Hi Drew,
On 4/7/21 7:59 PM, Andrew Jones wrote:
> By providing a proper ioremap function, we can just rely on devices
> calling it for each region they need (as they already do) instead of
> mapping a big assumed I/O range. The persistent maps weirdness allows
> us to call setup_vm after io_init. Why don't we just call setup_vm
> before io_init, I hear you ask? Well, that's because tests like sieve
> want to start with the MMU off and later call setup_vm, and all the
> while have working I/O. Some unit tests are just really demanding...
>
> Signed-off-by: Andrew Jones <drjones@xxxxxxxxxx>
> ---
> lib/arm/asm/io.h | 6 ++++
> lib/arm/asm/mmu-api.h | 1 +
> lib/arm/asm/mmu.h | 1 +
> lib/arm/asm/page.h | 2 ++
> lib/arm/mmu.c | 82 ++++++++++++++++++++++++++++++++++++++-----
> lib/arm64/asm/io.h | 6 ++++
> lib/arm64/asm/mmu.h | 1 +
> lib/arm64/asm/page.h | 2 ++
> 8 files changed, 93 insertions(+), 8 deletions(-)
>
> diff --git a/lib/arm/asm/io.h b/lib/arm/asm/io.h
> index ba3b0b2412ad..e4caa6ff5d1e 100644
> --- a/lib/arm/asm/io.h
> +++ b/lib/arm/asm/io.h
> @@ -77,6 +77,12 @@ static inline void __raw_writel(u32 val, volatile void __iomem *addr)
> : "r" (val));
> }
>
> +#define ioremap ioremap
> +static inline void __iomem *ioremap(phys_addr_t phys_addr, size_t size)
> +{
> + return __ioremap(phys_addr, size);
> +}
> +
> #define virt_to_phys virt_to_phys
> static inline phys_addr_t virt_to_phys(const volatile void *x)
> {
> diff --git a/lib/arm/asm/mmu-api.h b/lib/arm/asm/mmu-api.h
> index 05fc12b5afb8..b9a5a8f6b3c1 100644
> --- a/lib/arm/asm/mmu-api.h
> +++ b/lib/arm/asm/mmu-api.h
> @@ -17,6 +17,7 @@ extern void mmu_set_range_sect(pgd_t *pgtable, uintptr_t virt_offset,
> extern void mmu_set_range_ptes(pgd_t *pgtable, uintptr_t virt_offset,
> phys_addr_t phys_start, phys_addr_t phys_end,
> pgprot_t prot);
> +extern void mmu_set_persistent_maps(pgd_t *pgtable);
> extern pteval_t *mmu_get_pte(pgd_t *pgtable, uintptr_t vaddr);
> extern void mmu_clear_user(pgd_t *pgtable, unsigned long vaddr);
> #endif
> diff --git a/lib/arm/asm/mmu.h b/lib/arm/asm/mmu.h
> index 122874b8aebe..d88a4f16df42 100644
> --- a/lib/arm/asm/mmu.h
> +++ b/lib/arm/asm/mmu.h
> @@ -12,6 +12,7 @@
> #define PTE_SHARED L_PTE_SHARED
> #define PTE_AF PTE_EXT_AF
> #define PTE_WBWA L_PTE_MT_WRITEALLOC
> +#define PTE_UNCACHED L_PTE_MT_UNCACHED
>
> /* See B3.18.7 TLB maintenance operations */
>
> diff --git a/lib/arm/asm/page.h b/lib/arm/asm/page.h
> index 1fb5cd26ac66..8eb4a883808e 100644
> --- a/lib/arm/asm/page.h
> +++ b/lib/arm/asm/page.h
> @@ -47,5 +47,7 @@ typedef struct { pteval_t pgprot; } pgprot_t;
> extern phys_addr_t __virt_to_phys(unsigned long addr);
> extern unsigned long __phys_to_virt(phys_addr_t addr);
>
> +extern void *__ioremap(phys_addr_t phys_addr, size_t size);
> +
> #endif /* !__ASSEMBLY__ */
> #endif /* _ASMARM_PAGE_H_ */
> diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c
> index 15eef007f256..a7b7ae51afe3 100644
> --- a/lib/arm/mmu.c
> +++ b/lib/arm/mmu.c
> @@ -11,6 +11,7 @@
> #include <asm/mmu.h>
> #include <asm/setup.h>
> #include <asm/page.h>
> +#include <asm/io.h>
>
> #include "alloc_page.h"
> #include "vmalloc.h"
> @@ -21,6 +22,57 @@
>
> extern unsigned long etext;
>
> +#define MMU_MAX_PERSISTENT_MAPS 64
> +
> +struct mmu_persistent_map {
> + uintptr_t virt_offset;
> + phys_addr_t phys_start;
> + phys_addr_t phys_end;
> + pgprot_t prot;
> + bool sect;
> +};
> +
> +static struct mmu_persistent_map mmu_persistent_maps[MMU_MAX_PERSISTENT_MAPS];
> +
> +static void
> +mmu_set_persistent_range(uintptr_t virt_offset, phys_addr_t phys_start,
> + phys_addr_t phys_end, pgprot_t prot, bool sect)
> +{
> + int i;
> +
> + assert(phys_end);
> +
> + for (i = 0; i < MMU_MAX_PERSISTENT_MAPS; ++i) {
> + if (!mmu_persistent_maps[i].phys_end)
> + break;
> + }
> + assert(i < MMU_MAX_PERSISTENT_MAPS);
> +
> + mmu_persistent_maps[i] = (struct mmu_persistent_map){
> + .virt_offset = virt_offset,
> + .phys_start = phys_start,
> + .phys_end = phys_end,
> + .prot = prot,
> + .sect = sect,
> + };
> +}
> +
> +void mmu_set_persistent_maps(pgd_t *pgtable)
> +{
> + struct mmu_persistent_map *map;
> +
> + for (map = &mmu_persistent_maps[0]; map->phys_end; ++map) {
> + if (map->sect)
> + mmu_set_range_sect(pgtable, map->virt_offset,
> + map->phys_start, map->phys_end,
> + map->prot);
> + else
> + mmu_set_range_ptes(pgtable, map->virt_offset,
> + map->phys_start, map->phys_end,
> + map->prot);
> + }
> +}
I assume the purpose of all of this machinery is to add mappings to idmap that
were created before setup_mmu(). Or are you planning to use it for something else?
Why not allocate the idmap in __ioremap (if it's NULL) and add entries to it in
that function? Then setup_mmu() can allocate the idmap only if it's NULL, and the
mappings added by __ioremap would still be there.
Thanks,
Alex
> +
> pgd_t *mmu_idmap;
>
> /* CPU 0 starts with disabled MMU */
> @@ -157,7 +209,6 @@ void mmu_set_range_sect(pgd_t *pgtable, uintptr_t virt_offset,
> void *setup_mmu(phys_addr_t phys_end)
> {
> uintptr_t code_end = (uintptr_t)&etext;
> - struct mem_region *r;
>
> /* 0G-1G = I/O, 1G-3G = identity, 3G-4G = vmalloc */
> if (phys_end > (3ul << 30))
> @@ -172,13 +223,6 @@ void *setup_mmu(phys_addr_t phys_end)
>
> mmu_idmap = alloc_page();
>
> - for (r = mem_regions; r->end; ++r) {
> - if (!(r->flags & MR_F_IO))
> - continue;
> - mmu_set_range_sect(mmu_idmap, r->start, r->start, r->end,
> - __pgprot(PMD_SECT_UNCACHED | PMD_SECT_USER));
> - }
> -
> /* armv8 requires code shared between EL1 and EL0 to be read-only */
> mmu_set_range_ptes(mmu_idmap, PHYS_OFFSET,
> PHYS_OFFSET, code_end,
> @@ -188,10 +232,32 @@ void *setup_mmu(phys_addr_t phys_end)
> code_end, phys_end,
> __pgprot(PTE_WBWA | PTE_USER));
>
> + mmu_set_persistent_maps(mmu_idmap);
> +
> mmu_enable(mmu_idmap);
> return mmu_idmap;
> }
>
> +void __iomem *__ioremap(phys_addr_t phys_addr, size_t size)
> +{
> + phys_addr_t paddr_aligned = phys_addr & PAGE_MASK;
> + phys_addr_t paddr_end = PAGE_ALIGN(phys_addr + size);
> + pgprot_t prot = __pgprot(PTE_UNCACHED | PTE_USER);
> +
> + assert(sizeof(long) == 8 || !(phys_addr >> 32));
> +
> + mmu_set_persistent_range(paddr_aligned, paddr_aligned, paddr_end,
> + prot, false);
> +
> + if (mmu_enabled()) {
> + pgd_t *pgtable = current_thread_info()->pgtable;
> + mmu_set_range_ptes(pgtable, paddr_aligned, paddr_aligned,
> + paddr_end, prot);
> + }
> +
> + return (void __iomem *)(unsigned long)phys_addr;
> +}
> +
> phys_addr_t __virt_to_phys(unsigned long addr)
> {
> if (mmu_enabled()) {
> diff --git a/lib/arm64/asm/io.h b/lib/arm64/asm/io.h
> index e0a03b250d5b..be19f471c0fa 100644
> --- a/lib/arm64/asm/io.h
> +++ b/lib/arm64/asm/io.h
> @@ -71,6 +71,12 @@ static inline u64 __raw_readq(const volatile void __iomem *addr)
> return val;
> }
>
> +#define ioremap ioremap
> +static inline void __iomem *ioremap(phys_addr_t phys_addr, size_t size)
> +{
> + return __ioremap(phys_addr, size);
> +}
> +
> #define virt_to_phys virt_to_phys
> static inline phys_addr_t virt_to_phys(const volatile void *x)
> {
> diff --git a/lib/arm64/asm/mmu.h b/lib/arm64/asm/mmu.h
> index 72d75eafc882..72371b2d9fe3 100644
> --- a/lib/arm64/asm/mmu.h
> +++ b/lib/arm64/asm/mmu.h
> @@ -8,6 +8,7 @@
> #include <asm/barrier.h>
>
> #define PMD_SECT_UNCACHED PMD_ATTRINDX(MT_DEVICE_nGnRE)
> +#define PTE_UNCACHED PTE_ATTRINDX(MT_DEVICE_nGnRE)
> #define PTE_WBWA PTE_ATTRINDX(MT_NORMAL)
>
> static inline void flush_tlb_all(void)
> diff --git a/lib/arm64/asm/page.h b/lib/arm64/asm/page.h
> index ae4484b22114..d0fac6ea563d 100644
> --- a/lib/arm64/asm/page.h
> +++ b/lib/arm64/asm/page.h
> @@ -72,5 +72,7 @@ typedef struct { pteval_t pgprot; } pgprot_t;
> extern phys_addr_t __virt_to_phys(unsigned long addr);
> extern unsigned long __phys_to_virt(phys_addr_t addr);
>
> +extern void *__ioremap(phys_addr_t phys_addr, size_t size);
> +
> #endif /* !__ASSEMBLY__ */
> #endif /* _ASMARM64_PAGE_H_ */
