From 29e31da4ed26c3ffc9afa70427f84f60fe50600b Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Tue, 29 Apr 2025 10:35:11 +0530 Subject: [PATCH] arm64/mm: Re-organise setting up FEAT_S1PIE registers PIRE0_EL1 and PIR_EL1 mov_q cannot really move PIE_E[0|1] macros into a general purpose register as expected if those macro constants contain some 128 bit layout elements, that are required for D128 page tables. The primary issue is that for D128, PIE_E[0|1] are defined in terms of 128-bit types with shifting and masking, which the assembler can't accommodate. Instead pre-calculate these PIRE0_EL1/PIR_EL1 constants into asm-offsets.h based PIE_E0_ASM/PIE_E1_ASM which can then be used in arch/arm64/mm/proc.S. While here also drop PTE_MAYBE_NG/PTE_MAYBE_SHARED assembly overrides which are not required any longer, as the compiler toolchains are smart enough to compute both the PIE_[E0|E1]_ASM constants in all scenarios. Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: Ard Biesheuvel Cc: Ryan Roberts Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual Reviewed-by: Ryan Roberts Link: https://lore.kernel.org/r/20250429050511.1663235-1-anshuman.khandual@arm.com Signed-off-by: Will Deacon --- arch/arm64/kernel/asm-offsets.c | 2 ++ arch/arm64/mm/proc.S | 19 ++----------------- 2 files changed, 4 insertions(+), 17 deletions(-) diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index eb1a840e4110..30d4bbe68661 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -182,5 +182,7 @@ int main(void) #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS DEFINE(FTRACE_OPS_DIRECT_CALL, offsetof(struct ftrace_ops, direct_call)); #endif + DEFINE(PIE_E0_ASM, PIE_E0); + DEFINE(PIE_E1_ASM, PIE_E1); return 0; } diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index fb30c8804f87..80d470aa469d 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -512,26 +512,11 @@ alternative_else_nop_endif ubfx x1, x1, #ID_AA64MMFR3_EL1_S1PIE_SHIFT, #4 cbz x1, .Lskip_indirection - /* - * The PROT_* macros describing the various memory types may resolve to - * C expressions if they include the PTE_MAYBE_* macros, and so they - * can only be used from C code. The PIE_E* constants below are also - * defined in terms of those macros, but will mask out those - * PTE_MAYBE_* constants, whether they are set or not. So #define them - * as 0x0 here so we can evaluate the PIE_E* constants in asm context. - */ - -#define PTE_MAYBE_NG 0 -#define PTE_MAYBE_SHARED 0 - - mov_q x0, PIE_E0 + mov_q x0, PIE_E0_ASM msr REG_PIRE0_EL1, x0 - mov_q x0, PIE_E1 + mov_q x0, PIE_E1_ASM msr REG_PIR_EL1, x0 -#undef PTE_MAYBE_NG -#undef PTE_MAYBE_SHARED - orr tcr2, tcr2, TCR2_EL1_PIE msr REG_TCR2_EL1, x0 -- 2.50.1