As the pacas are statically initialised increasing NR_CPUS beyond 128,
means that any additional pacas will be empty ... which is bad.
This patch adds the required functionality to fill in any excess pacas
at runtime.
Signed-off-by: Tony Breeds <[EMAIL PROTECTED]>
---
Changes since v1:
- Addressed thinko pointed out by sfr.
- Addeed nicely worded comment about paca->kernel_toc from Segher
Paul, please consider befoer -rc1
arch/powerpc/kernel/paca.c | 61 +++++++++++++++++++++-----------
arch/powerpc/kernel/setup_64.c | 3 ++
arch/powerpc/platforms/Kconfig.cputype | 4 +-
include/asm-powerpc/paca.h | 20 ++++++++++
4 files changed, 65 insertions(+), 23 deletions(-)
diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index ac163bd..4c7db2e 100644
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -18,6 +18,15 @@
#include <asm/paca.h>
#include <asm/mmu.h>
+/*
+ * In order to handle "strange" values of NR_CPUS, Make sure we use
+ * max(NR_CPUS, NR_STATIC_PACAS) for array sizes below
+ */
+#if NR_CPUS > NR_STATIC_PACAS
+#define MAX_CPUS NR_CPUS
+#else
+#define MAX_CPUS NR_STATIC_PACAS
+#endif
/* This symbol is provided by the linker - let it fill in the paca
* field correctly */
@@ -33,7 +42,7 @@ extern unsigned long __toc_start;
* will suffice to ensure that it doesn't cross a page boundary.
*/
struct lppaca lppaca[] = {
- [0 ... (NR_CPUS-1)] = {
+ [0 ... (MAX_CPUS-1)] = {
.desc = 0xd397d781, /* "LpPa" */
.size = sizeof(struct lppaca),
.dyn_proc_status = 2,
@@ -50,7 +59,7 @@ struct lppaca lppaca[] = {
* initially, hence will all be invaild until we actually write them.
*/
struct slb_shadow slb_shadow[] __cacheline_aligned = {
- [0 ... (NR_CPUS-1)] = {
+ [0 ... (MAX_CPUS-1)] = {
.persistent = SLB_NUM_BOLTED,
.buffer_length = sizeof(struct slb_shadow),
},
@@ -76,7 +85,7 @@ struct slb_shadow slb_shadow[] __cacheline_aligned = {
.__current = &init_task, \
}
-struct paca_struct paca[] = {
+struct paca_struct paca[MAX_CPUS] = {
PACA_INIT(0),
#if NR_CPUS > 1
PACA_INIT( 1), PACA_INIT( 2), PACA_INIT( 3),
@@ -98,27 +107,37 @@ struct paca_struct paca[] = {
PACA_INIT( 52), PACA_INIT( 53), PACA_INIT( 54), PACA_INIT( 55),
PACA_INIT( 56), PACA_INIT( 57), PACA_INIT( 58), PACA_INIT( 59),
PACA_INIT( 60), PACA_INIT( 61), PACA_INIT( 62), PACA_INIT( 63),
-#if NR_CPUS > 64
- PACA_INIT( 64), PACA_INIT( 65), PACA_INIT( 66), PACA_INIT( 67),
- PACA_INIT( 68), PACA_INIT( 69), PACA_INIT( 70), PACA_INIT( 71),
- PACA_INIT( 72), PACA_INIT( 73), PACA_INIT( 74), PACA_INIT( 75),
- PACA_INIT( 76), PACA_INIT( 77), PACA_INIT( 78), PACA_INIT( 79),
- PACA_INIT( 80), PACA_INIT( 81), PACA_INIT( 82), PACA_INIT( 83),
- PACA_INIT( 84), PACA_INIT( 85), PACA_INIT( 86), PACA_INIT( 87),
- PACA_INIT( 88), PACA_INIT( 89), PACA_INIT( 90), PACA_INIT( 91),
- PACA_INIT( 92), PACA_INIT( 93), PACA_INIT( 94), PACA_INIT( 95),
- PACA_INIT( 96), PACA_INIT( 97), PACA_INIT( 98), PACA_INIT( 99),
- PACA_INIT(100), PACA_INIT(101), PACA_INIT(102), PACA_INIT(103),
- PACA_INIT(104), PACA_INIT(105), PACA_INIT(106), PACA_INIT(107),
- PACA_INIT(108), PACA_INIT(109), PACA_INIT(110), PACA_INIT(111),
- PACA_INIT(112), PACA_INIT(113), PACA_INIT(114), PACA_INIT(115),
- PACA_INIT(116), PACA_INIT(117), PACA_INIT(118), PACA_INIT(119),
- PACA_INIT(120), PACA_INIT(121), PACA_INIT(122), PACA_INIT(123),
- PACA_INIT(124), PACA_INIT(125), PACA_INIT(126), PACA_INIT(127),
-#endif
#endif
#endif
#endif
#endif
};
EXPORT_SYMBOL(paca);
+
+/*
+ * The first few (NR_STATIC_PACAS) paca entires are initiialised
+ * statically. populate the rest.
+ */
+void __init initialise_pacas(void)
+{
+ int cpu;
+
+ /* The TOC register (GPR2) points 32kB into the TOC, so that 64kB
+ * of the TOC can be addressed using a single machine instruction.
+ */
+ unsigned long kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL;
+
+ /* Can't use for_each_*_cpu, as they aren't functional yet */
+ for (cpu = NR_STATIC_PACAS; cpu < NR_CPUS; cpu++) {
+ struct paca_struct *new_paca = &paca[cpu];
+
+ new_paca->lppaca_ptr = &lppaca[cpu];
+ new_paca->lock_token = 0x8000;
+ new_paca->paca_index = cpu;
+ new_paca->kernel_toc = kernel_toc;
+ new_paca->hw_cpu_id = 0xffff;
+ new_paca->slb_shadow_ptr = &slb_shadow[cpu];
+ new_paca->__current = &init_task;
+
+ }
+}
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 31ada9f..5e382ac 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -170,6 +170,9 @@ void __init setup_paca(int cpu)
void __init early_setup(unsigned long dt_ptr)
{
+ /* Fill in any unititialised pacas */
+ initialise_pacas();
+
/* Identify CPU type */
identify_cpu(0, mfspr(SPRN_PVR));
diff --git a/arch/powerpc/platforms/Kconfig.cputype
b/arch/powerpc/platforms/Kconfig.cputype
index 5fc7fac..f7efaa9 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -220,8 +220,8 @@ config SMP
If you don't know what to do here, say N.
config NR_CPUS
- int "Maximum number of CPUs (2-128)"
- range 2 128
+ int "Maximum number of CPUs (2-1024)"
+ range 2 1024
depends on SMP
default "32" if PPC64
default "4"
diff --git a/include/asm-powerpc/paca.h b/include/asm-powerpc/paca.h
index eb61b9c..2a05cc0 100644
--- a/include/asm-powerpc/paca.h
+++ b/include/asm-powerpc/paca.h
@@ -16,10 +16,29 @@
#define _ASM_POWERPC_PACA_H
#ifdef __KERNEL__
+#include <linux/threads.h>
+
#include <asm/types.h>
#include <asm/lppaca.h>
#include <asm/mmu.h>
+/*
+ * iSeries needs the paca to be statically allocated and initialised.
+ * We will allocated this many, based on NR_CPUS.
+ */
+#if NR_CPUS > 32
+#define NR_STATIC_PACAS 64
+#elif NR_CPUS > 8
+#define NR_STATIC_PACAS 32
+#elif NR_CPUS > 4
+#define NR_STATIC_PACAS 8
+#elif NR_CPUS > 1
+#define NR_STATIC_PACAS 4
+#else
+#define NR_STATIC_PACAS 1
+#endif
+
+
register struct paca_struct *local_paca asm("r13");
#if defined(CONFIG_DEBUG_PREEMPT) && defined(CONFIG_SMP)
@@ -108,6 +127,7 @@ struct paca_struct {
};
extern struct paca_struct paca[];
+extern void initialise_pacas(void);
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_PACA_H */
--
1.5.5.1
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