diff mbox series

[v7,5/6] pmem: refactor pmem_clear_poison()

Message ID 20220405194747.2386619-6-jane.chu@oracle.com (mailing list archive)
State Superseded
Headers show
Series DAX poison recovery | expand

Commit Message

Jane Chu April 5, 2022, 7:47 p.m. UTC
Refactor the pmem_clear_poison() in order to share common code
later.

Signed-off-by: Jane Chu <jane.chu@oracle.com>
---
 drivers/nvdimm/pmem.c | 78 ++++++++++++++++++++++++++++---------------
 1 file changed, 52 insertions(+), 26 deletions(-)

Comments

Christoph Hellwig April 6, 2022, 5:04 a.m. UTC | #1
On Tue, Apr 05, 2022 at 01:47:46PM -0600, Jane Chu wrote:
> +	pmem_clear_bb(pmem, to_sect(pmem, offset), cleared >> SECTOR_SHIFT);
> +	return (cleared < len) ? BLK_STS_IOERR : BLK_STS_OK;

No need for the braces.  That being said perosnally I find a simple:

	if (cleared < len)
		return BLK_STS_IOERR;
	return BLK_STS_OK;

much easier to read anyway.

Otherwise looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>
Jane Chu April 6, 2022, 5:34 p.m. UTC | #2
On 4/5/2022 10:04 PM, Christoph Hellwig wrote:
> On Tue, Apr 05, 2022 at 01:47:46PM -0600, Jane Chu wrote:
>> +	pmem_clear_bb(pmem, to_sect(pmem, offset), cleared >> SECTOR_SHIFT);
>> +	return (cleared < len) ? BLK_STS_IOERR : BLK_STS_OK;
> 
> No need for the braces.  That being said perosnally I find a simple:
> 
> 	if (cleared < len)
> 		return BLK_STS_IOERR;
> 	return BLK_STS_OK;
> 
> much easier to read anyway.

will do.

> 
> Otherwise looks good:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Thanks!
-jane
Dan Williams April 12, 2022, 4:26 a.m. UTC | #3
On Tue, Apr 5, 2022 at 12:48 PM Jane Chu <jane.chu@oracle.com> wrote:
>
> Refactor the pmem_clear_poison() in order to share common code
> later.
>

I would just add a note here about why, i.e. to factor out the common
shared code between the typical write path and the recovery write
path.

> Signed-off-by: Jane Chu <jane.chu@oracle.com>
> ---
>  drivers/nvdimm/pmem.c | 78 ++++++++++++++++++++++++++++---------------
>  1 file changed, 52 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
> index 0400c5a7ba39..56596be70400 100644
> --- a/drivers/nvdimm/pmem.c
> +++ b/drivers/nvdimm/pmem.c
> @@ -45,10 +45,27 @@ 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);

Christoph already mentioned dropping the unnecessary parenthesis.

> +}
> +
> +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_clear_hwpoison(struct pmem_device *pmem, phys_addr_t offset,
> +               unsigned int len)

Perhaps now is a good time to rename this to something else like
pmem_clear_mce_nospec()? Just to make it more distinct from
pmem_clear_poison(). While "hwpoison" is the page flag name
pmem_clear_poison() is the function that's actually clearing the
poison in hardware ("hw") and the new pmem_clear_mce_nospec() is
toggling the page back into service.

> +{
> +       phys_addr_t phys = to_phys(pmem, offset);
>         unsigned long pfn_start, pfn_end, pfn;
> +       unsigned int blks = len >> SECTOR_SHIFT;
>
>         /* only pmem in the linear map supports HWPoison */
>         if (is_vmalloc_addr(pmem->virt_addr))
> @@ -67,35 +84,44 @@ static void hwpoison_clear(struct pmem_device *pmem,
>                 if (test_and_clear_pmem_poison(page))
>                         clear_mce_nospec(pfn);
>         }
> +
> +       dev_dbg(to_dev(pmem), "%#llx clear %u sector%s\n",
> +               (unsigned long long) to_sect(pmem, offset), blks,
> +               blks > 1 ? "s" : "");

In anticipation of better tracing support and the fact that this is no
longer called from pmem_clear_poison() let's drop it for now.

>  }
>
> -static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
> +static void pmem_clear_bb(struct pmem_device *pmem, sector_t sector, long blks)
> +{
> +       if (blks == 0)
> +               return;
> +       badblocks_clear(&pmem->bb, sector, blks);
> +       if (pmem->bb_state)
> +               sysfs_notify_dirent(pmem->bb_state);
> +}
> +
> +static long __pmem_clear_poison(struct pmem_device *pmem,
>                 phys_addr_t offset, unsigned int len)
>  {
> -       struct device *dev = to_dev(pmem);
> -       sector_t sector;
> -       long cleared;
> -       blk_status_t rc = BLK_STS_OK;
> -
> -       sector = (offset - pmem->data_offset) / 512;
> -
> -       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);
> +       phys_addr_t phys = to_phys(pmem, offset);
> +       long cleared = nvdimm_clear_poison(to_dev(pmem), phys, len);
> +
> +       if (cleared > 0) {
> +               pmem_clear_hwpoison(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);
> +       return (cleared < len) ? BLK_STS_IOERR : BLK_STS_OK;

I prefer "if / else" syntax instead of a ternary conditional.

>  }
>
>  static void write_pmem(void *pmem_addr, struct page *page,
> @@ -143,7 +169,7 @@ 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 +184,7 @@ 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))) {

With those small fixups you can add:

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Jane Chu April 14, 2022, 12:55 a.m. UTC | #4
On 4/11/2022 9:26 PM, Dan Williams wrote:
> On Tue, Apr 5, 2022 at 12:48 PM Jane Chu <jane.chu@oracle.com> wrote:
>>
>> Refactor the pmem_clear_poison() in order to share common code
>> later.
>>
> 
> I would just add a note here about why, i.e. to factor out the common
> shared code between the typical write path and the recovery write
> path.

Okay.

> 
>> Signed-off-by: Jane Chu <jane.chu@oracle.com>
>> ---
>>   drivers/nvdimm/pmem.c | 78 ++++++++++++++++++++++++++++---------------
>>   1 file changed, 52 insertions(+), 26 deletions(-)
>>
>> diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
>> index 0400c5a7ba39..56596be70400 100644
>> --- a/drivers/nvdimm/pmem.c
>> +++ b/drivers/nvdimm/pmem.c
>> @@ -45,10 +45,27 @@ 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);
> 
> Christoph already mentioned dropping the unnecessary parenthesis.
> 
>> +}
>> +
>> +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_clear_hwpoison(struct pmem_device *pmem, phys_addr_t offset,
>> +               unsigned int len)
> 
> Perhaps now is a good time to rename this to something else like
> pmem_clear_mce_nospec()? Just to make it more distinct from
> pmem_clear_poison(). While "hwpoison" is the page flag name
> pmem_clear_poison() is the function that's actually clearing the
> poison in hardware ("hw") and the new pmem_clear_mce_nospec() is
> toggling the page back into service.

I get your point. How about calling the function explicitly
pmem_mkpage_present()? or pmem_page_present_on()? or 
pmem_set_page_present()?  because setting a poisoned present requires 
both clearing the HWpoison bit & clear mce_nospec.

> 
>> +{
>> +       phys_addr_t phys = to_phys(pmem, offset);
>>          unsigned long pfn_start, pfn_end, pfn;
>> +       unsigned int blks = len >> SECTOR_SHIFT;
>>
>>          /* only pmem in the linear map supports HWPoison */
>>          if (is_vmalloc_addr(pmem->virt_addr))
>> @@ -67,35 +84,44 @@ static void hwpoison_clear(struct pmem_device *pmem,
>>                  if (test_and_clear_pmem_poison(page))
>>                          clear_mce_nospec(pfn);
>>          }
>> +
>> +       dev_dbg(to_dev(pmem), "%#llx clear %u sector%s\n",
>> +               (unsigned long long) to_sect(pmem, offset), blks,
>> +               blks > 1 ? "s" : "");
> 
> In anticipation of better tracing support and the fact that this is no
> longer called from pmem_clear_poison() let's drop it for now.

OKay.

> 
>>   }
>>
>> -static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
>> +static void pmem_clear_bb(struct pmem_device *pmem, sector_t sector, long blks)
>> +{
>> +       if (blks == 0)
>> +               return;
>> +       badblocks_clear(&pmem->bb, sector, blks);
>> +       if (pmem->bb_state)
>> +               sysfs_notify_dirent(pmem->bb_state);
>> +}
>> +
>> +static long __pmem_clear_poison(struct pmem_device *pmem,
>>                  phys_addr_t offset, unsigned int len)
>>   {
>> -       struct device *dev = to_dev(pmem);
>> -       sector_t sector;
>> -       long cleared;
>> -       blk_status_t rc = BLK_STS_OK;
>> -
>> -       sector = (offset - pmem->data_offset) / 512;
>> -
>> -       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);
>> +       phys_addr_t phys = to_phys(pmem, offset);
>> +       long cleared = nvdimm_clear_poison(to_dev(pmem), phys, len);
>> +
>> +       if (cleared > 0) {
>> +               pmem_clear_hwpoison(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);
>> +       return (cleared < len) ? BLK_STS_IOERR : BLK_STS_OK;
> 
> I prefer "if / else" syntax instead of a ternary conditional.
> 

Got it.

>>   }
>>
>>   static void write_pmem(void *pmem_addr, struct page *page,
>> @@ -143,7 +169,7 @@ 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 +184,7 @@ 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))) {
> 
> With those small fixups you can add:
> 
> Reviewed-by: Dan Williams <dan.j.williams@intel.com>

Thanks!
-jane
Dan Williams April 14, 2022, 2:02 a.m. UTC | #5
On Wed, Apr 13, 2022 at 5:55 PM Jane Chu <jane.chu@oracle.com> wrote:
>
> On 4/11/2022 9:26 PM, Dan Williams wrote:
> > On Tue, Apr 5, 2022 at 12:48 PM Jane Chu <jane.chu@oracle.com> wrote:
> >>
> >> Refactor the pmem_clear_poison() in order to share common code
> >> later.
> >>
> >
> > I would just add a note here about why, i.e. to factor out the common
> > shared code between the typical write path and the recovery write
> > path.
>
> Okay.
>
> >
> >> Signed-off-by: Jane Chu <jane.chu@oracle.com>
> >> ---
> >>   drivers/nvdimm/pmem.c | 78 ++++++++++++++++++++++++++++---------------
> >>   1 file changed, 52 insertions(+), 26 deletions(-)
> >>
> >> diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
> >> index 0400c5a7ba39..56596be70400 100644
> >> --- a/drivers/nvdimm/pmem.c
> >> +++ b/drivers/nvdimm/pmem.c
> >> @@ -45,10 +45,27 @@ 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);
> >
> > Christoph already mentioned dropping the unnecessary parenthesis.
> >
> >> +}
> >> +
> >> +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_clear_hwpoison(struct pmem_device *pmem, phys_addr_t offset,
> >> +               unsigned int len)
> >
> > Perhaps now is a good time to rename this to something else like
> > pmem_clear_mce_nospec()? Just to make it more distinct from
> > pmem_clear_poison(). While "hwpoison" is the page flag name
> > pmem_clear_poison() is the function that's actually clearing the
> > poison in hardware ("hw") and the new pmem_clear_mce_nospec() is
> > toggling the page back into service.
>
> I get your point. How about calling the function explicitly
> pmem_mkpage_present()?

Sure, I like pmem_mkpage_present().
diff mbox series

Patch

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 0400c5a7ba39..56596be70400 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -45,10 +45,27 @@  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_clear_hwpoison(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;
+	unsigned int blks = len >> SECTOR_SHIFT;
 
 	/* only pmem in the linear map supports HWPoison */
 	if (is_vmalloc_addr(pmem->virt_addr))
@@ -67,35 +84,44 @@  static void hwpoison_clear(struct pmem_device *pmem,
 		if (test_and_clear_pmem_poison(page))
 			clear_mce_nospec(pfn);
 	}
+
+	dev_dbg(to_dev(pmem), "%#llx clear %u sector%s\n",
+		(unsigned long long) to_sect(pmem, offset), blks,
+		blks > 1 ? "s" : "");
 }
 
-static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
+static void pmem_clear_bb(struct pmem_device *pmem, sector_t sector, long blks)
+{
+	if (blks == 0)
+		return;
+	badblocks_clear(&pmem->bb, sector, blks);
+	if (pmem->bb_state)
+		sysfs_notify_dirent(pmem->bb_state);
+}
+
+static long __pmem_clear_poison(struct pmem_device *pmem,
 		phys_addr_t offset, unsigned int len)
 {
-	struct device *dev = to_dev(pmem);
-	sector_t sector;
-	long cleared;
-	blk_status_t rc = BLK_STS_OK;
-
-	sector = (offset - pmem->data_offset) / 512;
-
-	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);
+	phys_addr_t phys = to_phys(pmem, offset);
+	long cleared = nvdimm_clear_poison(to_dev(pmem), phys, len);
+
+	if (cleared > 0) {
+		pmem_clear_hwpoison(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);
+	return (cleared < len) ? BLK_STS_IOERR : BLK_STS_OK;
 }
 
 static void write_pmem(void *pmem_addr, struct page *page,
@@ -143,7 +169,7 @@  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 +184,7 @@  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))) {