt(unsigned int dt_phys)
+static inline const struct machine_desc *setup_machine_fdt(void *dt_virt)
{
return NULL;
}
diff --git a/arch/arm/kernel/atags.h b/arch/arm/kernel/atags.h
index 067e12edc341..f2819c25b602 100644
--- a/arch/arm/kernel/atags.h
+++ b/arch/arm/kernel/atags.h
@@ -2,11 +2,11 @@
void convert_to_tag_list(struct tag *tags);

#ifdef CONFIG_ATAGS
-const struct machine_desc *setup_machine_tags(phys_addr_t __atags_pointer,
+const struct machine_desc *setup_machine_tags(void *__atags_vaddr,
unsigned int machine_nr);
#else
static inline const struct machine_desc * __init __noreturn
-setup_machine_tags(phys_addr_t __atags_pointer, unsigned int machine_nr)
+setup_machine_tags(void *__atags_vaddr, unsigned int machine_nr)
{
early_print("no ATAGS support: can't continue\n");
while (true);
diff --git a/arch/arm/kernel/atags_parse.c b/arch/arm/kernel/atags_parse.c
index ce02f92f4ab2..8288151631fc 100644
--- a/arch/arm/kernel/atags_parse.c
+++ b/arch/arm/kernel/atags_parse.c
@@ -176,7 +176,7 @@ static void __init squash_mem_tags(struct tag *tag)
}

const struct machine_desc * __init
-setup_machine_tags(phys_addr_t __atags_pointer, unsigned int machine_nr)
+setup_machine_tags(void *atags_vaddr, unsigned int machine_nr)
{
struct tag *tags = (struct tag *)&default_tags;
const struct machine_desc *mdesc = NULL, *p;
@@ -197,8 +197,8 @@ setup_machine_tags(phys_addr_t __atags_pointer, unsigned int machine_nr)
if (!mdesc)
return NULL;

- if (__atags_pointer)
- tags = phys_to_virt(__atags_pointer);
+ if (atags_vaddr)
+ tags = atags_vaddr;
else if (mdesc->atag_offset)
tags = (void *)(PAGE_OFFSET + mdesc->atag_offset);

diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
index 39c978698406..4e09883c276d 100644
--- a/arch/arm/kernel/devtree.c
+++ b/arch/arm/kernel/devtree.c
@@ -203,12 +203,12 @@ static const void * __init arch_get_next_mach(const char *const **match)

/**
* setup_machine_fdt - Machine setup when an dtb was passed to the kernel
- * @dt_phys: physical address of dt blob
+ * @dt_virt: virtual address of dt blob
*
* If a dtb was passed to the kernel in r2, then use it to choose the
* correct machine_desc and to setup the system.
*/
-const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
+const struct machine_desc * __init setup_machine_fdt(void *dt_virt)
{
const struct machine_desc *mdesc, *mdesc_best = NULL;

@@ -221,7 +221,7 @@ const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
mdesc_best = &__mach_desc_GENERIC_DT;
#endif

- if (!dt_phys || !early_init_dt_verify(phys_to_virt(dt_phys)))
+ if (!dt_virt || !early_init_dt_verify(dt_virt))
return NULL;

mdesc = of_flat_dt_match_machine(mdesc_best, arch_get_next_mach);
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index d0a464e317ea..d0cad48ff83b 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -89,6 +89,7 @@ unsigned int cacheid __read_mostly;
EXPORT_SYMBOL(cacheid);

unsigned int __atags_pointer __initdata;
+void *atags_vaddr __initdata;

unsigned int system_rev;
EXPORT_SYMBOL(system_rev);
@@ -1075,19 +1076,22 @@ void __init hyp_mode_check(void)

void __init setup_arch(char **cmdline_p)
{
- const struct machine_desc *mdesc;
+ const struct machine_desc *mdesc = NULL;
+
+ if (__atags_pointer)
+ atags_vaddr = phys_to_virt(__atags_pointer);

setup_processor();
- mdesc = setup_machine_fdt(__atags_pointer);
+ if (atags_vaddr)
+ mdesc = setup_machine_fdt(atags_vaddr);
if (!mdesc)
- mdesc = setup_machine_tags(__atags_pointer, __machine_arch_type);
+ mdesc = setup_machine_tags(atags_vaddr, __machine_arch_type);
if (!mdesc) {
early_print("\nError: invalid dtb and unrecognized/unsupported machine ID\n");
early_print(" r1=0x%08x, r2=0x%08x\n", __machine_arch_type,
__atags_pointer);
if (__atags_pointer)
- early_print(" r2[]=%*ph\n", 16,
- phys_to_virt(__atags_pointer));
+ early_print(" r2[]=%*ph\n", 16, atags_vaddr);
dump_machine_table();
}

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 48c2888297dd..e1cd9a05be04 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -1512,7 +1512,7 @@ static void __init map_lowmem(void)
}

#ifdef CONFIG_ARM_PV_FIXUP
-extern unsigned long __atags_pointer;
+extern void *atags_vaddr;
typedef void pgtables_remap(long long offset, unsigned long pgd, void *bdata);
pgtables_remap lpae_pgtables_remap_asm;

@@ -1543,7 +1543,7 @@ static void __init early_paging_init(const struct machine_desc *mdesc)
*/
lpae_pgtables_remap = (pgtables_remap *)(unsigned long)__pa(lpae_pgtables_remap_asm);
pa_pgd = __pa(swapper_pg_dir);
- boot_data = __va(__atags_pointer);
+ boot_data = atags_vaddr;
barrier();

pr_info("Switching physical address space to 0x%08llx\n",
--
2.25.1