* [PATCH]mmc: core: not to --qty when calculate timeout for SECURE_ERASE
@ 2012-04-13 4:19 Chuanxiao Dong
2012-05-21 11:05 ` Adrian Hunter
0 siblings, 1 reply; 4+ messages in thread
From: Chuanxiao Dong @ 2012-04-13 4:19 UTC (permalink / raw)
To: linux-mmc; +Cc: adrian.hunter, cjb
--qty when calculating erase timeout for trim/erase & secure trim/erase
can prevent the erase range crossing qty+1 erase groups, which made
the final timeout value is too large for the host.
When operate SECURE_ERASE, driver needs the erase range is aligned with
erase size, otherwise do nothing and return an error. That is to say
it is not necessary for SECURE_ERASE to --qty since it will never cross
an erase group.
Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
---
drivers/mmc/core/core.c | 9 ++++++++-
1 files changed, 8 insertions(+), 1 deletions(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index e541efb..b5a393a 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1761,7 +1761,7 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
if (!qty)
return 0;
- if (qty == 1)
+ if (qty == 1 && arg != MMC_SECURE_ERASE_ARG)
return 1;
/* Convert qty to sectors */
@@ -1772,6 +1772,13 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
else
max_discard = --qty * card->erase_size;
+ /*
+ * since SECURE_ERASE is erase group aligned, otherwise
+ * it cannot be erased in secure purpose, needn't --qty
+ */
+ if (arg == MMC_SECURE_ERASE_ARG)
+ max_discard += card->erase_size;
+
return max_discard;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH]mmc: core: not to --qty when calculate timeout for SECURE_ERASE
2012-04-13 4:19 [PATCH]mmc: core: not to --qty when calculate timeout for SECURE_ERASE Chuanxiao Dong
@ 2012-05-21 11:05 ` Adrian Hunter
2012-05-21 11:19 ` Dong, Chuanxiao
0 siblings, 1 reply; 4+ messages in thread
From: Adrian Hunter @ 2012-05-21 11:05 UTC (permalink / raw)
To: Chuanxiao Dong; +Cc: linux-mmc, cjb
On 13/04/12 07:19, Chuanxiao Dong wrote:
> --qty when calculating erase timeout for trim/erase & secure trim/erase
> can prevent the erase range crossing qty+1 erase groups, which made
> the final timeout value is too large for the host.
>
> When operate SECURE_ERASE, driver needs the erase range is aligned with
> erase size, otherwise do nothing and return an error. That is to say
> it is not necessary for SECURE_ERASE to --qty since it will never cross
> an erase group.
>
> Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
> ---
> drivers/mmc/core/core.c | 9 ++++++++-
> 1 files changed, 8 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index e541efb..b5a393a 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -1761,7 +1761,7 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
> if (!qty)
> return 0;
>
> - if (qty == 1)
> + if (qty == 1 && arg != MMC_SECURE_ERASE_ARG)
> return 1;
arg is never MMC_SECURE_ERASE_ARG
>
> /* Convert qty to sectors */
> @@ -1772,6 +1772,13 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
> else
> max_discard = --qty * card->erase_size;
>
> + /*
> + * since SECURE_ERASE is erase group aligned, otherwise
> + * it cannot be erased in secure purpose, needn't --qty
> + */
> + if (arg == MMC_SECURE_ERASE_ARG)
> + max_discard += card->erase_size;
> +
> return max_discard;
> }
>
What about:
From: Adrian Hunter <adrian.hunter@intel.com>
Date: Mon, 21 May 2012 13:32:42 +0300
Subject: [PATCH] mmc: core: fix max_discard calculation
The maximum discard calculation was unnecessarily pessimistic
in the case of erasing entire erase groups. In that case, the
quantity does not need to be decreased by 1 to allow for
misalignment because the erasure is always aligned to whole
erase groups.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
drivers/mmc/core/core.c | 22 +++++++++++++++++-----
1 files changed, 17 insertions(+), 5 deletions(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 0b6141d..36bfdce 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1742,7 +1742,7 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
{
struct mmc_host *host = card->host;
unsigned int max_discard, x, y, qty = 0, max_qty, timeout;
- unsigned int last_timeout = 0;
+ unsigned int last_timeout = 0, aligned_qty;
if (card->erase_shift)
max_qty = UINT_MAX >> card->erase_shift;
@@ -1769,16 +1769,28 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
if (!qty)
return 0;
- if (qty == 1)
- return 1;
+ if (arg & MMC_TRIM_ARGS) {
+ /*
+ * The requested number of sectors may not be aligned to an
+ * erase group, so we have to decrease the quantity by 1 (unless
+ * it is 1) e.g. trimming 2 sectors could cause 2 erase groups
+ * to be affected even though 2 sectors is less than the size of
+ * 1 erase group.
+ */
+ if (qty == 1)
+ return 1;
+ aligned_qty = qty - 1;
+ } else {
+ aligned_qty = qty;
+ }
/* Convert qty to sectors */
if (card->erase_shift)
- max_discard = --qty << card->erase_shift;
+ max_discard = aligned_qty << card->erase_shift;
else if (mmc_card_sd(card))
max_discard = qty;
else
- max_discard = --qty * card->erase_size;
+ max_discard = aligned_qty * card->erase_size;
return max_discard;
}
--
1.7.6.5
^ permalink raw reply related [flat|nested] 4+ messages in thread
* RE: [PATCH]mmc: core: not to --qty when calculate timeout for SECURE_ERASE
2012-05-21 11:05 ` Adrian Hunter
@ 2012-05-21 11:19 ` Dong, Chuanxiao
2012-05-21 11:27 ` Adrian Hunter
0 siblings, 1 reply; 4+ messages in thread
From: Dong, Chuanxiao @ 2012-05-21 11:19 UTC (permalink / raw)
To: Hunter, Adrian; +Cc: linux-mmc, cjb
> -----Original Message-----
> From: Hunter, Adrian
> Sent: Monday, May 21, 2012 7:06 PM
> To: Dong, Chuanxiao
> Cc: linux-mmc@vger.kernel.org; cjb@laptop.org
> Subject: Re: [PATCH]mmc: core: not to --qty when calculate timeout for
> SECURE_ERASE
>
> On 13/04/12 07:19, Chuanxiao Dong wrote:
> > --qty when calculating erase timeout for trim/erase & secure
> > trim/erase can prevent the erase range crossing qty+1 erase groups,
> > which made the final timeout value is too large for the host.
> >
> > When operate SECURE_ERASE, driver needs the erase range is aligned
> > with erase size, otherwise do nothing and return an error. That is to
> > say it is not necessary for SECURE_ERASE to --qty since it will never
> > cross an erase group.
> >
> > Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
> > ---
> > drivers/mmc/core/core.c | 9 ++++++++-
> > 1 files changed, 8 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index
> > e541efb..b5a393a 100644
> > --- a/drivers/mmc/core/core.c
> > +++ b/drivers/mmc/core/core.c
> > @@ -1761,7 +1761,7 @@ static unsigned int mmc_do_calc_max_discard(struct
> mmc_card *card,
> > if (!qty)
> > return 0;
> >
> > - if (qty == 1)
> > + if (qty == 1 && arg != MMC_SECURE_ERASE_ARG)
> > return 1;
>
> arg is never MMC_SECURE_ERASE_ARG
>
> >
> > /* Convert qty to sectors */
> > @@ -1772,6 +1772,13 @@ static unsigned int mmc_do_calc_max_discard(struct
> mmc_card *card,
> > else
> > max_discard = --qty * card->erase_size;
> >
> > + /*
> > + * since SECURE_ERASE is erase group aligned, otherwise
> > + * it cannot be erased in secure purpose, needn't --qty
> > + */
> > + if (arg == MMC_SECURE_ERASE_ARG)
> > + max_discard += card->erase_size;
> > +
> > return max_discard;
> > }
> >
>
> What about:
>
> From: Adrian Hunter <adrian.hunter@intel.com>
> Date: Mon, 21 May 2012 13:32:42 +0300
> Subject: [PATCH] mmc: core: fix max_discard calculation
>
> The maximum discard calculation was unnecessarily pessimistic in the case of
> erasing entire erase groups. In that case, the quantity does not need to be
> decreased by 1 to allow for misalignment because the erasure is always aligned to
> whole erase groups.
>
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> ---
> drivers/mmc/core/core.c | 22 +++++++++++++++++-----
> 1 files changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index
> 0b6141d..36bfdce 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -1742,7 +1742,7 @@ static unsigned int mmc_do_calc_max_discard(struct
> mmc_card *card, {
> struct mmc_host *host = card->host;
> unsigned int max_discard, x, y, qty = 0, max_qty, timeout;
> - unsigned int last_timeout = 0;
> + unsigned int last_timeout = 0, aligned_qty;
>
> if (card->erase_shift)
> max_qty = UINT_MAX >> card->erase_shift; @@ -1769,16 +1769,28 @@
> static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
> if (!qty)
> return 0;
>
> - if (qty == 1)
> - return 1;
> + if (arg & MMC_TRIM_ARGS) {
> + /*
> + * The requested number of sectors may not be aligned to an
> + * erase group, so we have to decrease the quantity by 1 (unless
> + * it is 1) e.g. trimming 2 sectors could cause 2 erase groups
> + * to be affected even though 2 sectors is less than the size of
> + * 1 erase group.
> + */
> + if (qty == 1)
> + return 1;
> + aligned_qty = qty - 1;
> + } else {
> + aligned_qty = qty;
> + }
>
> /* Convert qty to sectors */
> if (card->erase_shift)
> - max_discard = --qty << card->erase_shift;
> + max_discard = aligned_qty << card->erase_shift;
> else if (mmc_card_sd(card))
> max_discard = qty;
> else
> - max_discard = --qty * card->erase_size;
> + max_discard = aligned_qty * card->erase_size;
>
> return max_discard;
> }
Hi Hunter,
Your patch looks good to me.
Since you also mentioned that the arg will never be MMC_SECURE_ERASE_ARG, I want to know why not calculate erase size for secure trim/erase operations? As specification said, secure trim/erase operations has different timeout value with trim/erase.
Thanks
Chuanxiao
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH]mmc: core: not to --qty when calculate timeout for SECURE_ERASE
2012-05-21 11:19 ` Dong, Chuanxiao
@ 2012-05-21 11:27 ` Adrian Hunter
0 siblings, 0 replies; 4+ messages in thread
From: Adrian Hunter @ 2012-05-21 11:27 UTC (permalink / raw)
To: Dong, Chuanxiao; +Cc: linux-mmc, cjb
On 21/05/12 14:19, Dong, Chuanxiao wrote:
>
>
>> -----Original Message-----
>> From: Hunter, Adrian
>> Sent: Monday, May 21, 2012 7:06 PM
>> To: Dong, Chuanxiao
>> Cc: linux-mmc@vger.kernel.org; cjb@laptop.org
>> Subject: Re: [PATCH]mmc: core: not to --qty when calculate timeout for
>> SECURE_ERASE
>>
>> On 13/04/12 07:19, Chuanxiao Dong wrote:
>>> --qty when calculating erase timeout for trim/erase & secure
>>> trim/erase can prevent the erase range crossing qty+1 erase groups,
>>> which made the final timeout value is too large for the host.
>>>
>>> When operate SECURE_ERASE, driver needs the erase range is aligned
>>> with erase size, otherwise do nothing and return an error. That is to
>>> say it is not necessary for SECURE_ERASE to --qty since it will never
>>> cross an erase group.
>>>
>>> Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
>>> ---
>>> drivers/mmc/core/core.c | 9 ++++++++-
>>> 1 files changed, 8 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index
>>> e541efb..b5a393a 100644
>>> --- a/drivers/mmc/core/core.c
>>> +++ b/drivers/mmc/core/core.c
>>> @@ -1761,7 +1761,7 @@ static unsigned int mmc_do_calc_max_discard(struct
>> mmc_card *card,
>>> if (!qty)
>>> return 0;
>>>
>>> - if (qty == 1)
>>> + if (qty == 1 && arg != MMC_SECURE_ERASE_ARG)
>>> return 1;
>>
>> arg is never MMC_SECURE_ERASE_ARG
>>
>>>
>>> /* Convert qty to sectors */
>>> @@ -1772,6 +1772,13 @@ static unsigned int mmc_do_calc_max_discard(struct
>> mmc_card *card,
>>> else
>>> max_discard = --qty * card->erase_size;
>>>
>>> + /*
>>> + * since SECURE_ERASE is erase group aligned, otherwise
>>> + * it cannot be erased in secure purpose, needn't --qty
>>> + */
>>> + if (arg == MMC_SECURE_ERASE_ARG)
>>> + max_discard += card->erase_size;
>>> +
>>> return max_discard;
>>> }
>>>
>>
>> What about:
>>
>> From: Adrian Hunter <adrian.hunter@intel.com>
>> Date: Mon, 21 May 2012 13:32:42 +0300
>> Subject: [PATCH] mmc: core: fix max_discard calculation
>>
>> The maximum discard calculation was unnecessarily pessimistic in the case of
>> erasing entire erase groups. In that case, the quantity does not need to be
>> decreased by 1 to allow for misalignment because the erasure is always aligned to
>> whole erase groups.
>>
>> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
>> ---
>> drivers/mmc/core/core.c | 22 +++++++++++++++++-----
>> 1 files changed, 17 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index
>> 0b6141d..36bfdce 100644
>> --- a/drivers/mmc/core/core.c
>> +++ b/drivers/mmc/core/core.c
>> @@ -1742,7 +1742,7 @@ static unsigned int mmc_do_calc_max_discard(struct
>> mmc_card *card, {
>> struct mmc_host *host = card->host;
>> unsigned int max_discard, x, y, qty = 0, max_qty, timeout;
>> - unsigned int last_timeout = 0;
>> + unsigned int last_timeout = 0, aligned_qty;
>>
>> if (card->erase_shift)
>> max_qty = UINT_MAX >> card->erase_shift; @@ -1769,16 +1769,28 @@
>> static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
>> if (!qty)
>> return 0;
>>
>> - if (qty == 1)
>> - return 1;
>> + if (arg & MMC_TRIM_ARGS) {
>> + /*
>> + * The requested number of sectors may not be aligned to an
>> + * erase group, so we have to decrease the quantity by 1 (unless
>> + * it is 1) e.g. trimming 2 sectors could cause 2 erase groups
>> + * to be affected even though 2 sectors is less than the size of
>> + * 1 erase group.
>> + */
>> + if (qty == 1)
>> + return 1;
>> + aligned_qty = qty - 1;
>> + } else {
>> + aligned_qty = qty;
>> + }
>>
>> /* Convert qty to sectors */
>> if (card->erase_shift)
>> - max_discard = --qty << card->erase_shift;
>> + max_discard = aligned_qty << card->erase_shift;
>> else if (mmc_card_sd(card))
>> max_discard = qty;
>> else
>> - max_discard = --qty * card->erase_size;
>> + max_discard = aligned_qty * card->erase_size;
>>
>> return max_discard;
>> }
>
> Hi Hunter,
> Your patch looks good to me.
>
> Since you also mentioned that the arg will never be MMC_SECURE_ERASE_ARG, I want to know why not calculate erase size for secure trim/erase operations? As specification said, secure trim/erase operations has different timeout value with trim/erase.
There are 2 problems. First, there is only 1 value for maximum discard
whether secure or not. Secondly, the timeout for secure erase can be so
great that any quantity exceeds the maximum timeout.
>
> Thanks
> Chuanxiao
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-05-21 11:27 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-04-13 4:19 [PATCH]mmc: core: not to --qty when calculate timeout for SECURE_ERASE Chuanxiao Dong
2012-05-21 11:05 ` Adrian Hunter
2012-05-21 11:19 ` Dong, Chuanxiao
2012-05-21 11:27 ` Adrian Hunter
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