Messages in this thread Patch in this message |  | | Date | Mon, 16 Feb 2015 13:24:27 +0200 | From | Boaz Harrosh <> | Subject | [PATCH 3/3] pmem: Allow request_mem to fail, (CONFIG_BLK_DEV_PMEM_IGNORE_REQUEST_MEM_RET) |
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With old Kernels there was a bug in x86 where any unknown memory chip type would come up BUSY when calling request_mem_region_exclusive().
So for pmem to work with old Kernels and real NvDIMM chips we have a new Kconfig option CONFIG_BLK_DEV_PMEM_IGNORE_REQUEST_MEM_RET.
People have been running with hacked up pmem that will ignore the return code from request_mem_region_exclusive. So here it is official
Signed-off-by: Boaz Harrosh <boaz@plexistor.com> --- drivers/block/Kconfig | 12 ++++++++++++ drivers/block/pmem.c | 11 +++++++---- 2 files changed, 19 insertions(+), 4 deletions(-)
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig index 3b3200f..10879b8 100644 --- a/drivers/block/Kconfig +++ b/drivers/block/Kconfig @@ -430,6 +430,18 @@ config BLK_DEV_PMEM_USE_PAGES to other devices in the system, then you must say "Yes" here. If unsure leave as Yes. +config BLK_DEV_PMEM_IGNORE_REQUEST_MEM_RET + bool "Ignore the return code from request_mem_region_exclusive" + depends on BLK_DEV_PMEM + help + In Old Kernels type-12 Memory type which is used by NvDIMM + chips Comes out busy when calling request_mem_region_exclusive, + because of a bug. + If this option is set to "yes". The pmem will ignore the + failure, and continue as usual. If you have an old Kernel and + a real NvDIMM chip you must say yes here. + (Ignored if BLK_DEV_PMEM_USE_PAGES=y) + config CDROM_PKTCDVD tristate "Packet writing on CD/DVD media" depends on !UML diff --git a/drivers/block/pmem.c b/drivers/block/pmem.c index 9eb7ffe..f84d033 100644 --- a/drivers/block/pmem.c +++ b/drivers/block/pmem.c @@ -197,10 +197,12 @@ int pmem_mapmem(struct pmem_device *pmem) res_mem = request_mem_region_exclusive(pmem->phys_addr, pmem->size, "pmem"); - if (!res_mem) { + if (unlikely(!res_mem)) { pr_warn("pmem: request_mem_region_exclusive phys=0x%llx size=0x%zx failed\n", - pmem->phys_addr, pmem->size); - return -EINVAL; + pmem->phys_addr, pmem->size); +#ifndef CONFIG_BLK_DEV_PMEM_IGNORE_REQUEST_MEM_RET + return -EBUSY; +#endif } pmem->virt_addr = ioremap_cache(pmem->phys_addr, pmem->size); @@ -211,7 +213,8 @@ int pmem_mapmem(struct pmem_device *pmem) return 0; out_release: - release_mem_region(pmem->phys_addr, pmem->size); + if (res_mem) + release_mem_region(pmem->phys_addr, pmem->size); return err; } -- 1.9.3
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