floating point problem
In Linux PPC, the MSR[FP] bit (that is floating point available bit) is off (atleast for non-SMP). Due to this, whenever some floating point instruction is executed in 'user mode', it leads to a exception 'FPUnavailable'. The exception handler for this exception apart from setting the MSR[FP] bit, also sets the MSR[FE0] and MSR[FE1] bits. These bits basically enables the floating point exceptions so that if there are some floating point exception conditions encountered while exeuting a floating point instruction, an appropriate exception is raised. But whenever some floating point instruction is executed in 'kernel mode', 'FPUnavailabe' exception handler code does not set the 'MSR[FE0] and MSR[FE1]' bits. The result is that when we execute a piece of code that executes floating point instructions with some large values, we get 'floating point exceptions for overflow etc' but we get some rounded off values when we execute the same piece of code in a kernel module. We made a modification in the head.S file and commented out the setting of 'MSR[FE0] and MSR[FE1]' bits in the 'FPUnavailable' exception handler for user mode. Due to this we are getting correct results i.e. rounded off values. Problem is that we want to get the good results without changing the kernel. Either by having the user mode application to interact with some special module which can set the MSR[FP] bit before we execute the floating point instruction or by some other trick.Is there any solution apart from changing the kernel? thanks, Daljeet. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
floating point problem
In Linux PPC, the MSR[FP] bit (that is floating point available bit) is off (atleast for non-SMP). Due to this, whenever some floating point instruction is executed in 'user mode', it leads to a exception 'FPUnavailable'. The exception handler for this exception apart from setting the MSR[FP] bit, also sets the MSR[FE0] and MSR[FE1] bits. These bits basically enables the floating point exceptions so that if there are some floating point exception conditions encountered while exeuting a floating point instruction, an appropriate exception is raised. But whenever some floating point instruction is executed in 'kernel mode', 'FPUnavailabe' exception handler code does not set the 'MSR[FE0] and MSR[FE1]' bits. The result is that when we execute a piece of code that executes floating point instructions with some large values, we get 'floating point exceptions for overflow etc' but we get some rounded off values when we execute the same piece of code in a kernel module. We made a modification in the head.S file and commented out the setting of 'MSR[FE0] and MSR[FE1]' bits in the 'FPUnavailable' exception handler for user mode. Due to this we are getting correct results i.e. rounded off values. Problem is that we want to get the good results without changing the kernel. Either by having the user mode application to interact with some special module which can set the MSR[FP] bit before we execute the floating point instruction or by some other trick.Is there any solution apart from changing the kernel? thanks, Daljeet. - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
virt_to_bus and virt_to_phys on Apple G4 target
I am running linux 2.4.2 on Apple G4 machine. I think the 'PCI bus addresses' and 'physical addresses' are same on this architecture. I expected the two be different but according to asm/io.h 'virt_to_bus(addr) = virt_to_phys(addr) + PCI_DRAM_OFFSET'. I printed the value of 'PCI_DRAM_OFFSET' and that come out to be zero. Is this correct? If I somehow get the physical address of a user space buffer in a module and take this as a PCI bus address, will I be able to do DMA properly? thanks, Daljeet. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: mmap
I use the 'map_user_kiobuf' and 'lock_kiovec' kernel routines in a module for 'user space memory'. After that if I pass the '(iobuf->maplist[0])-mem_map) << PAGE_SHIFT)' to the hardware for DMA operations and it works fine for Intel platforms. Now how can I use the 'iobuf' struct obtained after lock_kiovec operation to get a PCI bus address that I can pass to hardware for DMA operations on my Apple machine.? thanks, Daljeet. |+---> || Gerd Knorr | ||| || | || 05/15/01 | || 01:03 PM | || Please | || respond to | || Gerd Knorr | || | |+---> >---| | | | To: [EMAIL PROTECTED]| | cc: (bcc: Daljeet Maini/India/IBM) | | Subject: Re: mmap | >---| [EMAIL PROTECTED] wrote: > I am doing the following: > > malloc some memory is user space > pass its pointer to some kernel module > in the kernel module...do a pci_alloc_consistent so that i get a memory > region for PCI DMA operations Wrong approach, you can use kiobufs if you want DMA to the malloc()ed userspace memory: * lock down the user memory using map_user_kiobuf() + lock_kiovec() (see linux/iobuf.h). * translate the iobuf->maplist into a scatterlist [1] * feed pci_map_sg() with the scatterlist to get DMA addresses. you can pass to the hardware. And the reverse to free everything when you are done of course. Gerd [1] IMHO it would be more useful if iobufs would use a scatterlist instead of an struct page* array. -- Gerd Knorr <[EMAIL PROTECTED]> -- SuSE Labs, Außenstelle Berlin - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: mmap
I use the 'map_user_kiobuf' and 'lock_kiovec' kernel routines in a module for 'user space memory'. After that if I pass the '(iobuf-maplist[0])-mem_map) PAGE_SHIFT)' to the hardware for DMA operations and it works fine for Intel platforms. Now how can I use the 'iobuf' struct obtained after lock_kiovec operation to get a PCI bus address that I can pass to hardware for DMA operations on my Apple machine.? thanks, Daljeet. |+--- || Gerd Knorr | || kraxel@bytes| || ex.org | || | || 05/15/01 | || 01:03 PM | || Please | || respond to | || Gerd Knorr | || | |+--- ---| | | | To: [EMAIL PROTECTED]| | cc: (bcc: Daljeet Maini/India/IBM) | | Subject: Re: mmap | ---| [EMAIL PROTECTED] wrote: I am doing the following: malloc some memory is user space pass its pointer to some kernel module in the kernel module...do a pci_alloc_consistent so that i get a memory region for PCI DMA operations Wrong approach, you can use kiobufs if you want DMA to the malloc()ed userspace memory: * lock down the user memory using map_user_kiobuf() + lock_kiovec() (see linux/iobuf.h). * translate the iobuf-maplist into a scatterlist [1] * feed pci_map_sg() with the scatterlist to get DMA addresses. you can pass to the hardware. And the reverse to free everything when you are done of course. Gerd [1] IMHO it would be more useful if iobufs would use a scatterlist instead of an struct page* array. -- Gerd Knorr [EMAIL PROTECTED] -- SuSE Labs, Außenstelle Berlin - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
virt_to_bus and virt_to_phys on Apple G4 target
I am running linux 2.4.2 on Apple G4 machine. I think the 'PCI bus addresses' and 'physical addresses' are same on this architecture. I expected the two be different but according to asm/io.h 'virt_to_bus(addr) = virt_to_phys(addr) + PCI_DRAM_OFFSET'. I printed the value of 'PCI_DRAM_OFFSET' and that come out to be zero. Is this correct? If I somehow get the physical address of a user space buffer in a module and take this as a PCI bus address, will I be able to do DMA properly? thanks, Daljeet. - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
interrupt problem....
I am experiencing a strange problem. I am doing a continuous DMA for long hours using a card on my system. In my code I enable interrupts and clear the interrupts in the interrupt handler which is called on completion of every DMA cycle. Now, the program works fine for say 16-20 hours but I think when the debug files'(where i put some debug information for each DMA cycle + system log files etc) size becomes too large, card stops generating interrupts. 1. There is a bit in card that tells that DMA is complete 2. There is a bit in card that tells card to generate interrupt when DMA is complete 3. If we clear the above two bits, the interrupt handling is complete Now, DMA is getting complete as the bits specified in the point 1 and 2 are getting set. I have added a 'printk' in the interrupt handler to see whether the card is generating interrupts or not. Card stops generating interrupt. Even if I delete all the debug files and start my program again, same thing happens. After I reboot the system and run my program, the card starts working properly with same code. I have noted following things: a) If I delete all the system log files and restrict the size of my debug file, the code runs fine for more than 48 hours. Basically I stop the program after having a 48 hour run. b) If the system log files has large size and I do not delete them before starting my program, the card stops generating interrupts after 16-20 hours of run. Any pointers to the problem.. Regards, Daljeet. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
interrupt problem....
I am experiencing a strange problem. I am doing a continuous DMA for long hours using a card on my system. In my code I enable interrupts and clear the interrupts in the interrupt handler which is called on completion of every DMA cycle. Now, the program works fine for say 16-20 hours but I think when the debug files'(where i put some debug information for each DMA cycle + system log files etc) size becomes too large, card stops generating interrupts. 1. There is a bit in card that tells that DMA is complete 2. There is a bit in card that tells card to generate interrupt when DMA is complete 3. If we clear the above two bits, the interrupt handling is complete Now, DMA is getting complete as the bits specified in the point 1 and 2 are getting set. I have added a 'printk' in the interrupt handler to see whether the card is generating interrupts or not. Card stops generating interrupt. Even if I delete all the debug files and start my program again, same thing happens. After I reboot the system and run my program, the card starts working properly with same code. I have noted following things: a) If I delete all the system log files and restrict the size of my debug file, the code runs fine for more than 48 hours. Basically I stop the program after having a 48 hour run. b) If the system log files has large size and I do not delete them before starting my program, the card stops generating interrupts after 16-20 hours of run. Any pointers to the problem.. Regards, Daljeet. - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
harddisk support
Hi, I do not know whether I should ask this question on this mailing list, but it definitely has to do either with the kernel confiuration or kernel support. In the '/dev' tree, the device file entries for SCSI harddisks ranges from '/dev/sda' to '/dev/sdp'. If I attach 17 scsi harddisks to a system, the 17th harddisk is shown as '/dev/sdq' in '/proc/partitions' but there is no entry in the '/dev' tree. If I try to access '/dev/sdq' either through fdisk or through any other simple C programs, it gives error saying, can not open device '/dev/sdq'. How can I access more than 16 harddisks? Regards, Daljeet. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
harddisk support
Hi, I do not know whether I should ask this question on this mailing list, but it definitely has to do either with the kernel confiuration or kernel support. In the '/dev' tree, the device file entries for SCSI harddisks ranges from '/dev/sda' to '/dev/sdp'. If I attach 17 scsi harddisks to a system, the 17th harddisk is shown as '/dev/sdq' in '/proc/partitions' but there is no entry in the '/dev' tree. If I try to access '/dev/sdq' either through fdisk or through any other simple C programs, it gives error saying, can not open device '/dev/sdq'. How can I access more than 16 harddisks? Regards, Daljeet. - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: pte_page
I am doing a DMA from a card to system memory. The system memory "physical address" is '0x104000'. I am doing this on x86 with kernel version 2.4.2. Can this address be the address of a user space buffer? Regards, Daljeet. |+---> || Ingo Molnar | || <[EMAIL PROTECTED]| || u> | || | || 05/30/01 | || 11:09 PM | || Please | || respond to | || mingo| || | |+---> >| || | To: Pete Wyckoff <[EMAIL PROTECTED]>| | cc: Daljeet Maini/India/IBM@IBMIN, | | [EMAIL PROTECTED] | | Subject: Re: pte_page| >| On Wed, 30 May 2001, Pete Wyckoff wrote: > > __pa(page_address(pte_page(pte))) is the address you want. [or > > pte_val(*pte) & (PAGE_SIZE-1) on x86 but this is platform-dependent.] > > Does this work on x86 non-kmapped highmem user pages too? (i.e. is > page->virtual valid for every potential user page.) you are right, the highmem-compatible solution is to use page-mem_map as the physical page index. Ingo - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: pte_page
I am doing a DMA from a card to system memory. The system memory physical address is '0x104000'. I am doing this on x86 with kernel version 2.4.2. Can this address be the address of a user space buffer? Regards, Daljeet. |+--- || Ingo Molnar | || [EMAIL PROTECTED]| || u | || | || 05/30/01 | || 11:09 PM | || Please | || respond to | || mingo| || | |+--- | || | To: Pete Wyckoff [EMAIL PROTECTED]| | cc: Daljeet Maini/India/IBM@IBMIN, | | [EMAIL PROTECTED] | | Subject: Re: pte_page| | On Wed, 30 May 2001, Pete Wyckoff wrote: __pa(page_address(pte_page(pte))) is the address you want. [or pte_val(*pte) (PAGE_SIZE-1) on x86 but this is platform-dependent.] Does this work on x86 non-kmapped highmem user pages too? (i.e. is page-virtual valid for every potential user page.) you are right, the highmem-compatible solution is to use page-mem_map as the physical page index. Ingo - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
pte_page
I use the 'pgt_offset', 'pmd_offset', 'pte_offset' and 'pte_page' inside a module to get the physical address of a user space virtual address. The physical address returned by 'pte_page' is not page aligned whereas the virtual address was page aligned. Can somebody tell me the reason? Also, can i use these functions to get the physical address of a kernel virtual address using init_mm? regards, Daljeet. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
pte_page
I use the 'pgt_offset', 'pmd_offset', 'pte_offset' and 'pte_page' inside a module to get the physical address of a user space virtual address. The physical address returned by 'pte_page' is not page aligned whereas the virtual address was page aligned. Can somebody tell me the reason? Also, can i use these functions to get the physical address of a kernel virtual address using init_mm? regards, Daljeet. - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
query regarding 'map_user_kiobuf'
I am using linux kernel version 2.4.2 on Intel PC. I have been trying my luck for over a week regarding usage of 'map_user_kiobuf' for doing a DMA into a memory area that belongs to user space. Actually my requirement is that I want to do DMA into a user space memory area. What I have done through suggestions is that allocate memory in user space. I pass user space buffer address to a kernel module. Inside the kernel module, I use 'map_user_kiobuf' passing user space buffer address to it. After using the 'map_user_kiobuf', I observed the followiing: 1. 'kiobuf->maplist[0]->virtual' contains a different virtual address than the user space buffer address 2. But these two addresses are mapped as when i write something using the address 'kiobuf->maplist[0]->virtual' inside the kernel, I see the same data in the user space buffer in my application. 3. I use the 'virt_to_phys' operation to the virtual address 'kiobuf->maplist[0]->virtual' to get the physical address. 4. I use this physical address for DMA operations. Now, using this information I do a DMA from card to system memory. What I have noticed is that DMA happens somewhere else in the system memory. I am not able to execute most of the commands (ls, chmod, cat, clear etc) after my user program exits. Am I doing the steps 3 and 4 above right? Regards, Daljeet. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
query regarding 'map_user_kiobuf'
I am using linux kernel version 2.4.2 on Intel PC. I have been trying my luck for over a week regarding usage of 'map_user_kiobuf' for doing a DMA into a memory area that belongs to user space. Actually my requirement is that I want to do DMA into a user space memory area. What I have done through suggestions is that allocate memory in user space. I pass user space buffer address to a kernel module. Inside the kernel module, I use 'map_user_kiobuf' passing user space buffer address to it. After using the 'map_user_kiobuf', I observed the followiing: 1. 'kiobuf-maplist[0]-virtual' contains a different virtual address than the user space buffer address 2. But these two addresses are mapped as when i write something using the address 'kiobuf-maplist[0]-virtual' inside the kernel, I see the same data in the user space buffer in my application. 3. I use the 'virt_to_phys' operation to the virtual address 'kiobuf-maplist[0]-virtual' to get the physical address. 4. I use this physical address for DMA operations. Now, using this information I do a DMA from card to system memory. What I have noticed is that DMA happens somewhere else in the system memory. I am not able to execute most of the commands (ls, chmod, cat, clear etc) after my user program exits. Am I doing the steps 3 and 4 above right? Regards, Daljeet. - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
bindprocessor
How can I bind a user space process to a particular processor in a SMP environment? thanks, Daljeet Maini - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
bindprocessor
How can I bind a user space process to a particular processor in a SMP environment? thanks, Daljeet Maini - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
CONFIG_APUS
When is the 'CONFIG_APUS' flag used ? Daljeet Maini IBM Global Services Ltd. - Bangalore Ph. No. - 5267117 Extn 2954 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
CONFIG_APUS
When is the 'CONFIG_APUS' flag used ? Daljeet Maini IBM Global Services Ltd. - Bangalore Ph. No. - 5267117 Extn 2954 - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: mmap
When I malloc the memory in user space, the memory may be discontinuous for large chunks of memory say 16k or 32k. Does the 'kiobuf' interface take care of this or it assumes it to be continuous? regards, Daljeet Maini IBM Global Services Ltd. - Bangalore Ph. No. - 5267117 Extn 2954 |+---> || Gerd Knorr | ||| || | || 05/15/01 | || 01:03 PM | || Please | || respond to | || Gerd Knorr | || | |+---> >| || | To: [EMAIL PROTECTED] | | cc: (bcc: Daljeet Maini/India/IBM) | | Subject: Re: mmap| >| [EMAIL PROTECTED] wrote: > I am doing the following: > > malloc some memory is user space > pass its pointer to some kernel module > in the kernel module...do a pci_alloc_consistent so that i get a memory > region for PCI DMA operations Wrong approach, you can use kiobufs if you want DMA to the malloc()ed userspace memory: * lock down the user memory using map_user_kiobuf() + lock_kiovec() (see linux/iobuf.h). * translate the iobuf->maplist into a scatterlist [1] * feed pci_map_sg() with the scatterlist to get DMA addresses. you can pass to the hardware. And the reverse to free everything when you are done of course. Gerd [1] IMHO it would be more useful if iobufs would use a scatterlist instead of an struct page* array. -- Gerd Knorr <[EMAIL PROTECTED]> -- SuSE Labs, Außenstelle Berlin - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
mmap
I am doing the following: malloc some memory is user space pass its pointer to some kernel module in the kernel module...do a pci_alloc_consistent so that i get a memory region for PCI DMA operations now the problem is that i want to remap the address range pointed by the user space pointer to the memory region allocated by the 'pci_alloc_consistent' inside the module. I think this is possible..need some hints thanks, Daljeet Maini IBM Global Services Ltd. - Bangalore Ph. No. - 5267117 Extn 2954 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
mmap
I am doing the following: malloc some memory is user space pass its pointer to some kernel module in the kernel module...do a pci_alloc_consistent so that i get a memory region for PCI DMA operations now the problem is that i want to remap the address range pointed by the user space pointer to the memory region allocated by the 'pci_alloc_consistent' inside the module. I think this is possible..need some hints thanks, Daljeet Maini IBM Global Services Ltd. - Bangalore Ph. No. - 5267117 Extn 2954 - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: mmap
When I malloc the memory in user space, the memory may be discontinuous for large chunks of memory say 16k or 32k. Does the 'kiobuf' interface take care of this or it assumes it to be continuous? regards, Daljeet Maini IBM Global Services Ltd. - Bangalore Ph. No. - 5267117 Extn 2954 |+--- || Gerd Knorr | || kraxel@bytes| || ex.org | || | || 05/15/01 | || 01:03 PM | || Please | || respond to | || Gerd Knorr | || | |+--- | || | To: [EMAIL PROTECTED] | | cc: (bcc: Daljeet Maini/India/IBM) | | Subject: Re: mmap| | [EMAIL PROTECTED] wrote: I am doing the following: malloc some memory is user space pass its pointer to some kernel module in the kernel module...do a pci_alloc_consistent so that i get a memory region for PCI DMA operations Wrong approach, you can use kiobufs if you want DMA to the malloc()ed userspace memory: * lock down the user memory using map_user_kiobuf() + lock_kiovec() (see linux/iobuf.h). * translate the iobuf-maplist into a scatterlist [1] * feed pci_map_sg() with the scatterlist to get DMA addresses. you can pass to the hardware. And the reverse to free everything when you are done of course. Gerd [1] IMHO it would be more useful if iobufs would use a scatterlist instead of an struct page* array. -- Gerd Knorr [EMAIL PROTECTED] -- SuSE Labs, Außenstelle Berlin - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
dma error
Hi, Was there any change in the PCI initialization code between versions 2.4.0-test8 and 2.4.2.? I am working on a card and for the same register settings of the card, DMA from host memory to card memory is successfull for the 2.4.0-test8 but on 2.4.2 kernel, the data transfer is successfull but data gets corrupted. However the DMA from card memory to system memory is succesull on both the versions of kernel. I am not on mailing list. So reply to my id as listed in CC. Thanks, Daljeet Maini - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
dma error
Hi, Was there any change in the PCI initialization code between versions 2.4.0-test8 and 2.4.2.? I am working on a card and for the same register settings of the card, DMA from host memory to card memory is successfull for the 2.4.0-test8 but on 2.4.2 kernel, the data transfer is successfull but data gets corrupted. However the DMA from card memory to system memory is succesull on both the versions of kernel. I am not on mailing list. So reply to my id as listed in CC. Thanks, Daljeet Maini - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
2.4.0-test8 compilation problem on netfinity
Hi, If I compile the 2.4.0-test8 kernel on uniprocessor intel machine with SMP support, I get no compilation problems. But when I compile on a 'netfinity' machine with 3 intel processors with SMP support, the telnet session in which I do this gets hung during 'make bzImage'. Though the 'bzImage' still gets created but when I try to boot the netfinity with that image, the system crashes and I get the following kernel messages: Calibrating delay loop... 1795 Bogo MIPS Stack at about c1e1bfbc OK. CPU1: Intel Pentium III (Cascades) stepping 04 CPU has booted. Booting processor 2/6 eip 2000 Setting warm reset code and vector 1. 2. 3. asserting INIT. Waiting for send to finish... Deasserting INIT. Waiting for send to finish... +#startup loops: 2 Sending STARTUP #1. After APIC write. Startup point 1. Waiting for send to finish... +Sending STARTUP #2. After apic_write (the above line was the last thing written to the screen, it was then froze at this point for at least 5 min.) Has anybody faced this problem before? If anybody has booted the 2.4.x with SMP support on the netfinity multi-processor machienes, kindly tell me the way. Regards, Daljeet Maini - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
2.4.0-test8 compilation problem on netfinity
Hi, If I compile the 2.4.0-test8 kernel on uniprocessor intel machine with SMP support, I get no compilation problems. But when I compile on a 'netfinity' machine with 3 intel processors with SMP support, the telnet session in which I do this gets hung during 'make bzImage'. Though the 'bzImage' still gets created but when I try to boot the netfinity with that image, the system crashes and I get the following kernel messages: Calibrating delay loop... 1795 Bogo MIPS Stack at about c1e1bfbc OK. CPU1: Intel Pentium III (Cascades) stepping 04 CPU has booted. Booting processor 2/6 eip 2000 Setting warm reset code and vector 1. 2. 3. asserting INIT. Waiting for send to finish... Deasserting INIT. Waiting for send to finish... +#startup loops: 2 Sending STARTUP #1. After APIC write. Startup point 1. Waiting for send to finish... +Sending STARTUP #2. After apic_write (the above line was the last thing written to the screen, it was then froze at this point for at least 5 min.) Has anybody faced this problem before? If anybody has booted the 2.4.x with SMP support on the netfinity multi-processor machienes, kindly tell me the way. Regards, Daljeet Maini - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
system call handling
Hi, By looking into the structure of GDT as used by linux kernel(file include/asm/desc.c, kernel ver 2.4), it appears as if linux kernel does not use the "call gate descriptors" for system call handling. Is this correct? If it is correct then how does the system calls are handled by the kernel (basically how does the control gets transferred to kernel)? Does the CS of linux kernel handles the system calls? what are the advantages of using this scheme? otherwise can anyone give pointers in the kernel source where i can look into? Thanks, daljeet. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
freeing memory
hi,
i am allocating some 1000 bytes of memory as folows
f_malloc()
{
.
for (i=1 to 10)
{
size = 1000;
pAddr[i] = (unsigned long) kmalloc(size, GFP_DMA | GFP_BUFFER);
}
...
}
and freeing the allocated memory as follows
f_free()
{
.
for (i=1 to 10)
{
kfree(pAddr[i]);
}
}
pAddr is defined as 'unsigned long pAddr[10]'
But when f_free executes i ran into problems and computer hangs.
What can be the problem?
regards,
daljeet.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
Please read the FAQ at http://www.tux.org/lkml/
freeing memory
hi,
i am allocating some 1000 bytes of memory as folows
f_malloc()
{
.
for (i=1 to 10)
{
size = 1000;
pAddr[i] = (unsigned long) kmalloc(size, GFP_DMA | GFP_BUFFER);
}
...
}
and freeing the allocated memory as follows
f_free()
{
.
for (i=1 to 10)
{
kfree(pAddr[i]);
}
}
pAddr is defined as 'unsigned long pAddr[10]'
But when f_free executes i ran into problems and computer hangs.
What can be the problem?
regards,
daljeet.
-
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the body of a message to [EMAIL PROTECTED]
Please read the FAQ at http://www.tux.org/lkml/
MAP_NR
can anyone tell the subsitute for MAP_NR in version 2.4? or is MAP_NR still there? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
MAP_NR
can anyone tell the subsitute for MAP_NR in version 2.4? or is MAP_NR still there? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
effect of pci_unregister_driver
Hi, If I have two identical network cards on my machine and I unregister the driver of one of them (say eth0) using the call "pci_unregister_driver(pdev->driver)" where pdev is the 'pci_dev' structure for eth0, does the device 'eth1' i.e. the other one gets effected by this. Regards, daljeet. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
mapping user space buffer to kernel address space
Hi, I have a user buffer and i want to map it to kernel address space can anyone tell how to do this like in AIX we have xmattach thanks daljeet - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
mapping user space buffer to kernel address space
Hi, I have a user buffer and i want to map it to kernel address space can anyone tell how to do this like in AIX we have xmattach thanks daljeet - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: File System issue
>I find out that doing the following command: >cp toto titi/toto >where toto is a file and titi is a directory do >not change the date stamp of >`titi'. i checked this out with 2.4-0test9. timestmap of directory is getting modified. you must be using very old kernel - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
executing a user space function in kernel module
Hi,
struct t{
int (*x)(int);
}fstruct;
main()
{
.
.
fstruct.x = f;
./*write fstruct to a device file*/
.
}
int f(int i)
{
printf("got %d\n",i);
return i;
}
i pass this structure to kernel module by writting to device file.
the write function of module is like
..
..
char *kbuf;
struct t *fstruct;
kbuf = kmalloc(count*sizeof(char), GFP_KERNEL);
copy_from_user((void*)kbuf,(void*)buf,count);
if( (filp->f_flags & O_ACCMODE)== O_WRONLY)
fstruct = (struct t*)kbuf;
printk("calling from kernel:%d\n",(fstruct->x)(8));
...
Now, is there any problem in executing a user space function in a kernel
module
by just passing a function pointer to the module
In Linux, is it possible to execute a function in kernel which is a part of
user application
and hence a part of user address space??
Thanks,
daljeet
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
Please read the FAQ at http://www.tux.org/lkml/
executing a user space function in kernel module
Hi,
struct t{
int (*x)(int);
}fstruct;
main()
{
.
.
fstruct.x = f;
./*write fstruct to a device file*/
.
}
int f(int i)
{
printf("got %d\n",i);
return i;
}
i pass this structure to kernel module by writting to device file.
the write function of module is like
..
..
char *kbuf;
struct t *fstruct;
kbuf = kmalloc(count*sizeof(char), GFP_KERNEL);
copy_from_user((void*)kbuf,(void*)buf,count);
if( (filp-f_flags O_ACCMODE)== O_WRONLY)
fstruct = (struct t*)kbuf;
printk("calling from kernel:%d\n",(fstruct-x)(8));
...
Now, is there any problem in executing a user space function in a kernel
module
by just passing a function pointer to the module
In Linux, is it possible to execute a function in kernel which is a part of
user application
and hence a part of user address space??
Thanks,
daljeet
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
Please read the FAQ at http://www.tux.org/lkml/
Re: File System issue
I find out that doing the following command: cp toto titi/toto where toto is a file and titi is a directory do not change the date stamp of `titi'. i checked this out with 2.4-0test9. timestmap of directory is getting modified. you must be using very old kernel - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
