linux-kernel - Re: [PATCH v3 2/2] PCI: dwc: Cleanup in dw_pcie_ep_raise_msi

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Message-ID: <Za7O7mfuQH7GxWVQ@x1-carbon>
Date: Mon, 22 Jan 2024 21:24:14 +0100
From: Niklas Cassel <cassel@...nel.org>
To: Dan Carpenter <dan.carpenter@...aro.org>
Cc: Jingoo Han <jingoohan1@...il.com>,
	Gustavo Pimentel <gustavo.pimentel@...opsys.com>,
	Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>,
	Lorenzo Pieralisi <lpieralisi@...nel.org>,
	Krzysztof Wilczyński <kw@...ux.com>,
	Rob Herring <robh@...nel.org>, Bjorn Helgaas <bhelgaas@...gle.com>,
	linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
	kernel-janitors@...r.kernel.org
Subject: Re: [PATCH v3 2/2] PCI: dwc: Cleanup in dw_pcie_ep_raise_msi_irq()

On Mon, Jan 22, 2024 at 06:21:00PM +0300, Dan Carpenter wrote:
> I recently changed the code in dw_pcie_ep_raise_msix_irq() to use
> ALIGN_DOWN(). The code in dw_pcie_ep_raise_msi_irq() is similar so
> update it to match as well.  (No effect on runtime, just a cleanup).
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@...aro.org>
> ---
> v2: Add this patch
> v3: Use ALIGN_DOWN() as a style improvement
> 
>  drivers/pci/controller/dwc/pcie-designware-ep.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index 51679c6702cf..1c8d2e938851 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -483,8 +483,8 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
>  		msg_data = dw_pcie_ep_readw_dbi(ep, func_no, reg);
>  	}
>  	aligned_offset = msg_addr_lower & (epc->mem->window.page_size - 1);
> -	msg_addr = ((u64)msg_addr_upper) << 32 |
> -			(msg_addr_lower & ~aligned_offset);
> +	msg_addr = ((u64)msg_addr_upper) << 32 | msg_addr_lower;
> +	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)
> -- 
> 2.43.0
> 

Reviewed-by: Niklas Cassel <cassel@...nel.org>


Although, if I'm being super nitpicky
(sorry... and feel free to ignore),
I think this is slightly cleaner:

--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -482,9 +482,10 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
                reg = ep_func->msi_cap + PCI_MSI_DATA_32;
                msg_data = dw_pcie_ep_readw_dbi(ep, func_no, reg);
        }
-       aligned_offset = msg_addr_lower & (epc->mem->window.page_size - 1);
-       msg_addr = ((u64)msg_addr_upper) << 32 |
-                       (msg_addr_lower & ~aligned_offset);
+       msg_addr = ((u64)msg_addr_upper) << 32 | msg_addr_lower;
+
+       aligned_offset = msg_addr & (epc->mem->window.page_size - 1);
+       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)