1 * Freescale MSI interrupt controller 1 * Freescale MSI interrupt controller
2 2
3 Required properties: 3 Required properties:
4 - compatible : compatible list, may contain on 4 - compatible : compatible list, may contain one or two entries
5 The first is "fsl,CHIP-msi", where CHIP is t 5 The first is "fsl,CHIP-msi", where CHIP is the processor(mpc8610, mpc8572,
6 etc.) and the second is "fsl,mpic-msi" or "f 6 etc.) and the second is "fsl,mpic-msi" or "fsl,ipic-msi" or
7 "fsl,mpic-msi-v4.3" depending on the parent 7 "fsl,mpic-msi-v4.3" depending on the parent type and version. If mpic
8 version is 4.3, the number of MSI registers 8 version is 4.3, the number of MSI registers is increased to 16, MSIIR1 is
9 provided to access these 16 registers, and c 9 provided to access these 16 registers, and compatible "fsl,mpic-msi-v4.3"
10 should be used. The first entry is optional; 10 should be used. The first entry is optional; the second entry is
11 required. 11 required.
12 12
13 - reg : It may contain one or two regions. The 13 - reg : It may contain one or two regions. The first region should contain
14 the address and the length of the shared mes 14 the address and the length of the shared message interrupt register set.
15 The second region should contain the address 15 The second region should contain the address of aliased MSIIR or MSIIR1
16 register for platforms that have such an ali 16 register for platforms that have such an alias, if using MSIIR1, the second
17 region must be added because different MSI g 17 region must be added because different MSI group has different MSIIR1 offset.
18 18
19 - interrupts : each one of the interrupts here 19 - interrupts : each one of the interrupts here is one entry per 32 MSIs,
20 and routed to the host interrupt controller. 20 and routed to the host interrupt controller. the interrupts should
21 be set as edge sensitive. If msi-available- 21 be set as edge sensitive. If msi-available-ranges is present, only
22 the interrupts that correspond to available 22 the interrupts that correspond to available ranges shall be present.
23 23
>> 24 - interrupt-parent: the phandle for the interrupt controller
>> 25 that services interrupts for this device. for 83xx cpu, the interrupts
>> 26 are routed to IPIC, and for 85xx/86xx cpu the interrupts are routed
>> 27 to MPIC.
>> 28
24 Optional properties: 29 Optional properties:
25 - msi-available-ranges: use <start count> styl 30 - msi-available-ranges: use <start count> style section to define which
26 msi interrupt can be used in the 256 msi int 31 msi interrupt can be used in the 256 msi interrupts. This property is
27 optional, without this, all the MSI interrup 32 optional, without this, all the MSI interrupts can be used.
28 Each available range must begin and end on a 33 Each available range must begin and end on a multiple of 32 (i.e.
29 no splitting an individual MSI register or t 34 no splitting an individual MSI register or the associated PIC interrupt).
30 MPIC v4.3 does not support this property bec 35 MPIC v4.3 does not support this property because the 32 interrupts of an
31 individual register are not continuous when 36 individual register are not continuous when using MSIIR1.
32 37
33 - msi-address-64: 64-bit PCI address of the MS 38 - msi-address-64: 64-bit PCI address of the MSIIR register. The MSIIR register
34 is used for MSI messaging. The address of M 39 is used for MSI messaging. The address of MSIIR in PCI address space is
35 the MSI message address. 40 the MSI message address.
36 41
37 This property may be used in virtualized env 42 This property may be used in virtualized environments where the hypervisor
38 has created an alternate mapping for the MSI 43 has created an alternate mapping for the MSIR block. See below for an
39 explanation. 44 explanation.
40 45
41 46
42 Example: 47 Example:
43 msi@41600 { 48 msi@41600 {
44 compatible = "fsl,mpc8610-msi" 49 compatible = "fsl,mpc8610-msi", "fsl,mpic-msi";
45 reg = <0x41600 0x80>; 50 reg = <0x41600 0x80>;
46 msi-available-ranges = <0 0x10 51 msi-available-ranges = <0 0x100>;
47 interrupts = < 52 interrupts = <
48 0xe0 0 53 0xe0 0
49 0xe1 0 54 0xe1 0
50 0xe2 0 55 0xe2 0
51 0xe3 0 56 0xe3 0
52 0xe4 0 57 0xe4 0
53 0xe5 0 58 0xe5 0
54 0xe6 0 59 0xe6 0
55 0xe7 0>; 60 0xe7 0>;
56 interrupt-parent = <&mpic>; 61 interrupt-parent = <&mpic>;
57 }; 62 };
58 63
59 msi@41600 { 64 msi@41600 {
60 compatible = "fsl,mpic-msi-v4. 65 compatible = "fsl,mpic-msi-v4.3";
61 reg = <0x41600 0x200 0x44148 4 66 reg = <0x41600 0x200 0x44148 4>;
62 interrupts = < 67 interrupts = <
63 0xe0 0 0 0 68 0xe0 0 0 0
64 0xe1 0 0 0 69 0xe1 0 0 0
65 0xe2 0 0 0 70 0xe2 0 0 0
66 0xe3 0 0 0 71 0xe3 0 0 0
67 0xe4 0 0 0 72 0xe4 0 0 0
68 0xe5 0 0 0 73 0xe5 0 0 0
69 0xe6 0 0 0 74 0xe6 0 0 0
70 0xe7 0 0 0 75 0xe7 0 0 0
71 0x100 0 0 0 76 0x100 0 0 0
72 0x101 0 0 0 77 0x101 0 0 0
73 0x102 0 0 0 78 0x102 0 0 0
74 0x103 0 0 0 79 0x103 0 0 0
75 0x104 0 0 0 80 0x104 0 0 0
76 0x105 0 0 0 81 0x105 0 0 0
77 0x106 0 0 0 82 0x106 0 0 0
78 0x107 0 0 0>; 83 0x107 0 0 0>;
79 }; 84 };
80 85
81 The Freescale hypervisor and msi-address-64 86 The Freescale hypervisor and msi-address-64
82 ------------------------------------------- 87 -------------------------------------------
83 Normally, PCI devices have access to all of CC 88 Normally, PCI devices have access to all of CCSR via an ATMU mapping. The
84 Freescale MSI driver calculates the address of 89 Freescale MSI driver calculates the address of MSIIR (in the MSI register
85 block) and sets that address as the MSI messag 90 block) and sets that address as the MSI message address.
86 91
87 In a virtualized environment, the hypervisor m 92 In a virtualized environment, the hypervisor may need to create an IOMMU
88 mapping for MSIIR. The Freescale ePAPR hyperv 93 mapping for MSIIR. The Freescale ePAPR hypervisor has this requirement
89 because of hardware limitations of the Periphe 94 because of hardware limitations of the Peripheral Access Management Unit
90 (PAMU), which is currently the only IOMMU that 95 (PAMU), which is currently the only IOMMU that the hypervisor supports.
91 The ATMU is programmed with the guest physical 96 The ATMU is programmed with the guest physical address, and the PAMU
92 intercepts transactions and reroutes them to t 97 intercepts transactions and reroutes them to the true physical address.
93 98
94 In the PAMU, each PCI controller is given only 99 In the PAMU, each PCI controller is given only one primary window. The
95 PAMU restricts DMA operations so that they can 100 PAMU restricts DMA operations so that they can only occur within a window.
96 Because PCI devices must be able to DMA to mem 101 Because PCI devices must be able to DMA to memory, the primary window must
97 be used to cover all of the guest's memory spa 102 be used to cover all of the guest's memory space.
98 103
99 PAMU primary windows can be divided into 256 s 104 PAMU primary windows can be divided into 256 subwindows, and each
100 subwindow can have its own address mapping ("g 105 subwindow can have its own address mapping ("guest physical" to "true
101 physical"). However, each subwindow has to ha 106 physical"). However, each subwindow has to have the same alignment, which
102 means they cannot be located at just any addre 107 means they cannot be located at just any address. Because of these
103 restrictions, it is usually impossible to crea 108 restrictions, it is usually impossible to create a 4KB subwindow that
104 covers MSIIR where it's normally located. 109 covers MSIIR where it's normally located.
105 110
106 Therefore, the hypervisor has to create a subw 111 Therefore, the hypervisor has to create a subwindow inside the same
107 primary window used for memory, but mapped to 112 primary window used for memory, but mapped to the MSIR block (where MSIIR
108 lives). The first subwindow after the end of 113 lives). The first subwindow after the end of guest memory is used for
109 this. The address specified in the msi-addres 114 this. The address specified in the msi-address-64 property is the PCI
110 address of MSIIR. The hypervisor configures t 115 address of MSIIR. The hypervisor configures the PAMU to map that address to
111 the true physical address of MSIIR. 116 the true physical address of MSIIR.
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