diff mbox series

[v2,04/13] drivers/ata: Stop using 32-bit MSR interfaces

Message ID 20260819102314.1499258-5-jgross@suse.com
State New
Headers show
Series x86/msr: Drop 32-bit MSR interfaces | expand

Commit Message

Juergen Gross Aug. 19, 2026, 10:23 a.m. UTC
The 32-bit MSR interfaces rdmsr() and wrmsr() are planned to be
removed. Use the related 64-bit variants instead.

In drivers/ata/pata_cs5536.c don't redefine rdmsr() and wrmsr() as
empty macros for avoiding misuse, but guard the affected code via
a simple #ifdef.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
V2:
- avoid sign extension when using wrmsrq() (Sashiko bot)
---
 drivers/ata/pata_cs5535.c | 20 ++++++++++----------
 drivers/ata/pata_cs5536.c | 17 ++++++++---------
 2 files changed, 18 insertions(+), 19 deletions(-)

Comments

David Laight Aug. 19, 2026, 1:40 p.m. UTC | #1
On Wed, 19 Aug 2026 12:23:05 +0200
Juergen Gross <jgross@suse.com> wrote:

> The 32-bit MSR interfaces rdmsr() and wrmsr() are planned to be
> removed. Use the related 64-bit variants instead.
> 
> In drivers/ata/pata_cs5536.c don't redefine rdmsr() and wrmsr() as
> empty macros for avoiding misuse, but guard the affected code via
> a simple #ifdef.
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>
> ---
> V2:
> - avoid sign extension when using wrmsrq() (Sashiko bot)
> ---
>  drivers/ata/pata_cs5535.c | 20 ++++++++++----------
>  drivers/ata/pata_cs5536.c | 17 ++++++++---------
>  2 files changed, 18 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/ata/pata_cs5535.c b/drivers/ata/pata_cs5535.c
> index d793fc441b46..e16c7f4c7c27 100644
> --- a/drivers/ata/pata_cs5535.c
> +++ b/drivers/ata/pata_cs5535.c
> @@ -90,7 +90,7 @@ static void cs5535_set_piomode(struct ata_port *ap, struct ata_device *adev)
>  	static const u16 pio_cmd_timings[5] = {
>  		0xF7F4, 0x53F3, 0x13F1, 0x5131, 0x1131
>  	};
> -	u32 reg, __maybe_unused dummy;
> +	u32 reg;
>  	struct ata_device *pair = ata_dev_pair(adev);
>  
>  	int mode = adev->pio_mode - XFER_PIO_0;
> @@ -102,16 +102,16 @@ static void cs5535_set_piomode(struct ata_port *ap, struct ata_device *adev)
>  		cmdmode = min(mode, pairmode);
>  		/* Write the other drive timing register if it changed */
>  		if (cmdmode < pairmode)
> -			wrmsr(ATAC_CH0D0_PIO + 2 * pair->devno,
> -				pio_cmd_timings[cmdmode] << 16 | pio_timings[pairmode], 0);
> +			wrmsrq(ATAC_CH0D0_PIO + 2 * pair->devno,
> +				(u32)pio_cmd_timings[cmdmode] << 16 | pio_timings[pairmode]);

That cast is horribly subtle.
Perhaps change the array to be u32 and shift the values in the array initialiser?

David

>  	}
>  	/* Write the drive timing register */
> -	wrmsr(ATAC_CH0D0_PIO + 2 * adev->devno,
> -		pio_cmd_timings[cmdmode] << 16 | pio_timings[mode], 0);
> +	wrmsrq(ATAC_CH0D0_PIO + 2 * adev->devno,
> +		(u32)pio_cmd_timings[cmdmode] << 16 | pio_timings[mode]);
>  
>  	/* Set the PIO "format 1" bit in the DMA timing register */
> -	rdmsr(ATAC_CH0D0_DMA + 2 * adev->devno, reg, dummy);
> -	wrmsr(ATAC_CH0D0_DMA + 2 * adev->devno, reg | 0x80000000UL, 0);
> +	rdmsrq(ATAC_CH0D0_DMA + 2 * adev->devno, reg);
> +	wrmsrq(ATAC_CH0D0_DMA + 2 * adev->devno, reg | 0x80000000UL);
>  }
>  
>  /**
> @@ -129,16 +129,16 @@ static void cs5535_set_dmamode(struct ata_port *ap, struct ata_device *adev)
>  	static const u32 mwdma_timings[3] = {
>  		0x7F0FFFF3, 0x7F035352, 0x7F024241
>  	};
> -	u32 reg, __maybe_unused dummy;
> +	u32 reg;
>  	int mode = adev->dma_mode;
>  
> -	rdmsr(ATAC_CH0D0_DMA + 2 * adev->devno, reg, dummy);
> +	rdmsrq(ATAC_CH0D0_DMA + 2 * adev->devno, reg);
>  	reg &= 0x80000000UL;
>  	if (mode >= XFER_UDMA_0)
>  		reg |= udma_timings[mode - XFER_UDMA_0];
>  	else
>  		reg |= mwdma_timings[mode - XFER_MW_DMA_0];
> -	wrmsr(ATAC_CH0D0_DMA + 2 * adev->devno, reg, 0);
> +	wrmsrq(ATAC_CH0D0_DMA + 2 * adev->devno, reg);
>  }
>  
>  static const struct scsi_host_template cs5535_sht = {
> diff --git a/drivers/ata/pata_cs5536.c b/drivers/ata/pata_cs5536.c
> index 73e81e160c91..61d232a82b5e 100644
> --- a/drivers/ata/pata_cs5536.c
> +++ b/drivers/ata/pata_cs5536.c
> @@ -32,11 +32,8 @@
>  static int use_msr;
>  module_param_named(msr, use_msr, int, 0644);
>  MODULE_PARM_DESC(msr, "Force using MSR to configure IDE function (Default: 0)");
> +#define MAYBE_USE_MSR
>  #else
> -#undef rdmsr	/* avoid accidental MSR usage on, e.g. x86-64 */
> -#undef wrmsr
> -#define rdmsr(x, y, z) do { } while (0)
> -#define wrmsr(x, y, z) do { } while (0)
>  #define use_msr 0
>  #endif
>  
> @@ -85,22 +82,24 @@ static const struct dmi_system_id udma_quirk_dmi_table[] = {
>  
>  static int cs5536_read(struct pci_dev *pdev, int reg, u32 *val)
>  {
> +#ifdef MAYBE_USE_MSR
>  	if (unlikely(use_msr)) {
> -		u32 dummy __maybe_unused;
> -
> -		rdmsr(MSR_IDE_CFG + reg, *val, dummy);
> +		rdmsrq(MSR_IDE_CFG + reg, *val);
>  		return 0;
>  	}
> +#endif
>  
>  	return pci_read_config_dword(pdev, PCI_IDE_CFG + reg * 4, val);
>  }
>  
> -static int cs5536_write(struct pci_dev *pdev, int reg, int val)
> +static int cs5536_write(struct pci_dev *pdev, int reg, u32 val)
>  {
> +#ifdef MAYBE_USE_MSR
>  	if (unlikely(use_msr)) {
> -		wrmsr(MSR_IDE_CFG + reg, val, 0);
> +		wrmsrq(MSR_IDE_CFG + reg, val);
>  		return 0;
>  	}
> +#endif
>  
>  	return pci_write_config_dword(pdev, PCI_IDE_CFG + reg * 4, val);
>  }
Juergen Gross Aug. 19, 2026, 3:27 p.m. UTC | #2
On 19.08.26 15:40, David Laight wrote:
> On Wed, 19 Aug 2026 12:23:05 +0200
> Juergen Gross <jgross@suse.com> wrote:
> 
>> The 32-bit MSR interfaces rdmsr() and wrmsr() are planned to be
>> removed. Use the related 64-bit variants instead.
>>
>> In drivers/ata/pata_cs5536.c don't redefine rdmsr() and wrmsr() as
>> empty macros for avoiding misuse, but guard the affected code via
>> a simple #ifdef.
>>
>> Signed-off-by: Juergen Gross <jgross@suse.com>
>> ---
>> V2:
>> - avoid sign extension when using wrmsrq() (Sashiko bot)
>> ---
>>   drivers/ata/pata_cs5535.c | 20 ++++++++++----------
>>   drivers/ata/pata_cs5536.c | 17 ++++++++---------
>>   2 files changed, 18 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/ata/pata_cs5535.c b/drivers/ata/pata_cs5535.c
>> index d793fc441b46..e16c7f4c7c27 100644
>> --- a/drivers/ata/pata_cs5535.c
>> +++ b/drivers/ata/pata_cs5535.c
>> @@ -90,7 +90,7 @@ static void cs5535_set_piomode(struct ata_port *ap, struct ata_device *adev)
>>   	static const u16 pio_cmd_timings[5] = {
>>   		0xF7F4, 0x53F3, 0x13F1, 0x5131, 0x1131
>>   	};
>> -	u32 reg, __maybe_unused dummy;
>> +	u32 reg;
>>   	struct ata_device *pair = ata_dev_pair(adev);
>>   
>>   	int mode = adev->pio_mode - XFER_PIO_0;
>> @@ -102,16 +102,16 @@ static void cs5535_set_piomode(struct ata_port *ap, struct ata_device *adev)
>>   		cmdmode = min(mode, pairmode);
>>   		/* Write the other drive timing register if it changed */
>>   		if (cmdmode < pairmode)
>> -			wrmsr(ATAC_CH0D0_PIO + 2 * pair->devno,
>> -				pio_cmd_timings[cmdmode] << 16 | pio_timings[pairmode], 0);
>> +			wrmsrq(ATAC_CH0D0_PIO + 2 * pair->devno,
>> +				(u32)pio_cmd_timings[cmdmode] << 16 | pio_timings[pairmode]);
> 
> That cast is horribly subtle.
> Perhaps change the array to be u32 and shift the values in the array initialiser?

I like this idea.

I'll send V3 for this patch only as a reply to V2 of this patch.


Juergen
diff mbox series

Patch

diff --git a/drivers/ata/pata_cs5535.c b/drivers/ata/pata_cs5535.c
index d793fc441b46..e16c7f4c7c27 100644
--- a/drivers/ata/pata_cs5535.c
+++ b/drivers/ata/pata_cs5535.c
@@ -90,7 +90,7 @@  static void cs5535_set_piomode(struct ata_port *ap, struct ata_device *adev)
 	static const u16 pio_cmd_timings[5] = {
 		0xF7F4, 0x53F3, 0x13F1, 0x5131, 0x1131
 	};
-	u32 reg, __maybe_unused dummy;
+	u32 reg;
 	struct ata_device *pair = ata_dev_pair(adev);
 
 	int mode = adev->pio_mode - XFER_PIO_0;
@@ -102,16 +102,16 @@  static void cs5535_set_piomode(struct ata_port *ap, struct ata_device *adev)
 		cmdmode = min(mode, pairmode);
 		/* Write the other drive timing register if it changed */
 		if (cmdmode < pairmode)
-			wrmsr(ATAC_CH0D0_PIO + 2 * pair->devno,
-				pio_cmd_timings[cmdmode] << 16 | pio_timings[pairmode], 0);
+			wrmsrq(ATAC_CH0D0_PIO + 2 * pair->devno,
+				(u32)pio_cmd_timings[cmdmode] << 16 | pio_timings[pairmode]);
 	}
 	/* Write the drive timing register */
-	wrmsr(ATAC_CH0D0_PIO + 2 * adev->devno,
-		pio_cmd_timings[cmdmode] << 16 | pio_timings[mode], 0);
+	wrmsrq(ATAC_CH0D0_PIO + 2 * adev->devno,
+		(u32)pio_cmd_timings[cmdmode] << 16 | pio_timings[mode]);
 
 	/* Set the PIO "format 1" bit in the DMA timing register */
-	rdmsr(ATAC_CH0D0_DMA + 2 * adev->devno, reg, dummy);
-	wrmsr(ATAC_CH0D0_DMA + 2 * adev->devno, reg | 0x80000000UL, 0);
+	rdmsrq(ATAC_CH0D0_DMA + 2 * adev->devno, reg);
+	wrmsrq(ATAC_CH0D0_DMA + 2 * adev->devno, reg | 0x80000000UL);
 }
 
 /**
@@ -129,16 +129,16 @@  static void cs5535_set_dmamode(struct ata_port *ap, struct ata_device *adev)
 	static const u32 mwdma_timings[3] = {
 		0x7F0FFFF3, 0x7F035352, 0x7F024241
 	};
-	u32 reg, __maybe_unused dummy;
+	u32 reg;
 	int mode = adev->dma_mode;
 
-	rdmsr(ATAC_CH0D0_DMA + 2 * adev->devno, reg, dummy);
+	rdmsrq(ATAC_CH0D0_DMA + 2 * adev->devno, reg);
 	reg &= 0x80000000UL;
 	if (mode >= XFER_UDMA_0)
 		reg |= udma_timings[mode - XFER_UDMA_0];
 	else
 		reg |= mwdma_timings[mode - XFER_MW_DMA_0];
-	wrmsr(ATAC_CH0D0_DMA + 2 * adev->devno, reg, 0);
+	wrmsrq(ATAC_CH0D0_DMA + 2 * adev->devno, reg);
 }
 
 static const struct scsi_host_template cs5535_sht = {
diff --git a/drivers/ata/pata_cs5536.c b/drivers/ata/pata_cs5536.c
index 73e81e160c91..61d232a82b5e 100644
--- a/drivers/ata/pata_cs5536.c
+++ b/drivers/ata/pata_cs5536.c
@@ -32,11 +32,8 @@ 
 static int use_msr;
 module_param_named(msr, use_msr, int, 0644);
 MODULE_PARM_DESC(msr, "Force using MSR to configure IDE function (Default: 0)");
+#define MAYBE_USE_MSR
 #else
-#undef rdmsr	/* avoid accidental MSR usage on, e.g. x86-64 */
-#undef wrmsr
-#define rdmsr(x, y, z) do { } while (0)
-#define wrmsr(x, y, z) do { } while (0)
 #define use_msr 0
 #endif
 
@@ -85,22 +82,24 @@  static const struct dmi_system_id udma_quirk_dmi_table[] = {
 
 static int cs5536_read(struct pci_dev *pdev, int reg, u32 *val)
 {
+#ifdef MAYBE_USE_MSR
 	if (unlikely(use_msr)) {
-		u32 dummy __maybe_unused;
-
-		rdmsr(MSR_IDE_CFG + reg, *val, dummy);
+		rdmsrq(MSR_IDE_CFG + reg, *val);
 		return 0;
 	}
+#endif
 
 	return pci_read_config_dword(pdev, PCI_IDE_CFG + reg * 4, val);
 }
 
-static int cs5536_write(struct pci_dev *pdev, int reg, int val)
+static int cs5536_write(struct pci_dev *pdev, int reg, u32 val)
 {
+#ifdef MAYBE_USE_MSR
 	if (unlikely(use_msr)) {
-		wrmsr(MSR_IDE_CFG + reg, val, 0);
+		wrmsrq(MSR_IDE_CFG + reg, val);
 		return 0;
 	}
+#endif
 
 	return pci_write_config_dword(pdev, PCI_IDE_CFG + reg * 4, val);
 }