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| author | Dan Williams <dan.j.williams@intel.com> | 2018-07-14 07:50:37 +0300 |
|---|---|---|
| committer | Dave Jiang <dave.jiang@intel.com> | 2018-08-20 19:22:45 +0300 |
| commit | c953cc987ab87d180e1d5de2f1c217abe33aac77 (patch) | |
| tree | 29e82381bba655d2141bf39c261312b56d128442 /drivers/nvdimm/pmem.c | |
| parent | 284ce4011ba60d6c487b668eea729b6294930806 (diff) | |
| download | linux-c953cc987ab87d180e1d5de2f1c217abe33aac77.tar.xz | |
libnvdimm, pmem: Restore page attributes when clearing errors
Use clear_mce_nospec() to restore WB mode for the kernel linear mapping
of a pmem page that was marked 'HWPoison'. A page with 'HWPoison' set
has also been marked UC in PAT (page attribute table) via
set_mce_nospec() to prevent speculative retrievals of poison.
The 'HWPoison' flag is only cleared when overwriting an entire page.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Diffstat (limited to 'drivers/nvdimm/pmem.c')
| -rw-r--r-- | drivers/nvdimm/pmem.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 8b1fd7f1a224..55c7a69751d3 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -20,6 +20,7 @@ #include <linux/hdreg.h> #include <linux/init.h> #include <linux/platform_device.h> +#include <linux/set_memory.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/badblocks.h> @@ -51,6 +52,30 @@ static struct nd_region *to_region(struct pmem_device *pmem) return to_nd_region(to_dev(pmem)->parent); } +static void hwpoison_clear(struct pmem_device *pmem, + phys_addr_t phys, unsigned int len) +{ + unsigned long pfn_start, pfn_end, pfn; + + /* only pmem in the linear map supports HWPoison */ + if (is_vmalloc_addr(pmem->virt_addr)) + return; + + pfn_start = PHYS_PFN(phys); + pfn_end = pfn_start + PHYS_PFN(len); + for (pfn = pfn_start; pfn < pfn_end; pfn++) { + struct page *page = pfn_to_page(pfn); + + /* + * Note, no need to hold a get_dev_pagemap() reference + * here since we're in the driver I/O path and + * outstanding I/O requests pin the dev_pagemap. + */ + if (test_and_clear_pmem_poison(page)) + clear_mce_nospec(pfn); + } +} + static blk_status_t pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset, unsigned int len) { @@ -65,6 +90,7 @@ static blk_status_t pmem_clear_poison(struct pmem_device *pmem, if (cleared < len) rc = BLK_STS_IOERR; if (cleared > 0 && cleared / 512) { + hwpoison_clear(pmem, pmem->phys_addr + offset, cleared); cleared /= 512; dev_dbg(dev, "%#llx clear %ld sector%s\n", (unsigned long long) sector, cleared, |