[PATCH] arm64: use mov_q instead of literal ldr

From: RÃmi Denis-Courmont
Date: Thu Mar 12 2020 - 05:50:07 EST


From: Remi Denis-Courmont <remi.denis.courmont@xxxxxxxxxx>

In practice, this requires only 2 instructions, or even only 1 for
the idmap_pg_dir size (with 4 or 64 KiB pages). Only the MAIR values
needed more than 2 instructions and it was already converted to mov_q
by 95b3f74bec203804658e17f86fe20755bb8abcb9.

Signed-off-by: Remi Denis-Courmont <remi.denis.courmont@xxxxxxxxxx>
---
arch/arm64/kernel/cpu-reset.S | 2 +-
arch/arm64/kernel/hyp-stub.S | 2 +-
arch/arm64/kernel/relocate_kernel.S | 4 +---
arch/arm64/kvm/hyp-init.S | 10 ++++------
arch/arm64/mm/proc.S | 2 +-
5 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/kernel/cpu-reset.S b/arch/arm64/kernel/cpu-reset.S
index 32c7bf858dd9..38087b4c0432 100644
--- a/arch/arm64/kernel/cpu-reset.S
+++ b/arch/arm64/kernel/cpu-reset.S
@@ -32,7 +32,7 @@
ENTRY(__cpu_soft_restart)
/* Clear sctlr_el1 flags. */
mrs x12, sctlr_el1
- ldr x13, =SCTLR_ELx_FLAGS
+ mov_q x13, SCTLR_ELx_FLAGS
bic x12, x12, x13
pre_disable_mmu_workaround
msr sctlr_el1, x12
diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S
index 73d46070b315..e473ead806ed 100644
--- a/arch/arm64/kernel/hyp-stub.S
+++ b/arch/arm64/kernel/hyp-stub.S
@@ -63,7 +63,7 @@ el1_sync:
beq 9f // Nothing to reset!

/* Someone called kvm_call_hyp() against the hyp-stub... */
- ldr x0, =HVC_STUB_ERR
+ mov_q x0, HVC_STUB_ERR
eret

9: mov x0, xzr
diff --git a/arch/arm64/kernel/relocate_kernel.S b/arch/arm64/kernel/relocate_kernel.S
index c1d7db71a726..c40ce496c78b 100644
--- a/arch/arm64/kernel/relocate_kernel.S
+++ b/arch/arm64/kernel/relocate_kernel.S
@@ -41,7 +41,7 @@ ENTRY(arm64_relocate_new_kernel)
cmp x0, #CurrentEL_EL2
b.ne 1f
mrs x0, sctlr_el2
- ldr x1, =SCTLR_ELx_FLAGS
+ mov_q x1, SCTLR_ELx_FLAGS
bic x0, x0, x1
pre_disable_mmu_workaround
msr sctlr_el2, x0
@@ -113,8 +113,6 @@ ENTRY(arm64_relocate_new_kernel)

ENDPROC(arm64_relocate_new_kernel)

-.ltorg
-
.align 3 /* To keep the 64-bit values below naturally aligned. */

.Lcopy_end:
diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S
index 84f32cf5abc7..6e6ed5581eed 100644
--- a/arch/arm64/kvm/hyp-init.S
+++ b/arch/arm64/kvm/hyp-init.S
@@ -60,7 +60,7 @@ alternative_else_nop_endif
msr ttbr0_el2, x4

mrs x4, tcr_el1
- ldr x5, =TCR_EL2_MASK
+ mov_q x5, TCR_EL2_MASK
and x4, x4, x5
mov x5, #TCR_EL2_RES1
orr x4, x4, x5
@@ -102,7 +102,7 @@ alternative_else_nop_endif
* as well as the EE bit on BE. Drop the A flag since the compiler
* is allowed to generate unaligned accesses.
*/
- ldr x4, =(SCTLR_EL2_RES1 | (SCTLR_ELx_FLAGS & ~SCTLR_ELx_A))
+ mov_q x4, (SCTLR_EL2_RES1 | (SCTLR_ELx_FLAGS & ~SCTLR_ELx_A))
CPU_BE( orr x4, x4, #SCTLR_ELx_EE)
msr sctlr_el2, x4
isb
@@ -142,7 +142,7 @@ reset:
* case we coming via HVC_SOFT_RESTART.
*/
mrs x5, sctlr_el2
- ldr x6, =SCTLR_ELx_FLAGS
+ mov_q x6, SCTLR_ELx_FLAGS
bic x5, x5, x6 // Clear SCTL_M and etc
pre_disable_mmu_workaround
msr sctlr_el2, x5
@@ -155,11 +155,9 @@ reset:
eret

1: /* Bad stub call */
- ldr x0, =HVC_STUB_ERR
+ mov_q x0, HVC_STUB_ERR
eret

SYM_CODE_END(__kvm_handle_stub_hvc)

- .ltorg
-
.popsection
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index 1b871f141eb4..6bd228067ebc 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -411,7 +411,7 @@ SYM_FUNC_START(__cpu_setup)
* Set/prepare TCR and TTBR. We use 512GB (39-bit) address range for
* both user and kernel.
*/
- ldr x10, =TCR_TxSZ(VA_BITS) | TCR_CACHE_FLAGS | TCR_SMP_FLAGS | \
+ mov_q x10, TCR_TxSZ(VA_BITS) | TCR_CACHE_FLAGS | TCR_SMP_FLAGS | \
TCR_TG_FLAGS | TCR_KASLR_FLAGS | TCR_ASID16 | \
TCR_TBI0 | TCR_A1 | TCR_KASAN_FLAGS
tcr_clear_errata_bits x10, x9, x5
--
2.25.1