2010/11/16 Pei Lin <telent997@xxxxxxxxx>: > 2010/11/10 kapil neeralgi <kapil.neeralgi@xxxxxxxxx>: >> Hi All, >> >> 1. I am looking into ethernet driver (/driver/net/gianfar) . >> Can you tell me which part is top half and bottom half. >> > See the Codes. Codes always show the truth. > >> 2. I want to Place the DMA ring buffers in some seperate IO memory. >> and map that IO memory on to the user space. >> Here the buffers are created using kmalloc , i want to >> create this buffer in my specified memory and map it to user space . >> how and where the change has to be made. >> > One way i could remember is boot kernel with the parameter "memmap", > split your memory for two parts, one for OS used, another for your > driver, so you can specified your memory layout for your driver used. > > http://www.kernel.org/doc/Documentation/kernel-parameters.txt > mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory > Amount of memory to be used when the kernel is not able > to see the whole system memory or for test. > [X86-32] Use together with memmap= to avoid physical > address space collisions. Without memmap= PCI devices > could be placed at addresses belonging to unused RAM. > > mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel > memory. > > memchunk=nn[KMG] > [KNL,SH] Allow user to override the default size for > per-device physically contiguous DMA buffers. > > memmap=exactmap [KNL,X86] Enable setting of an exact > E820 memory map, as specified by the user. > Such memmap=exactmap lines can be constructed based on > BIOS output or other requirements. See the memmap=nn@ss > option description. > > memmap=nn[KMG]@ss[KMG] > [KNL] Force usage of a specific region of memory > Region of memory to be used, from ss to ss+nn. > > memmap=nn[KMG]#ss[KMG] > [KNL,ACPI] Mark specific memory as ACPI data. > Region of memory to be used, from ss to ss+nn. > > memmap=nn[KMG]$ss[KMG] > [KNL,ACPI] Mark specific memory as reserved. > Region of memory to be used, from ss to ss+nn. > Example: Exclude memory from 0x18690000-0x1869ffff > memmap=64K$0x18690000 > or > memmap=0x10000$0x18690000 More elaboration is Greg KH's LDD 3. Recommend you to read it firstly. Chapter 15: Memory Mapping and DMA http://lwn.net/Kernel/LDD3/ >> regards >> kapil >> >> -- >> To unsubscribe from this list: send an email with >> "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx >> Please read the FAQ at http://kernelnewbies.org/FAQ >> >> > > > > -- > Best Regards > Lin > -- Best Regards Lin -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
