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From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
Date: Wed, 24 Jan 2024 17:40:39 +0200 (EET)
To: Dan Carpenter <dan.carpenter@linaro.org>
cc: Niklas Cassel <niklas.cassel@wdc.com>, Jingoo Han <jingoohan1@gmail.com>, 
    Gustavo Pimentel <gustavo.pimentel@synopsys.com>, 
    Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>, 
    Lorenzo Pieralisi <lpieralisi@kernel.org>, 
    =?ISO-8859-2?Q?Krzysztof_Wilczy=F1ski?= <kw@linux.com>, 
    Rob Herring <robh@kernel.org>, Bjorn Helgaas <bhelgaas@google.com>, 
    linux-pci@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>, 
    kernel-janitors@vger.kernel.org
Subject: Re: [PATCH v4 1/2] PCI: dwc: Fix a 64bit bug in
 dw_pcie_ep_raise_msix_irq()
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On Wed, 24 Jan 2024, Dan Carpenter wrote:

> The "msg_addr" variable is u64.  However, the "aligned_offset" is an
> unsigned int.  This means that when the code does:
> 
>         msg_addr &= ~aligned_offset;
> 
> it will unintentionally zero out the high 32 bits.  Use ALIGN_DOWN()
> to do the alignment instead.
> 
> Cc: stable@vger.kernel.org
> Fixes: 2217fffcd63f ("PCI: dwc: endpoint: Fix dw_pcie_ep_raise_msix_irq() alignment support")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> Reviewed-by: Niklas Cassel <cassel@kernel.org>
> ---
> v4: Add stable and r-b from Niklas
> v3: Use ALIGN_DOWN()
> v2: fix typo in commit message
> 
>  drivers/pci/controller/dwc/pcie-designware-ep.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index 5befed2dc02b..51679c6702cf 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -551,7 +551,7 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
>  	}
>  
>  	aligned_offset = msg_addr & (epc->mem->window.page_size - 1);
> -	msg_addr &= ~aligned_offset;
> +	msg_addr = ALIGN_DOWN(msg_addr, epc->mem->window.page_size);
>  	ret = dw_pcie_ep_map_addr(epc, func_no, 0, ep->msi_mem_phys, msg_addr,
>  				  epc->mem->window.page_size);
>  	if (ret)

Hi Dan,

You should also add the include for it:

#include <linux/align.h>


-- 
 i.