| Message ID | 20241026171441.3047904-3-samuel.holland@sifive.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | riscv: Relocatable NOMMU kernels | expand |
On Sat, Oct 26, 2024 at 1:16 PM Samuel Holland <samuel.holland@sifive.com> wrote: > > NOMMU kernels currently cannot access memory below the kernel link > address. Remove this restriction by setting PAGE_OFFSET to the actual > start of RAM, as determined from the devicetree. The kernel link address > must be a constant, so keep using CONFIG_PAGE_OFFSET for that purpose. > > Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Jesse Taube <mr.bossman075@gmail.com> > --- > > arch/riscv/include/asm/page.h | 12 ++++-------- > arch/riscv/include/asm/pgtable.h | 2 +- > 2 files changed, 5 insertions(+), 9 deletions(-) > > diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h > index 32d308a3355f..24d1ac052609 100644 > --- a/arch/riscv/include/asm/page.h > +++ b/arch/riscv/include/asm/page.h > @@ -26,12 +26,9 @@ > * When not using MMU this corresponds to the first free page in > * physical memory (aligned on a page boundary). > */ > -#ifdef CONFIG_64BIT > #ifdef CONFIG_MMU > +#ifdef CONFIG_64BIT > #define PAGE_OFFSET kernel_map.page_offset > -#else > -#define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL) > -#endif > /* > * By default, CONFIG_PAGE_OFFSET value corresponds to SV57 address space so > * define the PAGE_OFFSET value for SV48 and SV39. > @@ -41,6 +38,9 @@ > #else > #define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL) > #endif /* CONFIG_64BIT */ > +#else > +#define PAGE_OFFSET ((unsigned long)phys_ram_base) > +#endif /* CONFIG_MMU */ > > #ifndef __ASSEMBLY__ > > @@ -97,11 +97,7 @@ typedef struct page *pgtable_t; > #define MIN_MEMBLOCK_ADDR 0 > #endif > > -#ifdef CONFIG_MMU > #define ARCH_PFN_OFFSET (PFN_DOWN((unsigned long)phys_ram_base)) > -#else > -#define ARCH_PFN_OFFSET (PAGE_OFFSET >> PAGE_SHIFT) > -#endif /* CONFIG_MMU */ > > struct kernel_mapping { > unsigned long page_offset; > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index e79f15293492..e224ac66e635 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -12,7 +12,7 @@ > #include <asm/pgtable-bits.h> > > #ifndef CONFIG_MMU > -#define KERNEL_LINK_ADDR PAGE_OFFSET > +#define KERNEL_LINK_ADDR _AC(CONFIG_PAGE_OFFSET, UL) > #define KERN_VIRT_SIZE (UL(-1)) > #else > > -- > 2.45.1 > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv
diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h index 32d308a3355f..24d1ac052609 100644 --- a/arch/riscv/include/asm/page.h +++ b/arch/riscv/include/asm/page.h @@ -26,12 +26,9 @@ * When not using MMU this corresponds to the first free page in * physical memory (aligned on a page boundary). */ -#ifdef CONFIG_64BIT #ifdef CONFIG_MMU +#ifdef CONFIG_64BIT #define PAGE_OFFSET kernel_map.page_offset -#else -#define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL) -#endif /* * By default, CONFIG_PAGE_OFFSET value corresponds to SV57 address space so * define the PAGE_OFFSET value for SV48 and SV39. @@ -41,6 +38,9 @@ #else #define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL) #endif /* CONFIG_64BIT */ +#else +#define PAGE_OFFSET ((unsigned long)phys_ram_base) +#endif /* CONFIG_MMU */ #ifndef __ASSEMBLY__ @@ -97,11 +97,7 @@ typedef struct page *pgtable_t; #define MIN_MEMBLOCK_ADDR 0 #endif -#ifdef CONFIG_MMU #define ARCH_PFN_OFFSET (PFN_DOWN((unsigned long)phys_ram_base)) -#else -#define ARCH_PFN_OFFSET (PAGE_OFFSET >> PAGE_SHIFT) -#endif /* CONFIG_MMU */ struct kernel_mapping { unsigned long page_offset; diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index e79f15293492..e224ac66e635 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -12,7 +12,7 @@ #include <asm/pgtable-bits.h> #ifndef CONFIG_MMU -#define KERNEL_LINK_ADDR PAGE_OFFSET +#define KERNEL_LINK_ADDR _AC(CONFIG_PAGE_OFFSET, UL) #define KERN_VIRT_SIZE (UL(-1)) #else
NOMMU kernels currently cannot access memory below the kernel link address. Remove this restriction by setting PAGE_OFFSET to the actual start of RAM, as determined from the devicetree. The kernel link address must be a constant, so keep using CONFIG_PAGE_OFFSET for that purpose. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> --- arch/riscv/include/asm/page.h | 12 ++++-------- arch/riscv/include/asm/pgtable.h | 2 +- 2 files changed, 5 insertions(+), 9 deletions(-)