Commit f13c13a0 authored by Anton Blanchard's avatar Anton Blanchard Committed by Benjamin Herrenschmidt
Browse files

powerpc: Stop using non-architected shared_proc field in lppaca 



Although the shared_proc field in the lppaca works today, it is
not architected. A shared processor partition will always have a non
zero yield_count so use that instead. Create a wrapper so users
don't have to know about the details.

In order for older kernels to continue to work on KVM we need
to set the shared_proc bit. While here, remove the ugly bitfield.

Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 0c69f9c5

arch/powerpc/include/asm/lppaca.h

+14 −4
Original line number Diff line number Diff line
@@ -50,10 +50,8 @@ struct lppaca { 


	u32	desc;			/* Eye catcher 0xD397D781 */

	u16	size;			/* Size of this struct */

	u16	reserved1;

	u16	reserved2:14;

	u8	shared_proc:1;		/* Shared processor indicator */

	u8	secondary_thread:1;	/* Secondary thread indicator */

	u8	reserved1[3];

	u8	__old_status;		/* Old status, including shared proc */

	u8	reserved3[14];

	volatile u32 dyn_hw_node_id;	/* Dynamic hardware node id */

	volatile u32 dyn_hw_proc_id;	/* Dynamic hardware proc id */
@@ -107,6 +105,18 @@ extern struct lppaca lppaca[]; 


#define lppaca_of(cpu)	(*paca[cpu].lppaca_ptr)



/*

 * Old kernels used a reserved bit in the VPA to determine if it was running

 * in shared processor mode. New kernels look for a non zero yield count

 * but KVM still needs to set the bit to keep the old stuff happy.

 */

#define LPPACA_OLD_SHARED_PROC		2



static inline bool lppaca_shared_proc(struct lppaca *l)

{

	return l->yield_count != 0;

}



/*

 * SLB shadow buffer structure as defined in the PAPR.  The save_area

 * contains adjacent ESID and VSID pairs for each shadowed SLB.  The

arch/powerpc/include/asm/spinlock.h

+1 −1
Original line number Diff line number Diff line
@@ -96,7 +96,7 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock) 


#if defined(CONFIG_PPC_SPLPAR)

/* We only yield to the hypervisor if we are in shared processor mode */

#define SHARED_PROCESSOR (local_paca->lppaca_ptr->shared_proc)

#define SHARED_PROCESSOR (lppaca_shared_proc(local_paca->lppaca_ptr))

extern void __spin_yield(arch_spinlock_t *lock);

extern void __rw_yield(arch_rwlock_t *lock);

#else /* SPLPAR */

arch/powerpc/kernel/lparcfg.c

+3 −2
Original line number Diff line number Diff line
@@ -165,7 +165,7 @@ static void parse_ppp_data(struct seq_file *m) 
	           ppp_data.active_system_procs);



	/* pool related entries are appropriate for shared configs */

	if (lppaca_of(0).shared_proc) {

	if (lppaca_shared_proc(get_lppaca())) {

		unsigned long pool_idle_time, pool_procs;



		seq_printf(m, "pool=%d\n", ppp_data.pool_num);
@@ -473,7 +473,8 @@ static int pseries_lparcfg_data(struct seq_file *m, void *v) 
	seq_printf(m, "partition_potential_processors=%d\n",

		   partition_potential_processors);



	seq_printf(m, "shared_processor_mode=%d\n", lppaca_of(0).shared_proc);

	seq_printf(m, "shared_processor_mode=%d\n",

		   lppaca_shared_proc(get_lppaca()));



	seq_printf(m, "slb_size=%d\n", mmu_slb_size);

arch/powerpc/kvm/book3s_hv.c

+1 −1
Original line number Diff line number Diff line
@@ -217,7 +217,7 @@ struct kvm_vcpu *kvmppc_find_vcpu(struct kvm *kvm, int id) 


static void init_vpa(struct kvm_vcpu *vcpu, struct lppaca *vpa)

{

	vpa->shared_proc = 1;

	vpa->__old_status |= LPPACA_OLD_SHARED_PROC;

	vpa->yield_count = 1;

}

arch/powerpc/mm/numa.c

+1 −1
Original line number Diff line number Diff line
@@ -1609,7 +1609,7 @@ int start_topology_update(void) 
#endif

		}

	} else if (firmware_has_feature(FW_FEATURE_VPHN) &&

		   get_lppaca()->shared_proc) {

		   lppaca_shared_proc(get_lppaca())) {

		if (!vphn_enabled) {

			prrn_enabled = 0;

			vphn_enabled = 1;

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