On 10/07/2015 06:48 AM, Scott Wood wrote:
> Use an AS=1 trampoline TLB entry to allow all normal TLB1 entries to
> be loaded at once. This avoids the need to keep the translation that
> code is executing from in the same TLB entry in the final TLB
> configuration as during early boot, which in turn is helpful for
> relocatable kernels (e.g. kdump) where the kernel is not running from
> what would be the first TLB entry.
>
> On e6500, we limit map_mem_in_cams() to the primary hwthread of a
> core (the boot cpu is always considered primary, as a kdump kernel
> can be entered on any cpu). Each TLB only needs to be set up once,
> and when we do, we don't want another thread to be running when we
> create a temporary trampoline TLB1 entry.
>
> Signed-off-by: Scott Wood <scottwood at freescale.com>
> ---
> arch/powerpc/kernel/setup_64.c | 8 +++++
> arch/powerpc/mm/fsl_booke_mmu.c | 15 ++++++++--
> arch/powerpc/mm/mmu_decl.h | 1 +
> arch/powerpc/mm/tlb_nohash.c | 19 +++++++++++-
> arch/powerpc/mm/tlb_nohash_low.S | 63 ++++++++++++++++++++++++++++++++++++++++
> 5 files changed, 102 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
> index bdcbb71..505ec2c 100644
> --- a/arch/powerpc/kernel/setup_64.c
> +++ b/arch/powerpc/kernel/setup_64.c
> @@ -108,6 +108,14 @@ static void setup_tlb_core_data(void)
> for_each_possible_cpu(cpu) {
> int first = cpu_first_thread_sibling(cpu);
>
> + /*
> + * If we boot via kdump on a non-primary thread,
> + * make sure we point at the thread that actually
> + * set up this TLB.
> + */
> + if (cpu_first_thread_sibling(boot_cpuid) == first)
> + first = boot_cpuid;
> +
> paca[cpu].tcd_ptr = &paca[first].tcd;
>
> /*
> diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c
> index 354ba3c..36d3c55 100644
> --- a/arch/powerpc/mm/fsl_booke_mmu.c
> +++ b/arch/powerpc/mm/fsl_booke_mmu.c
> @@ -105,8 +105,9 @@ unsigned long p_mapped_by_tlbcam(phys_addr_t pa)
> * an unsigned long (for example, 32-bit implementations cannot support a 4GB
> * size).
> */
> -static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
> - unsigned long size, unsigned long flags, unsigned int pid)
> +static void preptlbcam(int index, unsigned long virt, phys_addr_t phys,
> + unsigned long size, unsigned long flags,
> + unsigned int pid)
> {
> unsigned int tsize;
>
> @@ -141,7 +142,13 @@ static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
> tlbcam_addrs[index].start = virt;
> tlbcam_addrs[index].limit = virt + size - 1;
> tlbcam_addrs[index].phys = phys;
> +}
>
> +void settlbcam(int index, unsigned long virt, phys_addr_t phys,
Nit: shouldn't this be left static? Also, now with this bulk TLB1 loading is it still used? Maybe it can be dropped.
---
Best Regards, Laurentiu
