[PATCH 3/3] Revert "arm64: Use FEAT_HAFDBS to track dirty pages when available"

[Chris Packham]

This reverts commit 6cdf6b7a340db4ddd008516181de7e08e3f8c213. This is
part of a series trying to make use of the arm64 hardware features for
tracking dirty pages. Unfortunately this series causes problems for the
AC5/AC5X SoCs. Having exhausted other options the consensus seems to be
reverting this series is the best course of action.

Signed-off-by: Chris Packham <judge.packham at gmail.com>
---

 arch/arm/cpu/armv8/cache_v8.c      | 16 +---------------
 arch/arm/include/asm/armv8/mmu.h   | 14 ++++----------
 arch/arm/include/asm/global_data.h |  1 -
 3 files changed, 5 insertions(+), 26 deletions(-)

diff --git a/arch/arm/cpu/armv8/cache_v8.c b/arch/arm/cpu/armv8/cache_v8.c
index 4760064ee18f..697334086fdc 100644
--- a/arch/arm/cpu/armv8/cache_v8.c
+++ b/arch/arm/cpu/armv8/cache_v8.c
@@ -93,8 +93,6 @@ u64 get_tcr(u64 *pips, u64 *pva_bits)
 
 	if (el == 1) {
 		tcr = TCR_EL1_RSVD | (ips << 32) | TCR_EPD1_DISABLE;
-		if (gd->arch.has_hafdbs)
-			tcr |= TCR_HA | TCR_HD;
 	} else if (el == 2) {
 		tcr = TCR_EL2_RSVD | (ips << 16);
 	} else {
@@ -202,9 +200,6 @@ static void __cmo_on_leaves(void (*cmo_fn)(unsigned long, unsigned long),
 		    attrs != PTE_BLOCK_MEMTYPE(MT_NORMAL_NC))
 			continue;
 
-		if (gd->arch.has_hafdbs && (pte & (PTE_RDONLY | PTE_DBM)) != PTE_DBM)
-			continue;
-
 		end = va + BIT(level2shift(level)) - 1;
 
 		/* No intersection with RAM? */
@@ -353,9 +348,6 @@ static void add_map(struct mm_region *map)
 	if (va_bits < 39)
 		level = 1;
 
-	if (gd->arch.has_hafdbs)
-		attrs |= PTE_DBM | PTE_RDONLY;
-
 	map_range(map->virt, map->phys, map->size, level,
 		  (u64 *)gd->arch.tlb_addr, attrs);
 }
@@ -407,13 +399,7 @@ static int count_ranges(void)
 __weak u64 get_page_table_size(void)
 {
 	u64 one_pt = MAX_PTE_ENTRIES * sizeof(u64);
-	u64 size, mmfr1;
-
-	asm volatile("mrs %0, id_aa64mmfr1_el1" : "=r" (mmfr1));
-	if ((mmfr1 & 0xf) == 2)
-		gd->arch.has_hafdbs = true;
-	else
-		gd->arch.has_hafdbs = false;
+	u64 size;
 
 	/* Account for all page tables we would need to cover our memory map */
 	size = one_pt * count_ranges();
diff --git a/arch/arm/include/asm/armv8/mmu.h b/arch/arm/include/asm/armv8/mmu.h
index 98a27db3166b..9f58cedb650c 100644
--- a/arch/arm/include/asm/armv8/mmu.h
+++ b/arch/arm/include/asm/armv8/mmu.h
@@ -49,13 +49,10 @@
 #define PTE_TYPE_BLOCK		(1 << 0)
 #define PTE_TYPE_VALID		(1 << 0)
 
-#define PTE_RDONLY		BIT(7)
-#define PTE_DBM			BIT(51)
-
-#define PTE_TABLE_PXN		BIT(59)
-#define PTE_TABLE_XN		BIT(60)
-#define PTE_TABLE_AP		BIT(61)
-#define PTE_TABLE_NS		BIT(63)
+#define PTE_TABLE_PXN		(1UL << 59)
+#define PTE_TABLE_XN		(1UL << 60)
+#define PTE_TABLE_AP		(1UL << 61)
+#define PTE_TABLE_NS		(1UL << 63)
 
 /*
  * Block
@@ -102,9 +99,6 @@
 #define TCR_TG0_16K		(2 << 14)
 #define TCR_EPD1_DISABLE	(1 << 23)
 
-#define TCR_HA			BIT(39)
-#define TCR_HD			BIT(40)
-
 #define TCR_EL1_RSVD		(1U << 31)
 #define TCR_EL2_RSVD		(1U << 31 | 1 << 23)
 #define TCR_EL3_RSVD		(1U << 31 | 1 << 23)
diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
index 1325b0644248..75bd9d56f893 100644
--- a/arch/arm/include/asm/global_data.h
+++ b/arch/arm/include/asm/global_data.h
@@ -52,7 +52,6 @@ struct arch_global_data {
 #if defined(CONFIG_ARM64)
 	unsigned long tlb_fillptr;
 	unsigned long tlb_emerg;
-	bool has_hafdbs;
 #endif
 #endif
 #ifdef CFG_SYS_MEM_RESERVE_SECURE
-- 
2.42.0