From 6ba688364856ad083be537f08e86ba97f433d405 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Wed, 1 Jun 2022 13:18:22 -0400 Subject: parisc: fix a crash with multicore scheduler With the kernel 5.18, the system will hang on boot if it is compiled with CONFIG_SCHED_MC. The last printed message is "Brought up 1 node, 1 CPU". The crash happens in sd_init tl->mask (which is cpu_coregroup_mask) returns an empty mask. This happens because cpu_topology[0].core_sibling is empty. Consequently, sd_span is set to an empty mask sd_id = cpumask_first(sd_span) sets sd_id == NR_CPUS (because the mask is empty) sd->shared = *per_cpu_ptr(sdd->sds, sd_id); sets sd->shared to NULL because sd_id is out of range atomic_inc(&sd->shared->ref); crashes without printing anything We can fix it by calling reset_cpu_topology() from init_cpu_topology() - this will initialize the sibling masks on CPUs, so that they're not empty. This patch also removes the variable "dualcores_found", it is useless, because during boot, init_cpu_topology is called before store_cpu_topology. Thus, set_sched_topology(parisc_mc_topology) is never called. We don't need to call it at all because default_topology in kernel/sched/topology.c contains the same items as parisc_mc_topology. Note that we should not call store_cpu_topology() from init_per_cpu() because it is called too early in the kernel initialization process and it results in the message "Failure to register CPU0 device". Before this patch, store_cpu_topology() would exit immediatelly because cpuid_topo->core id was uninitialized and it was 0. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org # v5.18 Signed-off-by: Helge Deller --- arch/parisc/kernel/processor.c | 2 -- arch/parisc/kernel/topology.c | 16 +--------------- 2 files changed, 1 insertion(+), 17 deletions(-) (limited to 'arch') diff --git a/arch/parisc/kernel/processor.c b/arch/parisc/kernel/processor.c index 26eb568f8b96..dddaaa6e7a82 100644 --- a/arch/parisc/kernel/processor.c +++ b/arch/parisc/kernel/processor.c @@ -327,8 +327,6 @@ int init_per_cpu(int cpunum) set_firmware_width(); ret = pdc_coproc_cfg(&coproc_cfg); - store_cpu_topology(cpunum); - if(ret >= 0 && coproc_cfg.ccr_functional) { mtctl(coproc_cfg.ccr_functional, 10); /* 10 == Coprocessor Control Reg */ diff --git a/arch/parisc/kernel/topology.c b/arch/parisc/kernel/topology.c index 9696e3cb6a2a..b9d845e314f8 100644 --- a/arch/parisc/kernel/topology.c +++ b/arch/parisc/kernel/topology.c @@ -20,8 +20,6 @@ static DEFINE_PER_CPU(struct cpu, cpu_devices); -static int dualcores_found; - /* * store_cpu_topology is called at boot when only one cpu is running * and with the mutex cpu_hotplug.lock locked, when several cpus have booted, @@ -60,7 +58,6 @@ void store_cpu_topology(unsigned int cpuid) if (p->cpu_loc) { cpuid_topo->core_id++; cpuid_topo->package_id = cpu_topology[cpu].package_id; - dualcores_found = 1; continue; } } @@ -80,22 +77,11 @@ void store_cpu_topology(unsigned int cpuid) cpu_topology[cpuid].package_id); } -static struct sched_domain_topology_level parisc_mc_topology[] = { -#ifdef CONFIG_SCHED_MC - { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) }, -#endif - - { cpu_cpu_mask, SD_INIT_NAME(DIE) }, - { NULL, }, -}; - /* * init_cpu_topology is called at boot when only one cpu is running * which prevent simultaneous write access to cpu_topology array */ void __init init_cpu_topology(void) { - /* Set scheduler topology descriptor */ - if (dualcores_found) - set_sched_topology(parisc_mc_topology); + reset_cpu_topology(); } -- cgit v1.2.3 From cf936af790a3ef5f41ff687ec91bfbffee141278 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Thu, 2 Jun 2022 13:50:44 +0200 Subject: parisc/stifb: Implement fb_is_primary_device() Implement fb_is_primary_device() function, so that fbcon detects if this framebuffer belongs to the default graphics card which was used to start the system. Signed-off-by: Helge Deller Cc: stable@vger.kernel.org # v5.10+ --- arch/parisc/include/asm/fb.h | 4 ++++ drivers/video/console/sticore.c | 17 +++++++++++++++++ drivers/video/fbdev/stifb.c | 4 ++-- 3 files changed, 23 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/parisc/include/asm/fb.h b/arch/parisc/include/asm/fb.h index c4cd6360f996..d63a2acb91f2 100644 --- a/arch/parisc/include/asm/fb.h +++ b/arch/parisc/include/asm/fb.h @@ -12,9 +12,13 @@ static inline void fb_pgprotect(struct file *file, struct vm_area_struct *vma, pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE; } +#if defined(CONFIG_STI_CONSOLE) || defined(CONFIG_FB_STI) +int fb_is_primary_device(struct fb_info *info); +#else static inline int fb_is_primary_device(struct fb_info *info) { return 0; } +#endif #endif /* _ASM_FB_H_ */ diff --git a/drivers/video/console/sticore.c b/drivers/video/console/sticore.c index f869b723494f..62005064911b 100644 --- a/drivers/video/console/sticore.c +++ b/drivers/video/console/sticore.c @@ -30,6 +30,7 @@ #include #include #include +#include #include "../fbdev/sticore.h" @@ -1127,6 +1128,22 @@ int sti_call(const struct sti_struct *sti, unsigned long func, return ret; } +/* check if given fb_info is the primary device */ +int fb_is_primary_device(struct fb_info *info) +{ + struct sti_struct *sti; + + sti = sti_get_rom(0); + + /* if no built-in graphics card found, allow any fb driver as default */ + if (!sti) + return true; + + /* return true if it's the default built-in framebuffer driver */ + return (sti->info == info); +} +EXPORT_SYMBOL(fb_is_primary_device); + MODULE_AUTHOR("Philipp Rumpf, Helge Deller, Thomas Bogendoerfer"); MODULE_DESCRIPTION("Core STI driver for HP's NGLE series graphics cards in HP PARISC machines"); MODULE_LICENSE("GPL v2"); diff --git a/drivers/video/fbdev/stifb.c b/drivers/video/fbdev/stifb.c index bebb2eea6448..38a861e22c33 100644 --- a/drivers/video/fbdev/stifb.c +++ b/drivers/video/fbdev/stifb.c @@ -1358,11 +1358,11 @@ static int __init stifb_init_fb(struct sti_struct *sti, int bpp_pref) goto out_err3; } + /* save for primary gfx device detection & unregister_framebuffer() */ + sti->info = info; if (register_framebuffer(&fb->info) < 0) goto out_err4; - sti->info = info; /* save for unregister_framebuffer() */ - fb_info(&fb->info, "%s %dx%d-%d frame buffer device, %s, id: %04x, mmio: 0x%04lx\n", fix->id, var->xres, -- cgit v1.2.3