linux-kernel - [PATCH v8 6/7] pmem: refactor pmem_clear

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Date:   Tue, 19 Apr 2022 20:04:34 -0600
From:   Jane Chu <jane.chu@...cle.com>
To:     dan.j.williams@...el.com, bp@...en8.de, hch@...radead.org,
        dave.hansen@...el.com, peterz@...radead.org, luto@...nel.org,
        david@...morbit.com, djwong@...nel.org,
        linux-fsdevel@...r.kernel.org, nvdimm@...ts.linux.dev,
        linux-kernel@...r.kernel.org, x86@...nel.org
Cc:     vishal.l.verma@...el.com, dave.jiang@...el.com, agk@...hat.com,
        snitzer@...hat.com, dm-devel@...hat.com, ira.weiny@...el.com,
        willy@...radead.org, vgoyal@...hat.com
Subject: [PATCH v8 6/7] pmem: refactor pmem_clear_poison()

Refactor the pmem_clear_poison() function such that the common
shared code between the typical write path and the recovery write
path is factored out.

Reviewed-by: Christoph Hellwig <hch@....de>
Reviewed-by: Dan Williams <dan.j.williams@...el.com>
Signed-off-by: Jane Chu <jane.chu@...cle.com>
---
 drivers/nvdimm/pmem.c | 73 ++++++++++++++++++++++++++++---------------
 1 file changed, 48 insertions(+), 25 deletions(-)

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 3c0cad38ec33..c3772304d417 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -45,9 +45,25 @@ 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)
+static phys_addr_t to_phys(struct pmem_device *pmem, phys_addr_t offset)
 {
+	return pmem->phys_addr + offset;
+}
+
+static sector_t to_sect(struct pmem_device *pmem, phys_addr_t offset)
+{
+	return (offset - pmem->data_offset) >> SECTOR_SHIFT;
+}
+
+static phys_addr_t to_offset(struct pmem_device *pmem, sector_t sector)
+{
+	return (sector << SECTOR_SHIFT) + pmem->data_offset;
+}
+
+static void pmem_mkpage_present(struct pmem_device *pmem, phys_addr_t offset,
+		unsigned int len)
+{
+	phys_addr_t phys = to_phys(pmem, offset);
 	unsigned long pfn_start, pfn_end, pfn;
 
 	/* only pmem in the linear map supports HWPoison */
@@ -69,33 +85,40 @@ static void hwpoison_clear(struct pmem_device *pmem,
 	}
 }
 
-static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
-		phys_addr_t offset, unsigned int len)
+static void pmem_clear_bb(struct pmem_device *pmem, sector_t sector, long blks)
 {
-	struct device *dev = to_dev(pmem);
-	sector_t sector;
-	long cleared;
-	blk_status_t rc = BLK_STS_OK;
+	if (blks == 0)
+		return;
+	badblocks_clear(&pmem->bb, sector, blks);
+	if (pmem->bb_state)
+		sysfs_notify_dirent(pmem->bb_state);
+}
 
-	sector = (offset - pmem->data_offset) / 512;
+static long __pmem_clear_poison(struct pmem_device *pmem,
+		phys_addr_t offset, unsigned int len)
+{
+	phys_addr_t phys = to_phys(pmem, offset);
+	long cleared = nvdimm_clear_poison(to_dev(pmem), phys, len);
 
-	cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
-	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,
-				cleared > 1 ? "s" : "");
-		badblocks_clear(&pmem->bb, sector, cleared);
-		if (pmem->bb_state)
-			sysfs_notify_dirent(pmem->bb_state);
+	if (cleared > 0) {
+		pmem_mkpage_present(pmem, offset, cleared);
+		arch_invalidate_pmem(pmem->virt_addr + offset, len);
 	}
+	return cleared;
+}
 
-	arch_invalidate_pmem(pmem->virt_addr + offset, len);
+static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
+		phys_addr_t offset, unsigned int len)
+{
+	long cleared = __pmem_clear_poison(pmem, offset, len);
 
-	return rc;
+	if (cleared < 0)
+		return BLK_STS_IOERR;
+
+	pmem_clear_bb(pmem, to_sect(pmem, offset), cleared >> SECTOR_SHIFT);
+	if (cleared < len)
+		return BLK_STS_IOERR;
+	return BLK_STS_OK;
 }
 
 static void write_pmem(void *pmem_addr, struct page *page,
@@ -143,7 +166,7 @@ static blk_status_t pmem_do_read(struct pmem_device *pmem,
 			sector_t sector, unsigned int len)
 {
 	blk_status_t rc;
-	phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
+	phys_addr_t pmem_off = to_offset(pmem, sector);
 	void *pmem_addr = pmem->virt_addr + pmem_off;
 
 	if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
@@ -158,7 +181,7 @@ static blk_status_t pmem_do_write(struct pmem_device *pmem,
 			struct page *page, unsigned int page_off,
 			sector_t sector, unsigned int len)
 {
-	phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
+	phys_addr_t pmem_off = to_offset(pmem, sector);
 	void *pmem_addr = pmem->virt_addr + pmem_off;
 
 	if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) {
-- 
2.18.4