From f2f6dad6ca3b06ae35a2e7b63f38158242c01531 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Sun, 6 Mar 2011 18:02:31 +0000 Subject: powerpc/iseries: Fix early init access to lppaca The combination of commit 8154c5d22d91cd16bd9985b0638c8957e4688d0e and 93c22703efa72c7527dbd586d1951c1f4a85fd70 Broke boot on iSeries. The problem is that iSeries very early boot code, which generates the device-tree and runs before our normal early initializations does need access the lppaca's very early, before the PACA array is initialized, and in fact even before the boot PACA has been initialized (it contains all 0's at this stage). However, the first patch above makes that code use the new llpaca_of(cpu) accessor, which itself is changed by the second patch to use the PACA array. We fix that by reverting iSeries to directly dereferencing the array. In addition, we fix all iterators in the iSeries code to always skip CPU whose number is above 63 which is the maximum size of that array and the maximum number of supported CPUs on these machines. Additionally, we make sure the boot_paca is properly initialized in our early startup code. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/lppaca.h | 16 ++++++++++++++++ arch/powerpc/kernel/paca.c | 14 -------------- arch/powerpc/platforms/iseries/dt.c | 6 +++--- arch/powerpc/platforms/iseries/setup.c | 1 + 4 files changed, 20 insertions(+), 17 deletions(-) diff --git a/arch/powerpc/include/asm/lppaca.h b/arch/powerpc/include/asm/lppaca.h index 380d48bacd1..26b8c807f8f 100644 --- a/arch/powerpc/include/asm/lppaca.h +++ b/arch/powerpc/include/asm/lppaca.h @@ -33,9 +33,25 @@ // //---------------------------------------------------------------------------- #include +#include #include #include +/* + * We only have to have statically allocated lppaca structs on + * legacy iSeries, which supports at most 64 cpus. + */ +#ifdef CONFIG_PPC_ISERIES +#if NR_CPUS < 64 +#define NR_LPPACAS NR_CPUS +#else +#define NR_LPPACAS 64 +#endif +#else /* not iSeries */ +#define NR_LPPACAS 1 +#endif + + /* The Hypervisor barfs if the lppaca crosses a page boundary. A 1k * alignment is sufficient to prevent this */ struct lppaca { diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c index ebf9846f3c3..f4adf89d761 100644 --- a/arch/powerpc/kernel/paca.c +++ b/arch/powerpc/kernel/paca.c @@ -26,20 +26,6 @@ extern unsigned long __toc_start; #ifdef CONFIG_PPC_BOOK3S -/* - * We only have to have statically allocated lppaca structs on - * legacy iSeries, which supports at most 64 cpus. - */ -#ifdef CONFIG_PPC_ISERIES -#if NR_CPUS < 64 -#define NR_LPPACAS NR_CPUS -#else -#define NR_LPPACAS 64 -#endif -#else /* not iSeries */ -#define NR_LPPACAS 1 -#endif - /* * The structure which the hypervisor knows about - this structure * should not cross a page boundary. The vpa_init/register_vpa call diff --git a/arch/powerpc/platforms/iseries/dt.c b/arch/powerpc/platforms/iseries/dt.c index fdb7384c0c4..f0491cc2890 100644 --- a/arch/powerpc/platforms/iseries/dt.c +++ b/arch/powerpc/platforms/iseries/dt.c @@ -242,8 +242,8 @@ static void __init dt_cpus(struct iseries_flat_dt *dt) pft_size[0] = 0; /* NUMA CEC cookie, 0 for non NUMA */ pft_size[1] = __ilog2(HvCallHpt_getHptPages() * HW_PAGE_SIZE); - for (i = 0; i < NR_CPUS; i++) { - if (lppaca_of(i).dyn_proc_status >= 2) + for (i = 0; i < NR_LPPACAS; i++) { + if (lppaca[i].dyn_proc_status >= 2) continue; snprintf(p, 32 - (p - buf), "@%d", i); @@ -251,7 +251,7 @@ static void __init dt_cpus(struct iseries_flat_dt *dt) dt_prop_str(dt, "device_type", device_type_cpu); - index = lppaca_of(i).dyn_hv_phys_proc_index; + index = lppaca[i].dyn_hv_phys_proc_index; d = &xIoHriProcessorVpd[index]; dt_prop_u32(dt, "i-cache-size", d->xInstCacheSize * 1024); diff --git a/arch/powerpc/platforms/iseries/setup.c b/arch/powerpc/platforms/iseries/setup.c index b0863410517..2946ae10fbf 100644 --- a/arch/powerpc/platforms/iseries/setup.c +++ b/arch/powerpc/platforms/iseries/setup.c @@ -680,6 +680,7 @@ void * __init iSeries_early_setup(void) * on but calling this function multiple times is fine. */ identify_cpu(0, mfspr(SPRN_PVR)); + initialise_paca(&boot_paca, 0); powerpc_firmware_features |= FW_FEATURE_ISERIES; powerpc_firmware_features |= FW_FEATURE_LPAR; -- cgit v1.2.3-18-g5258 From 36e8695ca5dcf48c837a6efe6f780c47ac9ec808 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 9 Mar 2011 13:00:14 +0000 Subject: powerpc/pseries: Disable VPNH feature This feature triggers nasty races in the scheduler between the rebuilding of the topology and the load balancing code, causing the machine to hang. Disable it for now until the races are fixed. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/mm/numa.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index fd481232957..0dc95c0aa3b 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -1516,7 +1516,8 @@ int start_topology_update(void) { int rc = 0; - if (firmware_has_feature(FW_FEATURE_VPHN) && + /* Disabled until races with load balancing are fixed */ + if (0 && firmware_has_feature(FW_FEATURE_VPHN) && get_lppaca()->shared_proc) { vphn_enabled = 1; setup_cpu_associativity_change_counters(); -- cgit v1.2.3-18-g5258