| Message ID | 20221121214056.1187700-13-farman@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vfio/ccw: channel program cleanup | expand |
On 11/21/22 4:40 PM, Eric Farman wrote: > The idal_nr_words() routine works well for 4K IDAWs, but lost its > ability to handle the old 2K formats with the removal of 31-bit > builds in commit 5a79859ae0f3 ("s390: remove 31 bit support"). > > Since there's nothing preventing a guest from generating this IDAW > format, let's re-introduce the math for them and use both when > calculating the number of IDAWs based on the bits specified in > the ORB. > > Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> > --- > arch/s390/include/asm/idals.h | 12 ++++++++++++ > drivers/s390/cio/vfio_ccw_cp.c | 17 ++++++++++++++++- > 2 files changed, 28 insertions(+), 1 deletion(-) > > diff --git a/arch/s390/include/asm/idals.h b/arch/s390/include/asm/idals.h > index 40eae2c08d61..0a05a893aedb 100644 > --- a/arch/s390/include/asm/idals.h > +++ b/arch/s390/include/asm/idals.h > @@ -23,6 +23,9 @@ > #define IDA_SIZE_LOG 12 /* 11 for 2k , 12 for 4k */ > #define IDA_BLOCK_SIZE (1L<<IDA_SIZE_LOG) > > +#define IDA_2K_SIZE_LOG 11 > +#define IDA_2K_BLOCK_SIZE (1L << IDA_2K_SIZE_LOG) > + > /* > * Test if an address/length pair needs an idal list. > */ > @@ -42,6 +45,15 @@ static inline unsigned int idal_nr_words(void *vaddr, unsigned int length) > (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG; > } > > +/* > + * Return the number of 2K IDA words needed for an address/length pair. > + */ > +static inline unsigned int idal_2k_nr_words(void *vaddr, unsigned int length) > +{ > + return ((__pa(vaddr) & (IDA_2K_BLOCK_SIZE-1)) + length + > + (IDA_2K_BLOCK_SIZE-1)) >> IDA_2K_SIZE_LOG; > +} > + > /* > * Create the list of idal words for an address/length pair. > */ > diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c > index 53246f4f95f7..6839e7195182 100644 > --- a/drivers/s390/cio/vfio_ccw_cp.c > +++ b/drivers/s390/cio/vfio_ccw_cp.c > @@ -502,6 +502,13 @@ static int ccwchain_fetch_tic(struct ccw1 *ccw, > * > * @ccw: The Channel Command Word being translated > * @cp: Channel Program being processed > + * > + * The ORB is examined, since it specifies what IDAWs could actually be > + * used by any CCW in the channel program, regardless of whether or not > + * the CCW actually does. An ORB that does not specify Format-2-IDAW > + * Control could still contain a CCW with an IDAL, which would be > + * Format-1 and thus only move 2K with each IDAW. Thus all CCWs within > + * the channel program must follow the same size requirements. > */ > static int ccw_count_idaws(struct ccw1 *ccw, > struct channel_program *cp) > @@ -529,7 +536,15 @@ static int ccw_count_idaws(struct ccw1 *ccw, > iova = ccw->cda; > } > > - return idal_nr_words((void *)iova, bytes); > + /* Format-1 IDAWs operate on 2K each */ > + if (!cp->orb.cmd.c64) > + return idal_2k_nr_words((void *)iova, bytes); > + > + /* Format-2 IDAWs operate on either 2K or 4K */ > + if (cp->orb.cmd.i2k) > + return idal_2k_nr_words((void *)iova, bytes); > + else Nit: The else is unnecessary, just unconditionally return idal_nr_words if you reach the end of the function. Either way: Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> > + return idal_nr_words((void *)iova, bytes); > } > > static int ccwchain_fetch_ccw(struct ccw1 *ccw,
diff --git a/arch/s390/include/asm/idals.h b/arch/s390/include/asm/idals.h index 40eae2c08d61..0a05a893aedb 100644 --- a/arch/s390/include/asm/idals.h +++ b/arch/s390/include/asm/idals.h @@ -23,6 +23,9 @@ #define IDA_SIZE_LOG 12 /* 11 for 2k , 12 for 4k */ #define IDA_BLOCK_SIZE (1L<<IDA_SIZE_LOG) +#define IDA_2K_SIZE_LOG 11 +#define IDA_2K_BLOCK_SIZE (1L << IDA_2K_SIZE_LOG) + /* * Test if an address/length pair needs an idal list. */ @@ -42,6 +45,15 @@ static inline unsigned int idal_nr_words(void *vaddr, unsigned int length) (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG; } +/* + * Return the number of 2K IDA words needed for an address/length pair. + */ +static inline unsigned int idal_2k_nr_words(void *vaddr, unsigned int length) +{ + return ((__pa(vaddr) & (IDA_2K_BLOCK_SIZE-1)) + length + + (IDA_2K_BLOCK_SIZE-1)) >> IDA_2K_SIZE_LOG; +} + /* * Create the list of idal words for an address/length pair. */ diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index 53246f4f95f7..6839e7195182 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -502,6 +502,13 @@ static int ccwchain_fetch_tic(struct ccw1 *ccw, * * @ccw: The Channel Command Word being translated * @cp: Channel Program being processed + * + * The ORB is examined, since it specifies what IDAWs could actually be + * used by any CCW in the channel program, regardless of whether or not + * the CCW actually does. An ORB that does not specify Format-2-IDAW + * Control could still contain a CCW with an IDAL, which would be + * Format-1 and thus only move 2K with each IDAW. Thus all CCWs within + * the channel program must follow the same size requirements. */ static int ccw_count_idaws(struct ccw1 *ccw, struct channel_program *cp) @@ -529,7 +536,15 @@ static int ccw_count_idaws(struct ccw1 *ccw, iova = ccw->cda; } - return idal_nr_words((void *)iova, bytes); + /* Format-1 IDAWs operate on 2K each */ + if (!cp->orb.cmd.c64) + return idal_2k_nr_words((void *)iova, bytes); + + /* Format-2 IDAWs operate on either 2K or 4K */ + if (cp->orb.cmd.i2k) + return idal_2k_nr_words((void *)iova, bytes); + else + return idal_nr_words((void *)iova, bytes); } static int ccwchain_fetch_ccw(struct ccw1 *ccw,
The idal_nr_words() routine works well for 4K IDAWs, but lost its ability to handle the old 2K formats with the removal of 31-bit builds in commit 5a79859ae0f3 ("s390: remove 31 bit support"). Since there's nothing preventing a guest from generating this IDAW format, let's re-introduce the math for them and use both when calculating the number of IDAWs based on the bits specified in the ORB. Signed-off-by: Eric Farman <farman@linux.ibm.com> --- arch/s390/include/asm/idals.h | 12 ++++++++++++ drivers/s390/cio/vfio_ccw_cp.c | 17 ++++++++++++++++- 2 files changed, 28 insertions(+), 1 deletion(-)