linux-kernel - [PATCH 1/4] of/fdt: Update zone_dma

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20201001161740.29064-2-nsaenzjulienne@suse.de>
Date:   Thu,  1 Oct 2020 18:17:37 +0200
From:   Nicolas Saenz Julienne <nsaenzjulienne@...e.de>
To:     robh+dt@...nel.org, catalin.marinas@....com, hch@....de,
        robin.murphy@....com, devicetree@...r.kernel.org,
        iommu@...ts.linux-foundation.org, linux-mm@...ck.org,
        Frank Rowand <frowand.list@...il.com>
Cc:     will@...nel.org, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-rpi-kernel@...ts.infradead.org,
        Nicolas Saenz Julienne <nsaenzjulienne@...e.de>
Subject: [PATCH 1/4] of/fdt: Update zone_dma_bits when running in bcm2711

arm64 wants to be able to set ZONE_DMA's size depending on the specific
platform its being run on. Ideally this could be achieved in a smart way
by parsing all dma-ranges and calculating the smaller DMA constraint in
the system. Easier said than done. We compromised on a simpler solution
as the only platform interested in using this is the Raspberry Pi 4.

So update zone_dma_bits if the machine's compatible string matches
Raspberry Pi 4's, otherwise let arm64's mm code deal with it.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@...e.de>
---
 drivers/of/fdt.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 4602e467ca8b..cd0d115ef329 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -25,6 +25,7 @@
 #include <linux/serial_core.h>
 #include <linux/sysfs.h>
 #include <linux/random.h>
+#include <linux/dma-direct.h>	/* for zone_dma_bits */
 
 #include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
 #include <asm/page.h>
@@ -1198,6 +1199,14 @@ void __init early_init_dt_scan_nodes(void)
 	of_scan_flat_dt(early_init_dt_scan_memory, NULL);
 }
 
+void __init early_init_dt_update_zone_dma_bits(void)
+{
+	unsigned long dt_root = of_get_flat_dt_root();
+
+	if (of_flat_dt_is_compatible(dt_root, "brcm,bcm2711"))
+		zone_dma_bits = 30;
+}
+
 bool __init early_init_dt_scan(void *params)
 {
 	bool status;
@@ -1207,6 +1216,7 @@ bool __init early_init_dt_scan(void *params)
 		return false;
 
 	early_init_dt_scan_nodes();
+	early_init_dt_update_zone_dma_bits();
 	return true;
 }
 
-- 
2.28.0