On Sat, Feb 27, 2016 at 06:07:36PM +0800, Huacai Chen wrote:
> Loongson-2 has a 4 entry itlb which is a subset of jtlb, Loongson-3 has
> a 4 entry itlb and a 4 entry dtlb which are subsets of jtlb. We should
> write diag register to invalidate itlb/dtlb when flushing jtlb because
> itlb/dtlb are not totally transparent to software.
>
> For Loongson-3A R2 (and newer), we should invalidate ITLB, DTLB, VTLB
> and FTLB before we enable/disable FTLB.
>
> Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx>
> ---
> arch/mips/kernel/cpu-probe.c | 2 ++
> arch/mips/mm/tlb-r4k.c | 27 +++++++++++++++------------
> 2 files changed, 17 insertions(+), 12 deletions(-)
>
> diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
> index 2a2ae86..ef605e2 100644
> --- a/arch/mips/kernel/cpu-probe.c
> +++ b/arch/mips/kernel/cpu-probe.c
> @@ -562,6 +562,8 @@ static int set_ftlb_enable(struct cpuinfo_mips *c, int enable)
> << MIPS_CONF7_FTLBP_SHIFT));
> break;
> case CPU_LOONGSON3:
> + /* Flush ITLB, DTLB, VTLB and FTLB */
> + write_c0_diag(1<<2 | 1<<3 | 1<<12 | 1<<13);
Too many magic numbers. Could you use defines for the magic numbers you're
writing to these registers?
> /* Loongson-3 cores use Config6 to enable the FTLB */
> config = read_c0_config6();
> if (enable)
> diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
> index c17d762..7593529 100644
> --- a/arch/mips/mm/tlb-r4k.c
> +++ b/arch/mips/mm/tlb-r4k.c
> @@ -28,25 +28,28 @@
> extern void build_tlb_refill_handler(void);
>
> /*
> - * LOONGSON2/3 has a 4 entry itlb which is a subset of dtlb,
> - * unfortunately, itlb is not totally transparent to software.
> + * LOONGSON-2 has a 4 entry itlb which is a subset of jtlb, LOONGSON-3 has
> + * a 4 entry itlb and a 4 entry dtlb which are subsets of jtlb. Unfortunately,
> + * itlb/dtlb are not totally transparent to software.
> */
> -static inline void flush_itlb(void)
> +static inline void flush_spec_tlb(void)
> {
> switch (current_cpu_type()) {
> case CPU_LOONGSON2:
> + write_c0_diag(0x4);
Same here.
> + break;
> case CPU_LOONGSON3:
> - write_c0_diag(4);
> + write_c0_diag(0xc);
And here.
Also, why did the magic number change from 4 to 0xc?
> break;
> default:
> break;
> }
> }
>
> -static inline void flush_itlb_vm(struct vm_area_struct *vma)
> +static inline void flush_spec_tlb_vm(struct vm_area_struct *vma)
> {
> if (vma->vm_flags & VM_EXEC)
> - flush_itlb();
> + flush_spec_tlb();
Hm.. "spec tlb" is not very descriptive in my opinion. How about
renameing this function to flush_micro_tlb().
Ralf
