Seems the subject was truncated? Maybe "re" means root entry? Then please fix it
On 05/11/15 at 05:52pm, Li, Zhen-Hua wrote:
> Add functions to load root entry table from old kernel, and to save updated
> root entry table.
> Add two member in struct intel_iommu, to store the RTA in old kernel, and
> the mapped virt address of it.
Please explain a bit what is "RTA" in patch log, it is unclear to most of people
who do not know iommu details.
>
> We use the old RTA in dump kernel, and when the iommu->root_entry is used as
> a cache in kdump kernel, its phys address will not be save to RTA register,
> but when its data is changed, we will save the new data to old root entry
> table.
>
> Li, Zhen-hua:
> The functions and logics.
>
> Takao Indoh:
> Add __iommu_flush_cache.
>
> Signed-off-by: Li, Zhen-Hua <zhen-h...@hp.com>
> Signed-off-by: Takao Indoh <indou.ta...@jp.fujitsu.com>
> ---
> drivers/iommu/intel-iommu.c | 54
> ++++++++++++++++++++++++++++++++++++++++++++-
> include/linux/intel-iommu.h | 3 +++
> 2 files changed, 56 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 0b97c15..3a5d446 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -371,6 +371,10 @@ static struct context_entry
> *device_to_existing_context_entry(
> struct intel_iommu *iommu,
> u8 bus, u8 devfn);
>
> +static void __iommu_load_old_root_entry(struct intel_iommu *iommu);
> +
> +static void __iommu_update_old_root_entry(struct intel_iommu *iommu, int
> index);
> +
> /*
> * A structure used to store the address allocated by ioremap();
> * The we need to call iounmap() to free them out of
> spin_lock_irqsave/unlock;
> @@ -382,7 +386,6 @@ struct iommu_remapped_entry {
> static LIST_HEAD(__iommu_remapped_mem);
> static DEFINE_MUTEX(__iommu_mem_list_lock);
>
> -
> /*
> * This domain is a statically identity mapping domain.
> * 1. This domain creats a static 1:1 mapping to all usable memory.
> @@ -4935,3 +4938,52 @@ int __iommu_free_mapped_mem(void)
> return 0;
> }
>
> +/*
> + * Load the old root entry table to new root entry table.
> + */
> +static void __iommu_load_old_root_entry(struct intel_iommu *iommu)
> +{
> + if ((!iommu)
> + || (!iommu->root_entry)
> + || (!iommu->root_entry_old_virt)
> + || (!iommu->root_entry_old_phys))
> + return;
> + memcpy(iommu->root_entry, iommu->root_entry_old_virt, PAGE_SIZE);
> +
> + __iommu_flush_cache(iommu, iommu->root_entry, PAGE_SIZE);
> +}
> +
> +/*
> + * When the data in new root entry table is changed, this function
> + * must be called to save the updated data to old root entry table.
> + */
> +static void __iommu_update_old_root_entry(struct intel_iommu *iommu, int
> index)
> +{
> + u8 start;
> + unsigned long size;
> + void __iomem *to;
> + void *from;
> +
> + if ((!iommu)
> + || (!iommu->root_entry)
> + || (!iommu->root_entry_old_virt)
> + || (!iommu->root_entry_old_phys))
> + return;
> +
> + if (index < -1 || index >= ROOT_ENTRY_NR)
> + return;
> +
> + if (index == -1) {
> + start = 0;
> + size = ROOT_ENTRY_NR * sizeof(struct root_entry);
> + } else {
> + start = index * sizeof(struct root_entry);
> + size = sizeof(struct root_entry);
> + }
> + to = iommu->root_entry_old_virt;
> + from = iommu->root_entry;
> + memcpy(to + start, from + start, size);
> +
> + __iommu_flush_cache(iommu, to + start, size);
> +}
> +
> diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
> index ced1fac..e7cac12 100644
> --- a/include/linux/intel-iommu.h
> +++ b/include/linux/intel-iommu.h
> @@ -340,6 +340,9 @@ struct intel_iommu {
> spinlock_t lock; /* protect context, domain ids */
> struct root_entry *root_entry; /* virtual address */
>
> + void __iomem *root_entry_old_virt; /* mapped from old root entry */
> + unsigned long root_entry_old_phys; /* root entry in old kernel */
> +
> struct iommu_flush flush;
> #endif
> struct q_inval *qi; /* Queued invalidation info */
> --
> 2.0.0-rc0
>
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