Hi Nikos,
I scanned the patches, will try to do a proper review next week. Some suggestions
below.
On 10/29/20 3:52 PM, Nikos Nikoleris wrote:
> Make the translation granule configurable for arm64. arm64 supports
> page sizes of 4K, 16K and 64K. By default, arm64 is configured with
> 64K pages. configure has been extended with a new argument:
>
> --page-shift=(12|14|16)
How about --page-size=4K/16K/64K, which accepts lower and upper case 'k'?
It might be just me, because I'm not familiar with memory management, but each
time I see page-shift I need to do the math in my head to get to the page size. I
think page-size is more intuitive. It's also somewhat similar to the kernel config
(CONFIG_ARM64_4K_PAGES, for example, and not CONFIG_ARM64_PAGE_SHIFT_12).
I might have missed it in the patch, how about printing an error message when the
configured page size is not supported by the hardware? kvm-unit-tests runs C code
before creating the page tables, and the UART is available very early, so it
shouldn't be too hard. We can put the check in setup_mmu().
Thanks,
Alex
>
> which allows the user to set the page shift and therefore the page
> size for arm64. Using the --page-shift for any other architecture
> results an error message.
>
> To allow for smaller page sizes and 42b VA, this change adds support
> for 4-level and 3-level page tables. At compile time, we determine how
> many levels in the page tables we needed.
>
> Signed-off-by: Nikos Nikoleris <nikos.nikoleris@xxxxxxx>
> ---
> configure | 21 +++++++++++
> lib/arm/asm/page.h | 4 ++
> lib/arm/asm/pgtable-hwdef.h | 4 ++
> lib/arm/asm/pgtable.h | 6 +++
> lib/arm/asm/thread_info.h | 4 +-
> lib/arm64/asm/page.h | 17 ++++++---
> lib/arm64/asm/pgtable-hwdef.h | 38 +++++++++++++------
> lib/arm64/asm/pgtable.h | 69 +++++++++++++++++++++++++++++++++--
> lib/arm/mmu.c | 26 ++++++++-----
> arm/cstart64.S | 12 +++++-
> 10 files changed, 169 insertions(+), 32 deletions(-)
>
> diff --git a/configure b/configure
> index 706aab5..94637ec 100755
> --- a/configure
> +++ b/configure
> @@ -25,6 +25,7 @@ vmm="qemu"
> errata_force=0
> erratatxt="$srcdir/errata.txt"
> host_key_document=
> +page_shift=
>
> usage() {
> cat <<-EOF
> @@ -105,6 +106,9 @@ while [[ "$1" = -* ]]; do
> --host-key-document)
> host_key_document="$arg"
> ;;
> + --page-shift)
> + page_shift="$arg"
> + ;;
> --help)
> usage
> ;;
> @@ -123,6 +127,22 @@ arch_name=$arch
> [ "$arch" = "aarch64" ] && arch="arm64"
> [ "$arch_name" = "arm64" ] && arch_name="aarch64"
>
> +if [ -z "$page_shift" ]; then
> + [ "$arch" = "arm64" ] && page_shift="16"
> + [ "$arch" = "arm" ] && page_shift="12"
> +else
> + if [ "$arch" != "arm64" ]; then
> + echo "--page-shift is not supported for $arch"
> + usage
> + fi
> +
> + if [ "$page_shift" != "12" ] && [ "$page_shift" != "14" ] &&
> + [ "$page_shift" != "16" ]; then
> + echo "Page shift of $page_shift not supported for arm64"
> + usage
> + fi
> +fi
> +
> [ -z "$processor" ] && processor="$arch"
>
> if [ "$processor" = "arm64" ]; then
> @@ -254,6 +274,7 @@ cat <<EOF >> lib/config.h
>
> #define CONFIG_UART_EARLY_BASE ${arm_uart_early_addr}
> #define CONFIG_ERRATA_FORCE ${errata_force}
> +#define CONFIG_PAGE_SHIFT ${page_shift}
>
> EOF
> fi
> diff --git a/lib/arm/asm/page.h b/lib/arm/asm/page.h
> index 039c9f7..ae0ac2c 100644
> --- a/lib/arm/asm/page.h
> +++ b/lib/arm/asm/page.h
> @@ -29,6 +29,10 @@ typedef struct { pteval_t pgprot; } pgprot_t;
> #define pgd_val(x) ((x).pgd)
> #define pgprot_val(x) ((x).pgprot)
>
> +/* For compatibility with arm64 page tables */
> +#define pud_t pgd_t
> +#define pud_val(x) pgd_val(x)
> +
> #define __pte(x) ((pte_t) { (x) } )
> #define __pmd(x) ((pmd_t) { (x) } )
> #define __pgd(x) ((pgd_t) { (x) } )
> diff --git a/lib/arm/asm/pgtable-hwdef.h b/lib/arm/asm/pgtable-hwdef.h
> index 4107e18..fe1d854 100644
> --- a/lib/arm/asm/pgtable-hwdef.h
> +++ b/lib/arm/asm/pgtable-hwdef.h
> @@ -19,6 +19,10 @@
> #define PTRS_PER_PTE 512
> #define PTRS_PER_PMD 512
>
> +/* For compatibility with arm64 page tables */
> +#define PUD_SIZE PGDIR_SIZE
> +#define PUD_MASK PGDIR_MASK
> +
> #define PMD_SHIFT 21
> #define PMD_SIZE (_AC(1,UL) << PMD_SHIFT)
> #define PMD_MASK (~((1 << PMD_SHIFT) - 1))
> diff --git a/lib/arm/asm/pgtable.h b/lib/arm/asm/pgtable.h
> index 078dd16..4759d82 100644
> --- a/lib/arm/asm/pgtable.h
> +++ b/lib/arm/asm/pgtable.h
> @@ -53,6 +53,12 @@ static inline pmd_t *pgd_page_vaddr(pgd_t pgd)
> return pgtable_va(pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK);
> }
>
> +/* For compatibility with arm64 page tables */
> +#define pud_valid(pud) pgd_valid(pud)
> +#define pud_offset(pgd, addr) ((pud_t *)pgd)
> +#define pud_free(pud)
> +#define pud_alloc(pgd, addr) pud_offset(pgd, addr)
> +
> #define pmd_index(addr) \
> (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
> #define pmd_offset(pgd, addr) \
> diff --git a/lib/arm/asm/thread_info.h b/lib/arm/asm/thread_info.h
> index 80ab395..eaa7258 100644
> --- a/lib/arm/asm/thread_info.h
> +++ b/lib/arm/asm/thread_info.h
> @@ -14,10 +14,12 @@
> #define THREAD_SHIFT PAGE_SHIFT
> #define THREAD_SIZE PAGE_SIZE
> #define THREAD_MASK PAGE_MASK
> +#define THREAD_ALIGNMENT PAGE_SIZE
> #else
> #define THREAD_SHIFT MIN_THREAD_SHIFT
> #define THREAD_SIZE (_AC(1,UL) << THREAD_SHIFT)
> #define THREAD_MASK (~(THREAD_SIZE-1))
> +#define THREAD_ALIGNMENT THREAD_SIZE
> #endif
>
> #ifndef __ASSEMBLY__
> @@ -38,7 +40,7 @@
>
> static inline void *thread_stack_alloc(void)
> {
> - void *sp = memalign(PAGE_SIZE, THREAD_SIZE);
> + void *sp = memalign(THREAD_ALIGNMENT, THREAD_SIZE);
> return sp + THREAD_START_SP;
> }
>
> diff --git a/lib/arm64/asm/page.h b/lib/arm64/asm/page.h
> index 46af552..726a0c0 100644
> --- a/lib/arm64/asm/page.h
> +++ b/lib/arm64/asm/page.h
> @@ -10,38 +10,43 @@
> * This work is licensed under the terms of the GNU GPL, version 2.
> */
>
> +#include <config.h>
> #include <linux/const.h>
>
> -#define PGTABLE_LEVELS 2
> #define VA_BITS 42
>
> -#define PAGE_SHIFT 16
> +#define PAGE_SHIFT CONFIG_PAGE_SHIFT
> #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
> #define PAGE_MASK (~(PAGE_SIZE-1))
>
> +#define PGTABLE_LEVELS (((VA_BITS) - 4) / (PAGE_SHIFT - 3))
> +
> #ifndef __ASSEMBLY__
>
> #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
>
> typedef u64 pteval_t;
> typedef u64 pmdval_t;
> +typedef u64 pudval_t;
> typedef u64 pgdval_t;
> typedef struct { pteval_t pte; } pte_t;
> +typedef struct { pmdval_t pmd; } pmd_t;
> +typedef struct { pudval_t pud; } pud_t;
> typedef struct { pgdval_t pgd; } pgd_t;
> typedef struct { pteval_t pgprot; } pgprot_t;
>
> #define pte_val(x) ((x).pte)
> +#define pmd_val(x) ((x).pmd)
> +#define pud_val(x) ((x).pud)
> #define pgd_val(x) ((x).pgd)
> #define pgprot_val(x) ((x).pgprot)
>
> #define __pte(x) ((pte_t) { (x) } )
> +#define __pmd(x) ((pmd_t) { (x) } )
> +#define __pud(x) ((pud_t) { (x) } )
> #define __pgd(x) ((pgd_t) { (x) } )
> #define __pgprot(x) ((pgprot_t) { (x) } )
>
> -typedef struct { pgd_t pgd; } pmd_t;
> -#define pmd_val(x) (pgd_val((x).pgd))
> -#define __pmd(x) ((pmd_t) { __pgd(x) } )
> -
> #define __va(x) ((void *)__phys_to_virt((phys_addr_t)(x)))
> #define __pa(x) __virt_to_phys((unsigned long)(x))
>
> diff --git a/lib/arm64/asm/pgtable-hwdef.h b/lib/arm64/asm/pgtable-hwdef.h
> index 3352489..f9110e1 100644
> --- a/lib/arm64/asm/pgtable-hwdef.h
> +++ b/lib/arm64/asm/pgtable-hwdef.h
> @@ -9,38 +9,54 @@
> * This work is licensed under the terms of the GNU GPL, version 2.
> */
>
> +#include <asm/page.h>
> +
> #define UL(x) _AC(x, UL)
>
> +#define PGTABLE_LEVEL_SHIFT(n) ((PAGE_SHIFT - 3) * (4 - (n)) + 3)
> #define PTRS_PER_PTE (1 << (PAGE_SHIFT - 3))
>
> +#if PGTABLE_LEVELS > 2
> +#define PMD_SHIFT PGTABLE_LEVEL_SHIFT(2)
> +#define PTRS_PER_PMD PTRS_PER_PTE
> +#define PMD_SIZE (UL(1) << PMD_SHIFT)
> +#define PMD_MASK (~(PMD_SIZE-1))
> +#endif
> +
> +#if PGTABLE_LEVELS > 3
> +#define PUD_SHIFT PGTABLE_LEVEL_SHIFT(1)
> +#define PTRS_PER_PUD PTRS_PER_PTE
> +#define PUD_SIZE (UL(1) << PUD_SHIFT)
> +#define PUD_MASK (~(PUD_SIZE-1))
> +#else
> +#define PUD_SIZE PGDIR_SIZE
> +#define PUD_MASK PGDIR_MASK
> +#endif
> +
> +#define PUD_VALID (_AT(pudval_t, 1) << 0)
> +
> /*
> * PGDIR_SHIFT determines the size a top-level page table entry can map
> * (depending on the configuration, this level can be 0, 1 or 2).
> */
> -#define PGDIR_SHIFT ((PAGE_SHIFT - 3) * PGTABLE_LEVELS + 3)
> +#define PGDIR_SHIFT PGTABLE_LEVEL_SHIFT(4 - PGTABLE_LEVELS)
> #define PGDIR_SIZE (_AC(1, UL) << PGDIR_SHIFT)
> #define PGDIR_MASK (~(PGDIR_SIZE-1))
> #define PTRS_PER_PGD (1 << (VA_BITS - PGDIR_SHIFT))
>
> #define PGD_VALID (_AT(pgdval_t, 1) << 0)
>
> -/* From include/asm-generic/pgtable-nopmd.h */
> -#define PMD_SHIFT PGDIR_SHIFT
> -#define PTRS_PER_PMD 1
> -#define PMD_SIZE (UL(1) << PMD_SHIFT)
> -#define PMD_MASK (~(PMD_SIZE-1))
> -
> /*
> * Section address mask and size definitions.
> */
> -#define SECTION_SHIFT PMD_SHIFT
> -#define SECTION_SIZE (_AC(1, UL) << SECTION_SHIFT)
> -#define SECTION_MASK (~(SECTION_SIZE-1))
> +#define SECTION_SHIFT PMD_SHIFT
> +#define SECTION_SIZE (_AC(1, UL) << SECTION_SHIFT)
> +#define SECTION_MASK (~(SECTION_SIZE-1))
>
> /*
> * Hardware page table definitions.
> *
> - * Level 1 descriptor (PMD).
> + * Level 0,1,2 descriptor (PGG, PUD and PMD).
> */
> #define PMD_TYPE_MASK (_AT(pmdval_t, 3) << 0)
> #define PMD_TYPE_FAULT (_AT(pmdval_t, 0) << 0)
> diff --git a/lib/arm64/asm/pgtable.h b/lib/arm64/asm/pgtable.h
> index e577d9c..c7632ae 100644
> --- a/lib/arm64/asm/pgtable.h
> +++ b/lib/arm64/asm/pgtable.h
> @@ -30,10 +30,12 @@
> #define pgtable_pa(x) ((unsigned long)(x))
>
> #define pgd_none(pgd) (!pgd_val(pgd))
> +#define pud_none(pud) (!pud_val(pud))
> #define pmd_none(pmd) (!pmd_val(pmd))
> #define pte_none(pte) (!pte_val(pte))
>
> #define pgd_valid(pgd) (pgd_val(pgd) & PGD_VALID)
> +#define pud_valid(pud) (pud_val(pud) & PUD_VALID)
> #define pmd_valid(pmd) (pmd_val(pmd) & PMD_SECT_VALID)
> #define pte_valid(pte) (pte_val(pte) & PTE_VALID)
>
> @@ -52,15 +54,76 @@ static inline pgd_t *pgd_alloc(void)
> return pgd;
> }
>
> -#define pmd_offset(pgd, addr) ((pmd_t *)pgd)
> -#define pmd_free(pmd)
> -#define pmd_alloc(pgd, addr) pmd_offset(pgd, addr)
> +static inline pud_t *pgd_page_vaddr(pgd_t pgd)
> +{
> + return pgtable_va(pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK);
> +}
> +
> +static inline pmd_t *pud_page_vaddr(pud_t pud)
> +{
> + return pgtable_va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK);
> +}
> +
>
> static inline pte_t *pmd_page_vaddr(pmd_t pmd)
> {
> return pgtable_va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
> }
>
> +#if PGTABLE_LEVELS > 2
> +#define pmd_index(addr) \
> + (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
> +#define pmd_offset(pud, addr) \
> + (pud_page_vaddr(*(pud)) + pmd_index(addr))
> +#define pmd_free(pmd) free_page(pmd)
> +static inline pmd_t *pmd_alloc_one(void)
> +{
> + assert(PTRS_PER_PMD * sizeof(pmd_t) == PAGE_SIZE);
> + pmd_t *pmd = alloc_page();
> + return pmd;
> +}
> +static inline pmd_t *pmd_alloc(pud_t *pud, unsigned long addr)
> +{
> + if (pud_none(*pud)) {
> + pud_t entry;
> + pud_val(entry) = pgtable_pa(pmd_alloc_one()) | PMD_TYPE_TABLE;
> + WRITE_ONCE(*pud, entry);
> + }
> + return pmd_offset(pud, addr);
> +}
> +#else
> +#define pmd_offset(pud, addr) ((pmd_t *)pud)
> +#define pmd_free(pmd)
> +#define pmd_alloc(pud, addr) pmd_offset(pud, addr)
> +#endif
> +
> +#if PGTABLE_LEVELS > 3
> +#define pud_index(addr) \
> + (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
> +#define pud_offset(pgd, addr) \
> + (pgd_page_vaddr(*(pgd)) + pud_index(addr))
> +#define pud_free(pud) free_page(pud)
> +static inline pud_t *pud_alloc_one(void)
> +{
> + assert(PTRS_PER_PMD * sizeof(pud_t) == PAGE_SIZE);
> + pud_t *pud = alloc_page();
> + return pud;
> +}
> +static inline pud_t *pud_alloc(pgd_t *pgd, unsigned long addr)
> +{
> + if (pgd_none(*pgd)) {
> + pgd_t entry;
> + pgd_val(entry) = pgtable_pa(pud_alloc_one()) | PMD_TYPE_TABLE;
> + WRITE_ONCE(*pgd, entry);
> + }
> + return pud_offset(pgd, addr);
> +}
> +#else
> +#define pud_offset(pgd, addr) ((pud_t *)pgd)
> +#define pud_free(pud)
> +#define pud_alloc(pgd, addr) pud_offset(pgd, addr)
> +#endif
> +
> #define pte_index(addr) \
> (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
> #define pte_offset(pmd, addr) \
> diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c
> index 540a1e8..6d1c75b 100644
> --- a/lib/arm/mmu.c
> +++ b/lib/arm/mmu.c
> @@ -81,7 +81,8 @@ void mmu_disable(void)
> static pteval_t *get_pte(pgd_t *pgtable, uintptr_t vaddr)
> {
> pgd_t *pgd = pgd_offset(pgtable, vaddr);
> - pmd_t *pmd = pmd_alloc(pgd, vaddr);
> + pud_t *pud = pud_alloc(pgd, vaddr);
> + pmd_t *pmd = pmd_alloc(pud, vaddr);
> pte_t *pte = pte_alloc(pmd, vaddr);
>
> return &pte_val(*pte);
> @@ -133,18 +134,20 @@ void mmu_set_range_sect(pgd_t *pgtable, uintptr_t virt_offset,
> phys_addr_t phys_start, phys_addr_t phys_end,
> pgprot_t prot)
> {
> - phys_addr_t paddr = phys_start & PGDIR_MASK;
> - uintptr_t vaddr = virt_offset & PGDIR_MASK;
> + phys_addr_t paddr = phys_start & PUD_MASK;
> + uintptr_t vaddr = virt_offset & PUD_MASK;
> uintptr_t virt_end = phys_end - paddr + vaddr;
> pgd_t *pgd;
> - pgd_t entry;
> + pud_t *pud;
> + pud_t entry;
>
> - for (; vaddr < virt_end; vaddr += PGDIR_SIZE, paddr += PGDIR_SIZE) {
> - pgd_val(entry) = paddr;
> - pgd_val(entry) |= PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S;
> - pgd_val(entry) |= pgprot_val(prot);
> + for (; vaddr < virt_end; vaddr += PUD_SIZE, paddr += PUD_SIZE) {
> + pud_val(entry) = paddr;
> + pud_val(entry) |= PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S;
> + pud_val(entry) |= pgprot_val(prot);
> pgd = pgd_offset(pgtable, vaddr);
> - WRITE_ONCE(*pgd, entry);
> + pud = pud_alloc(pgd, vaddr);
> + WRITE_ONCE(*pud, entry);
> flush_tlb_page(vaddr);
> }
> }
> @@ -207,6 +210,7 @@ unsigned long __phys_to_virt(phys_addr_t addr)
> void mmu_clear_user(pgd_t *pgtable, unsigned long vaddr)
> {
> pgd_t *pgd;
> + pud_t *pud;
> pmd_t *pmd;
> pte_t *pte;
>
> @@ -215,7 +219,9 @@ void mmu_clear_user(pgd_t *pgtable, unsigned long vaddr)
>
> pgd = pgd_offset(pgtable, vaddr);
> assert(pgd_valid(*pgd));
> - pmd = pmd_offset(pgd, vaddr);
> + pud = pud_offset(pgd, vaddr);
> + assert(pud_valid(*pud));
> + pmd = pmd_offset(pud, vaddr);
> assert(pmd_valid(*pmd));
>
> if (pmd_huge(*pmd)) {
> diff --git a/arm/cstart64.S b/arm/cstart64.S
> index ffdd49f..530ffb6 100644
> --- a/arm/cstart64.S
> +++ b/arm/cstart64.S
> @@ -157,6 +157,16 @@ halt:
> */
> #define MAIR(attr, mt) ((attr) << ((mt) * 8))
>
> +#if PAGE_SHIFT == 16
> +#define TCR_TG_FLAGS TCR_TG0_64K | TCR_TG1_64K
> +#elif PAGE_SHIFT == 14
> +#define TCR_TG_FLAGS TCR_TG0_16K | TCR_TG1_16K
> +#elif PAGE_SHIFT == 12
> +#define TCR_TG_FLAGS TCR_TG0_4K | TCR_TG1_4K
> +#else
> +#error Unsupported PAGE_SHIFT
> +#endif
> +
> .globl asm_mmu_enable
> asm_mmu_enable:
> tlbi vmalle1 // invalidate I + D TLBs
> @@ -164,7 +174,7 @@ asm_mmu_enable:
>
> /* TCR */
> ldr x1, =TCR_TxSZ(VA_BITS) | \
> - TCR_TG0_64K | TCR_TG1_64K | \
> + TCR_TG_FLAGS | \
> TCR_IRGN_WBWA | TCR_ORGN_WBWA | \
> TCR_SHARED
> mrs x2, id_aa64mmfr0_el1
