Hi Thomas, Here is the context-of-use -- The driver is for Crypto-Hardware-Accelerator(CHA). The user space creates the Descriptors(which has data to be encrypted, type of crypto-algorithm etc) which guides the CHA. A dummy malloc is implemented in kernel driver which uses kmalloc and user can request that memory(to create Descriptors) via IOCTL(CHA_MALLOC). The idea is (most likely) to avoid the "copy from usersapce". Then the descriptor pointer is filled with the data by user-space which passes it back to CHA via second IOCTL(CHA_CRYPT_REQUEST). In kernel the "__vpa" is used on the above descriptor and returned address is written into the hardware-registers of the Crypto-Accelerator. Yes I really wonder why this MACRO was created and why "virt_to_phys" was not used(kernel 2.4.28). Is this MACRO doing something else? #define __vpa(va) \ ((pte_val(*pte_offset(pmd_offset(pgd_offset_k(va),(va)),(va))) & \ PAGE_MASK) + (va & ~PAGE_MASK)) Now back to my original question will this MACRO do the samething in 2.6.10 kernel or I have to rewrite , like use "pte_offset_kernel" instead of "pte_offset". Regards -vikas -------------------------------------------------------- This e-mail, including any attachments, may be confidential, privileged or otherwise legally protected. It is intended only for the addressee. If you received this e-mail in error or from someone who was not authorized to send it to you, do not disseminate, copy or otherwise use this e-mail or its attachments. Please notify the sender immediately by reply e-mail and delete the e-mail from your system. -----Original Message----- From: kernelnewbies-bounce@xxxxxxxxxxxx [mailto:kernelnewbies-bounce@xxxxxxxxxxxx] On Behalf Of Thomas Petazzoni Sent: Tuesday, July 26, 2005 4:29 AM To: kernelnewbies@xxxxxxxxxxxx Subject: Re: porting a mm specific macro from 2.4 to 2.6 Hi, Vikas Aggarwal wrote: > #define __vpa(va) > ((pte_val(*pte_offset(pmd_offset(pgd_offset_k(va),(va)),(va))) & > PAGE_MASK) + (va & ~PAGE_MASK)) What is supposed to do this macro ? As far as I understand it, it's supposed to convert a virtual address into a physical one by traveling through the page tables. Is that it ? If yes, then the virt_to_phys() macro already does the job, but only for kernel virtual addresses (I think, I only had a quick look at the code). Directly translating user virtual addresses to physical addresses is, I think, a bad idea, because user stuff might be swapped. Then, can you give more details about the context of use ? (The code of the function is which it is used for example). Sincerly, Thomas -- Thomas Petazzoni thomas.petazzoni@xxxxxxxx -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/ -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
