linux-kernel - [PATCH AUTOSEL 5.15 04/45] arm64: mm: provide idmap pointer to cpu_replace

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Date:   Sun,  7 Aug 2022 21:35:08 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Ard Biesheuvel <ardb@...nel.org>, Will Deacon <will@...nel.org>,
        Sasha Levin <sashal@...nel.org>, catalin.marinas@....com,
        ryabinin.a.a@...il.com, pasha.tatashin@...een.com,
        anshuman.khandual@....com, broonie@...nel.org, maz@...nel.org,
        suzuki.poulose@....com, james.morse@....com,
        vladimir.murzin@....com, Julia.Lawall@...ia.fr,
        akpm@...ux-foundation.org, david@...hat.com,
        vijayb@...ux.microsoft.com, quic_sudaraja@...cinc.com,
        jianyong.wu@....com, rppt@...nel.org,
        linux-arm-kernel@...ts.infradead.org, kasan-dev@...glegroups.com
Subject: [PATCH AUTOSEL 5.15 04/45] arm64: mm: provide idmap pointer to cpu_replace_ttbr1()

From: Ard Biesheuvel <ardb@...nel.org>

[ Upstream commit 1682c45b920643cbde31d8a5b7ca7c2be92d6928 ]

In preparation for changing the way we initialize the permanent ID map,
update cpu_replace_ttbr1() so we can use it with the initial ID map as
well.

Signed-off-by: Ard Biesheuvel <ardb@...nel.org>
Link: https://lore.kernel.org/r/20220624150651.1358849-11-ardb@kernel.org
Signed-off-by: Will Deacon <will@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 arch/arm64/include/asm/mmu_context.h | 13 +++++++++----
 arch/arm64/kernel/cpufeature.c       |  2 +-
 arch/arm64/kernel/suspend.c          |  2 +-
 arch/arm64/mm/kasan_init.c           |  4 ++--
 arch/arm64/mm/mmu.c                  |  2 +-
 5 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h
index f4ba93d4ffeb..24ed534bb417 100644
--- a/arch/arm64/include/asm/mmu_context.h
+++ b/arch/arm64/include/asm/mmu_context.h
@@ -106,20 +106,25 @@ static inline void cpu_uninstall_idmap(void)
 		cpu_switch_mm(mm->pgd, mm);
 }
 
-static inline void cpu_install_idmap(void)
+static inline void __cpu_install_idmap(pgd_t *idmap)
 {
 	cpu_set_reserved_ttbr0();
 	local_flush_tlb_all();
 	cpu_set_idmap_tcr_t0sz();
 
-	cpu_switch_mm(lm_alias(idmap_pg_dir), &init_mm);
+	cpu_switch_mm(lm_alias(idmap), &init_mm);
+}
+
+static inline void cpu_install_idmap(void)
+{
+	__cpu_install_idmap(idmap_pg_dir);
 }
 
 /*
  * Atomically replaces the active TTBR1_EL1 PGD with a new VA-compatible PGD,
  * avoiding the possibility of conflicting TLB entries being allocated.
  */
-static inline void __nocfi cpu_replace_ttbr1(pgd_t *pgdp)
+static inline void __nocfi cpu_replace_ttbr1(pgd_t *pgdp, pgd_t *idmap)
 {
 	typedef void (ttbr_replace_func)(phys_addr_t);
 	extern ttbr_replace_func idmap_cpu_replace_ttbr1;
@@ -142,7 +147,7 @@ static inline void __nocfi cpu_replace_ttbr1(pgd_t *pgdp)
 
 	replace_phys = (void *)__pa_symbol(function_nocfi(idmap_cpu_replace_ttbr1));
 
-	cpu_install_idmap();
+	__cpu_install_idmap(idmap);
 	replace_phys(ttbr1);
 	cpu_uninstall_idmap();
 }
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index e71c9cfb46e8..e826509823a6 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -3013,7 +3013,7 @@ subsys_initcall_sync(init_32bit_el0_mask);
 
 static void __maybe_unused cpu_enable_cnp(struct arm64_cpu_capabilities const *cap)
 {
-	cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
+	cpu_replace_ttbr1(lm_alias(swapper_pg_dir), idmap_pg_dir);
 }
 
 /*
diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c
index 19ee7c33769d..40bf1551d1ad 100644
--- a/arch/arm64/kernel/suspend.c
+++ b/arch/arm64/kernel/suspend.c
@@ -52,7 +52,7 @@ void notrace __cpu_suspend_exit(void)
 
 	/* Restore CnP bit in TTBR1_EL1 */
 	if (system_supports_cnp())
-		cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
+		cpu_replace_ttbr1(lm_alias(swapper_pg_dir), idmap_pg_dir);
 
 	/*
 	 * PSTATE was not saved over suspend/resume, re-enable any detected
diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
index 61b52a92b8b6..674863348f67 100644
--- a/arch/arm64/mm/kasan_init.c
+++ b/arch/arm64/mm/kasan_init.c
@@ -235,7 +235,7 @@ static void __init kasan_init_shadow(void)
 	 */
 	memcpy(tmp_pg_dir, swapper_pg_dir, sizeof(tmp_pg_dir));
 	dsb(ishst);
-	cpu_replace_ttbr1(lm_alias(tmp_pg_dir));
+	cpu_replace_ttbr1(lm_alias(tmp_pg_dir), idmap_pg_dir);
 
 	clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);
 
@@ -279,7 +279,7 @@ static void __init kasan_init_shadow(void)
 				PAGE_KERNEL_RO));
 
 	memset(kasan_early_shadow_page, KASAN_SHADOW_INIT, PAGE_SIZE);
-	cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
+	cpu_replace_ttbr1(lm_alias(swapper_pg_dir), idmap_pg_dir);
 }
 
 static void __init kasan_init_depth(void)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 6680689242df..984f1f503328 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -780,7 +780,7 @@ void __init paging_init(void)
 
 	pgd_clear_fixmap();
 
-	cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
+	cpu_replace_ttbr1(lm_alias(swapper_pg_dir), idmap_pg_dir);
 	init_mm.pgd = swapper_pg_dir;
 
 	memblock_free(__pa_symbol(init_pg_dir),
-- 
2.35.1