diff options
Diffstat (limited to 'arch/powerpc/kernel/setup_64.c')
| -rw-r--r-- | arch/powerpc/kernel/setup_64.c | 180 |
1 files changed, 166 insertions, 14 deletions
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index b89c6aac48c9..c388cc3357fa 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -10,8 +10,6 @@ * 2 of the License, or (at your option) any later version. */ -#define DEBUG - #include <linux/export.h> #include <linux/string.h> #include <linux/sched.h> @@ -38,6 +36,7 @@ #include <linux/memory.h> #include <linux/nmi.h> +#include <asm/debugfs.h> #include <asm/io.h> #include <asm/kdump.h> #include <asm/prom.h> @@ -68,6 +67,9 @@ #include <asm/livepatch.h> #include <asm/opal.h> #include <asm/cputhreads.h> +#include <asm/hw_irq.h> + +#include "setup.h" #ifdef DEBUG #define DBG(fmt...) udbg_printf(fmt) @@ -187,6 +189,8 @@ static void __init fixup_boot_paca(void) get_paca()->cpu_start = 1; /* Allow percpu accesses to work until we setup percpu data */ get_paca()->data_offset = 0; + /* Mark interrupts disabled in PACA */ + irq_soft_mask_set(IRQS_DISABLED); } static void __init configure_exceptions(void) @@ -317,6 +321,13 @@ void __init early_setup(unsigned long dt_ptr) early_init_mmu(); /* + * After firmware and early platform setup code has set things up, + * we note the SPR values for configurable control/performance + * registers, and use those as initial defaults. + */ + record_spr_defaults(); + + /* * At this point, we can let interrupts switch to virtual mode * (the MMU has been setup), so adjust the MSR in the PACA to * have IR and DR set and enable AIL if it exists @@ -342,7 +353,7 @@ void __init early_setup(unsigned long dt_ptr) void early_setup_secondary(void) { /* Mark interrupts disabled in PACA */ - get_paca()->soft_enabled = 0; + irq_soft_mask_set(IRQS_DISABLED); /* Initialize the hash table or TLB handling */ early_init_mmu_secondary(); @@ -360,8 +371,16 @@ void early_setup_secondary(void) #if defined(CONFIG_SMP) || defined(CONFIG_KEXEC_CORE) static bool use_spinloop(void) { - if (!IS_ENABLED(CONFIG_PPC_BOOK3E)) + if (IS_ENABLED(CONFIG_PPC_BOOK3S)) { + /* + * See comments in head_64.S -- not all platforms insert + * secondaries at __secondary_hold and wait at the spin + * loop. + */ + if (firmware_has_feature(FW_FEATURE_OPAL)) + return false; return true; + } /* * When book3e boots from kexec, the ePAPR spin table does @@ -550,25 +569,31 @@ void __init initialize_cache_info(void) DBG(" <- initialize_cache_info()\n"); } -/* This returns the limit below which memory accesses to the linear - * mapping are guarnateed not to cause a TLB or SLB miss. This is - * used to allocate interrupt or emergency stacks for which our - * exception entry path doesn't deal with being interrupted. +/* + * This returns the limit below which memory accesses to the linear + * mapping are guarnateed not to cause an architectural exception (e.g., + * TLB or SLB miss fault). + * + * This is used to allocate PACAs and various interrupt stacks that + * that are accessed early in interrupt handlers that must not cause + * re-entrant interrupts. */ -static __init u64 safe_stack_limit(void) +__init u64 ppc64_bolted_size(void) { #ifdef CONFIG_PPC_BOOK3E /* Freescale BookE bolts the entire linear mapping */ - if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) + /* XXX: BookE ppc64_rma_limit setup seems to disagree? */ + if (early_mmu_has_feature(MMU_FTR_TYPE_FSL_E)) return linear_map_top; /* Other BookE, we assume the first GB is bolted */ return 1ul << 30; #else + /* BookS radix, does not take faults on linear mapping */ if (early_radix_enabled()) return ULONG_MAX; - /* BookS, the first segment is bolted */ - if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) + /* BookS hash, the first segment is bolted */ + if (early_mmu_has_feature(MMU_FTR_1T_SEGMENT)) return 1UL << SID_SHIFT_1T; return 1UL << SID_SHIFT; #endif @@ -576,7 +601,7 @@ static __init u64 safe_stack_limit(void) void __init irqstack_early_init(void) { - u64 limit = safe_stack_limit(); + u64 limit = ppc64_bolted_size(); unsigned int i; /* @@ -661,7 +686,7 @@ void __init emergency_stack_init(void) * initialized in kernel/irq.c. These are initialized here in order * to have emergency stacks available as early as possible. */ - limit = min(safe_stack_limit(), ppc64_rma_size); + limit = min(ppc64_bolted_size(), ppc64_rma_size); for_each_possible_cpu(i) { struct thread_info *ti; @@ -784,3 +809,130 @@ static int __init disable_hardlockup_detector(void) return 0; } early_initcall(disable_hardlockup_detector); + +#ifdef CONFIG_PPC_BOOK3S_64 +static enum l1d_flush_type enabled_flush_types; +static void *l1d_flush_fallback_area; +static bool no_rfi_flush; +bool rfi_flush; + +static int __init handle_no_rfi_flush(char *p) +{ + pr_info("rfi-flush: disabled on command line."); + no_rfi_flush = true; + return 0; +} +early_param("no_rfi_flush", handle_no_rfi_flush); + +/* + * The RFI flush is not KPTI, but because users will see doco that says to use + * nopti we hijack that option here to also disable the RFI flush. + */ +static int __init handle_no_pti(char *p) +{ + pr_info("rfi-flush: disabling due to 'nopti' on command line.\n"); + handle_no_rfi_flush(NULL); + return 0; +} +early_param("nopti", handle_no_pti); + +static void do_nothing(void *unused) +{ + /* + * We don't need to do the flush explicitly, just enter+exit kernel is + * sufficient, the RFI exit handlers will do the right thing. + */ +} + +void rfi_flush_enable(bool enable) +{ + if (rfi_flush == enable) + return; + + if (enable) { + do_rfi_flush_fixups(enabled_flush_types); + on_each_cpu(do_nothing, NULL, 1); + } else + do_rfi_flush_fixups(L1D_FLUSH_NONE); + + rfi_flush = enable; +} + +static void init_fallback_flush(void) +{ + u64 l1d_size, limit; + int cpu; + + l1d_size = ppc64_caches.l1d.size; + limit = min(ppc64_bolted_size(), ppc64_rma_size); + + /* + * Align to L1d size, and size it at 2x L1d size, to catch possible + * hardware prefetch runoff. We don't have a recipe for load patterns to + * reliably avoid the prefetcher. + */ + l1d_flush_fallback_area = __va(memblock_alloc_base(l1d_size * 2, l1d_size, limit)); + memset(l1d_flush_fallback_area, 0, l1d_size * 2); + + for_each_possible_cpu(cpu) { + paca[cpu].rfi_flush_fallback_area = l1d_flush_fallback_area; + paca[cpu].l1d_flush_size = l1d_size; + } +} + +void __init setup_rfi_flush(enum l1d_flush_type types, bool enable) +{ + if (types & L1D_FLUSH_FALLBACK) { + pr_info("rfi-flush: Using fallback displacement flush\n"); + init_fallback_flush(); + } + + if (types & L1D_FLUSH_ORI) + pr_info("rfi-flush: Using ori type flush\n"); + + if (types & L1D_FLUSH_MTTRIG) + pr_info("rfi-flush: Using mttrig type flush\n"); + + enabled_flush_types = types; + + if (!no_rfi_flush) + rfi_flush_enable(enable); +} + +#ifdef CONFIG_DEBUG_FS +static int rfi_flush_set(void *data, u64 val) +{ + if (val == 1) + rfi_flush_enable(true); + else if (val == 0) + rfi_flush_enable(false); + else + return -EINVAL; + + return 0; +} + +static int rfi_flush_get(void *data, u64 *val) +{ + *val = rfi_flush ? 1 : 0; + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(fops_rfi_flush, rfi_flush_get, rfi_flush_set, "%llu\n"); + +static __init int rfi_flush_debugfs_init(void) +{ + debugfs_create_file("rfi_flush", 0600, powerpc_debugfs_root, NULL, &fops_rfi_flush); + return 0; +} +device_initcall(rfi_flush_debugfs_init); +#endif + +ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf) +{ + if (rfi_flush) + return sprintf(buf, "Mitigation: RFI Flush\n"); + + return sprintf(buf, "Vulnerable\n"); +} +#endif /* CONFIG_PPC_BOOK3S_64 */ |