On 19/08/16 18:52, Aneesh Kumar K.V wrote:
> From: Benjamin Herrenschmidt <b...@kernel.crashing.org>
>
> Just using the hash ops won't work anymore since radix will have
> NULL in there. Instead create an mmu_cleanup_all() function which
> will do the right thing based on the MMU mode.
>
> For Radix, for now I clear UPRT and the PTCR, effectively switching
> back to Radix with no partition table setup.
>
> Currently set it to NULL on BookE thought it might be a good idea
> to wipe the TLB there (Scott ?)
>
> Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
> Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
> ---
> arch/powerpc/include/asm/mmu-book3e.h | 3 +++
> arch/powerpc/include/asm/mmu.h | 4 ++++
> arch/powerpc/kernel/machine_kexec_64.c | 13 +++----------
> arch/powerpc/mm/pgtable-book3s64.c | 9 +++++++++
> arch/powerpc/mm/pgtable-radix.c | 12 ++++++++++++
> 5 files changed, 31 insertions(+), 10 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/mmu-book3e.h
> b/arch/powerpc/include/asm/mmu-book3e.h
> index cd4f04a74802..b62a8d43a06c 100644
> --- a/arch/powerpc/include/asm/mmu-book3e.h
> +++ b/arch/powerpc/include/asm/mmu-book3e.h
> @@ -313,6 +313,9 @@ extern int book3e_htw_mode;
> * return 1, indicating that the tlb requires preloading.
> */
> #define HUGETLB_NEED_PRELOAD
> +
> +#define mmu_cleanup_all NULL
> +
> #endif
>
> #endif /* !__ASSEMBLY__ */
> diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
> index e2fb408f8398..79c989a05aa1 100644
> --- a/arch/powerpc/include/asm/mmu.h
> +++ b/arch/powerpc/include/asm/mmu.h
> @@ -204,6 +204,10 @@ extern unsigned int __start___mmu_ftr_fixup,
> __stop___mmu_ftr_fixup;
> * make it match the size our of bolted TLB area
> */
> extern u64 ppc64_rma_size;
> +
> +/* Cleanup function used by kexec */
> +extern void mmu_cleanup_all(void);
> +extern void radix__mmu_cleanup_all(void);
> #endif /* CONFIG_PPC64 */
>
> struct mm_struct;
> diff --git a/arch/powerpc/kernel/machine_kexec_64.c
> b/arch/powerpc/kernel/machine_kexec_64.c
> index 4c780a342282..8cbd870dd557 100644
> --- a/arch/powerpc/kernel/machine_kexec_64.c
> +++ b/arch/powerpc/kernel/machine_kexec_64.c
> @@ -30,6 +30,7 @@
> #include <asm/smp.h>
> #include <asm/hw_breakpoint.h>
> #include <asm/asm-prototypes.h>
> +#include <asm/firmware.h>
>
> #ifdef CONFIG_PPC_BOOK3E
> int default_machine_kexec_prepare(struct kimage *image)
> @@ -55,9 +56,6 @@ int default_machine_kexec_prepare(struct kimage *image)
> const unsigned long *basep;
> const unsigned int *sizep;
>
> - if (!mmu_hash_ops.hpte_clear_all)
> - return -ENOENT;
> -
> /*
> * Since we use the kernel fault handlers and paging code to
> * handle the virtual mode, we must make sure no destination
> @@ -379,13 +377,8 @@ void default_machine_kexec(struct kimage *image)
> * a toc is easier in C, so pass in what we can.
> */
> kexec_sequence(&kexec_stack, image->start, image,
> - page_address(image->control_code_page),
> -#ifdef CONFIG_PPC_STD_MMU
> - mmu_hash_ops.hpte_clear_all
> -#else
> - NULL
> -#endif
> - );
> + page_address(image->control_code_page),
> + mmu_cleanup_all);
> /* NOTREACHED */
> }
>
> diff --git a/arch/powerpc/mm/pgtable-book3s64.c
> b/arch/powerpc/mm/pgtable-book3s64.c
> index 7328886bca4c..f4f437cbabf1 100644
> --- a/arch/powerpc/mm/pgtable-book3s64.c
> +++ b/arch/powerpc/mm/pgtable-book3s64.c
> @@ -116,3 +116,12 @@ void update_mmu_cache_pmd(struct vm_area_struct *vma,
> unsigned long addr,
> return;
> }
> #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
> +
> +/* For use by kexec */
> +void mmu_cleanup_all(void)
> +{
> + if (radix_enabled())
> + radix__mmu_cleanup_all();
> + else if (mmu_hash_ops.hpte_clear_all)
> + mmu_hash_ops.hpte_clear_all();
> +}
> diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
> index 035a1a2b1002..790a1e1bb0e5 100644
> --- a/arch/powerpc/mm/pgtable-radix.c
> +++ b/arch/powerpc/mm/pgtable-radix.c
> @@ -395,6 +395,18 @@ void radix__early_init_mmu_secondary(void)
> }
> }
>
> +void radix__mmu_cleanup_all(void)
> +{
> + unsigned long lpcr;
> +
> + if (!firmware_has_feature(FW_FEATURE_LPAR)) {
> + lpcr = mfspr(SPRN_LPCR);
> + mtspr(SPRN_LPCR, lpcr & ~LPCR_UPRT);
I suspect the new kernel will do the right thing w.r.t LPCR
> + mtspr(SPRN_PTCR, 0);
Do we care to free the partition_tb at this point? Probably not since
we are going to reboot soon, but I think it'll help with anyone (read
NMMU) holding stray references.
> + radix__flush_tlb_all();
> + }
> +}
> +
> void radix__setup_initial_memory_limit(phys_addr_t first_memblock_base,
> phys_addr_t first_memblock_size)
> {
>
Acked-by: Balbir Singh <bsinghar...@gmail.com>
