On 04/10/15 at 04:42pm, Li, Zhen-Hua wrote:
> Add some functions to copy the data from old kernel.
> These functions are used to copy context tables and page tables.
> 
> To avoid calling iounmap between spin_lock_irqsave and spin_unlock_irqrestore,
> use a link here, store the pointers , and then use iounmap to free them in
> another place.
> 
> Li, Zhen-hua:
>     The functions and logics.
> 
> Takao Indoh:
>     Check if pfn is ram:
>         if (page_is_ram(pfn))
> 
> Signed-off-by: Li, Zhen-Hua <[email protected]>
> Signed-off-by: Takao Indoh <[email protected]>
> ---
>  drivers/iommu/intel-iommu.c | 102 
> ++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/intel-iommu.h |   6 +++
>  2 files changed, 108 insertions(+)
> 
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index ff5ac04..5ba403a 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -373,6 +373,17 @@ static struct context_entry 
> *device_to_existing_context_entry(
>                               struct intel_iommu *iommu,
>                               u8 bus, u8 devfn);
>  
> +/*
> + * 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;
> + */
> +struct iommu_remapped_entry {
> +     struct list_head list;
> +     void __iomem *mem;
> +};
> +static LIST_HEAD(__iommu_remapped_mem);
> +static DEFINE_MUTEX(__iommu_mem_list_lock);
> +
>  
>  /*
>   * This domain is a statically identity mapping domain.
> @@ -4817,3 +4828,94 @@ static struct context_entry 
> *device_to_existing_context_entry(
>       return ret;
>  }
>  
> +/*
> + * Copy memory from a physically-addressed area into a virtually-addressed 
> area
> + */

I don't find where __iommu_load_from_oldmem is called. Obsolete code of
this patch?

> +int __iommu_load_from_oldmem(void *to, unsigned long from, unsigned long 
> size)
> +{
> +     unsigned long pfn;              /* Page Frame Number */
> +     size_t csize = (size_t)size;    /* Num(bytes to copy) */
> +     unsigned long offset;           /* Lower 12 bits of to */
> +     void __iomem *virt_mem;
> +     struct iommu_remapped_entry *mapped;
> +
> +     pfn = from >> VTD_PAGE_SHIFT;
> +     offset = from & (~VTD_PAGE_MASK);
> +
> +     if (page_is_ram(pfn)) {
> +             memcpy(to, pfn_to_kaddr(pfn) + offset, csize);
> +     } else{
> +
> +             mapped = kzalloc(sizeof(struct iommu_remapped_entry),
> +                             GFP_KERNEL);
> +             if (!mapped)
> +                     return -ENOMEM;
> +
> +             virt_mem = ioremap_cache((unsigned long)from, size);
> +             if (!virt_mem) {
> +                     kfree(mapped);
> +                     return -ENOMEM;
> +             }
> +             memcpy(to, virt_mem, size);
> +
> +             mutex_lock(&__iommu_mem_list_lock);
> +             mapped->mem = virt_mem;
> +             list_add_tail(&mapped->list, &__iommu_remapped_mem);
> +             mutex_unlock(&__iommu_mem_list_lock);
> +     }
> +     return size;
> +}
> +
> +/*
> + * Copy memory from a virtually-addressed area into a physically-addressed 
> area
> + */
> +int __iommu_save_to_oldmem(unsigned long to, void *from, unsigned long size)
> +{
> +     unsigned long pfn;              /* Page Frame Number */
> +     size_t csize = (size_t)size;    /* Num(bytes to copy) */
> +     unsigned long offset;           /* Lower 12 bits of to */
> +     void __iomem *virt_mem;
> +     struct iommu_remapped_entry *mapped;
> +
> +     pfn = to >> VTD_PAGE_SHIFT;
> +     offset = to & (~VTD_PAGE_MASK);
> +
> +     if (page_is_ram(pfn)) {
> +             memcpy(pfn_to_kaddr(pfn) + offset, from, csize);
> +     } else{
> +             mapped = kzalloc(sizeof(struct iommu_remapped_entry),
> +                             GFP_KERNEL);
> +             if (!mapped)
> +                     return -ENOMEM;
> +
> +             virt_mem = ioremap_cache((unsigned long)to, size);
> +             if (!virt_mem) {
> +                     kfree(mapped);
> +                     return -ENOMEM;
> +             }
> +             memcpy(virt_mem, from, size);
> +             mutex_lock(&__iommu_mem_list_lock);
> +             mapped->mem = virt_mem;
> +             list_add_tail(&mapped->list, &__iommu_remapped_mem);
> +             mutex_unlock(&__iommu_mem_list_lock);
> +     }
> +     return size;
> +}
> +
> +/*
> + * Free the mapped memory for ioremap;
> + */
> +int __iommu_free_mapped_mem(void)
> +{
> +     struct iommu_remapped_entry *mem_entry, *tmp;
> +
> +     mutex_lock(&__iommu_mem_list_lock);
> +     list_for_each_entry_safe(mem_entry, tmp, &__iommu_remapped_mem, list) {
> +             iounmap(mem_entry->mem);
> +             list_del(&mem_entry->list);
> +             kfree(mem_entry);
> +     }
> +     mutex_unlock(&__iommu_mem_list_lock);
> +     return 0;
> +}
> +
> diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
> index a65208a..4bca7b5 100644
> --- a/include/linux/intel-iommu.h
> +++ b/include/linux/intel-iommu.h
> @@ -368,4 +368,10 @@ extern int dmar_ir_support(void);
>  
>  extern const struct attribute_group *intel_iommu_groups[];
>  
> +extern int __iommu_load_from_oldmem(void *to, unsigned long from,
> +                                     unsigned long size);
> +extern int __iommu_save_to_oldmem(unsigned long to, void *from,
> +                                     unsigned long size);
> +extern int __iommu_free_mapped_mem(void);
> +
>  #endif
> -- 
> 2.0.0-rc0
> 
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