From e09b41010ba33a20a87472ee821fa407a5b8da36 Mon Sep 17 00:00:00 2001 From: José Pekkarinen Date: Mon, 11 Apr 2016 10:41:07 +0300 Subject: These changes are the raw update to linux-4.4.6-rt14. Kernel sources are taken from kernel.org, and rt patch from the rt wiki download page. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen --- kernel/arch/arm/mm/context.c | 38 ++++++++++++++++++++++++++------------ 1 file changed, 26 insertions(+), 12 deletions(-) (limited to 'kernel/arch/arm/mm/context.c') diff --git a/kernel/arch/arm/mm/context.c b/kernel/arch/arm/mm/context.c index 845769e41..c8c8b9ed0 100644 --- a/kernel/arch/arm/mm/context.c +++ b/kernel/arch/arm/mm/context.c @@ -165,13 +165,28 @@ static void flush_context(unsigned int cpu) __flush_icache_all(); } -static int is_reserved_asid(u64 asid) +static bool check_update_reserved_asid(u64 asid, u64 newasid) { int cpu; - for_each_possible_cpu(cpu) - if (per_cpu(reserved_asids, cpu) == asid) - return 1; - return 0; + bool hit = false; + + /* + * Iterate over the set of reserved ASIDs looking for a match. + * If we find one, then we can update our mm to use newasid + * (i.e. the same ASID in the current generation) but we can't + * exit the loop early, since we need to ensure that all copies + * of the old ASID are updated to reflect the mm. Failure to do + * so could result in us missing the reserved ASID in a future + * generation. + */ + for_each_possible_cpu(cpu) { + if (per_cpu(reserved_asids, cpu) == asid) { + hit = true; + per_cpu(reserved_asids, cpu) = newasid; + } + } + + return hit; } static u64 new_context(struct mm_struct *mm, unsigned int cpu) @@ -181,12 +196,14 @@ static u64 new_context(struct mm_struct *mm, unsigned int cpu) u64 generation = atomic64_read(&asid_generation); if (asid != 0) { + u64 newasid = generation | (asid & ~ASID_MASK); + /* * If our current ASID was active during a rollover, we * can continue to use it and this was just a false alarm. */ - if (is_reserved_asid(asid)) - return generation | (asid & ~ASID_MASK); + if (check_update_reserved_asid(asid, newasid)) + return newasid; /* * We had a valid ASID in a previous life, so try to re-use @@ -194,7 +211,7 @@ static u64 new_context(struct mm_struct *mm, unsigned int cpu) */ asid &= ~ASID_MASK; if (!__test_and_set_bit(asid, asid_map)) - goto bump_gen; + return newasid; } /* @@ -216,11 +233,8 @@ static u64 new_context(struct mm_struct *mm, unsigned int cpu) __set_bit(asid, asid_map); cur_idx = asid; - -bump_gen: - asid |= generation; cpumask_clear(mm_cpumask(mm)); - return asid; + return asid | generation; } void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk) -- cgit 1.2.3-korg