Re: [PATCH 22/38] MIPS: VDSO: Drop gic_get_usm_range() usage

[Marc Zyngier <marc.zyngier@arm.com>]

On 13/08/17 05:36, Paul Burton wrote:
> We don't really need gic_get_usm_range() to abstract discovery of the
> address of the GIC user-visible section now that we have access to its
> base address globally.
> 
> Switch to calculating it ourselves, which will allow us to stop
> requiring the irqchip driver to care about a counter exposed to userland
> for use via the VDSO.
> 
> Signed-off-by: Paul Burton <paul.burton@imgtec.com>
> Cc: Jason Cooper <jason@lakedaemon.net>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: linux-mips@linux-mips.org
> ---
> 
>  arch/mips/kernel/vdso.c | 15 +++++----------
>  1 file changed, 5 insertions(+), 10 deletions(-)
> 
> diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c
> index 093517e85a6c..019035d7225c 100644
> --- a/arch/mips/kernel/vdso.c
> +++ b/arch/mips/kernel/vdso.c
> @@ -13,13 +13,13 @@
>  #include <linux/err.h>
>  #include <linux/init.h>
>  #include <linux/ioport.h>
> -#include <linux/irqchip/mips-gic.h>
>  #include <linux/mm.h>
>  #include <linux/sched.h>
>  #include <linux/slab.h>
>  #include <linux/timekeeper_internal.h>
>  
>  #include <asm/abi.h>
> +#include <asm/mips-cps.h>
>  #include <asm/vdso.h>
>  
>  /* Kernel-provided data used by the VDSO. */
> @@ -99,9 +99,8 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
>  {
>  	struct mips_vdso_image *image = current->thread.abi->vdso;
>  	struct mm_struct *mm = current->mm;
> -	unsigned long gic_size, vvar_size, size, base, data_addr, vdso_addr;
> +	unsigned long gic_size, vvar_size, size, base, data_addr, vdso_addr, gic_pfn;
>  	struct vm_area_struct *vma;
> -	struct resource gic_res;
>  	int ret;
>  
>  	if (down_write_killable(&mm->mmap_sem))
> @@ -125,7 +124,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
>  	 * only map a page even though the total area is 64K, as we only need
>  	 * the counter registers at the start.
>  	 */
> -	gic_size = gic_present ? PAGE_SIZE : 0;
> +	gic_size = mips_gic_present() ? PAGE_SIZE : 0;
>  	vvar_size = gic_size + PAGE_SIZE;
>  	size = vvar_size + image->size;
>  
> @@ -148,13 +147,9 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
>  
>  	/* Map GIC user page. */
>  	if (gic_size) {
> -		ret = gic_get_usm_range(&gic_res);
> -		if (ret)
> -			goto out;
> +		gic_pfn = virt_to_phys(mips_gic_base + MIPS_GIC_USER_OFS) >> PAGE_SHIFT;

virt_to_pfn() instead?

>  
> -		ret = io_remap_pfn_range(vma, base,
> -					 gic_res.start >> PAGE_SHIFT,
> -					 gic_size,
> +		ret = io_remap_pfn_range(vma, base, gic_pfn, gic_size,
>  					 pgprot_noncached(PAGE_READONLY));
>  		if (ret)
>  			goto out;
> 

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...