The branch main has been updated by andrew:
URL:
https://cgit.FreeBSD.org/src/commit/?id=05f6f65c3bdaf241ec819babda666445bf8e9909
commit 05f6f65c3bdaf241ec819babda666445bf8e9909
Author: Harry Moulton <harry.moul...@arm.com>
AuthorDate: 2025-02-17 15:58:39 +0000
Commit: Andrew Turner <and...@freebsd.org>
CommitDate: 2025-02-17 16:07:35 +0000
arm64: add CHECK_CPU_FEAT() for checking feature support in assembly
Add a new macro under asm.h to check whether a given CPU feature is
supported. There are a number of existing places where an ID register is
checked, and these have been updated in this change. These are for GIC
special registers, HAFDBS and HCX.
When calling, pass a temporary registers who's value is not important,
the name of the ID register (minus the exception level), the name of the
feature, and a label to jump to should the feature not be present. The
feature name should match with the macros defined in armreg.h or
hypervisor.h. Any feature-specific instructions can then be placed
between the macro and the label.
Reviewed by: andrew
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D48813
Signed-off-by: Harry Moulton <harry.moul...@arm.com>
---
sys/arm64/arm64/locore.S | 17 ++++-------------
sys/arm64/include/asm.h | 10 ++++++++++
2 files changed, 14 insertions(+), 13 deletions(-)
diff --git a/sys/arm64/arm64/locore.S b/sys/arm64/arm64/locore.S
index f3b846eee412..88193b6c93f7 100644
--- a/sys/arm64/arm64/locore.S
+++ b/sys/arm64/arm64/locore.S
@@ -403,10 +403,7 @@ LENTRY(enter_kernel_el)
* Configure the Extended Hypervisor register. This is only valid if
* FEAT_HCX is enabled.
*/
- mrs x2, id_aa64mmfr1_el1
- ubfx x2, x2, #ID_AA64MMFR1_HCX_SHIFT, #ID_AA64MMFR1_HCX_WIDTH
- cbz x2, 2f
-
+ CHECK_CPU_FEAT(x2, ID_AA64MMFR1, HCX, 2f)
/* Extended Hypervisor Configuration */
mov x2, xzr
msr HCRX_EL2_REG, x2
@@ -422,12 +419,8 @@ LENTRY(enter_kernel_el)
/* Zero vttbr_el2 so a hypervisor can tell the host and guest apart */
msr vttbr_el2, xzr
- /* Configure GICv3 CPU interface */
- mrs x2, id_aa64pfr0_el1
- /* Extract GIC bits from the register */
- ubfx x2, x2, #ID_AA64PFR0_GIC_SHIFT, #ID_AA64PFR0_GIC_BITS
- /* GIC[3:0] != 0000 - GIC CPU interface via special regs. supported */
- cbz x2, 3f
+ /* Check the CPU supports GIC, and configure the CPU interface */
+ CHECK_CPU_FEAT(x2, ID_AA64PFR0, GIC, 3f)
mrs x2, icc_sre_el2
orr x2, x2, #ICC_SRE_EL2_EN /* Enable access from insecure EL1 */
@@ -958,9 +951,7 @@ LENTRY(start_mmu)
* HW management of dirty state is set in C code as it may
* need to be disabled because of CPU errata.
*/
- mrs x3, id_aa64mmfr1_el1
- and x3, x3, #(ID_AA64MMFR1_HAFDBS_MASK)
- cbz x3, 1f
+ CHECK_CPU_FEAT(x3, ID_AA64MMFR1, HAFDBS, 1f)
orr x2, x2, #(TCR_HA)
1:
diff --git a/sys/arm64/include/asm.h b/sys/arm64/include/asm.h
index cc0a7d8293c9..4f373dc4b7e1 100644
--- a/sys/arm64/include/asm.h
+++ b/sys/arm64/include/asm.h
@@ -72,6 +72,16 @@
/* Alias for link register x30 */
#define lr x30
+/*
+ * Check whether a given cpu feature is present, in the case it is not we jump
+ * to the given label. The tmp register should be a register able to hold the
+ * temporary data.
+ */
+#define CHECK_CPU_FEAT(tmp, feat_reg, feat, label) \
+ mrs tmp, ##feat_reg##_el1; \
+ ubfx tmp, tmp, ##feat_reg##_##feat##_SHIFT,
##feat_reg##_##feat##_WIDTH; \
+ cbz tmp, label
+
/*
* Sets the trap fault handler. The exception handler will return to the
* address in the handler register on a data abort or the xzr register to
