[PATCH v5 0/2] Q40 IDE fixes

[PATCH v5 0/2] Q40 IDE fixes

[Michael Schmitz]

Version 5 of the pata_falcon bugfix patch for Q40 support.

Review comments from Sergey, Damien and Geert have been addressed.

Cheers,

   Michael

[PATCH v5 1/2] ata: pata_falcon: fix IO base selection for Q40

[Michael Schmitz]

With commit 44b1fbc0f5f3 ("m68k/q40: Replace q40ide driver
with pata_falcon and falconide"), the Q40 IDE driver was
replaced by pata_falcon.c.

Both IO and memory resources were defined for the Q40 IDE
platform device, but definition of the IDE register addresses
was modeled after the Falcon case, both in use of the memory
resources and in including register shift and byte vs. word
offset in the address.

This was correct for the Falcon case, which does not apply
any address translation to the register addresses. In the
Q40 case, all of device base address, byte access offset
and register shift is included in the platform specific
ISA access translation (in asm/mm_io.h).

As a consequence, such address translation gets applied
twice, and register addresses are mangled.

Use the device base address from the platform IO resource
for Q40 (the IO address translation will then add the correct
ISA window base address and byte access offset), with register
shift 1. Use MMIO base address and register shift 2 as before
for Falcon.

Encode PIO_OFFSET into IO port addresses for all registers
for Q40 except the data transfer register. Encode the MMIO
offset there (pata_falcon_data_xfer() directly uses raw IO
with no address translation).

Reported-by: William R Sowerbutts <will@sowerbutts.com>
Closes: https://lore.kernel.org/r/CAMuHMdUU62jjunJh9cqSqHT87B0H0A4udOOPs=WN7WZKpcagVA@mail.gmail.com
Link: https://lore.kernel.org/r/CAMuHMdUU62jjunJh9cqSqHT87B0H0A4udOOPs=WN7WZKpcagVA@mail.gmail.com
Fixes: 44b1fbc0f5f3 ("m68k/q40: Replace q40ide driver with pata_falcon and falconide")
Cc: stable@vger.kernel.org
Cc: Finn Thain <fthain@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: William R Sowerbutts <will@sowerbutts.com>
Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>

---

Changes from v4:

Geert Uytterhoeven:
- use %px for ap->ioaddr.data_addr

Changes from v3:

Sergey Shtylyov:
- change use of reg_scale to reg_shift

Geert Uytterhoeven:
- factor out ata_port_desc() from platform specific code

Changes from v2:

Finn Thain:
- add back stable Cc:

Changes from v1:

Damien Le Moal:
- change patch title
- drop stable backport tag

Changes from RFC v3:

- split off byte swap option into separate patch

Geert Uytterhoeven:
- review comments

Changes from RFC v2:
- add driver parameter 'data_swap' as bit mask for drives to swap

Changes from RFC v1:

Finn Thain:
- take care to supply IO address suitable for ioread8/iowrite8
- use MMIO address for data transfer
---
 drivers/ata/pata_falcon.c | 50 +++++++++++++++++++++++----------------
 1 file changed, 29 insertions(+), 21 deletions(-)

diff --git a/drivers/ata/pata_falcon.c b/drivers/ata/pata_falcon.c
index 996516e64f13..616064b02de6 100644
--- a/drivers/ata/pata_falcon.c
+++ b/drivers/ata/pata_falcon.c
@@ -123,8 +123,8 @@ static int __init pata_falcon_init_one(struct platform_device *pdev)
 	struct resource *base_res, *ctl_res, *irq_res;
 	struct ata_host *host;
 	struct ata_port *ap;
-	void __iomem *base;
-	int irq = 0;
+	void __iomem *base, *ctl_base;
+	int irq = 0, io_offset = 1, reg_shift = 2; /* Falcon defaults */
 
 	dev_info(&pdev->dev, "Atari Falcon and Q40/Q60 PATA controller\n");
 
@@ -165,26 +165,34 @@ static int __init pata_falcon_init_one(struct platform_device *pdev)
 	ap->pio_mask = ATA_PIO4;
 	ap->flags |= ATA_FLAG_SLAVE_POSS | ATA_FLAG_NO_IORDY;
 
-	base = (void __iomem *)base_mem_res->start;
 	/* N.B. this assumes data_addr will be used for word-sized I/O only */
-	ap->ioaddr.data_addr		= base + 0 + 0 * 4;
-	ap->ioaddr.error_addr		= base + 1 + 1 * 4;
-	ap->ioaddr.feature_addr		= base + 1 + 1 * 4;
-	ap->ioaddr.nsect_addr		= base + 1 + 2 * 4;
-	ap->ioaddr.lbal_addr		= base + 1 + 3 * 4;
-	ap->ioaddr.lbam_addr		= base + 1 + 4 * 4;
-	ap->ioaddr.lbah_addr		= base + 1 + 5 * 4;
-	ap->ioaddr.device_addr		= base + 1 + 6 * 4;
-	ap->ioaddr.status_addr		= base + 1 + 7 * 4;
-	ap->ioaddr.command_addr		= base + 1 + 7 * 4;
-
-	base = (void __iomem *)ctl_mem_res->start;
-	ap->ioaddr.altstatus_addr	= base + 1;
-	ap->ioaddr.ctl_addr		= base + 1;
-
-	ata_port_desc(ap, "cmd 0x%lx ctl 0x%lx",
-		      (unsigned long)base_mem_res->start,
-		      (unsigned long)ctl_mem_res->start);
+	ap->ioaddr.data_addr = (void __iomem *)base_mem_res->start;
+
+	if (base_res) {		/* only Q40 has IO resources */
+		io_offset = 0x10000;
+		reg_shift = 0;
+		base = (void __iomem *)base_res->start;
+		ctl_base = (void __iomem *)ctl_res->start;
+	} else {
+		base = (void __iomem *)base_mem_res->start;
+		ctl_base = (void __iomem *)ctl_mem_res->start;
+	}
+
+	ap->ioaddr.error_addr	= base + io_offset + (1 << reg_shift);
+	ap->ioaddr.feature_addr	= base + io_offset + (1 << reg_shift);
+	ap->ioaddr.nsect_addr	= base + io_offset + (2 << reg_shift);
+	ap->ioaddr.lbal_addr	= base + io_offset + (3 << reg_shift);
+	ap->ioaddr.lbam_addr	= base + io_offset + (4 << reg_shift);
+	ap->ioaddr.lbah_addr	= base + io_offset + (5 << reg_shift);
+	ap->ioaddr.device_addr	= base + io_offset + (6 << reg_shift);
+	ap->ioaddr.status_addr	= base + io_offset + (7 << reg_shift);
+	ap->ioaddr.command_addr	= base + io_offset + (7 << reg_shift);
+
+	ap->ioaddr.altstatus_addr	= ctl_base + io_offset;
+	ap->ioaddr.ctl_addr		= ctl_base + io_offset;
+
+	ata_port_desc(ap, "cmd %px ctl %px data %px",
+		      base, ctl_base, ap->ioaddr.data_addr);
 
 	irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 	if (irq_res && irq_res->start > 0) {
-- 
2.17.1

[PATCH v5 2/2] ata: pata_falcon: add data_swab option to byte-swap disk data

[Michael Schmitz]

Some users of pata_falcon on Q40 have IDE disks in default
IDE little endian byte order, whereas legacy disks use
host-native big-endian byte order as on the Atari Falcon.

Add module parameter 'data_swab' to allow connecting drives
with non-native data byte order. Drives selected by the
data_swap bit mask will have their user data byte-swapped to
host byte order, i.e. 'pata_falcon.data_swab=2' will byte-swap
all user data on drive B, leaving data on drive A in native
byte order. On Q40, drives on a second IDE interface may be
added to the bit mask as bits 2 and 3.

Default setting is no byte swapping, i.e. compatibility with
the native Falcon or Q40 operating system disk format.

Cc: William R Sowerbutts <will@sowerbutts.com>
Cc: Finn Thain <fthain@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: William R Sowerbutts <will@sowerbutts.com>
Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>

---

Changes since v4:

Damien Le Moal:
- spell out bitmask shift calculation

Changes since v2:

Geert Uytterhoeven:
- only shift swap bitmask if pdev->id > 0

Finn Thain:
- use pdev->devno directly for byte swap check

Changes since v1:

Damien Le Moal:
- change patch title
- drop swap_data flag

Finn Thain:
- drop allocation of ap->private struct, use field as bitmask

Changes since RFC v4:

Geert Uytterhoeven:
- don't shift static module parameter for drive 3/4 bitmask
- simplify bit mask calculation to always use pdev->id

Finn Thain:
- correct bit numbers for drive 3/4

Changes since RFC v3:

- split off this byte swap handling into separate patch

- add hint regarding third and fourth drive on Q40

Finn Thain:
- rename module parameter to 'data_swab' to better reflect its use

William Sowerbutts:
- correct IDE drive number used in data swap conditional
---
 drivers/ata/pata_falcon.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/ata/pata_falcon.c b/drivers/ata/pata_falcon.c
index 616064b02de6..8da044fa1825 100644
--- a/drivers/ata/pata_falcon.c
+++ b/drivers/ata/pata_falcon.c
@@ -33,6 +33,11 @@
 #define DRV_NAME "pata_falcon"
 #define DRV_VERSION "0.1.0"
 
+static int pata_falcon_swap_mask;
+
+module_param_named(data_swab, pata_falcon_swap_mask, int, 0444);
+MODULE_PARM_DESC(data_swab, "Data byte swap enable/disable bitmap (0x1==drive1, 0x2==drive2, 0x4==drive3, 0x8==drive4, default==0)");
+
 static const struct scsi_host_template pata_falcon_sht = {
 	ATA_PIO_SHT(DRV_NAME),
 };
@@ -50,7 +55,7 @@ static unsigned int pata_falcon_data_xfer(struct ata_queued_cmd *qc,
 
 	if (dev->class == ATA_DEV_ATA && cmd &&
 	    !blk_rq_is_passthrough(scsi_cmd_to_rq(cmd)))
-		swap = 0;
+		swap = (uintptr_t)ap->private_data & BIT(dev->devno);
 
 	/* Transfer multiple of 2 bytes */
 	if (rw == READ) {
@@ -124,7 +129,7 @@ static int __init pata_falcon_init_one(struct platform_device *pdev)
 	struct ata_host *host;
 	struct ata_port *ap;
 	void __iomem *base, *ctl_base;
-	int irq = 0, io_offset = 1, reg_shift = 2; /* Falcon defaults */
+	int irq = 0, io_offset = 1, reg_shift = 2, mask_shift; /* Falcon defaults */
 
 	dev_info(&pdev->dev, "Atari Falcon and Q40/Q60 PATA controller\n");
 
@@ -194,6 +199,12 @@ static int __init pata_falcon_init_one(struct platform_device *pdev)
 	ata_port_desc(ap, "cmd %px ctl %px data %px",
 		      base, ctl_base, ap->ioaddr.data_addr);
 
+	if (pdev->id > 0)
+		mask_shift = 2;
+	else
+		mask_shift = 0;
+	ap->private_data = (void *)(uintptr_t)(pata_falcon_swap_mask >> mask_shift);
+
 	irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 	if (irq_res && irq_res->start > 0) {
 		irq = irq_res->start;
-- 
2.17.1

Re: [PATCH v5 2/2] ata: pata_falcon: add data_swab option to byte-swap disk data

[Geert Uytterhoeven]

Hi Michael,

On Fri, Aug 25, 2023 at 3:13 AM Michael Schmitz <schmitzmic@gmail.com> wrote:
> Some users of pata_falcon on Q40 have IDE disks in default
> IDE little endian byte order, whereas legacy disks use
> host-native big-endian byte order as on the Atari Falcon.
>
> Add module parameter 'data_swab' to allow connecting drives
> with non-native data byte order. Drives selected by the
> data_swap bit mask will have their user data byte-swapped to
> host byte order, i.e. 'pata_falcon.data_swab=2' will byte-swap
> all user data on drive B, leaving data on drive A in native
> byte order. On Q40, drives on a second IDE interface may be
> added to the bit mask as bits 2 and 3.
>
> Default setting is no byte swapping, i.e. compatibility with
> the native Falcon or Q40 operating system disk format.
>
> Cc: William R Sowerbutts <will@sowerbutts.com>
> Cc: Finn Thain <fthain@linux-m68k.org>
> Cc: Geert Uytterhoeven <geert@linux-m68k.org>
> Tested-by: William R Sowerbutts <will@sowerbutts.com>
> Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
> Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
>
> ---
>
> Changes since v4:
>
> Damien Le Moal:
> - spell out bitmask shift calculation

Thanks for the update!

Sorry to bother you again...

> --- a/drivers/ata/pata_falcon.c
> +++ b/drivers/ata/pata_falcon.c

> @@ -124,7 +129,7 @@ static int __init pata_falcon_init_one(struct platform_device *pdev)
>         struct ata_host *host;
>         struct ata_port *ap;
>         void __iomem *base, *ctl_base;
> -       int irq = 0, io_offset = 1, reg_shift = 2; /* Falcon defaults */
> +       int irq = 0, io_offset = 1, reg_shift = 2, mask_shift; /* Falcon defaults */

The comment does not apply to the mask_shift variable, unless you
pre-initialize it to 0...

>
>         dev_info(&pdev->dev, "Atari Falcon and Q40/Q60 PATA controller\n");
>
> @@ -194,6 +199,12 @@ static int __init pata_falcon_init_one(struct platform_device *pdev)
>         ata_port_desc(ap, "cmd %px ctl %px data %px",
>                       base, ctl_base, ap->ioaddr.data_addr);
>
> +       if (pdev->id > 0)
> +               mask_shift = 2;
> +       else
> +               mask_shift = 0;

... and drop the else.

> +       ap->private_data = (void *)(uintptr_t)(pata_falcon_swap_mask >> mask_shift);
> +
>         irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
>         if (irq_res && irq_res->start > 0) {
>                 irq = irq_res->start;

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v5 2/2] ata: pata_falcon: add data_swab option to byte-swap disk data

[Michael Schmitz]

Hi Geert,

Am 25.08.23 um 19:46 schrieb Geert Uytterhoeven:
> Hi Michael,
>
> On Fri, Aug 25, 2023 at 3:13 AM Michael Schmitz <schmitzmic@gmail.com> wrote:
>> Some users of pata_falcon on Q40 have IDE disks in default
>> IDE little endian byte order, whereas legacy disks use
>> host-native big-endian byte order as on the Atari Falcon.
>>
>> Add module parameter 'data_swab' to allow connecting drives
>> with non-native data byte order. Drives selected by the
>> data_swap bit mask will have their user data byte-swapped to
>> host byte order, i.e. 'pata_falcon.data_swab=2' will byte-swap
>> all user data on drive B, leaving data on drive A in native
>> byte order. On Q40, drives on a second IDE interface may be
>> added to the bit mask as bits 2 and 3.
>>
>> Default setting is no byte swapping, i.e. compatibility with
>> the native Falcon or Q40 operating system disk format.
>>
>> Cc: William R Sowerbutts <will@sowerbutts.com>
>> Cc: Finn Thain <fthain@linux-m68k.org>
>> Cc: Geert Uytterhoeven <geert@linux-m68k.org>
>> Tested-by: William R Sowerbutts <will@sowerbutts.com>
>> Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
>> Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
>> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
>>
>> ---
>>
>> Changes since v4:
>>
>> Damien Le Moal:
>> - spell out bitmask shift calculation
> Thanks for the update!
>
> Sorry to bother you again...
>
>> --- a/drivers/ata/pata_falcon.c
>> +++ b/drivers/ata/pata_falcon.c
>> @@ -124,7 +129,7 @@ static int __init pata_falcon_init_one(struct platform_device *pdev)
>>         struct ata_host *host;
>>         struct ata_port *ap;
>>         void __iomem *base, *ctl_base;
>> -       int irq = 0, io_offset = 1, reg_shift = 2; /* Falcon defaults */
>> +       int irq = 0, io_offset = 1, reg_shift = 2, mask_shift; /* Falcon defaults */
> The comment does not apply to the mask_shift variable, unless you
> pre-initialize it to 0...

It does not apply to mask_shift even then - '0' is the default for the
first Q40 ISA adapter also, not just for Falcon.

I'll move mask_shift to its own line so the comment can be correct.

>
>>         dev_info(&pdev->dev, "Atari Falcon and Q40/Q60 PATA controller\n");
>>
>> @@ -194,6 +199,12 @@ static int __init pata_falcon_init_one(struct platform_device *pdev)
>>         ata_port_desc(ap, "cmd %px ctl %px data %px",
>>                       base, ctl_base, ap->ioaddr.data_addr);
>>
>> +       if (pdev->id > 0)
>> +               mask_shift = 2;
>> +       else
>> +               mask_shift = 0;
> ... and drop the else.

Damien did seem quite partial to that one, so I'll leave it.

Cheers,

    Michael

>
>> +       ap->private_data = (void *)(uintptr_t)(pata_falcon_swap_mask >> mask_shift);
>> +
>>         irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
>>         if (irq_res && irq_res->start > 0) {
>>                 irq = irq_res->start;
> Gr{oetje,eeting}s,
>
>                         Geert
>

Re: [PATCH v5 2/2] ata: pata_falcon: add data_swab option to byte-swap disk data

[Damien Le Moal]

On 8/26/23 09:44, Michael Schmitz wrote:
> Hi Geert,
> 
> Am 25.08.23 um 19:46 schrieb Geert Uytterhoeven:
>> Hi Michael,
>>
>> On Fri, Aug 25, 2023 at 3:13 AM Michael Schmitz <schmitzmic@gmail.com> wrote:
>>> Some users of pata_falcon on Q40 have IDE disks in default
>>> IDE little endian byte order, whereas legacy disks use
>>> host-native big-endian byte order as on the Atari Falcon.
>>>
>>> Add module parameter 'data_swab' to allow connecting drives
>>> with non-native data byte order. Drives selected by the
>>> data_swap bit mask will have their user data byte-swapped to
>>> host byte order, i.e. 'pata_falcon.data_swab=2' will byte-swap
>>> all user data on drive B, leaving data on drive A in native
>>> byte order. On Q40, drives on a second IDE interface may be
>>> added to the bit mask as bits 2 and 3.
>>>
>>> Default setting is no byte swapping, i.e. compatibility with
>>> the native Falcon or Q40 operating system disk format.
>>>
>>> Cc: William R Sowerbutts <will@sowerbutts.com>
>>> Cc: Finn Thain <fthain@linux-m68k.org>
>>> Cc: Geert Uytterhoeven <geert@linux-m68k.org>
>>> Tested-by: William R Sowerbutts <will@sowerbutts.com>
>>> Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
>>> Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
>>> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
>>>
>>> ---
>>>
>>> Changes since v4:
>>>
>>> Damien Le Moal:
>>> - spell out bitmask shift calculation
>> Thanks for the update!
>>
>> Sorry to bother you again...
>>
>>> --- a/drivers/ata/pata_falcon.c
>>> +++ b/drivers/ata/pata_falcon.c
>>> @@ -124,7 +129,7 @@ static int __init pata_falcon_init_one(struct platform_device *pdev)
>>>         struct ata_host *host;
>>>         struct ata_port *ap;
>>>         void __iomem *base, *ctl_base;
>>> -       int irq = 0, io_offset = 1, reg_shift = 2; /* Falcon defaults */
>>> +       int irq = 0, io_offset = 1, reg_shift = 2, mask_shift; /* Falcon defaults */
>> The comment does not apply to the mask_shift variable, unless you
>> pre-initialize it to 0...
> 
> It does not apply to mask_shift even then - '0' is the default for the
> first Q40 ISA adapter also, not just for Falcon.
> 
> I'll move mask_shift to its own line so the comment can be correct.
> 
>>
>>>         dev_info(&pdev->dev, "Atari Falcon and Q40/Q60 PATA controller\n");
>>>
>>> @@ -194,6 +199,12 @@ static int __init pata_falcon_init_one(struct platform_device *pdev)
>>>         ata_port_desc(ap, "cmd %px ctl %px data %px",
>>>                       base, ctl_base, ap->ioaddr.data_addr);
>>>
>>> +       if (pdev->id > 0)
>>> +               mask_shift = 2;
>>> +       else
>>> +               mask_shift = 0;
>> ... and drop the else.
> 
> Damien did seem quite partial to that one, so I'll leave it.

I am OK with mask_shift initialized to 0 when declared.
So whichever you prefer is fine.
What I do not like is the use of "?" instead of the easier to read plain "if" :)

> 
> Cheers,
> 
>     Michael
> 
>>
>>> +       ap->private_data = (void *)(uintptr_t)(pata_falcon_swap_mask >> mask_shift);
>>> +
>>>         irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
>>>         if (irq_res && irq_res->start > 0) {
>>>                 irq = irq_res->start;
>> Gr{oetje,eeting}s,
>>
>>                         Geert
>>
> 

-- 
Damien Le Moal
Western Digital Research

Re: [PATCH v5 0/2] Q40 IDE fixes

[William R Sowerbutts]

I have tested this on my Q40 and I am pleased to report that it works 
(including the feature to selectively byteswap drives)

Thanks!

Will

On Fri, Aug 25, 2023 at 01:13:33PM +1200, Michael Schmitz wrote:
>Version 5 of the pata_falcon bugfix patch for Q40 support.
>
>Review comments from Sergey, Damien and Geert have been addressed.
>
>Cheers,
>
>   Michael
>
>

_________________________________________________________________________
William R Sowerbutts                                  will@sowerbutts.com
"Carpe post meridiem"                               http://sowerbutts.com
         main(){char*s=">#=0> ^#X@#@^7=",c=0,m;for(;c<15;c++)for
         (m=-1;m<7;putchar(m++/6&c%3/2?10:s[c]-31&1<<m?42:32));}