[ppc64] shared processor support, from Dave Engebretsen
Initial round of code to add shared processor support into 2.6.
This adds h_call interfaces, paca/VPA fields, and vpa register.
Add adds new idle loop code.
---
arch/ppc64/kernel/chrp_setup.c | 2
arch/ppc64/kernel/idle.c | 251 ++++++++++++++++++++++++++++-------
arch/ppc64/kernel/pSeries_lpar.c | 25 +++
arch/ppc64/kernel/setup.c | 8 +
arch/ppc64/kernel/smp.c | 16 ++
include/asm-ppc64/hvcall.h | 18 ++
include/asm-ppc64/iSeries/ItLpPaca.h | 5
include/asm-ppc64/memory.h | 25 ++-
include/asm-ppc64/naca.h | 7
include/asm-ppc64/paca.h | 12 +
include/asm-ppc64/processor.h | 1
11 files changed, 306 insertions(+), 64 deletions(-)
diff -puN arch/ppc64/kernel/pSeries_lpar.c~ppc64-sharedproc arch/ppc64/kernel/pSeries_lpar.c
--- 25/arch/ppc64/kernel/pSeries_lpar.c~ppc64-sharedproc 2004-01-13 23:22:44.000000000 -0800
+++ 25-akpm/arch/ppc64/kernel/pSeries_lpar.c 2004-01-13 23:22:44.000000000 -0800
@@ -37,6 +37,31 @@
#include <asm/hvcall.h>
#include <asm/prom.h>
+long poll_pending(void)
+{
+ unsigned long dummy;
+ return plpar_hcall(H_POLL_PENDING, 0, 0, 0, 0,
+ &dummy, &dummy, &dummy);
+}
+
+long prod_processor(void)
+{
+ plpar_hcall_norets(H_PROD);
+ return(0);
+}
+
+long cede_processor(void)
+{
+ plpar_hcall_norets(H_CEDE);
+ return(0);
+}
+
+long register_vpa(unsigned long flags, unsigned long proc, unsigned long vpa)
+{
+ plpar_hcall_norets(H_REGISTER_VPA, flags, proc, vpa);
+ return(0);
+}
+
long plpar_pte_remove(unsigned long flags,
unsigned long ptex,
unsigned long avpn,
diff -puN arch/ppc64/kernel/setup.c~ppc64-sharedproc arch/ppc64/kernel/setup.c
--- 25/arch/ppc64/kernel/setup.c~ppc64-sharedproc 2004-01-13 23:22:44.000000000 -0800
+++ 25-akpm/arch/ppc64/kernel/setup.c 2004-01-13 23:22:44.000000000 -0800
@@ -58,6 +58,7 @@ extern void iSeries_init_early( void );
extern void pSeries_init_early( void );
extern void pSeriesLP_init_early(void);
extern void mm_init_ppc64( void );
+extern void vpa_init(int cpu);
unsigned long decr_overclock = 1;
unsigned long decr_overclock_proc0 = 1;
@@ -211,6 +212,13 @@ void setup_system(unsigned long r3, unsi
mm_init_ppc64();
+ if (cur_cpu_spec->firmware_features & FW_FEATURE_SPLPAR) {
+ vpa_init(boot_cpuid);
+ }
+
+ /* Select the correct idle loop for the platform. */
+ idle_setup();
+
switch (systemcfg->platform) {
#ifdef CONFIG_PPC_ISERIES
case PLATFORM_ISERIES_LPAR:
diff -puN arch/ppc64/kernel/smp.c~ppc64-sharedproc arch/ppc64/kernel/smp.c
--- 25/arch/ppc64/kernel/smp.c~ppc64-sharedproc 2004-01-13 23:22:44.000000000 -0800
+++ 25-akpm/arch/ppc64/kernel/smp.c 2004-01-13 23:22:44.000000000 -0800
@@ -266,6 +266,16 @@ static void __init smp_space_timers(unsi
}
#ifdef CONFIG_PPC_PSERIES
+void vpa_init(int cpu) {
+ unsigned long flags;
+
+ /* Register the Virtual Processor Area (VPA) */
+ printk(KERN_INFO "register_vpa: cpu 0x%x\n", cpu);
+ flags = 1UL << (63 - 18);
+ paca[cpu].xLpPaca.xSLBCount = 64; /* SLB restore highwater mark */
+ register_vpa(flags, cpu, __pa((unsigned long)&(paca[cpu].xLpPaca)));
+}
+
static void __devinit pSeries_setup_cpu(int cpu)
{
if (OpenPIC_Addr) {
@@ -670,6 +680,12 @@ int __devinit start_secondary(void *unus
if (smp_ops->take_timebase)
smp_ops->take_timebase();
+ get_paca()->yielded = 0;
+
+ if (cur_cpu_spec->firmware_features & FW_FEATURE_SPLPAR) {
+ vpa_init(cpu);
+ }
+
local_irq_enable();
return cpu_idle(NULL);
diff -puN include/asm-ppc64/hvcall.h~ppc64-sharedproc include/asm-ppc64/hvcall.h
--- 25/include/asm-ppc64/hvcall.h~ppc64-sharedproc 2004-01-13 23:22:44.000000000 -0800
+++ 25-akpm/include/asm-ppc64/hvcall.h 2004-01-13 23:22:44.000000000 -0800
@@ -9,6 +9,14 @@
#define H_PTEG_Full -6 /* PTEG is full */
#define H_Not_Found -7 /* PTE was not found" */
#define H_Reserved_DABR -8 /* DABR address is reserved by the hypervisor on this processor" */
+#define H_NoMem -9
+#define H_Authority -10
+#define H_Permission -11
+#define H_Dropped -12
+#define H_SourceParm -13
+#define H_DestParm -14
+#define H_RemoteParm -15
+#define H_Resource -16
/* Flags */
#define H_LARGE_PAGE (1UL<<(63-16))
@@ -58,6 +66,16 @@
#define H_IPOLL 0x70
#define H_XIRR 0x74
#define H_PERFMON 0x7c
+#define H_MIGRATE_DMA 0x78
+#define H_REGISTER_VPA 0xDC
+#define H_CEDE 0xE0
+#define H_CONFER 0xE4
+#define H_PROD 0xE8
+#define H_GET_PPP 0xEC
+#define H_SET_PPP 0xF0
+#define H_SET_PURR 0xF4
+#define H_PIC 0xF8
+#define H_POLL_PENDING 0x1D8
/* plpar_hcall() -- Generic call interface using above opcodes
*
diff -puN include/asm-ppc64/iSeries/ItLpPaca.h~ppc64-sharedproc include/asm-ppc64/iSeries/ItLpPaca.h
--- 25/include/asm-ppc64/iSeries/ItLpPaca.h~ppc64-sharedproc 2004-01-13 23:22:44.000000000 -0800
+++ 25-akpm/include/asm-ppc64/iSeries/ItLpPaca.h 2004-01-13 23:22:44.000000000 -0800
@@ -110,7 +110,10 @@ struct ItLpPaca
u64 xPDCSavedSPRG1; // Saved SPRG1 for PMC int x68-x6F
u64 xPDCSavedSRR0; // Saved SRR0 for PMC int x70-x77
volatile u32 xVirtualDecr; // Virtual DECR for shared procsx78-x7B
- u32 xRsvd2_2; // Reserved x7C-x7F
+ u16 xSLBCount; // # of SLBs to maintain x7C-x7D
+ u8 xIdle; // Indicate OS is idle x7E
+ u8 xRsvd2_2; // Reserved x7F
+
//=============================================================================
// CACHE_LINE_3 0x0100 - 0x007F: This line is shared with other processors
diff -puN include/asm-ppc64/paca.h~ppc64-sharedproc include/asm-ppc64/paca.h
--- 25/include/asm-ppc64/paca.h~ppc64-sharedproc 2004-01-13 23:22:44.000000000 -0800
+++ 25-akpm/include/asm-ppc64/paca.h 2004-01-13 23:22:44.000000000 -0800
@@ -94,7 +94,9 @@ struct paca_struct {
u32 *prof_buffer; /* iSeries profiling buffer 0x38 */
u32 *prof_stext; /* iSeries start of kernel text 0x40 */
u32 prof_len; /* iSeries length of profile buffer -1 0x48 */
- u8 rsvd2[128-76]; /* 0x4C */
+ u8 yielded; /* 0 = this processor is running 0x4c */
+ /* 1 = this processor is yielded */
+ u8 rsvd2[128-77]; /* 0x49 */
/*=====================================================================================
* CACHE_LINE_3 0x0100 - 0x017F
@@ -117,7 +119,7 @@ struct paca_struct {
struct ItLpRegSave xRegSav; /* Register save for proc */
/*=====================================================================================
- * CACHE_LINE_17-18 0x0800 - 0x0EFF Reserved
+ * CACHE_LINE_17-18 0x0800 - 0x08FF Reserved
*=====================================================================================
*/
struct rtas_args xRtas; /* Per processor RTAS struct */
@@ -126,10 +128,12 @@ struct paca_struct {
u8 rsvd5[256-16-sizeof(struct rtas_args)];
/*=====================================================================================
- * CACHE_LINE_19-30 0x0800 - 0x0EFF Reserved
+ * CACHE_LINE_19-30 0x0900 - 0x0EFF Reserved
*=====================================================================================
*/
- u8 rsvd6[0x600];
+ u64 slb_shadow[0x20];
+ u64 dispatch_log;
+ u8 rsvd6[0x500 - 0x8];
/*=====================================================================================
* CACHE_LINE_31 0x0F00 - 0x0F7F Exception stack
diff -puN include/asm-ppc64/memory.h~ppc64-sharedproc include/asm-ppc64/memory.h
--- 25/include/asm-ppc64/memory.h~ppc64-sharedproc 2004-01-13 23:22:44.000000000 -0800
+++ 25-akpm/include/asm-ppc64/memory.h 2004-01-13 23:22:44.000000000 -0800
@@ -42,23 +42,28 @@ static inline void isync(void)
#endif
/* Macros for adjusting thread priority (hardware multi-threading) */
-
-#if defined(CONFIG_PPC_ISERIES) || defined(CONFIG_HMT)
+#define HMT_very_low() asm volatile("or 31,31,31 # very low priority")
#define HMT_low() asm volatile("or 1,1,1 # low priority")
+#define HMT_medium_low() asm volatile("or 6,6,6 # medium low priority")
#define HMT_medium() asm volatile("or 2,2,2 # medium priority")
+#define HMT_medium_high() asm volatile("or 5,5,5 # medium high priority")
#define HMT_high() asm volatile("or 3,3,3 # high priority")
+#define HMT_VERY_LOW "\tor 31,31,31 # very low priority\n"
#define HMT_LOW "\tor 1,1,1 # low priority\n"
+#define HMT_MEDIUM_LOW "\tor 6,6,6 # medium low priority\n"
#define HMT_MEDIUM "\tor 2,2,2 # medium priority\n"
+#define HMT_MEDIUM_HIGH "\tor 5,5,5 # medium high priority\n"
#define HMT_HIGH "\tor 3,3,3 # high priority\n"
-#else
-#define HMT_low() do { } while(0)
-#define HMT_medium() do { } while(0)
-#define HMT_high() do { } while(0)
-#define HMT_LOW
-#define HMT_MEDIUM
-#define HMT_HIGH
-#endif
+/*
+ * Various operational modes for SMT
+ * Off : never run threaded
+ * On : always run threaded
+ * Dynamic: Allow the system to switch modes as needed
+ */
+#define SMT_OFF 0
+#define SMT_ON 1
+#define SMT_DYNAMIC 2
#endif
diff -puN include/asm-ppc64/naca.h~ppc64-sharedproc include/asm-ppc64/naca.h
--- 25/include/asm-ppc64/naca.h~ppc64-sharedproc 2004-01-13 23:22:44.000000000 -0800
+++ 25-akpm/include/asm-ppc64/naca.h 2004-01-13 23:22:44.000000000 -0800
@@ -37,7 +37,12 @@ struct naca_struct {
u32 dCacheL1LinesPerPage; /* L1 d-cache lines / page 0x64 */
u32 iCacheL1LogLineSize; /* L1 i-cache line size Log2 0x68 */
u32 iCacheL1LinesPerPage; /* L1 i-cache lines / page 0x6c */
- u64 resv0[2]; /* Reserved 0x70 - 0x7F */
+ u64 smt_snooze_delay; /* Delay (in usec) before 0x70 */
+ /* entering ST mode */
+ u8 smt_state; /* 0 = SMT off 0x78 */
+ /* 1 = SMT on */
+ /* 2 = SMT dynamic */
+ u8 resv0[7]; /* Reserved 0x70 - 0x7F */
};
extern struct naca_struct *naca;
diff -puN include/asm-ppc64/processor.h~ppc64-sharedproc include/asm-ppc64/processor.h
--- 25/include/asm-ppc64/processor.h~ppc64-sharedproc 2004-01-13 23:22:44.000000000 -0800
+++ 25-akpm/include/asm-ppc64/processor.h 2004-01-13 23:22:44.000000000 -0800
@@ -378,6 +378,7 @@
#define PLATFORM_PSERIES 0x0100
#define PLATFORM_PSERIES_LPAR 0x0101
#define PLATFORM_ISERIES_LPAR 0x0201
+#define PLATFORM_LPAR 0x0001
/*
* List of interrupt controllers.
diff -puN arch/ppc64/kernel/chrp_setup.c~ppc64-sharedproc arch/ppc64/kernel/chrp_setup.c
--- 25/arch/ppc64/kernel/chrp_setup.c~ppc64-sharedproc 2004-01-13 23:22:44.000000000 -0800
+++ 25-akpm/arch/ppc64/kernel/chrp_setup.c 2004-01-13 23:22:44.000000000 -0800
@@ -273,7 +273,7 @@ chrp_init(unsigned long r3, unsigned lon
ppc_md.progress = chrp_progress;
- /* build up the firmware_features bitmask field
+ /* Build up the firmware_features bitmask field
* using contents of device-tree/ibm,hypertas-functions.
* Ultimately this functionality may be moved into prom.c prom_init().
*/
diff -puN arch/ppc64/kernel/idle.c~ppc64-sharedproc arch/ppc64/kernel/idle.c
--- 25/arch/ppc64/kernel/idle.c~ppc64-sharedproc 2004-01-13 23:22:44.000000000 -0800
+++ 25-akpm/arch/ppc64/kernel/idle.c 2004-01-13 23:22:44.000000000 -0800
@@ -1,5 +1,13 @@
/*
- * idle.c
+ * Idle daemon for PowerPC. Idle daemon will handle any action
+ * that needs to be taken when the system becomes idle.
+ *
+ * Originally Written by Cort Dougan (cort@cs.nmt.edu)
+ *
+ * iSeries supported added by Mike Corrigan <mikejc@us.ibm.com>
+ *
+ * Additional shared processor, SMT, and firmware support
+ * Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
@@ -26,99 +34,104 @@
#include <asm/processor.h>
#include <asm/mmu.h>
#include <asm/cache.h>
+#include <asm/cputable.h>
#include <asm/time.h>
-
-#ifdef CONFIG_PPC_ISERIES
-
#include <asm/iSeries/LparData.h>
#include <asm/iSeries/HvCall.h>
#include <asm/iSeries/ItLpQueue.h>
-unsigned long maxYieldTime = 0;
-unsigned long minYieldTime = 0xffffffffffffffffUL;
+extern long cede_processor(void);
+extern long poll_pending(void);
+
+int (*idle_loop)(void);
+#ifdef CONFIG_PPC_ISERIES
static void yield_shared_processor(void)
{
- unsigned long tb;
- unsigned long yieldTime;
+ struct paca_struct *lpaca = get_paca();
HvCall_setEnabledInterrupts(HvCall_MaskIPI |
HvCall_MaskLpEvent |
HvCall_MaskLpProd |
HvCall_MaskTimeout);
- tb = get_tb();
- /* Compute future tb value when yield should expire */
- HvCall_yieldProcessor(HvCall_YieldTimed, tb+tb_ticks_per_jiffy);
-
- yieldTime = get_tb() - tb;
- if (yieldTime > maxYieldTime)
- maxYieldTime = yieldTime;
+ if (!ItLpQueue_isLpIntPending(paca->lpQueuePtr)) {
+ /*
+ * Compute future tb value when yield should expire.
+ * We want to be woken up when the next decrementer is
+ * to fire.
+ */
+
+ local_irq_disable();
+ lpaca->yielded = 1; /* Indicate a prod is desired */
+ lpaca->xLpPaca.xIdle = 1; /* Inform the HV we are idle */
+
+ HvCall_yieldProcessor(HvCall_YieldTimed,
+ lpaca->next_jiffy_update_tb);
- if (yieldTime < minYieldTime)
- minYieldTime = yieldTime;
+ lpaca->yielded = 0; /* Back to IPI's */
+ locale_irq_enable();
- /*
- * The decrementer stops during the yield. Force a fake decrementer
- * here and let the timer_interrupt code sort out the actual time.
- */
- get_paca()->xLpPaca.xIntDword.xFields.xDecrInt = 1;
+ /*
+ * The decrementer stops during the yield. Force a fake
+ * decrementer here and let the timer_interrupt code sort
+ * out the actual time.
+ */
+ lpaca->xLpPaca.xIntDword.xFields.xDecrInt = 1;
+ }
+
process_iSeries_events();
}
-int cpu_idle(void)
+int iSeries_idle(void)
{
struct paca_struct *lpaca;
long oldval;
unsigned long CTRL;
-#warning fix iseries run light
-#if 0
+ /* endless loop with no priority at all */
+ current->nice = 20;
+ current->counter = -100;
+
/* ensure iSeries run light will be out when idle */
current->thread.flags &= ~PPC_FLAG_RUN_LIGHT;
CTRL = mfspr(CTRLF);
CTRL &= ~RUNLATCH;
mtspr(CTRLT, CTRL);
-#endif
+ init_idle();
lpaca = get_paca();
- while (1) {
+ for (;;) {
if (lpaca->xLpPaca.xSharedProc) {
if (ItLpQueue_isLpIntPending(lpaca->lpQueuePtr))
process_iSeries_events();
- if (!need_resched())
+ if (!current->need_resched)
yield_shared_processor();
} else {
- oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
-
+ /* Avoid an IPI by setting need_resched */
+ oldval = xchg(¤t->need_resched, -1);
if (!oldval) {
- set_thread_flag(TIF_POLLING_NRFLAG);
-
- while (!need_resched()) {
+ while(current->need_resched == -1) {
HMT_medium();
if (ItLpQueue_isLpIntPending(lpaca->lpQueuePtr))
process_iSeries_events();
HMT_low();
}
-
- HMT_medium();
- clear_thread_flag(TIF_POLLING_NRFLAG);
- } else {
- set_need_resched();
}
}
-
- if (need_resched())
+ HMT_medium();
+ if (current->need_resched) {
+ lpaca->xLpPaca.xIdle = 0;
schedule();
+ check_pgt_cache();
+ }
}
-
return 0;
}
+#endif
-#else /* CONFIG_PPC_ISERIES */
-
-int cpu_idle(void)
+int default_idle(void)
{
long oldval;
@@ -145,9 +158,153 @@ int cpu_idle(void)
return 0;
}
-#endif /* CONFIG_PPC_ISERIES */
+int dedicated_idle(void)
+{
+ long oldval;
+ struct paca_struct *lpaca = get_paca(), *ppaca;;
+ unsigned long start_snooze;
+
+ ppaca = &paca[(lpaca->xPacaIndex) ^ 1];
+
+ while (1) {
+ /* Indicate to the HV that we are idle. Now would be
+ * a good time to find other work to dispatch. */
+ lpaca->xLpPaca.xIdle = 1;
+
+ oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
+ if (!oldval) {
+ set_thread_flag(TIF_POLLING_NRFLAG);
+ start_snooze = __get_tb();
+ while (!need_resched()) {
+ /* need_resched could be 1 or 0 at this
+ * point. If it is 0, set it to 0, so
+ * an IPI/Prod is sent. If it is 1, keep
+ * it that way & schedule work.
+ */
+ if (__get_tb() <
+ (start_snooze +
+ naca->smt_snooze_delay*tb_ticks_per_usec)) {
+ HMT_low(); /* Low thread priority */
+ continue;
+ }
+
+ HMT_very_low(); /* Low power mode */
-void default_idle(void)
+ /* If the SMT mode is system controlled & the
+ * partner thread is doing work, switch into
+ * ST mode.
+ */
+ if((naca->smt_state == SMT_DYNAMIC) &&
+ (!(ppaca->xLpPaca.xIdle))) {
+ /* Indicate we are no longer polling for
+ * work, and then clear need_resched. If
+ * need_resched was 1, set it back to 1
+ * and schedule work
+ */
+ clear_thread_flag(TIF_POLLING_NRFLAG);
+ oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
+ if(oldval == 1) {
+ set_need_resched();
+ break;
+ }
+
+ /* DRENG: Go HMT_medium here ? */
+ local_irq_disable();
+ lpaca->yielded = 1;
+
+ /* SMT dynamic mode. Cede will result
+ * in this thread going dormant, if the
+ * partner thread is still doing work.
+ * Thread wakes up if partner goes idle,
+ * an interrupt is presented, or a prod
+ * occurs. Returning from the cede
+ * enables external interrupts.
+ */
+ cede_processor();
+
+ lpaca->yielded = 0;
+ } else {
+ /* Give the HV an opportunity at the
+ * processor, since we are not doing
+ * any work.
+ */
+ poll_pending();
+ }
+ }
+ } else {
+ set_need_resched();
+ }
+
+ HMT_medium();
+ lpaca->xLpPaca.xIdle = 0;
+ schedule();
+ }
+ return 0;
+}
+
+int shared_idle(void)
{
- barrier();
+ struct paca_struct *lpaca = get_paca();
+
+ while (1) {
+ /* Indicate to the HV that we are idle. Now would be
+ * a good time to find other work to dispatch. */
+ lpaca->xLpPaca.xIdle = 1;
+
+ if (!need_resched()) {
+ local_irq_disable();
+ lpaca->yielded = 1;
+
+ /*
+ * Yield the processor to the hypervisor. We return if
+ * an external interrupt occurs (which are driven prior
+ * to returning here) or if a prod occurs from another
+ * processor. When returning here, external interrupts
+ * are enabled.
+ */
+ cede_processor();
+
+ lpaca->yielded = 0;
+ }
+
+ HMT_medium();
+ lpaca->xLpPaca.xIdle = 0;
+ schedule();
+ }
+
+ return 0;
+}
+
+int cpu_idle(void)
+{
+ idle_loop();
+ return 0;
}
+
+int idle_setup(void)
+{
+#ifdef CONFIG_PPC_ISERIES
+ idle_loop = iSeries_idle;
+#else
+ if (systemcfg->platform & PLATFORM_PSERIES) {
+ if (cur_cpu_spec->firmware_features & FW_FEATURE_SPLPAR) {
+ if(get_paca()->xLpPaca.xSharedProc) {
+ printk("idle = shared_idle\n");
+ idle_loop = shared_idle;
+ } else {
+ printk("idle = dedicated_idle\n");
+ idle_loop = dedicated_idle;
+ }
+ } else {
+ printk("idle = default_idle\n");
+ idle_loop = default_idle;
+ }
+ } else {
+ printk("idle_setup: unknown platform, use default_idle\n");
+ idle_loop = default_idle;
+ }
+#endif
+
+ return 1;
+}
+
_