1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
From: Felix Fietkau <nbd@nbd.name>
Date: Fri, 4 Sep 2020 18:42:42 +0200
Subject: [PATCH] pci: pcie-mediatek: add support for coherent DMA
It improves performance by eliminating the need for a cache flush for DMA on
attached devices
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
--- a/arch/arm64/boot/dts/mediatek/mt7622.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt7622.dtsi
@@ -837,6 +837,9 @@
bus-range = <0x00 0xff>;
ranges = <0x82000000 0 0x20000000 0x0 0x20000000 0 0x8000000>;
status = "disabled";
+ dma-coherent;
+ mediatek,hifsys = <&hifsys>;
+ mediatek,cci-control = <&cci_control2>;
#interrupt-cells = <1>;
interrupt-map-mask = <0 0 0 7>;
@@ -881,6 +884,9 @@
bus-range = <0x00 0xff>;
ranges = <0x82000000 0 0x28000000 0x0 0x28000000 0 0x8000000>;
status = "disabled";
+ dma-coherent;
+ mediatek,hifsys = <&hifsys>;
+ mediatek,cci-control = <&cci_control2>;
#interrupt-cells = <1>;
interrupt-map-mask = <0 0 0 7>;
--- a/drivers/pci/controller/pcie-mediatek.c
+++ b/drivers/pci/controller/pcie-mediatek.c
@@ -20,6 +20,7 @@
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/of_platform.h>
+#include <linux/of_address.h>
#include <linux/pci.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
@@ -139,6 +140,11 @@
#define PCIE_LINK_STATUS_V2 0x804
#define PCIE_PORT_LINKUP_V2 BIT(10)
+/* DMA channel mapping */
+#define HIFSYS_DMA_AG_MAP 0x008
+#define HIFSYS_DMA_AG_MAP_PCIE0 BIT(0)
+#define HIFSYS_DMA_AG_MAP_PCIE1 BIT(1)
+
struct mtk_pcie_port;
/**
@@ -1060,6 +1066,27 @@ static int mtk_pcie_setup(struct mtk_pci
struct mtk_pcie_port *port, *tmp;
int err, slot;
+ if (of_dma_is_coherent(node)) {
+ struct regmap *con;
+ u32 mask;
+
+ con = syscon_regmap_lookup_by_phandle(node,
+ "mediatek,cci-control");
+ /* enable CPU/bus coherency */
+ if (!IS_ERR(con))
+ regmap_write(con, 0, 3);
+
+ con = syscon_regmap_lookup_by_phandle(node,
+ "mediatek,hifsys");
+ if (IS_ERR(con)) {
+ dev_err(dev, "missing hifsys node\n");
+ return PTR_ERR(con);
+ }
+
+ mask = HIFSYS_DMA_AG_MAP_PCIE0 | HIFSYS_DMA_AG_MAP_PCIE1;
+ regmap_update_bits(con, HIFSYS_DMA_AG_MAP, mask, mask);
+ }
+
slot = of_get_pci_domain_nr(dev->of_node);
if (slot < 0) {
for_each_available_child_of_node(node, child) {
|
