From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
To: catalin.marinas@arm.com, hch@lst.de, wahrenst@gmx.net,
marc.zyngier@arm.com, robh+dt@kernel.org,
Robin Murphy <robin.murphy@arm.com>,
linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
linux-arch@vger.kernel.org, iommu@lists.linux-foundation.org,
linux-mm@kvack.org, linux-riscv@lists.infradead.org,
Will Deacon <will@kernel.org>
Cc: phill@raspberryi.org, f.fainelli@gmail.com,
nsaenzjulienne@suse.de, linux-kernel@vger.kernel.org,
eric@anholt.net, mbrugger@suse.com,
linux-rpi-kernel@lists.infradead.org, akpm@linux-foundation.org,
frowand.list@gmail.com, m.szyprowski@samsung.com
Subject: [PATCH v2 08/11] arm64: use both ZONE_DMA and ZONE_DMA32
Date: Tue, 20 Aug 2019 16:58:16 +0200 [thread overview]
Message-ID: <20190820145821.27214-9-nsaenzjulienne@suse.de> (raw)
In-Reply-To: <20190820145821.27214-1-nsaenzjulienne@suse.de>
So far all arm64 devices have supported 32 bit DMA masks for their
peripherals. This is not true anymore for the Raspberry Pi 4 as most of
it's peripherals can only address the first GB or memory of a total of
up to 4 GB.
This goes against ZONE_DMA32's original intent, and breaks other
subsystems as it's expected for ZONE_DMA32 to be addressable with a 32
bit mask. So it was decided to use ZONE_DMA for this specific case.
ZONE_DMA will contain the memory addressable by all the SoC's
peripherals and ZONE_DMA32 the rest of the 32 bit addressable memory. If
all peripherals where able to address the whole 32 bit addressable space
ZONE_DMA32 will be left empty.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
Changes in v2:
- ZONE_DMA will never be left empty
- Update comment to reflect new zones split
arch/arm64/Kconfig | 4 ++++
arch/arm64/mm/init.c | 39 +++++++++++++++++++++++++++++++--------
2 files changed, 35 insertions(+), 8 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 3adcec05b1f6..a9fd71d3bc8e 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -266,6 +266,10 @@ config GENERIC_CSUM
config GENERIC_CALIBRATE_DELAY
def_bool y
+config ZONE_DMA
+ bool "Support DMA zone" if EXPERT
+ default y
+
config ZONE_DMA32
bool "Support DMA32 zone" if EXPERT
default y
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index bc7999020c71..c51ce79b692b 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -50,6 +50,14 @@
s64 memstart_addr __ro_after_init = -1;
EXPORT_SYMBOL(memstart_addr);
+/*
+ * We create both ZONE_DMA and ZONE_DMA32. ZONE_DMA's size is decided based on
+ * whether all the device's peripherals are able to address the first naturally
+ * aligned 4G of memory. If not, ZONE_DMA covers the area common to all them
+ * and ZONE_DMA32 the rest. If ZONE_DMA fits the whole 4G area, ZONE_DMA32 is
+ * left empty.
+ */
+phys_addr_t arm64_dma_phys_limit __ro_after_init;
phys_addr_t arm64_dma32_phys_limit __ro_after_init;
#ifdef CONFIG_KEXEC_CORE
@@ -191,6 +199,9 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
{
unsigned long max_zone_pfns[MAX_NR_ZONES] = {0};
+#ifdef CONFIG_ZONE_DMA
+ max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit);
+#endif
#ifdef CONFIG_ZONE_DMA32
max_zone_pfns[ZONE_DMA32] = PFN_DOWN(arm64_dma32_phys_limit);
#endif
@@ -206,13 +217,17 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
struct memblock_region *reg;
unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
unsigned long max_dma32 = min;
+ unsigned long max_dma = min;
memset(zone_size, 0, sizeof(zone_size));
- /* 4GB maximum for 32-bit only capable devices */
+#ifdef CONFIG_ZONE_DMA
+ max_dma = PFN_DOWN(arm64_dma_phys_limit);
+ zone_size[ZONE_DMA] = max_dma - min;
+#endif
#ifdef CONFIG_ZONE_DMA32
max_dma32 = PFN_DOWN(arm64_dma32_phys_limit);
- zone_size[ZONE_DMA32] = max_dma32 - min;
+ zone_size[ZONE_DMA32] = max_dma32 - max_dma;
#endif
zone_size[ZONE_NORMAL] = max - max_dma32;
@@ -224,11 +239,17 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
if (start >= max)
continue;
-
+#ifdef CONFIG_ZONE_DMA
+ if (start < max_dma) {
+ unsigned long dma_end = min_not_zero(end, max_dma);
+ zhole_size[ZONE_DMA] -= dma_end - start;
+ }
+#endif
#ifdef CONFIG_ZONE_DMA32
if (start < max_dma32) {
- unsigned long dma_end = min(end, max_dma32);
- zhole_size[ZONE_DMA32] -= dma_end - start;
+ unsigned long dma32_end = min(end, max_dma32);
+ unsigned long dma32_start = max(start, max_dma);
+ zhole_size[ZONE_DMA32] -= dma32_end - dma32_start;
}
#endif
if (end > max_dma32) {
@@ -416,7 +437,9 @@ void __init arm64_memblock_init(void)
early_init_fdt_scan_reserved_mem();
- /* 4GB maximum for 32-bit only capable devices */
+ if (IS_ENABLED(CONFIG_ZONE_DMA))
+ arm64_dma_phys_limit = max_zone_dma_phys();
+
if (IS_ENABLED(CONFIG_ZONE_DMA32))
arm64_dma32_phys_limit = max_zone_dma32_phys();
else
@@ -428,7 +451,7 @@ void __init arm64_memblock_init(void)
high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
- dma_contiguous_reserve(arm64_dma32_phys_limit);
+ dma_contiguous_reserve(arm64_dma_phys_limit ? : arm64_dma32_phys_limit);
}
void __init bootmem_init(void)
@@ -531,7 +554,7 @@ static void __init free_unused_memmap(void)
*/
void __init mem_init(void)
{
- if (swiotlb_force == SWIOTLB_FORCE ||
+ if (swiotlb_force == SWIOTLB_FORCE || arm64_dma_phys_limit ||
max_pfn > (arm64_dma32_phys_limit >> PAGE_SHIFT))
swiotlb_init(1);
else
--
2.22.0
next prev parent reply other threads:[~2019-08-20 14:58 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-20 14:58 [PATCH v2 00/11] Raspberry Pi 4 DMA addressing support Nicolas Saenz Julienne
2019-08-20 14:58 ` [PATCH v2 01/11] asm-generic: add dma_zone_size Nicolas Saenz Julienne
2019-08-26 7:09 ` Christoph Hellwig
2019-08-26 13:46 ` Nicolas Saenz Julienne
2019-08-28 9:44 ` Nicolas Saenz Julienne
2019-08-30 14:45 ` Catalin Marinas
2019-08-30 17:24 ` Nicolas Saenz Julienne
2019-09-02 13:01 ` Christoph Hellwig
2019-08-20 14:58 ` [PATCH v2 02/11] arm: use generic dma_zone_size Nicolas Saenz Julienne
2019-08-20 14:58 ` [PATCH v2 03/11] of/fdt: add of_fdt_machine_is_compatible function Nicolas Saenz Julienne
2019-08-20 17:16 ` Rob Herring
2019-08-20 17:27 ` Nicolas Saenz Julienne
2019-08-20 14:58 ` [PATCH v2 04/11] of/fdt: add early_init_dt_get_dma_zone_size() Nicolas Saenz Julienne
2019-08-20 17:14 ` Rob Herring
2019-08-20 14:58 ` [PATCH v2 05/11] arm64: mm: use arm64_dma_phys_limit instead of calling max_zone_dma_phys() Nicolas Saenz Julienne
2019-08-20 14:58 ` [PATCH v2 06/11] arm64: rename variables used to calculate ZONE_DMA32's size Nicolas Saenz Julienne
2019-08-20 14:58 ` [PATCH v2 07/11] arm64: re-introduce max_zone_dma_phys() Nicolas Saenz Julienne
2019-08-20 14:58 ` Nicolas Saenz Julienne [this message]
2019-08-20 14:58 ` [PATCH v2 09/11] dma-direct: turn ARCH_ZONE_DMA_BITS into a variable Nicolas Saenz Julienne
2019-08-26 7:05 ` Christoph Hellwig
2019-08-26 11:33 ` Michael Ellerman
2019-08-20 14:58 ` [PATCH v2 10/11] arm64: edit zone_dma_bits to fine tune dma-direct min mask Nicolas Saenz Julienne
2019-08-26 7:06 ` Christoph Hellwig
2019-08-26 11:08 ` Nicolas Saenz Julienne
2019-08-27 7:03 ` Petr Tesarik
2019-08-20 14:58 ` [PATCH v2 11/11] mm: refresh ZONE_DMA and ZONE_DMA32 comments in 'enum zone_type' Nicolas Saenz Julienne
2019-08-26 7:07 ` Christoph Hellwig
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190820145821.27214-9-nsaenzjulienne@suse.de \
--to=nsaenzjulienne@suse.de \
--cc=akpm@linux-foundation.org \
--cc=catalin.marinas@arm.com \
--cc=devicetree@vger.kernel.org \
--cc=eric@anholt.net \
--cc=f.fainelli@gmail.com \
--cc=frowand.list@gmail.com \
--cc=hch@lst.de \
--cc=iommu@lists.linux-foundation.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-riscv@lists.infradead.org \
--cc=linux-rpi-kernel@lists.infradead.org \
--cc=m.szyprowski@samsung.com \
--cc=marc.zyngier@arm.com \
--cc=mbrugger@suse.com \
--cc=phill@raspberryi.org \
--cc=robh+dt@kernel.org \
--cc=robin.murphy@arm.com \
--cc=wahrenst@gmx.net \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).