Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---
xen/arch/riscv/include/asm/config.h | 6 +++++
xen/arch/riscv/include/asm/mm.h | 2 ++
xen/arch/riscv/mm.c | 37 +++++++++++++++++++++++++----
3 files changed, 40 insertions(+), 5 deletions(-)
diff --git a/xen/arch/riscv/include/asm/config.h b/xen/arch/riscv/include/asm/config.h
index 50583aafdc..2395bafb91 100644
--- a/xen/arch/riscv/include/asm/config.h
+++ b/xen/arch/riscv/include/asm/config.h
@@ -74,6 +74,9 @@
#error "unsupported RV_STAGE1_MODE"
#endif
+#define XEN_SIZE MB(2)
+#define XEN_VIRT_END (XEN_VIRT_START + XEN_SIZE)
+
#define DIRECTMAP_SLOT_END 509
#define DIRECTMAP_SLOT_START 200
#define DIRECTMAP_VIRT_START SLOTN(DIRECTMAP_SLOT_START)
@@ -99,6 +102,9 @@
#define VMAP_VIRT_START SLOTN(VMAP_SLOT_START)
#define VMAP_VIRT_SIZE GB(1)
+#define BOOT_FDT_VIRT_START XEN_VIRT_END
+#define BOOT_FDT_VIRT_SIZE MB(4)
+
#else
#error "RV32 isn't supported"
#endif
diff --git a/xen/arch/riscv/include/asm/mm.h b/xen/arch/riscv/include/asm/mm.h
index 25af9e1aaa..d1db7ce098 100644
--- a/xen/arch/riscv/include/asm/mm.h
+++ b/xen/arch/riscv/include/asm/mm.h
@@ -255,4 +255,6 @@ static inline unsigned int arch_get_dma_bitsize(void)
return 32; /* TODO */
}
+void* early_fdt_map(paddr_t fdt_paddr);
+
#endif /* _ASM_RISCV_MM_H */
diff --git a/xen/arch/riscv/mm.c b/xen/arch/riscv/mm.c
index 7d09e781bf..ccc91f9a01 100644
--- a/xen/arch/riscv/mm.c
+++ b/xen/arch/riscv/mm.c
@@ -1,5 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0-only */
+#include <xen/bootfdt.h>
#include <xen/bug.h>
#include <xen/compiler.h>
#include <xen/init.h>
@@ -7,7 +8,9 @@
#include <xen/macros.h>
#include <xen/mm.h>
#include <xen/pfn.h>
+#include <xen/libfdt/libfdt.h>
#include <xen/sections.h>
+#include <xen/sizes.h>
#include <asm/early_printk.h>
#include <asm/csr.h>
@@ -20,7 +23,7 @@ struct mmu_desc {
unsigned int pgtbl_count;
pte_t *next_pgtbl;
pte_t *pgtbl_base;
-};
+} mmu_desc = { CONFIG_PAGING_LEVELS, 0, NULL, 0 };
static unsigned long __ro_after_init phys_offset;
@@ -39,9 +42,11 @@ static unsigned long __ro_after_init phys_offset;
* isn't 2 MB aligned.
*
* CONFIG_PAGING_LEVELS page tables are needed for the identity mapping,
- * except that the root page table is shared with the initial mapping
+ * except that the root page table is shared with the initial mapping.
+ *
+ * CONFIG_PAGING_LEVELS page tables are needed for device tree mapping.
*/
-#define PGTBL_INITIAL_COUNT ((CONFIG_PAGING_LEVELS - 1) * 2 + 1)
+#define PGTBL_INITIAL_COUNT ((CONFIG_PAGING_LEVELS - 1) * 3 + 1 + 1)
pte_t __section(".bss.page_aligned") __aligned(PAGE_SIZE)
stage1_pgtbl_root[PAGETABLE_ENTRIES];
@@ -207,8 +212,6 @@ static bool __init check_pgtbl_mode_support(struct mmu_desc *mmu_desc,
*/
void __init setup_initial_pagetables(void)
{
- struct mmu_desc mmu_desc = { CONFIG_PAGING_LEVELS, 0, NULL, NULL };
-
/*
* Access to _start, _end is always PC-relative thereby when access
* them we will get load adresses of start and end of Xen.
@@ -296,6 +299,30 @@ unsigned long __init calc_phys_offset(void)
return phys_offset;
}
+void* __init early_fdt_map(paddr_t fdt_paddr)
+{
+ unsigned long dt_phys_base = fdt_paddr;
+ unsigned long dt_virt_base;
+ unsigned long dt_virt_size;
+
+ BUILD_BUG_ON(MIN_FDT_ALIGN < 8);
+ if ( !fdt_paddr || fdt_paddr % MIN_FDT_ALIGN || fdt_paddr % SZ_2M ||
+ fdt_totalsize(fdt_paddr) > BOOT_FDT_VIRT_SIZE )
+ return NULL;
+
+ BUILD_BUG_ON(BOOT_FDT_VIRT_START % SZ_2M);
+
+ dt_virt_base = BOOT_FDT_VIRT_START;
+ dt_virt_size = BOOT_FDT_VIRT_SIZE;
+
+ /* Map device tree */
+ setup_initial_mapping(&mmu_desc, dt_virt_base,
+ dt_virt_base + dt_virt_size,
+ dt_phys_base);
+
+ return (void *)dt_virt_base;
+}
+
void put_page(struct page_info *page)
{
BUG_ON("unimplemented");
--
2.45.2On 03.07.2024 12:42, Oleksii Kurochko wrote:
> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
> ---
> xen/arch/riscv/include/asm/config.h | 6 +++++
> xen/arch/riscv/include/asm/mm.h | 2 ++
> xen/arch/riscv/mm.c | 37 +++++++++++++++++++++++++----
> 3 files changed, 40 insertions(+), 5 deletions(-)
I don't think a change like this can come without any description.
> --- a/xen/arch/riscv/include/asm/config.h
> +++ b/xen/arch/riscv/include/asm/config.h
> @@ -74,6 +74,9 @@
> #error "unsupported RV_STAGE1_MODE"
> #endif
>
> +#define XEN_SIZE MB(2)
> +#define XEN_VIRT_END (XEN_VIRT_START + XEN_SIZE)
Probably wants accompanying by an assertion in the linker script. Or else
how would one notice when Xen grows bigger than this?
> @@ -99,6 +102,9 @@
> #define VMAP_VIRT_START SLOTN(VMAP_SLOT_START)
> #define VMAP_VIRT_SIZE GB(1)
>
> +#define BOOT_FDT_VIRT_START XEN_VIRT_END
> +#define BOOT_FDT_VIRT_SIZE MB(4)
Is the 4 selected arbitrarily, or derived from something?
Also maybe better to keep these #define-s sorted by address? (As to "keep":
I didn't check whether they currently are.)
> --- a/xen/arch/riscv/include/asm/mm.h
> +++ b/xen/arch/riscv/include/asm/mm.h
> @@ -255,4 +255,6 @@ static inline unsigned int arch_get_dma_bitsize(void)
> return 32; /* TODO */
> }
>
> +void* early_fdt_map(paddr_t fdt_paddr);
Nit: * and blank want to change places.
> --- a/xen/arch/riscv/mm.c
> +++ b/xen/arch/riscv/mm.c
> @@ -1,5 +1,6 @@
> /* SPDX-License-Identifier: GPL-2.0-only */
>
> +#include <xen/bootfdt.h>
> #include <xen/bug.h>
> #include <xen/compiler.h>
> #include <xen/init.h>
> @@ -7,7 +8,9 @@
> #include <xen/macros.h>
> #include <xen/mm.h>
> #include <xen/pfn.h>
> +#include <xen/libfdt/libfdt.h>
This wants to move up, to retain sorting.
> #include <xen/sections.h>
> +#include <xen/sizes.h>
>
> #include <asm/early_printk.h>
> #include <asm/csr.h>
> @@ -20,7 +23,7 @@ struct mmu_desc {
> unsigned int pgtbl_count;
> pte_t *next_pgtbl;
> pte_t *pgtbl_base;
> -};
> +} mmu_desc = { CONFIG_PAGING_LEVELS, 0, NULL, 0 };
__initdata and static?
> @@ -39,9 +42,11 @@ static unsigned long __ro_after_init phys_offset;
> * isn't 2 MB aligned.
> *
> * CONFIG_PAGING_LEVELS page tables are needed for the identity mapping,
> - * except that the root page table is shared with the initial mapping
> + * except that the root page table is shared with the initial mapping.
> + *
> + * CONFIG_PAGING_LEVELS page tables are needed for device tree mapping.
> */
> -#define PGTBL_INITIAL_COUNT ((CONFIG_PAGING_LEVELS - 1) * 2 + 1)
> +#define PGTBL_INITIAL_COUNT ((CONFIG_PAGING_LEVELS - 1) * 3 + 1 + 1)
Considering what would happen if two or three more of such requirements
were added, maybe better
#define PGTBL_INITIAL_COUNT (CONFIG_PAGING_LEVELS * 3 - 1)
? However, why is it CONFIG_PAGING_LEVELS that's needed, and not
CONFIG_PAGING_LEVELS - 1? The top level table is the same as the
identity map's, isn't it?
> @@ -296,6 +299,30 @@ unsigned long __init calc_phys_offset(void)
> return phys_offset;
> }
>
> +void* __init early_fdt_map(paddr_t fdt_paddr)
See earlier remark regarding * placement.
Jan
On Wed, 2024-07-10 at 12:38 +0200, Jan Beulich wrote:
> On 03.07.2024 12:42, Oleksii Kurochko wrote:
> > Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
> > ---
> > xen/arch/riscv/include/asm/config.h | 6 +++++
> > xen/arch/riscv/include/asm/mm.h | 2 ++
> > xen/arch/riscv/mm.c | 37
> > +++++++++++++++++++++++++----
> > 3 files changed, 40 insertions(+), 5 deletions(-)
>
> I don't think a change like this can come without any description.
>
> > --- a/xen/arch/riscv/include/asm/config.h
> > +++ b/xen/arch/riscv/include/asm/config.h
> > @@ -74,6 +74,9 @@
> > #error "unsupported RV_STAGE1_MODE"
> > #endif
> >
> > +#define XEN_SIZE MB(2)
> > +#define XEN_VIRT_END (XEN_VIRT_START + XEN_SIZE)
>
> Probably wants accompanying by an assertion in the linker script. Or
> else
> how would one notice when Xen grows bigger than this?
I use XEN_SIZE in the linker script here:
ASSERT(_end - _start <= MB(2), "Xen too large for early-boot
assumptions")
>
> > @@ -99,6 +102,9 @@
> > #define VMAP_VIRT_START SLOTN(VMAP_SLOT_START)
> > #define VMAP_VIRT_SIZE GB(1)
> >
> > +#define BOOT_FDT_VIRT_START XEN_VIRT_END
> > +#define BOOT_FDT_VIRT_SIZE MB(4)
>
> Is the 4 selected arbitrarily, or derived from something?
Yes, it was chosen arbitrarily. I just checked that I don't have any
DTBs larger than 2 MB, but decided to add a little extra space and
doubled it to an additional 2 MB.
>
> Also maybe better to keep these #define-s sorted by address? (As to
> "keep":
> I didn't check whether they currently are.)
>
> > --- a/xen/arch/riscv/include/asm/mm.h
> > +++ b/xen/arch/riscv/include/asm/mm.h
> > @@ -255,4 +255,6 @@ static inline unsigned int
> > arch_get_dma_bitsize(void)
> > return 32; /* TODO */
> > }
> >
> > +void* early_fdt_map(paddr_t fdt_paddr);
>
> Nit: * and blank want to change places.
>
> > --- a/xen/arch/riscv/mm.c
> > +++ b/xen/arch/riscv/mm.c
> > @@ -1,5 +1,6 @@
> > /* SPDX-License-Identifier: GPL-2.0-only */
> >
> > +#include <xen/bootfdt.h>
> > #include <xen/bug.h>
> > #include <xen/compiler.h>
> > #include <xen/init.h>
> > @@ -7,7 +8,9 @@
> > #include <xen/macros.h>
> > #include <xen/mm.h>
> > #include <xen/pfn.h>
> > +#include <xen/libfdt/libfdt.h>
>
> This wants to move up, to retain sorting.
>
> > #include <xen/sections.h>
> > +#include <xen/sizes.h>
> >
> > #include <asm/early_printk.h>
> > #include <asm/csr.h>
> > @@ -20,7 +23,7 @@ struct mmu_desc {
> > unsigned int pgtbl_count;
> > pte_t *next_pgtbl;
> > pte_t *pgtbl_base;
> > -};
> > +} mmu_desc = { CONFIG_PAGING_LEVELS, 0, NULL, 0 };
>
> __initdata and static?
>
> > @@ -39,9 +42,11 @@ static unsigned long __ro_after_init
> > phys_offset;
> > * isn't 2 MB aligned.
> > *
> > * CONFIG_PAGING_LEVELS page tables are needed for the identity
> > mapping,
> > - * except that the root page table is shared with the initial
> > mapping
> > + * except that the root page table is shared with the initial
> > mapping.
> > + *
> > + * CONFIG_PAGING_LEVELS page tables are needed for device tree
> > mapping.
> > */
> > -#define PGTBL_INITIAL_COUNT ((CONFIG_PAGING_LEVELS - 1) * 2 + 1)
> > +#define PGTBL_INITIAL_COUNT ((CONFIG_PAGING_LEVELS - 1) * 3 + 1 +
> > 1)
>
> Considering what would happen if two or three more of such
> requirements
> were added, maybe better
>
> #define PGTBL_INITIAL_COUNT (CONFIG_PAGING_LEVELS * 3 - 1)
>
> ? However, why is it CONFIG_PAGING_LEVELS that's needed, and not
> CONFIG_PAGING_LEVELS - 1? The top level table is the same as the
> identity map's, isn't it?
The top level table is the same, but I just wanted to be sure that if
DTB size is bigger then 2Mb then we need 2xL0 page tables.
Am I missing something?
~ Oleksii
>
> > @@ -296,6 +299,30 @@ unsigned long __init calc_phys_offset(void)
> > return phys_offset;
> > }
> >
> > +void* __init early_fdt_map(paddr_t fdt_paddr)
>
> See earlier remark regarding * placement.
>
> Jan
On 11.07.2024 11:31, Oleksii wrote: > On Wed, 2024-07-10 at 12:38 +0200, Jan Beulich wrote: >> On 03.07.2024 12:42, Oleksii Kurochko wrote: >>> --- a/xen/arch/riscv/include/asm/config.h >>> +++ b/xen/arch/riscv/include/asm/config.h >>> @@ -74,6 +74,9 @@ >>> #error "unsupported RV_STAGE1_MODE" >>> #endif >>> >>> +#define XEN_SIZE MB(2) >>> +#define XEN_VIRT_END (XEN_VIRT_START + XEN_SIZE) >> >> Probably wants accompanying by an assertion in the linker script. Or >> else >> how would one notice when Xen grows bigger than this? > I use XEN_SIZE in the linker script here: > ASSERT(_end - _start <= MB(2), "Xen too large for early-boot > assumptions") And that's the problem: You want to switch to using XEN_SIZE there. There should never be two separate constant that need updating at the same time. Keep such to a single place. >>> @@ -99,6 +102,9 @@ >>> #define VMAP_VIRT_START SLOTN(VMAP_SLOT_START) >>> #define VMAP_VIRT_SIZE GB(1) >>> >>> +#define BOOT_FDT_VIRT_START XEN_VIRT_END >>> +#define BOOT_FDT_VIRT_SIZE MB(4) >> >> Is the 4 selected arbitrarily, or derived from something? > Yes, it was chosen arbitrarily. I just checked that I don't have any > DTBs larger than 2 MB, but decided to add a little extra space and > doubled it to an additional 2 MB. Code comment then, please, or at the very least mention of this in the description. >>> @@ -39,9 +42,11 @@ static unsigned long __ro_after_init >>> phys_offset; >>> * isn't 2 MB aligned. >>> * >>> * CONFIG_PAGING_LEVELS page tables are needed for the identity >>> mapping, >>> - * except that the root page table is shared with the initial >>> mapping >>> + * except that the root page table is shared with the initial >>> mapping. >>> + * >>> + * CONFIG_PAGING_LEVELS page tables are needed for device tree >>> mapping. >>> */ >>> -#define PGTBL_INITIAL_COUNT ((CONFIG_PAGING_LEVELS - 1) * 2 + 1) >>> +#define PGTBL_INITIAL_COUNT ((CONFIG_PAGING_LEVELS - 1) * 3 + 1 + >>> 1) >> >> Considering what would happen if two or three more of such >> requirements >> were added, maybe better >> >> #define PGTBL_INITIAL_COUNT (CONFIG_PAGING_LEVELS * 3 - 1) >> >> ? However, why is it CONFIG_PAGING_LEVELS that's needed, and not >> CONFIG_PAGING_LEVELS - 1? The top level table is the same as the >> identity map's, isn't it? > The top level table is the same, but I just wanted to be sure that if > DTB size is bigger then 2Mb then we need 2xL0 page tables. Makes sense, but then needs expressing that way (by using BOOT_FDT_VIRT_SIZE). Otherwise (see also above) think of what will happen if BOOT_FDT_VIRT_SIZE is updated without touching this expression. Jan
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