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>

arch/arm64/kvm/hyp/tlb.c

@@ -33,12 +33,12 @@ static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm,
 		 * in the TCR_EL1 register. We also need to prevent it to
 		 * allocate IPA->PA walks, so we enable the S1 MMU...
 		 */
-		val = cxt->tcr = read_sysreg_el1(tcr);
+		val = cxt->tcr = read_sysreg_el1(SYS_TCR);
 		val |= TCR_EPD1_MASK | TCR_EPD0_MASK;
-		write_sysreg_el1(val, tcr);
-		val = cxt->sctlr = read_sysreg_el1(sctlr);
+		write_sysreg_el1(val, SYS_TCR);
+		val = cxt->sctlr = read_sysreg_el1(SYS_SCTLR);
 		val |= SCTLR_ELx_M;
-		write_sysreg_el1(val, sctlr);
+		write_sysreg_el1(val, SYS_SCTLR);
 	}
 
 	/*
@@ -85,8 +85,8 @@ static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm,
 
 	if (cpus_have_const_cap(ARM64_WORKAROUND_1165522)) {
 		/* Restore the registers to what they were */
-		write_sysreg_el1(cxt->tcr, tcr);
-		write_sysreg_el1(cxt->sctlr, sctlr);
+		write_sysreg_el1(cxt->tcr, SYS_TCR);
+		write_sysreg_el1(cxt->sctlr, SYS_SCTLR);
 	}
 
 	local_irq_restore(cxt->flags);