* [PATCH 3/3] arm64: use mov_q instead of literal ldr
@ 2020-03-04 9:36 Rémi Denis-Courmont
2020-03-04 14:38 ` Mark Rutland
2020-03-20 18:16 ` Catalin Marinas
0 siblings, 2 replies; 3+ messages in thread
From: Rémi Denis-Courmont @ 2020-03-04 9:36 UTC (permalink / raw)
To: linux-arm-kernel
From: Remi Denis-Courmont <remi.denis.courmont@huawei.com>
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@huawei.com>
---
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 160be2b4696d..37d7dc5ec10d 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
ENDPROC(__kvm_handle_stub_hvc)
- .ltorg
-
.popsection
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index 76899c6eee2b..1df303405223 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -408,7 +408,7 @@ 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
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 3/3] arm64: use mov_q instead of literal ldr
2020-03-04 9:36 [PATCH 3/3] arm64: use mov_q instead of literal ldr Rémi Denis-Courmont
@ 2020-03-04 14:38 ` Mark Rutland
2020-03-20 18:16 ` Catalin Marinas
1 sibling, 0 replies; 3+ messages in thread
From: Mark Rutland @ 2020-03-04 14:38 UTC (permalink / raw)
To: Rémi Denis-Courmont
Cc: catalin.marinas, will, james.morse, linux-arm-kernel, ard.biesheuvel
On Wed, Mar 04, 2020 at 11:36:31AM +0200, Rémi Denis-Courmont wrote:
> From: Remi Denis-Courmont <remi.denis.courmont@huawei.com>
>
> 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@huawei.com>
FWIW, this looks reasonable to me (even without patch 1), so:
Acked-by: Mark Rutland <mark.rutland@arm.com>
Mark.
> ---
> 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 160be2b4696d..37d7dc5ec10d 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
>
> ENDPROC(__kvm_handle_stub_hvc)
>
> - .ltorg
> -
> .popsection
> diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
> index 76899c6eee2b..1df303405223 100644
> --- a/arch/arm64/mm/proc.S
> +++ b/arch/arm64/mm/proc.S
> @@ -408,7 +408,7 @@ 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
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 3/3] arm64: use mov_q instead of literal ldr
2020-03-04 9:36 [PATCH 3/3] arm64: use mov_q instead of literal ldr Rémi Denis-Courmont
2020-03-04 14:38 ` Mark Rutland
@ 2020-03-20 18:16 ` Catalin Marinas
1 sibling, 0 replies; 3+ messages in thread
From: Catalin Marinas @ 2020-03-20 18:16 UTC (permalink / raw)
To: Rémi Denis-Courmont; +Cc: linux-arm-kernel
On Wed, Mar 04, 2020 at 11:36:31AM +0200, Rémi Denis-Courmont wrote:
> From: Remi Denis-Courmont <remi.denis.courmont@huawei.com>
>
> 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@huawei.com>
Queued for 5.7. Thanks.
--
Catalin
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2020-03-20 18:16 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-04 9:36 [PATCH 3/3] arm64: use mov_q instead of literal ldr Rémi Denis-Courmont
2020-03-04 14:38 ` Mark Rutland
2020-03-20 18:16 ` Catalin Marinas
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.