Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5ee07612 authored by Christian Borntraeger's avatar Christian Borntraeger
Browse files

ppc/kvm: Replace ACCESS_ONCE with READ_ONCE 

ACCESS_ONCE does not work reliably on non-scalar types. For
example gcc 4.6 and 4.7 might remove the volatile tag for such
accesses during the SRA (scalar replacement of aggregates) step
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145

)

Change the ppc/kvm code to replace ACCESS_ONCE with READ_ONCE.

Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: default avatarAlexander Graf <agraf@suse.de>
parent b1940cd2

arch/powerpc/kvm/book3s_hv_rm_xics.c

+4 −4
Original line number Diff line number Diff line
@@ -152,7 +152,7 @@ static void icp_rm_down_cppr(struct kvmppc_xics *xics, struct kvmppc_icp *icp, 
	 * in virtual mode.

	 */

	do {

		old_state = new_state = ACCESS_ONCE(icp->state);

		old_state = new_state = READ_ONCE(icp->state);



		/* Down_CPPR */

		new_state.cppr = new_cppr;
@@ -211,7 +211,7 @@ unsigned long kvmppc_rm_h_xirr(struct kvm_vcpu *vcpu) 
	 * pending priority

	 */

	do {

		old_state = new_state = ACCESS_ONCE(icp->state);

		old_state = new_state = READ_ONCE(icp->state);



		xirr = old_state.xisr | (((u32)old_state.cppr) << 24);

		if (!old_state.xisr)
@@ -277,7 +277,7 @@ int kvmppc_rm_h_ipi(struct kvm_vcpu *vcpu, unsigned long server, 
	 * whenever the MFRR is made less favored.

	 */

	do {

		old_state = new_state = ACCESS_ONCE(icp->state);

		old_state = new_state = READ_ONCE(icp->state);



		/* Set_MFRR */

		new_state.mfrr = mfrr;
@@ -352,7 +352,7 @@ int kvmppc_rm_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr) 
	icp_rm_clr_vcpu_irq(icp->vcpu);



	do {

		old_state = new_state = ACCESS_ONCE(icp->state);

		old_state = new_state = READ_ONCE(icp->state);



		reject = 0;

		new_state.cppr = cppr;

arch/powerpc/kvm/book3s_xics.c

+8 −8
Original line number Diff line number Diff line
@@ -327,7 +327,7 @@ static bool icp_try_to_deliver(struct kvmppc_icp *icp, u32 irq, u8 priority, 
		 icp->server_num);



	do {

		old_state = new_state = ACCESS_ONCE(icp->state);

		old_state = new_state = READ_ONCE(icp->state);



		*reject = 0;
@@ -512,7 +512,7 @@ static void icp_down_cppr(struct kvmppc_xics *xics, struct kvmppc_icp *icp, 
	 * in virtual mode.

	 */

	do {

		old_state = new_state = ACCESS_ONCE(icp->state);

		old_state = new_state = READ_ONCE(icp->state);



		/* Down_CPPR */

		new_state.cppr = new_cppr;
@@ -567,7 +567,7 @@ static noinline unsigned long kvmppc_h_xirr(struct kvm_vcpu *vcpu) 
	 * pending priority

	 */

	do {

		old_state = new_state = ACCESS_ONCE(icp->state);

		old_state = new_state = READ_ONCE(icp->state);



		xirr = old_state.xisr | (((u32)old_state.cppr) << 24);

		if (!old_state.xisr)
@@ -634,7 +634,7 @@ static noinline int kvmppc_h_ipi(struct kvm_vcpu *vcpu, unsigned long server, 
	 * whenever the MFRR is made less favored.

	 */

	do {

		old_state = new_state = ACCESS_ONCE(icp->state);

		old_state = new_state = READ_ONCE(icp->state);



		/* Set_MFRR */

		new_state.mfrr = mfrr;
@@ -679,7 +679,7 @@ static int kvmppc_h_ipoll(struct kvm_vcpu *vcpu, unsigned long server) 
		if (!icp)

			return H_PARAMETER;

	}

	state = ACCESS_ONCE(icp->state);

	state = READ_ONCE(icp->state);

	kvmppc_set_gpr(vcpu, 4, ((u32)state.cppr << 24) | state.xisr);

	kvmppc_set_gpr(vcpu, 5, state.mfrr);

	return H_SUCCESS;
@@ -721,7 +721,7 @@ static noinline void kvmppc_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr) 
				      BOOK3S_INTERRUPT_EXTERNAL_LEVEL);



	do {

		old_state = new_state = ACCESS_ONCE(icp->state);

		old_state = new_state = READ_ONCE(icp->state);



		reject = 0;

		new_state.cppr = cppr;
@@ -885,7 +885,7 @@ static int xics_debug_show(struct seq_file *m, void *private) 
		if (!icp)

			continue;



		state.raw = ACCESS_ONCE(icp->state.raw);

		state.raw = READ_ONCE(icp->state.raw);

		seq_printf(m, "cpu server %#lx XIRR:%#x PPRI:%#x CPPR:%#x MFRR:%#x OUT:%d NR:%d\n",

			   icp->server_num, state.xisr,

			   state.pending_pri, state.cppr, state.mfrr,
@@ -1082,7 +1082,7 @@ int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval) 
	 * the ICS states before the ICP states.

	 */

	do {

		old_state = ACCESS_ONCE(icp->state);

		old_state = READ_ONCE(icp->state);



		if (new_state.mfrr <= old_state.mfrr) {

			resend = false;