[v1] Register Xen's load address as a boot module

[PATCH v1 2/3] xen/riscv: switch LINK_TO_LOAD() to virt_to_maddr()

Posted by Oleksii Kurochko 2 months, 3 weeks ago

Except for switching LINK_TO_LOAD() to virt_to_maddr(),
LINK_TO_LOAD() is dropped, as virt_to_maddr() covers all
the cases where LINK_TO_LOAD() is used.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---
 xen/arch/riscv/mm.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/xen/arch/riscv/mm.c b/xen/arch/riscv/mm.c
index 7a1919e07e..59da61716c 100644
--- a/xen/arch/riscv/mm.c
+++ b/xen/arch/riscv/mm.c
@@ -29,7 +29,6 @@ struct mmu_desc {
 unsigned long __ro_after_init phys_offset;
 
 #define LOAD_TO_LINK(addr) ((unsigned long)(addr) - phys_offset)
-#define LINK_TO_LOAD(addr) ((unsigned long)(addr) + phys_offset)
 
 /*
  * It is expected that Xen won't be more then 2 MB.
@@ -122,7 +121,7 @@ static void __init setup_initial_mapping(struct mmu_desc *mmu_desc,
                 unsigned long paddr = (page_addr - map_start) + pa_start;
                 unsigned int permissions = PTE_LEAF_DEFAULT;
                 unsigned long addr = is_identity_mapping
-                                     ? page_addr : LINK_TO_LOAD(page_addr);
+                                     ? page_addr : virt_to_maddr(page_addr);
                 pte_t pte_to_be_written;
 
                 index = pt_index(0, page_addr);
@@ -225,7 +224,7 @@ void __init setup_fixmap_mappings(void)
 
     BUG_ON(pte_is_valid(*pte));
 
-    tmp = paddr_to_pte(LINK_TO_LOAD((unsigned long)&xen_fixmap), PTE_TABLE);
+    tmp = paddr_to_pte(virt_to_maddr(&xen_fixmap), PTE_TABLE);
     write_pte(pte, tmp);
 
     RISCV_FENCE(rw, rw);
@@ -312,7 +311,7 @@ void __init remove_identity_mapping(void)
     pte_t *pgtbl;
     unsigned int index, xen_index;
     unsigned long ident_start =
-        LINK_TO_LOAD(turn_on_mmu) & XEN_PT_LEVEL_MAP_MASK(0);
+        virt_to_maddr((unsigned long)turn_on_mmu) & XEN_PT_LEVEL_MAP_MASK(0);
 
     for ( pgtbl = stage1_pgtbl_root, i = CONFIG_PAGING_LEVELS; i; i-- )
     {
-- 
2.46.1

Re: [PATCH v1 2/3] xen/riscv: switch LINK_TO_LOAD() to virt_to_maddr()

Posted by Jan Beulich 2 months, 2 weeks ago

On 30.09.2024 17:08, Oleksii Kurochko wrote:
> Except for switching LINK_TO_LOAD() to virt_to_maddr(),
> LINK_TO_LOAD() is dropped, as virt_to_maddr() covers all
> the cases where LINK_TO_LOAD() is used.

Why "Except for ..."? I'm afraid I can'rt make sense of this.

> @@ -225,7 +224,7 @@ void __init setup_fixmap_mappings(void)
>  
>      BUG_ON(pte_is_valid(*pte));
>  
> -    tmp = paddr_to_pte(LINK_TO_LOAD((unsigned long)&xen_fixmap), PTE_TABLE);
> +    tmp = paddr_to_pte(virt_to_maddr(&xen_fixmap), PTE_TABLE);

Just like you don't open-code a cast here, ...

> @@ -312,7 +311,7 @@ void __init remove_identity_mapping(void)
>      pte_t *pgtbl;
>      unsigned int index, xen_index;
>      unsigned long ident_start =
> -        LINK_TO_LOAD(turn_on_mmu) & XEN_PT_LEVEL_MAP_MASK(0);
> +        virt_to_maddr((unsigned long)turn_on_mmu) & XEN_PT_LEVEL_MAP_MASK(0);

... you shouldn't do so here. The virt_to_maddr() wrapper macro does so already.

Jan

Re: [PATCH v1 2/3] xen/riscv: switch LINK_TO_LOAD() to virt_to_maddr()

Posted by oleksii.kurochko@gmail.com 2 months, 2 weeks ago

On Tue, 2024-10-01 at 17:44 +0200, Jan Beulich wrote:
> On 30.09.2024 17:08, Oleksii Kurochko wrote:
> > Except for switching LINK_TO_LOAD() to virt_to_maddr(),
> > LINK_TO_LOAD() is dropped, as virt_to_maddr() covers all
> > the cases where LINK_TO_LOAD() is used.
> 
> Why "Except for ..."? I'm afraid I can'rt make sense of this.
I will reword that for clarity:
   Use virt_to_maddr() instead of LINK_TO_LOAD as virt_to_maddr()
   covers all the cases where LINK_TO_LOAD() is used.
   
Thanks.

~ Oleksii
> 
> > @@ -225,7 +224,7 @@ void __init setup_fixmap_mappings(void)
> >  
> >      BUG_ON(pte_is_valid(*pte));
> >  
> > -    tmp = paddr_to_pte(LINK_TO_LOAD((unsigned long)&xen_fixmap),
> > PTE_TABLE);
> > +    tmp = paddr_to_pte(virt_to_maddr(&xen_fixmap), PTE_TABLE);
> 
> Just like you don't open-code a cast here, ...
> 
> > @@ -312,7 +311,7 @@ void __init remove_identity_mapping(void)
> >      pte_t *pgtbl;
> >      unsigned int index, xen_index;
> >      unsigned long ident_start =
> > -        LINK_TO_LOAD(turn_on_mmu) & XEN_PT_LEVEL_MAP_MASK(0);
> > +        virt_to_maddr((unsigned long)turn_on_mmu) &
> > XEN_PT_LEVEL_MAP_MASK(0);
> 
> ... you shouldn't do so here. The virt_to_maddr() wrapper macro does
> so already.
> 
> Jan