[PATCH] soc: ixp4xx/qmgr: fix invalid __iomem access

[PATCH] soc: ixp4xx/qmgr: fix invalid __iomem access

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

Sparse reports a compile time warning when dereferencing an
__iomem pointer:

drivers/soc/ixp4xx/ixp4xx-qmgr.c:149:37: warning: dereference of noderef expression
drivers/soc/ixp4xx/ixp4xx-qmgr.c:153:40: warning: dereference of noderef expression
drivers/soc/ixp4xx/ixp4xx-qmgr.c:154:40: warning: dereference of noderef expression
drivers/soc/ixp4xx/ixp4xx-qmgr.c:174:38: warning: dereference of noderef expression
drivers/soc/ixp4xx/ixp4xx-qmgr.c:174:44: warning: dereference of noderef expression

Use __raw_readl() here for consistency with the rest of the file.
This should really get converted to some proper accessor, as the
__raw functions are not meant to be used in drivers, but the driver
has used these since the start, so for the moment, let's only fix
the warning.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: d4c9e9fc9751 ("IXP42x: Add QMgr support for IXP425 rev. A0 processors.")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/soc/ixp4xx/ixp4xx-qmgr.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/soc/ixp4xx/ixp4xx-qmgr.c b/drivers/soc/ixp4xx/ixp4xx-qmgr.c
index c6bf6ef257c0..9154c7029b05 100644
--- a/drivers/soc/ixp4xx/ixp4xx-qmgr.c
+++ b/drivers/soc/ixp4xx/ixp4xx-qmgr.c
@@ -146,12 +146,12 @@ static irqreturn_t qmgr_irq1_a0(int irq, void *pdev)
 	/* ACK - it may clear any bits so don't rely on it */
 	__raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[0]);
 
-	en_bitmap = qmgr_regs->irqen[0];
+	en_bitmap = __raw_readl(&qmgr_regs->irqen[0]);
 	while (en_bitmap) {
 		i = __fls(en_bitmap); /* number of the last "low" queue */
 		en_bitmap &= ~BIT(i);
-		src = qmgr_regs->irqsrc[i >> 3];
-		stat = qmgr_regs->stat1[i >> 3];
+		src = __raw_readl(&qmgr_regs->irqsrc[i >> 3]);
+		stat = __raw_readl(&qmgr_regs->stat1[i >> 3]);
 		if (src & 4) /* the IRQ condition is inverted */
 			stat = ~stat;
 		if (stat & BIT(src & 3)) {
@@ -171,7 +171,8 @@ static irqreturn_t qmgr_irq2_a0(int irq, void *pdev)
 	/* ACK - it may clear any bits so don't rely on it */
 	__raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[1]);
 
-	req_bitmap = qmgr_regs->irqen[1] & qmgr_regs->statne_h;
+	req_bitmap = __raw_readl(&qmgr_regs->irqen[1]) &
+		     __raw_readl(&qmgr_regs->statne_h);
 	while (req_bitmap) {
 		i = __fls(req_bitmap); /* number of the last "high" queue */
 		req_bitmap &= ~BIT(i);
-- 
2.29.2

Re: [PATCH] soc: ixp4xx/qmgr: fix invalid __iomem access

[Linus Walleij]

On Tue, Aug 3, 2021 at 10:17 AM Arnd Bergmann <arnd@kernel.org> wrote:

> From: Arnd Bergmann <arnd@arndb.de>
>
> Sparse reports a compile time warning when dereferencing an
> __iomem pointer:
>
> drivers/soc/ixp4xx/ixp4xx-qmgr.c:149:37: warning: dereference of noderef expression
> drivers/soc/ixp4xx/ixp4xx-qmgr.c:153:40: warning: dereference of noderef expression
> drivers/soc/ixp4xx/ixp4xx-qmgr.c:154:40: warning: dereference of noderef expression
> drivers/soc/ixp4xx/ixp4xx-qmgr.c:174:38: warning: dereference of noderef expression
> drivers/soc/ixp4xx/ixp4xx-qmgr.c:174:44: warning: dereference of noderef expression
>
> Use __raw_readl() here for consistency with the rest of the file.
> This should really get converted to some proper accessor, as the
> __raw functions are not meant to be used in drivers, but the driver
> has used these since the start, so for the moment, let's only fix
> the warning.
>
> Reported-by: kernel test robot <lkp@intel.com>
> Fixes: d4c9e9fc9751 ("IXP42x: Add QMgr support for IXP425 rev. A0 processors.")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij