diff mbox series

[v2,2/3] scsi: BusLogic remove bus_to_virt

Message ID 20220617125750.728590-3-arnd@kernel.org
State New
Headers show
Series phase out CONFIG_VIRT_TO_BUS | expand

Commit Message

Arnd Bergmann June 17, 2022, 12:57 p.m. UTC 
From: Arnd Bergmann <arnd@arndb.de>

The BusLogic driver is the last remaining driver that relies on the
deprecated bus_to_virt() function, which in turn only works on a few
architectures, and is incompatible with both swiotlb and iommu support.

Before commit 391e2f25601e ("[SCSI] BusLogic: Port driver to 64-bit."),
the driver had a dependency on x86-32, presumably because of this
problem. However, the change introduced another bug that made it still
impossible to use the driver on any 64-bit machine.

This was in turn fixed in commit 56f396146af2 ("scsi: BusLogic: Fix
64-bit system enumeration error for Buslogic"), 8 years later, which
shows that there are not a lot of users.

Maciej is still using the driver on 32-bit hardware, and Khalid mentioned
that the driver works with the device emulation used in VirtualBox
and VMware. Both of those only emulate it for Windows 2000 and older
operating systems that did not ship with the better LSI logic driver.

Do a minimum fix that searches through the list of descriptors to find
one that matches the bus address. This is clearly as inefficient as
was indicated in the code comment about the lack of a bus_to_virt()
replacement. A better fix would likely involve changing out the entire
descriptor allocation for a simpler one, but that would be much
more invasive.

Cc: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: Matt Wang <wwentao@vmware.com>
Cc: Khalid Aziz <khalid@gonehiking.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/scsi/BusLogic.c | 27 ++++++++++++++++-----------
 drivers/scsi/Kconfig    |  2 +-
 2 files changed, 17 insertions(+), 12 deletions(-)

Comments

Robin Murphy June 17, 2022, 2:02 p.m. UTC | #1 
On 2022-06-17 13:57, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The BusLogic driver is the last remaining driver that relies on the
> deprecated bus_to_virt() function, which in turn only works on a few
> architectures, and is incompatible with both swiotlb and iommu support.
> 
> Before commit 391e2f25601e ("[SCSI] BusLogic: Port driver to 64-bit."),
> the driver had a dependency on x86-32, presumably because of this
> problem. However, the change introduced another bug that made it still
> impossible to use the driver on any 64-bit machine.
> 
> This was in turn fixed in commit 56f396146af2 ("scsi: BusLogic: Fix
> 64-bit system enumeration error for Buslogic"), 8 years later, which
> shows that there are not a lot of users.
> 
> Maciej is still using the driver on 32-bit hardware, and Khalid mentioned
> that the driver works with the device emulation used in VirtualBox
> and VMware. Both of those only emulate it for Windows 2000 and older
> operating systems that did not ship with the better LSI logic driver.
> 
> Do a minimum fix that searches through the list of descriptors to find
> one that matches the bus address. This is clearly as inefficient as
> was indicated in the code comment about the lack of a bus_to_virt()
> replacement. A better fix would likely involve changing out the entire
> descriptor allocation for a simpler one, but that would be much
> more invasive.

FWIW, if efficiency *is* a practical concern, even under the current 
allocation scheme it looks like there are only 4 actual DMA allocations 
to search through. From a quick scan (since it's too hot here not to get 
distracted...), if I wanted to optimise this in future I'd probably 
remove the semi-redundant allocgrp_* fields from struct blogic_ccb and 
hang a dedicated list of the block allocations off the adapter - at that 
point the lookup could likely already be more efficient than a 
theoretical dma_to_virt() interface would be if it had to go off and 
walk an IOMMU pagetable. Then the next question would be whether it's 
viable to make a single 32KB allocation rather 4*8KB, so it's no longer 
even a list.

For now, though, I agree with the simple change that's clear and easy to 
reason about:

Reviewed-by: Robin Murphy <robin.murphy@arm.com>

Thanks,
Robin.

> Cc: Maciej W. Rozycki <macro@orcam.me.uk>
> Cc: Matt Wang <wwentao@vmware.com>
> Cc: Khalid Aziz <khalid@gonehiking.org>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>   drivers/scsi/BusLogic.c | 27 ++++++++++++++++-----------
>   drivers/scsi/Kconfig    |  2 +-
>   2 files changed, 17 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/scsi/BusLogic.c b/drivers/scsi/BusLogic.c
> index a897c8f914cf..d057abfcdd5c 100644
> --- a/drivers/scsi/BusLogic.c
> +++ b/drivers/scsi/BusLogic.c
> @@ -2515,12 +2515,26 @@ static int blogic_resultcode(struct blogic_adapter *adapter,
>   	return (hoststatus << 16) | tgt_status;
>   }
>   
> +/*
> + * turn the dma address from an inbox into a ccb pointer
> + * This is rather inefficient.
> + */
> +static struct blogic_ccb *
> +blogic_inbox_to_ccb(struct blogic_adapter *adapter, struct blogic_inbox *inbox)
> +{
> +	struct blogic_ccb *ccb;
> +
> +	for (ccb = adapter->all_ccbs; ccb; ccb = ccb->next_all)
> +		if (inbox->ccb == ccb->dma_handle)
> +			break;
> +
> +	return ccb;
> +}
>   
>   /*
>     blogic_scan_inbox scans the Incoming Mailboxes saving any
>     Incoming Mailbox entries for completion processing.
>   */
> -
>   static void blogic_scan_inbox(struct blogic_adapter *adapter)
>   {
>   	/*
> @@ -2540,16 +2554,7 @@ static void blogic_scan_inbox(struct blogic_adapter *adapter)
>   	enum blogic_cmplt_code comp_code;
>   
>   	while ((comp_code = next_inbox->comp_code) != BLOGIC_INBOX_FREE) {
> -		/*
> -		   We are only allowed to do this because we limit our
> -		   architectures we run on to machines where bus_to_virt(
> -		   actually works.  There *needs* to be a dma_addr_to_virt()
> -		   in the new PCI DMA mapping interface to replace
> -		   bus_to_virt() or else this code is going to become very
> -		   innefficient.
> -		 */
> -		struct blogic_ccb *ccb =
> -			(struct blogic_ccb *) bus_to_virt(next_inbox->ccb);
> +		struct blogic_ccb *ccb = blogic_inbox_to_ccb(adapter, adapter->next_inbox);
>   		if (comp_code != BLOGIC_CMD_NOTFOUND) {
>   			if (ccb->status == BLOGIC_CCB_ACTIVE ||
>   					ccb->status == BLOGIC_CCB_RESET) {
> diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
> index cf75588a2587..56bdc08d0b77 100644
> --- a/drivers/scsi/Kconfig
> +++ b/drivers/scsi/Kconfig
> @@ -513,7 +513,7 @@ config SCSI_HPTIOP
>   
>   config SCSI_BUSLOGIC
>   	tristate "BusLogic SCSI support"
> -	depends on PCI && SCSI && VIRT_TO_BUS
> +	depends on PCI && SCSI
>   	help
>   	  This is support for BusLogic MultiMaster and FlashPoint SCSI Host
>   	  Adapters. Consult the SCSI-HOWTO, available from
Hannes Reinecke June 21, 2022, 8:45 a.m. UTC | #2 
On 6/17/22 14:57, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The BusLogic driver is the last remaining driver that relies on the
> deprecated bus_to_virt() function, which in turn only works on a few
> architectures, and is incompatible with both swiotlb and iommu support.
> 
> Before commit 391e2f25601e ("[SCSI] BusLogic: Port driver to 64-bit."),
> the driver had a dependency on x86-32, presumably because of this
> problem. However, the change introduced another bug that made it still
> impossible to use the driver on any 64-bit machine.
> 
> This was in turn fixed in commit 56f396146af2 ("scsi: BusLogic: Fix
> 64-bit system enumeration error for Buslogic"), 8 years later, which
> shows that there are not a lot of users.
> 
> Maciej is still using the driver on 32-bit hardware, and Khalid mentioned
> that the driver works with the device emulation used in VirtualBox
> and VMware. Both of those only emulate it for Windows 2000 and older
> operating systems that did not ship with the better LSI logic driver.
> 
> Do a minimum fix that searches through the list of descriptors to find
> one that matches the bus address. This is clearly as inefficient as
> was indicated in the code comment about the lack of a bus_to_virt()
> replacement. A better fix would likely involve changing out the entire
> descriptor allocation for a simpler one, but that would be much
> more invasive.
> 
> Cc: Maciej W. Rozycki <macro@orcam.me.uk>
> Cc: Matt Wang <wwentao@vmware.com>
> Cc: Khalid Aziz <khalid@gonehiking.org>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>   drivers/scsi/BusLogic.c | 27 ++++++++++++++++-----------
>   drivers/scsi/Kconfig    |  2 +-
>   2 files changed, 17 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/scsi/BusLogic.c b/drivers/scsi/BusLogic.c
> index a897c8f914cf..d057abfcdd5c 100644
> --- a/drivers/scsi/BusLogic.c
> +++ b/drivers/scsi/BusLogic.c
> @@ -2515,12 +2515,26 @@ static int blogic_resultcode(struct blogic_adapter *adapter,
>   	return (hoststatus << 16) | tgt_status;
>   }
>   
> +/*
> + * turn the dma address from an inbox into a ccb pointer
> + * This is rather inefficient.
> + */
> +static struct blogic_ccb *
> +blogic_inbox_to_ccb(struct blogic_adapter *adapter, struct blogic_inbox *inbox)
> +{
> +	struct blogic_ccb *ccb;
> +
> +	for (ccb = adapter->all_ccbs; ccb; ccb = ccb->next_all)
> +		if (inbox->ccb == ccb->dma_handle)
> +			break;
> +
> +	return ccb;
> +}
>   
>   /*
>     blogic_scan_inbox scans the Incoming Mailboxes saving any
>     Incoming Mailbox entries for completion processing.
>   */
> -
>   static void blogic_scan_inbox(struct blogic_adapter *adapter)
>   {
>   	/*
> @@ -2540,16 +2554,7 @@ static void blogic_scan_inbox(struct blogic_adapter *adapter)
>   	enum blogic_cmplt_code comp_code;
>   
>   	while ((comp_code = next_inbox->comp_code) != BLOGIC_INBOX_FREE) {
> -		/*
> -		   We are only allowed to do this because we limit our
> -		   architectures we run on to machines where bus_to_virt(
> -		   actually works.  There *needs* to be a dma_addr_to_virt()
> -		   in the new PCI DMA mapping interface to replace
> -		   bus_to_virt() or else this code is going to become very
> -		   innefficient.
> -		 */
> -		struct blogic_ccb *ccb =
> -			(struct blogic_ccb *) bus_to_virt(next_inbox->ccb);
> +		struct blogic_ccb *ccb = blogic_inbox_to_ccb(adapter, adapter->next_inbox);
>   		if (comp_code != BLOGIC_CMD_NOTFOUND) {
>   			if (ccb->status == BLOGIC_CCB_ACTIVE ||
>   					ccb->status == BLOGIC_CCB_RESET) {
> diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
> index cf75588a2587..56bdc08d0b77 100644
> --- a/drivers/scsi/Kconfig
> +++ b/drivers/scsi/Kconfig
> @@ -513,7 +513,7 @@ config SCSI_HPTIOP
>   
>   config SCSI_BUSLOGIC
>   	tristate "BusLogic SCSI support"
> -	depends on PCI && SCSI && VIRT_TO_BUS
> +	depends on PCI && SCSI
>   	help
>   	  This is support for BusLogic MultiMaster and FlashPoint SCSI Host
>   	  Adapters. Consult the SCSI-HOWTO, available from

CCB handling in the driver is ugly anyway, so that'll be good enough.

Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
Khalid Aziz June 21, 2022, 9:56 p.m. UTC | #3 
On 6/17/22 06:57, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The BusLogic driver is the last remaining driver that relies on the
> deprecated bus_to_virt() function, which in turn only works on a few
> architectures, and is incompatible with both swiotlb and iommu support.
> 
> Before commit 391e2f25601e ("[SCSI] BusLogic: Port driver to 64-bit."),
> the driver had a dependency on x86-32, presumably because of this
> problem. However, the change introduced another bug that made it still
> impossible to use the driver on any 64-bit machine.
> 
> This was in turn fixed in commit 56f396146af2 ("scsi: BusLogic: Fix
> 64-bit system enumeration error for Buslogic"), 8 years later, which
> shows that there are not a lot of users.
> 
> Maciej is still using the driver on 32-bit hardware, and Khalid mentioned
> that the driver works with the device emulation used in VirtualBox
> and VMware. Both of those only emulate it for Windows 2000 and older
> operating systems that did not ship with the better LSI logic driver.
> 
> Do a minimum fix that searches through the list of descriptors to find
> one that matches the bus address. This is clearly as inefficient as
> was indicated in the code comment about the lack of a bus_to_virt()
> replacement. A better fix would likely involve changing out the entire
> descriptor allocation for a simpler one, but that would be much
> more invasive.
> 
> Cc: Maciej W. Rozycki <macro@orcam.me.uk>
> Cc: Matt Wang <wwentao@vmware.com>
> Cc: Khalid Aziz <khalid@gonehiking.org>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>   drivers/scsi/BusLogic.c | 27 ++++++++++++++++-----------
>   drivers/scsi/Kconfig    |  2 +-
>   2 files changed, 17 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/scsi/BusLogic.c b/drivers/scsi/BusLogic.c
> index a897c8f914cf..d057abfcdd5c 100644
> --- a/drivers/scsi/BusLogic.c
> +++ b/drivers/scsi/BusLogic.c
> @@ -2515,12 +2515,26 @@ static int blogic_resultcode(struct blogic_adapter *adapter,
>   	return (hoststatus << 16) | tgt_status;
>   }
>   
> +/*
> + * turn the dma address from an inbox into a ccb pointer
> + * This is rather inefficient.
> + */
> +static struct blogic_ccb *
> +blogic_inbox_to_ccb(struct blogic_adapter *adapter, struct blogic_inbox *inbox)
> +{
> +	struct blogic_ccb *ccb;
> +
> +	for (ccb = adapter->all_ccbs; ccb; ccb = ccb->next_all)
> +		if (inbox->ccb == ccb->dma_handle)
> +			break;
> +
> +	return ccb;
> +}
>   
>   /*
>     blogic_scan_inbox scans the Incoming Mailboxes saving any
>     Incoming Mailbox entries for completion processing.
>   */
> -
>   static void blogic_scan_inbox(struct blogic_adapter *adapter)
>   {
>   	/*
> @@ -2540,16 +2554,7 @@ static void blogic_scan_inbox(struct blogic_adapter *adapter)
>   	enum blogic_cmplt_code comp_code;
>   
>   	while ((comp_code = next_inbox->comp_code) != BLOGIC_INBOX_FREE) {
> -		/*
> -		   We are only allowed to do this because we limit our
> -		   architectures we run on to machines where bus_to_virt(
> -		   actually works.  There *needs* to be a dma_addr_to_virt()
> -		   in the new PCI DMA mapping interface to replace
> -		   bus_to_virt() or else this code is going to become very
> -		   innefficient.
> -		 */
> -		struct blogic_ccb *ccb =
> -			(struct blogic_ccb *) bus_to_virt(next_inbox->ccb);
> +		struct blogic_ccb *ccb = blogic_inbox_to_ccb(adapter, adapter->next_inbox);

This change looks good enough as workaround to not use bus_to_virt() for 
now. There are two problems I see though. One, I do worry about 
blogic_inbox_to_ccb() returning NULL for ccb which should not happen 
unless the mailbox pointer was corrupted which would indicate a bigger 
problem. Nevertheless a NULL pointer causing kernel panic concerns me. 
How about adding a check before we dereference ccb?

Second, with this patch applied, I am seeing errors from the driver:

=====================
[ 1623.902685]  sdb: sdb1 sdb2
[ 1623.903245] sd 2:0:0:0: [sdb] Attached SCSI disk
[ 1623.911000] scsi2: Illegal CCB #76 status 2 in Incoming Mailbox
[ 1623.911005] scsi2: Illegal CCB #76 status 2 in Incoming Mailbox
[ 1623.911070] scsi2: Illegal CCB #79 status 2 in Incoming Mailbox
[ 1651.458008] scsi2: Warning: Partition Table appears to have Geometry 
256/63 which is
[ 1651.458013] scsi2: not compatible with current BusLogic Host Adapter 
Geometry 255/63
[ 1658.797609] scsi2: Resetting BusLogic BT-958D Failed
[ 1659.533208] sd 2:0:0:0: Device offlined - not ready after error recovery
[ 1659.533331] sd 2:0:0:0: Device offlined - not ready after error recovery
[ 1659.533333] sd 2:0:0:0: Device offlined - not ready after error recovery
[ 1659.533342] sd 2:0:0:0: [sdb] tag#101 FAILED Result: 
hostbyte=DID_TIME_OUT driverbyte=DRIVER_OK cmd_age=35s
[ 1659.533345] sd 2:0:0:0: [sdb] tag#101 CDB: Read(10) 28 00 00 00 00 28 
00 00 10 00
[ 1659.533346] I/O error, dev sdb, sector 40 op 0x0:(READ) flags 0x80700 
phys_seg 1 prio class 0

=================

This is on VirtualBox using emulated BusLogic adapter.

This patch needs more refinement.

Thanks,
Khalid



>   		if (comp_code != BLOGIC_Cn erroneousMD_NOTFOUND) {
>   			if (ccb->status == BLOGIC_CCB_ACTIVE ||
>   					ccb->status == BLOGIC_CCB_RESET) {
> diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
> index cf75588a2587..56bdc08d0b77 100644
> --- a/drivers/scsi/Kconfig
> +++ b/drivers/scsi/Kconfig
> @@ -513,7 +513,7 @@ config SCSI_HPTIOP
>   
>   config SCSI_BUSLOGIC
>   	tristate "BusLogic SCSI support"
> -	depends on PCI && SCSI && VIRT_TO_BUS
> +	depends on PCI && SCSI
>   	help
>   	  This is support for BusLogic MultiMaster and FlashPoint SCSI Host
>   	  Adapters. Consult the SCSI-HOWTO, available from
Arnd Bergmann June 23, 2022, 2:47 p.m. UTC | #4 
On Tue, Jun 21, 2022 at 11:56 PM Khalid Aziz <khalid@gonehiking.org> wrote:
> >       while ((comp_code = next_inbox->comp_code) != BLOGIC_INBOX_FREE) {
> > -             /*
> > -                We are only allowed to do this because we limit our
> > -                architectures we run on to machines where bus_to_virt(
> > -                actually works.  There *needs* to be a dma_addr_to_virt()
> > -                in the new PCI DMA mapping interface to replace
> > -                bus_to_virt() or else this code is going to become very
> > -                innefficient.
> > -              */
> > -             struct blogic_ccb *ccb =
> > -                     (struct blogic_ccb *) bus_to_virt(next_inbox->ccb);
> > +             struct blogic_ccb *ccb = blogic_inbox_to_ccb(adapter, adapter->next_inbox);
>
> This change looks good enough as workaround to not use bus_to_virt() for
> now. There are two problems I see though. One, I do worry about
> blogic_inbox_to_ccb() returning NULL for ccb which should not happen
> unless the mailbox pointer was corrupted which would indicate a bigger
> problem. Nevertheless a NULL pointer causing kernel panic concerns me.
> How about adding a check before we dereference ccb?

Right, makes sense

> Second, with this patch applied, I am seeing errors from the driver:
>
> =====================
> [ 1623.902685]  sdb: sdb1 sdb2
> [ 1623.903245] sd 2:0:0:0: [sdb] Attached SCSI disk
> [ 1623.911000] scsi2: Illegal CCB #76 status 2 in Incoming Mailbox
> [ 1623.911005] scsi2: Illegal CCB #76 status 2 in Incoming Mailbox
> [ 1623.911070] scsi2: Illegal CCB #79 status 2 in Incoming Mailbox
> [ 1651.458008] scsi2: Warning: Partition Table appears to have Geometry
> 256/63 which is
> [ 1651.458013] scsi2: not compatible with current BusLogic Host Adapter
> Geometry 255/63
> [ 1658.797609] scsi2: Resetting BusLogic BT-958D Failed
> [ 1659.533208] sd 2:0:0:0: Device offlined - not ready after error recovery
> [ 1659.533331] sd 2:0:0:0: Device offlined - not ready after error recovery
> [ 1659.533333] sd 2:0:0:0: Device offlined - not ready after error recovery
> [ 1659.533342] sd 2:0:0:0: [sdb] tag#101 FAILED Result:
> hostbyte=DID_TIME_OUT driverbyte=DRIVER_OK cmd_age=35s
> [ 1659.533345] sd 2:0:0:0: [sdb] tag#101 CDB: Read(10) 28 00 00 00 00 28
> 00 00 10 00
> [ 1659.533346] I/O error, dev sdb, sector 40 op 0x0:(READ) flags 0x80700
> phys_seg 1 prio class 0
>
> =================
>
> This is on VirtualBox using emulated BusLogic adapter.
>
> This patch needs more refinement.

Thanks for testing the patch, too bad it didn't work. At least I quickly found
one stupid mistake on my end, hope it's the only one.

Can you test it again with this patch on top?

diff --git a/drivers/scsi/BusLogic.c b/drivers/scsi/BusLogic.c
index d057abfcdd5c..9e67f2ee25ee 100644
--- a/drivers/scsi/BusLogic.c
+++ b/drivers/scsi/BusLogic.c
@@ -2554,8 +2554,14 @@ static void blogic_scan_inbox(struct
blogic_adapter *adapter)
        enum blogic_cmplt_code comp_code;

        while ((comp_code = next_inbox->comp_code) != BLOGIC_INBOX_FREE) {
-               struct blogic_ccb *ccb = blogic_inbox_to_ccb(adapter,
adapter->next_inbox);
-               if (comp_code != BLOGIC_CMD_NOTFOUND) {
+               struct blogic_ccb *ccb = blogic_inbox_to_ccb(adapter,
next_inbox);
+               if (!ccb) {
+                       /*
+                        * This should never happen, unless the CCB list is
+                        * corrupted in memory.
+                        */
+                       blogic_warn("Could not find CCB for dma
address 0x%x\n", adapter, next_inbox->ccb);
+               } else if (comp_code != BLOGIC_CMD_NOTFOUND) {
                        if (ccb->status == BLOGIC_CCB_ACTIVE ||
                                        ccb->status == BLOGIC_CCB_RESET) {
Khalid Aziz June 24, 2022, 3:38 p.m. UTC | #5 
On 6/23/22 08:47, Arnd Bergmann wrote:
> 
> 
> Can you test it again with this patch on top?
> 
> diff --git a/drivers/scsi/BusLogic.c b/drivers/scsi/BusLogic.c
> index d057abfcdd5c..9e67f2ee25ee 100644
> --- a/drivers/scsi/BusLogic.c
> +++ b/drivers/scsi/BusLogic.c
> @@ -2554,8 +2554,14 @@ static void blogic_scan_inbox(struct
> blogic_adapter *adapter)
>          enum blogic_cmplt_code comp_code;
> 
>          while ((comp_code = next_inbox->comp_code) != BLOGIC_INBOX_FREE) {
> -               struct blogic_ccb *ccb = blogic_inbox_to_ccb(adapter,
> adapter->next_inbox);
> -               if (comp_code != BLOGIC_CMD_NOTFOUND) {
> +               struct blogic_ccb *ccb = blogic_inbox_to_ccb(adapter,
> next_inbox);
> +               if (!ccb) {
> +                       /*
> +                        * This should never happen, unless the CCB list is
> +                        * corrupted in memory.
> +                        */
> +                       blogic_warn("Could not find CCB for dma
> address 0x%x\n", adapter, next_inbox->ccb);
> +               } else if (comp_code != BLOGIC_CMD_NOTFOUND) {
>                          if (ccb->status == BLOGIC_CCB_ACTIVE ||
>                                          ccb->status == BLOGIC_CCB_RESET) {

Hi Arnd,

Driver works with this change. next_inbox is the correct pointer to pass.

Thanks,
Khalid
Arnd Bergmann June 24, 2022, 3:43 p.m. UTC | #6 
On Fri, Jun 24, 2022 at 5:38 PM Khalid Aziz <khalid@gonehiking.org> wrote:
> On 6/23/22 08:47, Arnd Bergmann wrote:
>
> Driver works with this change. next_inbox is the correct pointer to pass.

Ok, great! I'll add a 'Tested-by' line then. I was already in the process of
preparing a v3 patch set, will send out the fixed patch in a bit.

         Arnd
diff mbox series

Patch

diff --git a/drivers/scsi/BusLogic.c b/drivers/scsi/BusLogic.c
index a897c8f914cf..d057abfcdd5c 100644
--- a/drivers/scsi/BusLogic.c
+++ b/drivers/scsi/BusLogic.c
@@ -2515,12 +2515,26 @@  static int blogic_resultcode(struct blogic_adapter *adapter,
 	return (hoststatus << 16) | tgt_status;
 }
 
+/*
+ * turn the dma address from an inbox into a ccb pointer
+ * This is rather inefficient.
+ */
+static struct blogic_ccb *
+blogic_inbox_to_ccb(struct blogic_adapter *adapter, struct blogic_inbox *inbox)
+{
+	struct blogic_ccb *ccb;
+
+	for (ccb = adapter->all_ccbs; ccb; ccb = ccb->next_all)
+		if (inbox->ccb == ccb->dma_handle)
+			break;
+
+	return ccb;
+}
 
 /*
   blogic_scan_inbox scans the Incoming Mailboxes saving any
   Incoming Mailbox entries for completion processing.
 */
-
 static void blogic_scan_inbox(struct blogic_adapter *adapter)
 {
 	/*
@@ -2540,16 +2554,7 @@  static void blogic_scan_inbox(struct blogic_adapter *adapter)
 	enum blogic_cmplt_code comp_code;
 
 	while ((comp_code = next_inbox->comp_code) != BLOGIC_INBOX_FREE) {
-		/*
-		   We are only allowed to do this because we limit our
-		   architectures we run on to machines where bus_to_virt(
-		   actually works.  There *needs* to be a dma_addr_to_virt()
-		   in the new PCI DMA mapping interface to replace
-		   bus_to_virt() or else this code is going to become very
-		   innefficient.
-		 */
-		struct blogic_ccb *ccb =
-			(struct blogic_ccb *) bus_to_virt(next_inbox->ccb);
+		struct blogic_ccb *ccb = blogic_inbox_to_ccb(adapter, adapter->next_inbox);
 		if (comp_code != BLOGIC_CMD_NOTFOUND) {
 			if (ccb->status == BLOGIC_CCB_ACTIVE ||
 					ccb->status == BLOGIC_CCB_RESET) {
diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index cf75588a2587..56bdc08d0b77 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -513,7 +513,7 @@  config SCSI_HPTIOP
 
 config SCSI_BUSLOGIC
 	tristate "BusLogic SCSI support"
-	depends on PCI && SCSI && VIRT_TO_BUS
+	depends on PCI && SCSI
 	help
 	  This is support for BusLogic MultiMaster and FlashPoint SCSI Host
 	  Adapters. Consult the SCSI-HOWTO, available from