KVM: arm64: Migrate _elx sysreg accessors to msr_s/mrs_s

Currently, the {read,write}_sysreg_el*() accessors for accessing
particular ELs' sysregs in the presence of VHE rely on some local
hacks and define their system register encodings in a way that is
inconsistent with the core definitions in <asm/sysreg.h>.

As a result, it is necessary to add duplicate definitions for any
system register that already needs a definition in sysreg.h for
other reasons.

This is a bit of a maintenance headache, and the reasons for the
_el*() accessors working the way they do is a bit historical.

This patch gets rid of the shadow sysreg definitions in
<asm/kvm_hyp.h>, converts the _el*() accessors to use the core
__msr_s/__mrs_s interface, and converts all call sites to use the
standard sysreg #define names (i.e., upper case, with SYS_ prefix).

This patch will conflict heavily anyway, so the opportunity
to clean up some bad whitespace in the context of the changes is
taken.

The change exposes a few system registers that have no sysreg.h
definition, due to msr_s/mrs_s being used in place of msr/mrs:
additions are made in order to fill in the gaps.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://www.spinics.net/lists/kvm-arm/msg31717.html
[Rebased to v4.21-rc1]
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
[Rebased to v5.2-rc5, changelog updates]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 5 insertions, 45 deletions

diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index 286f7e7e1be4..86825aa20852 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -18,7 +18,7 @@
 #define read_sysreg_elx(r,nvh,vh)					\
 	({								\
 		u64 reg;						\
-		asm volatile(ALTERNATIVE("mrs %0, " __stringify(r##nvh),\
+		asm volatile(ALTERNATIVE(__mrs_s("%0", r##nvh),	\
 					 __mrs_s("%0", r##vh),		\
 					 ARM64_HAS_VIRT_HOST_EXTN)	\
 			     : "=r" (reg));				\
@@ -28,7 +28,7 @@
 #define write_sysreg_elx(v,r,nvh,vh)					\
 	do {								\
 		u64 __val = (u64)(v);					\
-		asm volatile(ALTERNATIVE("msr " __stringify(r##nvh) ", %x0",\
+		asm volatile(ALTERNATIVE(__msr_s(r##nvh, "%x0"),	\
 					 __msr_s(r##vh, "%x0"),		\
 					 ARM64_HAS_VIRT_HOST_EXTN)	\
 					 : : "rZ" (__val));		\
@@ -37,55 +37,15 @@
 /*
  * Unified accessors for registers that have a different encoding
  * between VHE and non-VHE. They must be specified without their "ELx"
- * encoding.
+ * encoding, but with the SYS_ prefix, as defined in asm/sysreg.h.
  */
-#define read_sysreg_el2(r)						\
-	({								\
-		u64 reg;						\
-		asm volatile(ALTERNATIVE("mrs %0, " __stringify(r##_EL2),\
-					 "mrs %0, " __stringify(r##_EL1),\
-					 ARM64_HAS_VIRT_HOST_EXTN)	\
-			     : "=r" (reg));				\
-		reg;							\
-	})
-
-#define write_sysreg_el2(v,r)						\
-	do {								\
-		u64 __val = (u64)(v);					\
-		asm volatile(ALTERNATIVE("msr " __stringify(r##_EL2) ", %x0",\
-					 "msr " __stringify(r##_EL1) ", %x0",\
-					 ARM64_HAS_VIRT_HOST_EXTN)	\
-					 : : "rZ" (__val));		\
-	} while (0)
 
 #define read_sysreg_el0(r)	read_sysreg_elx(r, _EL0, _EL02)
 #define write_sysreg_el0(v,r)	write_sysreg_elx(v, r, _EL0, _EL02)
 #define read_sysreg_el1(r)	read_sysreg_elx(r, _EL1, _EL12)
 #define write_sysreg_el1(v,r)	write_sysreg_elx(v, r, _EL1, _EL12)
-
-/* The VHE specific system registers and their encoding */
-#define sctlr_EL12              sys_reg(3, 5, 1, 0, 0)
-#define cpacr_EL12              sys_reg(3, 5, 1, 0, 2)
-#define ttbr0_EL12              sys_reg(3, 5, 2, 0, 0)
-#define ttbr1_EL12              sys_reg(3, 5, 2, 0, 1)
-#define tcr_EL12                sys_reg(3, 5, 2, 0, 2)
-#define afsr0_EL12              sys_reg(3, 5, 5, 1, 0)
-#define afsr1_EL12              sys_reg(3, 5, 5, 1, 1)
-#define esr_EL12                sys_reg(3, 5, 5, 2, 0)
-#define far_EL12                sys_reg(3, 5, 6, 0, 0)
-#define mair_EL12               sys_reg(3, 5, 10, 2, 0)
-#define amair_EL12              sys_reg(3, 5, 10, 3, 0)
-#define vbar_EL12               sys_reg(3, 5, 12, 0, 0)
-#define contextidr_EL12         sys_reg(3, 5, 13, 0, 1)
-#define cntkctl_EL12            sys_reg(3, 5, 14, 1, 0)
-#define cntp_tval_EL02          sys_reg(3, 5, 14, 2, 0)
-#define cntp_ctl_EL02           sys_reg(3, 5, 14, 2, 1)
-#define cntp_cval_EL02          sys_reg(3, 5, 14, 2, 2)
-#define cntv_tval_EL02          sys_reg(3, 5, 14, 3, 0)
-#define cntv_ctl_EL02           sys_reg(3, 5, 14, 3, 1)
-#define cntv_cval_EL02          sys_reg(3, 5, 14, 3, 2)
-#define spsr_EL12               sys_reg(3, 5, 4, 0, 0)
-#define elr_EL12                sys_reg(3, 5, 4, 0, 1)
+#define read_sysreg_el2(r)	read_sysreg_elx(r, _EL2, _EL1)
+#define write_sysreg_el2(v,r)	write_sysreg_elx(v, r, _EL2, _EL1)
 
 /**
  * hyp_alternate_select - Generates patchable code sequences that are