* Jim Kukunas <james.t.kuku...@linux.intel.com> wrote:
> For obtaining the physical address, we always take the slow path
> of slow_virt_to_phys(). In the future, we should probably special
> case data addresses to avoid walking the page table. For obtaining
> a virtual address, this patch introduces a slow path of
> slow_xip_phys_to_virt().
>
> Signed-off-by: Jim Kukunas <james.t.kuku...@linux.intel.com>
> ---
> arch/x86/include/asm/page.h | 15 +++++++++++++++
> arch/x86/mm/pageattr.c | 11 +++++++++++
> 2 files changed, 26 insertions(+)
>
> diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h
> index 802dde3..b54c7be 100644
> --- a/arch/x86/include/asm/page.h
> +++ b/arch/x86/include/asm/page.h
> @@ -6,6 +6,7 @@
> #ifdef __KERNEL__
>
> #include <asm/page_types.h>
> +#include <asm/pgtable_types.h>
>
> #ifdef CONFIG_X86_64
> #include <asm/page_64.h>
> @@ -37,8 +38,15 @@ static inline void copy_user_page(void *to, void *from,
> unsigned long vaddr,
> alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO | movableflags, vma, vaddr)
> #define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
>
> +
> +#ifdef CONFIG_XIP_KERNEL /* TODO special case text translations */
> +#define __pa(x) slow_virt_to_phys((void *)(x))
> +#define __pa_nodebug slow_virt_to_phys((void *)(x))
> +#else
> #define __pa(x) __phys_addr((unsigned long)(x))
> #define __pa_nodebug(x) __phys_addr_nodebug((unsigned long)(x))
> +#endif
Ugh. This needs to be fixed properly. slow_virt_to_phys() is very
painful.
> +#ifdef CONFIG_XIP_KERNEL
> +unsigned long slow_xip_phys_to_virt(phys_addr_t x)
> +{
> + if (x >= CONFIG_XIP_BASE && x <= (phys_addr_t)phys_sdata) {
> + unsigned long off = x - CONFIG_XIP_BASE;
> + return PAGE_OFFSET + off;
> + }
> + return x + PAGE_OFFSET;
> +}
> +#endif
So why not relocate the kernel properly before loading it into flash,
instead of hacking these runtime translations into va/pa?
Thanks,
Ingo
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