sme_pgtable_calc() is unnecessary complex. It can be re-written in a more stream-lined way.
As a side effect, we would get the code ready to boot-time switching between paging modes. Signed-off-by: Kirill A. Shutemov <[email protected]> --- arch/x86/mm/mem_encrypt_identity.c | 42 +++++++++++--------------------------- 1 file changed, 12 insertions(+), 30 deletions(-) diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c index 69635a02ce9e..613686cc56ae 100644 --- a/arch/x86/mm/mem_encrypt_identity.c +++ b/arch/x86/mm/mem_encrypt_identity.c @@ -230,8 +230,7 @@ static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd) static unsigned long __init sme_pgtable_calc(unsigned long len) { - unsigned long p4d_size, pud_size, pmd_size, pte_size; - unsigned long total; + unsigned long entries = 0, tables = 0; /* * Perform a relatively simplistic calculation of the pagetable @@ -245,42 +244,25 @@ static unsigned long __init sme_pgtable_calc(unsigned long len) * Incrementing the count for each covers the case where the addresses * cross entries. */ - if (IS_ENABLED(CONFIG_X86_5LEVEL)) { - p4d_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1; - p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D; - pud_size = (ALIGN(len, P4D_SIZE) / P4D_SIZE) + 1; - pud_size *= sizeof(pud_t) * PTRS_PER_PUD; - } else { - p4d_size = 0; - pud_size = (ALIGN(len, PGDIR_SIZE) / PGDIR_SIZE) + 1; - pud_size *= sizeof(pud_t) * PTRS_PER_PUD; - } - pmd_size = (ALIGN(len, PUD_SIZE) / PUD_SIZE) + 1; - pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD; - pte_size = 2 * sizeof(pte_t) * PTRS_PER_PTE; - total = p4d_size + pud_size + pmd_size + pte_size; + /* PGDIR_SIZE is equal to P4D_SIZE on 4-level machine. */ + if (PTRS_PER_P4D > 1) + entries += (DIV_ROUND_UP(len, PGDIR_SIZE) + 1) * sizeof(p4d_t) * PTRS_PER_P4D; + entries += (DIV_ROUND_UP(len, P4D_SIZE) + 1) * sizeof(pud_t) * PTRS_PER_PUD; + entries += (DIV_ROUND_UP(len, PUD_SIZE) + 1) * sizeof(pmd_t) * PTRS_PER_PMD; + entries += 2 * sizeof(pte_t) * PTRS_PER_PTE; /* * Now calculate the added pagetable structures needed to populate * the new pagetables. */ - if (IS_ENABLED(CONFIG_X86_5LEVEL)) { - p4d_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE; - p4d_size *= sizeof(p4d_t) * PTRS_PER_P4D; - pud_size = ALIGN(total, P4D_SIZE) / P4D_SIZE; - pud_size *= sizeof(pud_t) * PTRS_PER_PUD; - } else { - p4d_size = 0; - pud_size = ALIGN(total, PGDIR_SIZE) / PGDIR_SIZE; - pud_size *= sizeof(pud_t) * PTRS_PER_PUD; - } - pmd_size = ALIGN(total, PUD_SIZE) / PUD_SIZE; - pmd_size *= sizeof(pmd_t) * PTRS_PER_PMD; - total += p4d_size + pud_size + pmd_size; + if (PTRS_PER_P4D > 1) + tables += DIV_ROUND_UP(entries, PGDIR_SIZE) * sizeof(p4d_t) * PTRS_PER_P4D; + tables += DIV_ROUND_UP(entries, P4D_SIZE) * sizeof(pud_t) * PTRS_PER_PUD; + tables += DIV_ROUND_UP(entries, PUD_SIZE) * sizeof(pmd_t) * PTRS_PER_PMD; - return total; + return entries + tables; } void __init __nostackprotector sme_encrypt_kernel(struct boot_params *bp) -- 2.15.1
