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From: Andrey Smirnov <andrew.smirnov@gmail.com>
To: barebox@lists.infradead.org
Cc: Andrey Smirnov <andrew.smirnov@gmail.com>
Subject: [PATCH v4 28/29] ARM: mmu: Introduce ARM_TTB_SIZE
Date: Mon, 21 May 2018 20:15:09 -0700	[thread overview]
Message-ID: <20180522031510.25505-29-andrew.smirnov@gmail.com> (raw)
In-Reply-To: <20180522031510.25505-1-andrew.smirnov@gmail.com>

Commit 1c33aacf8a247ab45814b43ac0ca903677afffae ("ARM: use memalign to
allocate page table"), reasonalby changed TTB allocation size from
SZ_32K to SZ_16K (TTB's real size), but it also changed alignment from
SZ_16K to SZ_64K for unclear reasons.

Reading various TTBR related ARM documentation it seems that worst
case alignment for it is 16KiB (bits [0, 13 - N] must be zero) which
also matches early TTB allocation code.

Since both early and regular MMU code has to share this paramter,
introduce ARM_TTB_SIZE and use it in both cases for both size and
alignment.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
 arch/arm/cpu/mmu.c                 | 2 +-
 arch/arm/include/asm/barebox-arm.h | 8 +++++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/arm/cpu/mmu.c b/arch/arm/cpu/mmu.c
index 5f82b63ca..a89f420f2 100644
--- a/arch/arm/cpu/mmu.c
+++ b/arch/arm/cpu/mmu.c
@@ -469,7 +469,7 @@ static int mmu_init(void)
 			pr_crit("Critical Error: Can't request SDRAM region for ttb at %p\n",
 					ttb);
 	} else {
-		ttb = xmemalign(0x10000, 0x4000);
+		ttb = xmemalign(ARM_TTB_SIZE, ARM_TTB_SIZE);
 	}
 
 	pr_debug("ttb: 0x%p\n", ttb);
diff --git a/arch/arm/include/asm/barebox-arm.h b/arch/arm/include/asm/barebox-arm.h
index f55c8bb0c..d97f68c54 100644
--- a/arch/arm/include/asm/barebox-arm.h
+++ b/arch/arm/include/asm/barebox-arm.h
@@ -32,6 +32,12 @@
 #include <linux/compiler.h>
 #include <asm/barebox-arm-head.h>
 
+/*
+ * We have a 4GiB address space split into 1MiB sections, with each
+ * section header taking 4 bytes
+ */
+#define ARM_TTB_SIZE	(SZ_4G / SZ_1M * sizeof(u32))
+
 unsigned long get_runtime_offset(void);
 
 /* global_variable_offset() - Access global variables when not running at link address
@@ -117,7 +123,7 @@ static inline unsigned long arm_mem_ttb(unsigned long membase,
 					unsigned long endmem)
 {
 	endmem = arm_mem_stack(membase, endmem);
-	endmem = ALIGN_DOWN(endmem, SZ_16K) - SZ_16K;
+	endmem = ALIGN_DOWN(endmem, ARM_TTB_SIZE) - ARM_TTB_SIZE;
 
 	return endmem;
 }
-- 
2.17.0


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  parent reply	other threads:[~2018-05-22  3:16 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-22  3:14 [PATCH v4 00/29] ARM MMU code improvements and on-demand PTE allocation Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 01/29] ARM: mmu: Remove unused ARM_VECTORS_SIZE Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 02/29] ARM: mmu: Make use of IS_ALIGNED in arm_mmu_remap_sdram() Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 03/29] ARM: mmu: Use ALIGN and ALIGN_DOWN in map_cachable() Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 04/29] ARM: mmu: Introduce set_ttbr() Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 05/29] ARM: mmu: Introduce set_domain() Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 06/29] ARM: mmu: Share code for create_sections() Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 07/29] ARM: mmu: Separate index and address in create_sections() Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 08/29] sizes.h: Sync with Linux 4.16 Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 09/29] ARM: mmu: Specify size in bytes in create_sections() Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 10/29] ARM: mmu: Share code for initial flat mapping creation Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 11/29] ARM: mmu: Share PMD_SECT_DEF_CACHED Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 12/29] ARM: mmu: Drop needless shifting in map_io_sections() Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 13/29] ARM: mmu: Replace hardcoded shifts with pgd_index() from Linux Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 14/29] ARM: mmu: Trivial simplification in arm_mmu_remap_sdram() Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 15/29] ARM: mmu: Replace various SZ_1M with PGDIR_SIZE Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 16/29] ARM: mmu: Use PAGE_SIZE when specifying size of one page Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 17/29] ARM: mmu: Define and use PTRS_PER_PTE Andrey Smirnov
2018-05-22  3:14 ` [PATCH v4 18/29] ARM: mmu: Use PAGE_SIZE instead of magic right shift by 12 Andrey Smirnov
2018-05-22  3:15 ` [PATCH v4 19/29] ARM: mmu: Use xmemalign in arm_create_pte() Andrey Smirnov
2018-05-22  3:15 ` [PATCH v4 20/29] ARM: mmu: Use xmemalign in mmu_init() Andrey Smirnov
2018-05-22  3:15 ` [PATCH v4 21/29] ARM: mmu: Share code between dma_alloc_*() functions Andrey Smirnov
2018-05-22  3:15 ` [PATCH v4 22/29] ARM: mmu: Pass PTE flags a parameter to arm_create_pte() Andrey Smirnov
2018-05-22  3:15 ` [PATCH v4 23/29] ARM: mmu: Make sure that address is 1M aligned in arm_create_pte() Andrey Smirnov
2018-05-22  3:15 ` [PATCH v4 24/29] ARM: mmu: Use find_pte() to find PTE in create_vector_table() Andrey Smirnov
2018-05-22  3:15 ` [PATCH v4 25/29] ARM: mmu: Use dma_inv_range() in dma_sync_single_for_cpu() Andrey Smirnov
2018-05-22  3:15 ` [PATCH v4 26/29] ARM: mmu: Simplify the use of dma_flush_range() Andrey Smirnov
2018-05-22  3:15 ` [PATCH v4 27/29] ARM: mmu: Implement on-demand PTE allocation Andrey Smirnov
2018-05-22  3:15 ` Andrey Smirnov [this message]
2018-05-22  3:15 ` [PATCH v4 29/29] ARM: mmu: Do not try to pick early TTB up Andrey Smirnov
2018-05-22  7:16 ` [PATCH v4 00/29] ARM MMU code improvements and on-demand PTE allocation Sascha Hauer
2018-05-22 18:37   ` Andrey Smirnov

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