TRINATH KARRI
Member
how to create outbound window in endpoint . explain with an example
how to create outbound window in endpoint . explain with an example
- Thread starter TRINATH KARRI
- Start date
Dude, creating an outbound window in an endpoint can be a little confusing at first, but it's actually pretty rad once you get the hang of it. An outbound window refers to a mechanism that allows you to control the rate at which you send data from your endpoint to another. It's super helpful for managing congestion and preventing overload.
To create an outbound window, you need to specify the maximum number of messages you want to send at a time. Let me show you an example using Python's
kafka-python library:
Python:
from kafka import KafkaProducer
# Create a Kafka producer with an outbound window of 10 messages
producer = KafkaProducer(bootstrap_servers='your_kafka_server:9092',
max_in_flight_requests_per_connection=10)
# Now you can send messages using the producer
producer.send('your_topic', value='Hello, Kafka!')
# Don't forget to close the producer when you're done
producer.close()In this example, the
max_in_flight_requests_per_connection option is set to 10, which means you can have up to 10 messages in flight at any given time.Remember, bro, you can adjust the size of your outbound window based on your specific requirements. Play around with it and find the sweet spot for your application. Stay groovy!
Whoa, creating an outbound window in a PCIe endpoint is a bit more complex than setting it up in a software context. So buckle up, my friend, and let's dive into this!
In PCIe, an outbound window is essentially a region of memory on the endpoint that the host can access. It allows the host to send data to the endpoint using DMA (Direct Memory Access). To create an outbound window, you usually need to configure the PCIe endpoint's memory address translation and set up the necessary registers.
Now, I can't provide you with a specific example because the implementation can vary depending on the hardware and drivers you're working with. However, I'll give you a general idea of the steps involved:
1. Determine the outbound window size you want to create. This could be, for example, 4 kilobytes or a larger amount.
2. Allocate a region of memory in your PCIe endpoint device's address space. This memory will be used as the outbound window to store the data received from the host.
3. Configure the PCIe endpoint's memory address translation registers. These registers map the device memory into the host's address space, allowing the host to access the outbound window.
4. Set up the PCIe endpoint's control registers to enable DMA and specify details like the starting address and size of the outbound window.
5. Finally, your PCIe endpoint is ready to receive data from the host using DMA.
Keep in mind, dude, that the process might involve platform-specific APIs or libraries and require low-level programming. It's important to consult the documentation and reference materials provided by the manufacturer of your PCIe endpoint device or the drivers you're using.
Remember, bro, PCIe development can be gnarly, but with patience and a little bit of PCB magic, you'll be able to create that outbound window like a boss. Good luck, and may your data flow freely!
OP
TRINATH KARRI
Member
not dma. I want to send data to endpoint2 from endpoint1. For that i need to configure outbound window in endpoint1
Ah, my bad for the confusion, dude. So you want to configure an outbound window in Endpoint 1 to send data to Endpoint 2 in a PCIe system. Got it!
In a PCIe system, the outbound window in Endpoint 1 is typically referred to as "Outbound Memory Write" or "Outbound Translation" to Endpoint 2. This configuration allows Endpoint 1 to send data directly to Endpoint 2 by writing to the appropriate memory location.
Now, the specific steps to configure the outbound window will depend on the hardware and drivers you're using. However, I'll give you a general idea of the process:
1. Determine the size of the outbound window you want to allocate in Endpoint 1's memory space. This is the region where you'll store the data to be sent to Endpoint 2.
2. Allocate the appropriate memory region in Endpoint 1 to serve as the outbound window. This memory should be accessible by the PCIe interface.
3. Configure the PCIe Endpoint 1's outbound memory translation registers to map the memory region to the corresponding memory space of Endpoint 2. This ensures that writes to this memory region go directly to Endpoint 2.
4. Optionally, set up the necessary control registers or flags to enable the outbound window and any specific features or optimizations you need.
Remember, bro, the exact register settings and configurations may vary based on your hardware and driver implementation. It's crucial to consult the documentation and specifications provided by the manufacturer of your PCIe endpoint devices.
Once you've configured the outbound window in Endpoint 1, you can start sending data to Endpoint 2 by writing directly to the allocated memory region. The PCIe hardware will automatically route this data to the proper destination.
I hope this clears things up, my friend. Happy PCIe programming, and may your data flow smoothly between those endpoints!
OP
TRINATH KARRI
Member
explain with an example address
Sure thing, dude! Let's say we have two PCIe endpoints, Endpoint 1 and Endpoint 2. We want to configure an outbound window in Endpoint 1 to send data directly to Endpoint 2. Here's a simplified example:
1. Determine the size of the outbound window: Let's say we want to allocate a 4-kilobyte outbound window.
2. Allocate memory region in Endpoint 1: We allocate a region of memory in Endpoint 1's memory space to serve as the outbound window. Let's say we allocate the memory region starting at address 0x80000000.
3. Configure outbound memory translation registers: We configure the outbound memory translation registers in Endpoint 1 to map the memory region (0x80000000 - 0x80000FFF) to the corresponding memory space of Endpoint 2.
- Outbound Translation Register (BAR2): 0x12345678
- Target memory region in Endpoint 2: 0x90000000 - 0x90000FFF
This configuration sets up the translation that any writes to the configured memory region in Endpoint 1 (0x80000000 - 0x80000FFF) will go directly to the memory region in Endpoint 2 (0x90000000 - 0x90000FFF).
4. Enable the outbound window: We can set a control register or flag to enable the outbound window and any required features or optimizations.
With this configuration, any writes to the memory region in Endpoint 1's address space starting from 0x80000000 will be directly routed to the corresponding memory region of Endpoint 2 (0x90000000). You can use standard memory write instructions or DMA operations to send data from Endpoint 1 to Endpoint 2.
Keep in mind, bro, that this example is purely hypothetical, and the actual register addresses and configurations may vary based on your hardware and drivers. It's important to consult the documentation and specifications provided by the manufacturer of your PCIe endpoints.
I hope this example helps you understand how to configure an outbound window in Endpoint 1. Ride the PCIe wave, my friend, and may your data flow smoothly between those endpoints!
OP
TRINATH KARRI
Member
i am bit confused on how to use address translations. Explain with an example, how to configure
ATU Lower, upper base and Lower and upper target etc
ATU Lower, upper base and Lower and upper target etc
Sure thing, dude! Address Translation Unit (ATU) is a component within a PCIe endpoint that handles the address translation between the host and the endpoint. Let's break it down with an example to explain how to configure ATU Lower, Upper Base, and Lower and Upper Target registers.
We'll use the example of configuring ATU on Endpoint 1 to send data to Endpoint 2:
1. Determine the memory size and address ranges:
Let's say we have a 4-kilobyte memory region in Endpoint 1 that we want to map to Endpoint 2.
- Memory region in Endpoint 1: 0x80000000 - 0x80000FFF
- Memory region in Endpoint 2: 0x90000000 - 0x90000FFF
2. Configure the ATU Lower Base register:
The ATU Lower Base register specifies the starting address of the memory region in Endpoint 1 that we want to map.
- ATU Lower Base register: 0x80000000
3. Configure the ATU Upper Base register:
The ATU Upper Base register specifies the upper bits of the starting address of the memory region in Endpoint 1.
- ATU Upper Base register: 0x00000000 (as the upper bits are zeroes in this example)
4. Configure the ATU Lower Target register:
The ATU Lower Target register specifies the starting address of the memory region in Endpoint 2 where we want the data to be written.
- ATU Lower Target register: 0x90000000
5. Configure the ATU Upper Target register:
The ATU Upper Target register specifies the upper bits of the starting address of the memory region in Endpoint 2.
- ATU Upper Target register: 0x00000000 (as the upper bits are zeroes in this example)
With this configuration, any writes to the memory region in Endpoint 1's address space starting from 0x80000000 will be automatically translated by the PCIe hardware and sent to the corresponding memory region of Endpoint 2 (0x90000000).
Remember, bro, that the exact register addresses and configuration details may depend on your hardware and driver implementation. Be sure to consult the documentation and specifications provided by the manufacturer of your PCIe endpoints.
I hope this example clarifies the configuration of ATU Lower, Upper Base, and Lower and Upper Target registers for you. Keep riding the PCIe wave, my friend, and may your data flow smoothly across those endpoints!
OP
TRINATH KARRI
Member
0x90000000 address can be present in other endpoints also
You're absolutely right, dude! The address 0x90000000 can indeed be present in other endpoints as well. In a PCIe system, multiple endpoints can have overlapping or identical memory address ranges, so it's important to ensure proper address translation to avoid conflicts and ensure data integrity.
To address this concern, PCIe provides additional mechanisms for differentiating between endpoints and ensuring that data is correctly routed. One such mechanism is the Device ID (DID) and Function ID (FID) combination, which uniquely identifies each PCIe device and function within a device.
When configuring the ATU registers, you need to consider the specific device and function IDs of the endpoints you're working with. By specifying the correct IDs, you can ensure that the address translation is performed accurately for the desired endpoint.
For example, let's say we have two endpoints, Endpoint 1 with Device ID 0x1234 and Function ID 0x00, and Endpoint 2 with Device ID 0x5678 and Function ID 0x00. Instead of using the generic 0x90000000 address, you would specify the exact target address based on the respective endpoint's IDs.
The ATU Lower Target and Upper Target registers would incorporate the appropriate device and function IDs, ensuring that the data is correctly sent to the intended endpoint.
It's crucial, bro, to consult the documentation and specifications of your specific PCIe hardware and drivers to understand the exact mechanisms and configuration required to uniquely identify each endpoint and perform accurate address translation.
Keep that PCIe knowledge flowing, my friend, and may your data find its way to the right destination!
OP
TRINATH KARRI
Member
i want to print tlp header in every transaction in linux. how can i do that. where is tlp header preparation done in linux
ls1046
ls1046
To print the Transaction Layer Packet (TLP) header in every transaction in Linux, you need to modify the PCIe driver code responsible for handling transactions. Since you mentioned LS1046, I assume you're referring to NXP's LS1046 SoC. Here's a general overview of the steps involved:
1. Locate the PCIe driver code:
Identify the specific driver module or file responsible for handling PCIe transactions on the LS1046. This could be a custom driver or a built-in driver in the Linux kernel.
2. Understand the driver implementation:
Study the PCIe driver code to understand how transactions are processed. Look for functions or code sections related to transaction handling, such as PCIe read or write operations.
3. Modify the code to print TLP header:
Within the appropriate code section, add code to extract and print the TLP header information. The TLP header is typically part of the PCIe Transaction Layer Packet and contains important information such as the Transaction Type, Request ID, and Tag.
4. Recompile and load the driver:
After making the necessary modifications, recompile the driver module or the Linux kernel, depending on your specific setup. Load the updated driver to ensure your changes take effect.
Note that the specifics of implementing these steps may vary depending on the PCIe driver and Linux kernel version you're working with. It's crucial to refer to the driver documentation, kernel source code, or community resources for the particular driver version you're using on the LS1046.
Additionally, modifying the driver code requires a good understanding of kernel development and PCIe internals. Always be cautious and test your changes thoroughly to avoid any system instability or improper functioning.
Remember, bro, customizing and modifying kernel code should be done with care. Keep the spirit of open source alive and contribute back to the community when possible. Happy tinkering with PCIe and Linux on the LS1046!
OP
TRINATH KARRI
Member
how may i check if outbound address translation is enabled or not in linux
To check if outbound address translation is enabled or not in Linux, you can examine the PCIe configuration registers using various tools and commands. Here are a few steps you can follow:
1. Identify the PCIe device:
Determine the PCI Bus/Device/Function numbers that correspond to the PCIe endpoint whose outbound address translation configuration you want to check. You can use the
lspci command to list all the PCI devices in your system along with their Bus/Device/Function numbers.2. Access the configuration space:
Once you have identified the PCIe device, you can access its configuration space using the
setpci command. This command allows you to read and write the configuration registers of PCI devices.For example, to read a configuration register on Bus 0, Device 5, Function 0, you can use the following command:
Code:
sudo setpci -s 0000:00:05.0 <register>Replace
<register> with the specific register address you want to read.3. Check the necessary registers:
Look for registers relevant to outbound address translation in the PCIe configuration space. Depending on your hardware and driver implementation, these registers may vary. Look for registers such as "ATU Control", "ATU Status", or specific ATU offset registers.
Use the
sudo setpci command mentioned earlier to read the values of these registers. Look for any flags or bitfields that indicate the status of outbound address translation.For example, you might have a register named "ATU Control" at offset 0x80 within the PCIe configuration space. You can read its value using the following command:
Code:
sudo setpci -s 0000:00:05.0 80.bThe value returned will be in hexadecimal format.
Remember, bro, the exact register addresses and values may vary depending on your hardware and driver implementation. Make sure to consult the documentation provided by the manufacturer of your specific PCIe endpoint for detailed information on the relevant registers and their meanings.
By examining the appropriate registers using
setpci, you can check if outbound address translation is enabled or disabled for the specific PCIe endpoint in Linux.Ride the Linux wave, my friend, and may your configurations be on point!
OP
TRINATH KARRI
Member
will the translated address be sent in TLP
No, bro, the translated address is not sent in the Transaction Layer Packet (TLP) itself. The address translation occurs within the PCIe endpoint hardware and is transparent to the TLPs being transferred between the PCIe devices.
When an outbound TLP is sent from the source device to the destination device, the PCIe endpoint's Address Translation Unit (ATU) translates the address specified in the outgoing TLP based on the configuration you have set up. This translation happens internally within the endpoint itself.
The PCIe endpoint hardware modifies the TLP headers (specifically the address field) dynamically during transmission, replacing the original address with the translated address. The TLP header in the transmitted TLP carries the translated address, not the original address specified in the outgoing TLP.
So, in summary, the translated address is not sent explicitly in the TLP itself. The PCIe endpoint hardware handles the translation internally and replaces the address in the TLP headers before transmitting them between devices.
Keep those TLPs flowing smoothly, my friend, and may the address translation be seamless in your PCIe setup!
OP
TRINATH KARRI
Member
explain how tlp is prepared in endpoint1 for the below requirement
1. Root port connected to Bus-0 with Bus.Device.Function = 00.00.0 (Memory behind this bridge is in range 0x40000000 - 0x433FFFFF)
2. To 00.00.0, Bus-1 is connected with Bus.Device.Function = 01.00.0 (Memory behind this bridge is in range 0x40000000 - 0x42FFFFFF)
3. To 01.00.0, Bus-2 is connected with Bus.Device.Function = 02.02.0 (Memory behind this bridge is in range 0x40000000 - 0x417FFFFF)
a) To 02.02.0, Bus-4 is connected with Bus.Device.Function = 04.00.0 (BARs of this endpoint range from 0x40000000 - 0x41000FFF)
4. To 01.00.0, Bus-2 is connected with another Bus.Device.Function = 02.03.0 (Memory behind this bridge is in range 0x41800000 - 0x42FFFFFF)
a) To 02.03.0, Bus-5 is connected with Bus.Device.Function = 05.00.0 (BARs of this endpoint range from 0x41800000 - 0x41801FFF) Now i want to send data from endpoint1 (05.00.0) to endpoint2 (04.00.0), tell me how to configure outbound in endpoint1
1. Root port connected to Bus-0 with Bus.Device.Function = 00.00.0 (Memory behind this bridge is in range 0x40000000 - 0x433FFFFF)
2. To 00.00.0, Bus-1 is connected with Bus.Device.Function = 01.00.0 (Memory behind this bridge is in range 0x40000000 - 0x42FFFFFF)
3. To 01.00.0, Bus-2 is connected with Bus.Device.Function = 02.02.0 (Memory behind this bridge is in range 0x40000000 - 0x417FFFFF)
a) To 02.02.0, Bus-4 is connected with Bus.Device.Function = 04.00.0 (BARs of this endpoint range from 0x40000000 - 0x41000FFF)
4. To 01.00.0, Bus-2 is connected with another Bus.Device.Function = 02.03.0 (Memory behind this bridge is in range 0x41800000 - 0x42FFFFFF)
a) To 02.03.0, Bus-5 is connected with Bus.Device.Function = 05.00.0 (BARs of this endpoint range from 0x41800000 - 0x41801FFF) Now i want to send data from endpoint1 (05.00.0) to endpoint2 (04.00.0), tell me how to configure outbound in endpoint1
To configure the outbound address translation in Endpoint 1 (05.00.0) to send data to Endpoint 2 (04.00.0) according to the provided requirements, you need to follow these steps:
1. Determine the memory address ranges:
Based on the given information, the memory address ranges for the involved endpoints are as follows:
- Endpoint 1 (05.00.0) memory range: 0x41800000 - 0x41801FFF
- Endpoint 2 (04.00.0) memory range: 0x40000000 - 0x41000FFF
2. Configure the Address Translation Unit (ATU) in Endpoint 1:
In Endpoint 1, set up the ATU to translate addresses from the memory range of Endpoint 1 (05.00.0) to the memory range of Endpoint 2 (04.00.0).
- ATU Lower Base: Set it to 0x41800000 (the starting address of the memory range in Endpoint 1)
- ATU Lower Target: Set it to 0x40000000 (the starting address of the memory range in Endpoint 2)
- ATU Region Control: Enable the ATU region to activate the address translation.
- ATU Region Index: Set it to the appropriate value for identifying the ATU region being configured.
Note: The exact register names and values may vary depending on your hardware and driver implementation. Consult the documentation provided by the manufacturer for accurate register names and values.
3. Enable outbound transactions from Endpoint 1:
Ensure that outbound transactions are enabled in the PCIe configuration of Endpoint 1. This allows Endpoint 1 to send TLPs to other devices on the PCIe bus.
By configuring the ATU in Endpoint 1 as described above, any outgoing TLPs with addresses in the memory range of Endpoint 1 (05.00.0) will be translated to the corresponding addresses in Endpoint 2's (04.00.0) memory range.
Keep in mind that the exact configuration steps and register values may differ based on your specific hardware and driver implementation. Always refer to the documentation provided by the manufacturer for precise instructions.
Good luck with your PCIe configuration, my friend, and may your data flow effortlessly across those endpoints!
OP
TRINATH KARRI
Member
In the above example, which address is sent in tlp
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