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powerpc/64s: Do not allocate lppaca if we are not virtualized
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The "lppaca" is a structure registered with the hypervisor. This is
unnecessary when running on non-virtualised platforms. One field from
the lppaca (pmcregs_in_use) is also used by the host, so move the host
part out into the paca (lppaca field is still updated in
guest mode).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fix non-pseries build with some #ifdefs]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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Nicholas Piggin authored and Michael Ellerman committed Mar 30, 2018
1 parent 0834d62 commit 8e0b634
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Showing 7 changed files with 46 additions and 10 deletions.
12 changes: 10 additions & 2 deletions arch/powerpc/include/asm/paca.h
Original file line number Diff line number Diff line change
Expand Up @@ -46,7 +46,10 @@ extern unsigned int debug_smp_processor_id(void); /* from linux/smp.h */
#define get_paca() local_paca
#endif

#ifdef CONFIG_PPC_PSERIES
#define get_lppaca() (get_paca()->lppaca_ptr)
#endif

#define get_slb_shadow() (get_paca()->slb_shadow_ptr)

struct task_struct;
Expand All @@ -58,7 +61,7 @@ struct task_struct;
* processor.
*/
struct paca_struct {
#ifdef CONFIG_PPC_BOOK3S
#ifdef CONFIG_PPC_PSERIES
/*
* Because hw_cpu_id, unlike other paca fields, is accessed
* routinely from other CPUs (from the IRQ code), we stick to
Expand All @@ -67,7 +70,8 @@ struct paca_struct {
*/

struct lppaca *lppaca_ptr; /* Pointer to LpPaca for PLIC */
#endif /* CONFIG_PPC_BOOK3S */
#endif /* CONFIG_PPC_PSERIES */

/*
* MAGIC: the spinlock functions in arch/powerpc/lib/locks.c
* load lock_token and paca_index with a single lwz
Expand Down Expand Up @@ -160,10 +164,14 @@ struct paca_struct {
u64 saved_msr; /* MSR saved here by enter_rtas */
u16 trap_save; /* Used when bad stack is encountered */
u8 irq_soft_mask; /* mask for irq soft masking */
u8 soft_enabled; /* irq soft-enable flag */
u8 irq_happened; /* irq happened while soft-disabled */
u8 io_sync; /* writel() needs spin_unlock sync */
u8 irq_work_pending; /* IRQ_WORK interrupt while soft-disable */
u8 nap_state_lost; /* NV GPR values lost in power7_idle */
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
u8 pmcregs_in_use; /* pseries puts this in lppaca */
#endif
u64 sprg_vdso; /* Saved user-visible sprg */
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
u64 tm_scratch; /* TM scratch area for reclaim */
Expand Down
4 changes: 4 additions & 0 deletions arch/powerpc/include/asm/plpar_wrappers.h
Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,8 @@
#ifndef _ASM_POWERPC_PLPAR_WRAPPERS_H
#define _ASM_POWERPC_PLPAR_WRAPPERS_H

#ifdef CONFIG_PPC_PSERIES

#include <linux/string.h>
#include <linux/irqflags.h>

Expand Down Expand Up @@ -340,4 +342,6 @@ static inline long plpar_get_cpu_characteristics(struct h_cpu_char_result *p)
return rc;
}

#endif /* CONFIG_PPC_PSERIES */

#endif /* _ASM_POWERPC_PLPAR_WRAPPERS_H */
13 changes: 12 additions & 1 deletion arch/powerpc/include/asm/pmc.h
Original file line number Diff line number Diff line change
Expand Up @@ -31,10 +31,21 @@ void ppc_enable_pmcs(void);

#ifdef CONFIG_PPC_BOOK3S_64
#include <asm/lppaca.h>
#include <asm/firmware.h>

static inline void ppc_set_pmu_inuse(int inuse)
{
get_lppaca()->pmcregs_in_use = inuse;
#if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE)
if (firmware_has_feature(FW_FEATURE_LPAR)) {
#ifdef CONFIG_PPC_PSERIES
get_lppaca()->pmcregs_in_use = inuse;
#endif
} else {
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
get_paca()->pmcregs_in_use = inuse;
#endif
}
#endif
}

extern void power4_enable_pmcs(void);
Expand Down
5 changes: 5 additions & 0 deletions arch/powerpc/kernel/asm-offsets.c
Original file line number Diff line number Diff line change
Expand Up @@ -221,12 +221,17 @@ int main(void)
OFFSET(PACA_EXMC, paca_struct, exmc);
OFFSET(PACA_EXSLB, paca_struct, exslb);
OFFSET(PACA_EXNMI, paca_struct, exnmi);
#ifdef CONFIG_PPC_PSERIES
OFFSET(PACALPPACAPTR, paca_struct, lppaca_ptr);
#endif
OFFSET(PACA_SLBSHADOWPTR, paca_struct, slb_shadow_ptr);
OFFSET(SLBSHADOW_STACKVSID, slb_shadow, save_area[SLB_NUM_BOLTED - 1].vsid);
OFFSET(SLBSHADOW_STACKESID, slb_shadow, save_area[SLB_NUM_BOLTED - 1].esid);
OFFSET(SLBSHADOW_SAVEAREA, slb_shadow, save_area);
OFFSET(LPPACA_PMCINUSE, lppaca, pmcregs_in_use);
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
OFFSET(PACA_PMCINUSE, paca_struct, pmcregs_in_use);
#endif
OFFSET(LPPACA_DTLIDX, lppaca, dtl_idx);
OFFSET(LPPACA_YIELDCOUNT, lppaca, yield_count);
OFFSET(PACA_DTL_RIDX, paca_struct, dtl_ridx);
Expand Down
16 changes: 13 additions & 3 deletions arch/powerpc/kernel/paca.c
Original file line number Diff line number Diff line change
Expand Up @@ -20,7 +20,7 @@

#include "setup.h"

#ifdef CONFIG_PPC_BOOK3S
#ifdef CONFIG_PPC_PSERIES

/*
* The structure which the hypervisor knows about - this structure
Expand All @@ -47,6 +47,9 @@ static long __initdata lppaca_size;

static void __init allocate_lppacas(int nr_cpus, unsigned long limit)
{
if (early_cpu_has_feature(CPU_FTR_HVMODE))
return;

if (nr_cpus <= NR_LPPACAS)
return;

Expand All @@ -60,6 +63,9 @@ static struct lppaca * __init new_lppaca(int cpu)
{
struct lppaca *lp;

if (early_cpu_has_feature(CPU_FTR_HVMODE))
return NULL;

if (cpu < NR_LPPACAS)
return &lppaca[cpu];

Expand All @@ -73,6 +79,9 @@ static void __init free_lppacas(void)
{
long new_size = 0, nr;

if (early_cpu_has_feature(CPU_FTR_HVMODE))
return;

if (!lppaca_size)
return;
nr = num_possible_cpus() - NR_LPPACAS;
Expand Down Expand Up @@ -157,9 +166,10 @@ EXPORT_SYMBOL(paca);

void __init initialise_paca(struct paca_struct *new_paca, int cpu)
{
#ifdef CONFIG_PPC_BOOK3S
#ifdef CONFIG_PPC_PSERIES
new_paca->lppaca_ptr = new_lppaca(cpu);
#else
#endif
#ifdef CONFIG_PPC_BOOK3E
new_paca->kernel_pgd = swapper_pg_dir;
#endif
new_paca->lock_token = 0x8000;
Expand Down
3 changes: 1 addition & 2 deletions arch/powerpc/kvm/book3s_hv_interrupts.S
Original file line number Diff line number Diff line change
Expand Up @@ -79,8 +79,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
li r5, 0
mtspr SPRN_MMCRA, r5
isync
ld r3, PACALPPACAPTR(r13) /* is the host using the PMU? */
lbz r5, LPPACA_PMCINUSE(r3)
lbz r5, PACA_PMCINUSE(r13) /* is the host using the PMU? */
cmpwi r5, 0
beq 31f /* skip if not */
mfspr r5, SPRN_MMCR1
Expand Down
3 changes: 1 addition & 2 deletions arch/powerpc/kvm/book3s_hv_rmhandlers.S
Original file line number Diff line number Diff line change
Expand Up @@ -113,8 +113,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
mtspr SPRN_SPRG_VDSO_WRITE,r3

/* Reload the host's PMU registers */
ld r3, PACALPPACAPTR(r13) /* is the host using the PMU? */
lbz r4, LPPACA_PMCINUSE(r3)
lbz r4, PACA_PMCINUSE(r13) /* is the host using the PMU? */
cmpwi r4, 0
beq 23f /* skip if not */
BEGIN_FTR_SECTION
Expand Down

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