Re: [PATCH 0/3] Add new ie31200_edac driver
On Fri, Apr 04, 2014 at 09:13:45PM +, Jason Baron wrote: > Hi, > > Add support for memory errors for the Intel E3-1200 processors. > > While testing the driver, I found that doing a readq() on the > memory mapped memory controller hub registers caused a hard lockup > on my x86_64 system. It turns out that a read across a DW boundary > is a no no here. > > " > Software must not access B0/D0/F0 32-bit memory-mapped registers with > requests that cross a DW boundary. > " > > (http://www.intel.com/content/www/us/en/processors/xeon/xeon-e3-1200-family-vol-2-datasheet.html > p. 16) > > Thus, I've added a generic lo_hi_[read|write]_q API, to deal with > this issue. > > I think longer term the right thing is maybe to simply add these > definitions to include/asm-generic/io.h, as I didn't see any > in tree users of 'io-64-nonatomic-hi-lo.h', and simply remove > io-64-nonatomic-hi-lo.h and io-64-nonatomic-lo-hi.h. But I didn't want to > tie that cleanup to this edac driver submission. Makes sense to me. There are a couple of drivers which include io-64-nonatomic-lo-hi.h though. As part of the cleanup, it might be even clearer to do the lo_hi_* calls directly instead of the readq/writeq defines as a means of documenting that this particular code cannot stomach doubleword-crossing accesses. x86 guys, opinions? Especially patch 1/3, should I pick it up or you want? Thanks. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 0/3] Add new ie31200_edac driver
On Fri, Apr 04, 2014 at 09:13:45PM +, Jason Baron wrote: Hi, Add support for memory errors for the Intel E3-1200 processors. While testing the driver, I found that doing a readq() on the memory mapped memory controller hub registers caused a hard lockup on my x86_64 system. It turns out that a read across a DW boundary is a no no here. Software must not access B0/D0/F0 32-bit memory-mapped registers with requests that cross a DW boundary. (http://www.intel.com/content/www/us/en/processors/xeon/xeon-e3-1200-family-vol-2-datasheet.html p. 16) Thus, I've added a generic lo_hi_[read|write]_q API, to deal with this issue. I think longer term the right thing is maybe to simply add these definitions to include/asm-generic/io.h, as I didn't see any in tree users of 'io-64-nonatomic-hi-lo.h', and simply remove io-64-nonatomic-hi-lo.h and io-64-nonatomic-lo-hi.h. But I didn't want to tie that cleanup to this edac driver submission. Makes sense to me. There are a couple of drivers which include io-64-nonatomic-lo-hi.h though. As part of the cleanup, it might be even clearer to do the lo_hi_* calls directly instead of the readq/writeq defines as a means of documenting that this particular code cannot stomach doubleword-crossing accesses. x86 guys, opinions? Especially patch 1/3, should I pick it up or you want? Thanks. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. -- -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 0/3] Add new ie31200_edac driver
Hi, Add support for memory errors for the Intel E3-1200 processors. While testing the driver, I found that doing a readq() on the memory mapped memory controller hub registers caused a hard lockup on my x86_64 system. It turns out that a read across a DW boundary is a no no here. " Software must not access B0/D0/F0 32-bit memory-mapped registers with requests that cross a DW boundary. " (http://www.intel.com/content/www/us/en/processors/xeon/xeon-e3-1200-family-vol-2-datasheet.html p. 16) Thus, I've added a generic lo_hi_[read|write]_q API, to deal with this issue. I think longer term the right thing is maybe to simply add these definitions to include/asm-generic/io.h, as I didn't see any in tree users of 'io-64-nonatomic-hi-lo.h', and simply remove io-64-nonatomic-hi-lo.h and io-64-nonatomic-lo-hi.h. But I didn't want to tie that cleanup to this edac driver submission. Thanks, -Jason Jason Baron (3): readq/writeq: Add explicit lo_hi_[read|write]_q and hi_lo_[read|write]_q x38_edac: make use of lo_hi_readq() ie31200_edac: Add driver drivers/edac/Kconfig| 7 + drivers/edac/Makefile | 1 + drivers/edac/ie31200_edac.c | 540 drivers/edac/x38_edac.c | 15 +- include/asm-generic/io-64-nonatomic-hi-lo.h | 14 +- include/asm-generic/io-64-nonatomic-lo-hi.h | 14 +- 6 files changed, 572 insertions(+), 19 deletions(-) create mode 100644 drivers/edac/ie31200_edac.c -- 1.8.2.rc2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 0/3] Add new ie31200_edac driver
Hi, Add support for memory errors for the Intel E3-1200 processors. While testing the driver, I found that doing a readq() on the memory mapped memory controller hub registers caused a hard lockup on my x86_64 system. It turns out that a read across a DW boundary is a no no here. Software must not access B0/D0/F0 32-bit memory-mapped registers with requests that cross a DW boundary. (http://www.intel.com/content/www/us/en/processors/xeon/xeon-e3-1200-family-vol-2-datasheet.html p. 16) Thus, I've added a generic lo_hi_[read|write]_q API, to deal with this issue. I think longer term the right thing is maybe to simply add these definitions to include/asm-generic/io.h, as I didn't see any in tree users of 'io-64-nonatomic-hi-lo.h', and simply remove io-64-nonatomic-hi-lo.h and io-64-nonatomic-lo-hi.h. But I didn't want to tie that cleanup to this edac driver submission. Thanks, -Jason Jason Baron (3): readq/writeq: Add explicit lo_hi_[read|write]_q and hi_lo_[read|write]_q x38_edac: make use of lo_hi_readq() ie31200_edac: Add driver drivers/edac/Kconfig| 7 + drivers/edac/Makefile | 1 + drivers/edac/ie31200_edac.c | 540 drivers/edac/x38_edac.c | 15 +- include/asm-generic/io-64-nonatomic-hi-lo.h | 14 +- include/asm-generic/io-64-nonatomic-lo-hi.h | 14 +- 6 files changed, 572 insertions(+), 19 deletions(-) create mode 100644 drivers/edac/ie31200_edac.c -- 1.8.2.rc2 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
