[PATCH] ppc64: Allow non zero boot cpuids
Anton Blanchard
anton at samba.org
Sun Mar 12 12:52:02 EST 2006
Hi,
We currently have a hack to flip the boot cpu and its secondary thread
to logical cpuid 0 and 1. There are a few issues:
- The logical - physical mapping will differ depending on which cpu is
boot cpu. This is most apparent on kexec, where we might kexec on any
cpu and therefore change the mapping.
- There are some strange bugs when we flip cpus between nodes - the
scheduler locks up.
The patch below does a first pass early on to work out the logical cpuid
of the boot thread. We then fix up some paca structures to match.
Ive also removed the boot_cpuid_phys variable for ppc64, to be
consistent we use get_hard_smp_processor_id(boot_cpuid) everywhere.
Signed-off-by: Anton Blanchard <anton at samba.org>
---
Index: build/arch/powerpc/kernel/setup-common.c
===================================================================
--- build.orig/arch/powerpc/kernel/setup-common.c 2006-03-08 14:54:48.000000000 +1100
+++ build/arch/powerpc/kernel/setup-common.c 2006-03-08 14:55:39.000000000 +1100
@@ -353,12 +353,13 @@ void __init check_for_initrd(void)
* must be called before using this.
*
* While we're here, we may as well set the "physical" cpu ids in the paca.
+ *
+ * NOTE: This must match the parsing done in early_init_dt_scan_cpus.
*/
void __init smp_setup_cpu_maps(void)
{
struct device_node *dn = NULL;
int cpu = 0;
- int swap_cpuid = 0;
while ((dn = of_find_node_by_type(dn, "cpu")) && cpu < NR_CPUS) {
int *intserv;
@@ -377,24 +378,11 @@ void __init smp_setup_cpu_maps(void)
for (j = 0; j < nthreads && cpu < NR_CPUS; j++) {
cpu_set(cpu, cpu_present_map);
set_hard_smp_processor_id(cpu, intserv[j]);
-
- if (intserv[j] == boot_cpuid_phys)
- swap_cpuid = cpu;
cpu_set(cpu, cpu_possible_map);
cpu++;
}
}
- /* Swap CPU id 0 with boot_cpuid_phys, so we can always assume that
- * boot cpu is logical 0.
- */
- if (boot_cpuid_phys != get_hard_smp_processor_id(0)) {
- u32 tmp;
- tmp = get_hard_smp_processor_id(0);
- set_hard_smp_processor_id(0, boot_cpuid_phys);
- set_hard_smp_processor_id(swap_cpuid, tmp);
- }
-
#ifdef CONFIG_PPC64
/*
* On pSeries LPAR, we need to know how many cpus
Index: build/arch/powerpc/kernel/setup_64.c
===================================================================
--- build.orig/arch/powerpc/kernel/setup_64.c 2006-03-08 14:54:55.000000000 +1100
+++ build/arch/powerpc/kernel/setup_64.c 2006-03-08 14:55:39.000000000 +1100
@@ -73,7 +73,6 @@
int have_of = 1;
int boot_cpuid = 0;
-int boot_cpuid_phys = 0;
dev_t boot_dev;
u64 ppc64_pft_size;
@@ -208,7 +207,6 @@ static struct machdep_calls __initdata *
void __init early_setup(unsigned long dt_ptr)
{
- struct paca_struct *lpaca = get_paca();
static struct machdep_calls **mach;
/* Enable early debugging if any specified (see udbg.h) */
@@ -223,6 +221,14 @@ void __init early_setup(unsigned long dt
*/
early_init_devtree(__va(dt_ptr));
+ /* Now we know the logical id of our boot cpu, setup the paca. */
+ setup_boot_paca();
+
+ /* Fix up paca fields required for the boot cpu */
+ get_paca()->cpu_start = 1;
+ get_paca()->stab_real = __pa((u64)&initial_stab);
+ get_paca()->stab_addr = (u64)&initial_stab;
+
/*
* Iterate all ppc_md structures until we find the proper
* one for the current machine type
@@ -260,7 +266,7 @@ void __init early_setup(unsigned long dt
if (cpu_has_feature(CPU_FTR_SLB))
slb_initialize();
else
- stab_initialize(lpaca->stab_real);
+ stab_initialize(get_paca()->stab_real);
}
DBG(" <- early_setup()\n");
Index: build/arch/powerpc/platforms/pseries/xics.c
===================================================================
--- build.orig/arch/powerpc/platforms/pseries/xics.c 2006-03-08 14:54:48.000000000 +1100
+++ build/arch/powerpc/platforms/pseries/xics.c 2006-03-08 14:55:39.000000000 +1100
@@ -499,7 +499,7 @@ nextnode:
np;
np = of_find_node_by_type(np, "cpu")) {
ireg = (uint *)get_property(np, "reg", &ilen);
- if (ireg && ireg[0] == boot_cpuid_phys) {
+ if (ireg && ireg[0] == get_hard_smp_processor_id(boot_cpuid)) {
ireg = (uint *)get_property(np, "ibm,ppc-interrupt-gserver#s",
&ilen);
i = ilen / sizeof(int);
Index: build/include/asm-powerpc/smp.h
===================================================================
--- build.orig/include/asm-powerpc/smp.h 2006-03-08 14:54:49.000000000 +1100
+++ build/include/asm-powerpc/smp.h 2006-03-08 14:55:39.000000000 +1100
@@ -29,7 +29,6 @@
#endif
extern int boot_cpuid;
-extern int boot_cpuid_phys;
extern void cpu_die(void);
@@ -99,6 +98,7 @@ extern void smp_release_cpus(void);
#else
/* 32-bit */
#ifndef CONFIG_SMP
+extern int boot_cpuid_phys;
#define get_hard_smp_processor_id(cpu) boot_cpuid_phys
#define set_hard_smp_processor_id(cpu, phys)
#endif
Index: build/arch/powerpc/kernel/head_64.S
===================================================================
--- build.orig/arch/powerpc/kernel/head_64.S 2006-03-08 14:54:48.000000000 +1100
+++ build/arch/powerpc/kernel/head_64.S 2006-03-08 14:55:39.000000000 +1100
@@ -1840,21 +1840,6 @@ _STATIC(start_here_multiplatform)
bl .__save_cpu_setup
sync
- /* Setup a valid physical PACA pointer in SPRG3 for early_setup
- * note that boot_cpuid can always be 0 nowadays since there is
- * nowhere it can be initialized differently before we reach this
- * code
- */
- LOAD_REG_IMMEDIATE(r27, boot_cpuid)
- add r27,r27,r26
- lwz r27,0(r27)
-
- LOAD_REG_IMMEDIATE(r24, paca) /* Get base vaddr of paca array */
- mulli r13,r27,PACA_SIZE /* Calculate vaddr of right paca */
- add r13,r13,r24 /* for this processor. */
- add r13,r13,r26 /* convert to physical addr */
- mtspr SPRN_SPRG3,r13
-
/* Do very early kernel initializations, including initial hash table,
* stab and slb setup before we turn on relocation. */
@@ -1923,6 +1908,17 @@ _STATIC(start_here_common)
/* Not reached */
BUG_OPCODE
+/* Put the paca pointer into r13 and SPRG3 */
+_GLOBAL(setup_boot_paca)
+ LOAD_REG_IMMEDIATE(r3, boot_cpuid)
+ lwz r3,0(r3)
+ LOAD_REG_IMMEDIATE(r4, paca) /* Get base vaddr of paca array */
+ mulli r3,r3,PACA_SIZE /* Calculate vaddr of right paca */
+ add r13,r3,r4 /* for this processor. */
+ mtspr SPRN_SPRG3,r13
+
+ blr
+
/*
* We put a few things here that have to be page-aligned.
* This stuff goes at the beginning of the bss, which is page-aligned.
Index: build/arch/powerpc/kernel/prom.c
===================================================================
--- build.orig/arch/powerpc/kernel/prom.c 2006-03-08 14:54:48.000000000 +1100
+++ build/arch/powerpc/kernel/prom.c 2006-03-08 14:55:39.000000000 +1100
@@ -858,35 +858,70 @@ void __init unflatten_device_tree(void)
DBG(" <- unflatten_device_tree()\n");
}
-
static int __init early_init_dt_scan_cpus(unsigned long node,
- const char *uname, int depth, void *data)
+ const char *uname, int depth,
+ void *data)
{
- u32 *prop;
- unsigned long size;
- char *type = of_get_flat_dt_prop(node, "device_type", &size);
+ static int logical_cpuid = 0;
+ char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+ u32 *prop, *intserv;
+ int i, nthreads;
+ unsigned long len;
+ int found = 0;
/* We are scanning "cpu" nodes only */
if (type == NULL || strcmp(type, "cpu") != 0)
return 0;
- boot_cpuid = 0;
- boot_cpuid_phys = 0;
- if (initial_boot_params && initial_boot_params->version >= 2) {
- /* version 2 of the kexec param format adds the phys cpuid
- * of booted proc.
- */
- boot_cpuid_phys = initial_boot_params->boot_cpuid_phys;
+ /* Get physical cpuid */
+ intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len);
+ if (intserv) {
+ nthreads = len / sizeof(int);
} else {
- /* Check if it's the boot-cpu, set it's hw index now */
- if (of_get_flat_dt_prop(node,
+ intserv = of_get_flat_dt_prop(node, "reg", NULL);
+ nthreads = 1;
+ }
+
+ /*
+ * Now see if any of these threads match our boot cpu.
+ * NOTE: This must match the parsing done in smp_setup_cpu_maps.
+ */
+ for (i = 0; i < nthreads; i++) {
+ /*
+ * version 2 of the kexec param format adds the phys cpuid of
+ * booted proc.
+ */
+ if (initial_boot_params && initial_boot_params->version >= 2) {
+ if (intserv[i] ==
+ initial_boot_params->boot_cpuid_phys) {
+ found = 1;
+ break;
+ }
+ } else {
+ /*
+ * Check if it's the boot-cpu, set it's hw index now,
+ * unfortunately this format did not support booting
+ * off secondary threads.
+ */
+ if (of_get_flat_dt_prop(node,
"linux,boot-cpu", NULL) != NULL) {
- prop = of_get_flat_dt_prop(node, "reg", NULL);
- if (prop != NULL)
- boot_cpuid_phys = *prop;
+ found = 1;
+ break;
+ }
}
+
+#ifdef CONFIG_SMP
+ /* logical cpu id is always 0 on UP kernels */
+ logical_cpuid++;
+#endif
+ }
+
+ if (found) {
+ DBG("boot cpu: logical %d physical %d\n", logical_cpuid,
+ intserv[i]);
+ boot_cpuid = logical_cpuid;
+ set_hard_smp_processor_id(boot_cpuid, intserv[i]);
}
- set_hard_smp_processor_id(0, boot_cpuid_phys);
#ifdef CONFIG_ALTIVEC
/* Check if we have a VMX and eventually update CPU features */
@@ -905,16 +940,10 @@ static int __init early_init_dt_scan_cpu
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_PPC_PSERIES
- /*
- * Check for an SMT capable CPU and set the CPU feature. We do
- * this by looking at the size of the ibm,ppc-interrupt-server#s
- * property
- */
- prop = (u32 *)of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s",
- &size);
- cur_cpu_spec->cpu_features &= ~CPU_FTR_SMT;
- if (prop && ((size / sizeof(u32)) > 1))
+ if (nthreads > 1)
cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
+ else
+ cur_cpu_spec->cpu_features &= ~CPU_FTR_SMT;
#endif
return 0;
Index: build/arch/powerpc/kernel/paca.c
===================================================================
--- build.orig/arch/powerpc/kernel/paca.c 2006-03-08 14:54:48.000000000 +1100
+++ build/arch/powerpc/kernel/paca.c 2006-03-08 14:55:39.000000000 +1100
@@ -56,14 +56,11 @@ struct lppaca lppaca[] = {
* processors. The processor VPD array needs one entry per physical
* processor (not thread).
*/
-#define PACA_INIT_COMMON(number, start, asrr, asrv) \
+#define PACA_INIT_COMMON(number) \
.lppaca_ptr = &lppaca[number], \
.lock_token = 0x8000, \
.paca_index = (number), /* Paca Index */ \
.kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL, \
- .stab_real = (asrr), /* Real pointer to segment table */ \
- .stab_addr = (asrv), /* Virt pointer to segment table */ \
- .cpu_start = (start), /* Processor start */ \
.hw_cpu_id = 0xffff,
#ifdef CONFIG_PPC_ISERIES
@@ -72,30 +69,20 @@ struct lppaca lppaca[] = {
#define PACA_INIT(number) \
{ \
- PACA_INIT_COMMON(number, 0, 0, 0) \
- PACA_INIT_ISERIES(number) \
-}
-
-#define BOOTCPU_PACA_INIT(number) \
-{ \
- PACA_INIT_COMMON(number, 1, 0, (u64)&initial_stab) \
+ PACA_INIT_COMMON(number) \
PACA_INIT_ISERIES(number) \
}
#else
#define PACA_INIT(number) \
{ \
- PACA_INIT_COMMON(number, 0, 0, 0) \
+ PACA_INIT_COMMON(number) \
}
-#define BOOTCPU_PACA_INIT(number) \
-{ \
- PACA_INIT_COMMON(number, 1, STAB0_PHYS_ADDR, (u64)&initial_stab) \
-}
#endif
struct paca_struct paca[] = {
- BOOTCPU_PACA_INIT(0),
+ PACA_INIT(0),
#if NR_CPUS > 1
PACA_INIT( 1), PACA_INIT( 2), PACA_INIT( 3),
#if NR_CPUS > 4
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