2024-01-22 16:47:47

by Dan Carpenter

[permalink] [raw]
Subject: [PATCH v3 1/2] PCI: dwc: Fix a 64bit bug in dw_pcie_ep_raise_msix_irq()

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.

Fixes: 2217fffcd63f ("PCI: dwc: endpoint: Fix dw_pcie_ep_raise_msix_irq() alignment support")
Signed-off-by: Dan Carpenter <[email protected]>
---
v2: fix typo in commit message
v3: Use ALIGN_DOWN() instead of ANDing with ~aligned_offset (this is a
style improvement).

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)
--
2.43.0



2024-01-22 16:48:26

by Dan Carpenter

[permalink] [raw]
Subject: [PATCH v3 2/2] PCI: dwc: Cleanup in dw_pcie_ep_raise_msi_irq()

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 <[email protected]>
---
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


2024-01-22 20:01:07

by Niklas Cassel

[permalink] [raw]
Subject: Re: [PATCH v3 1/2] PCI: dwc: Fix a 64bit bug in dw_pcie_ep_raise_msix_irq()

On Mon, Jan 22, 2024 at 06:19:52PM +0300, 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.
>
> Fixes: 2217fffcd63f ("PCI: dwc: endpoint: Fix dw_pcie_ep_raise_msix_irq() alignment support")
> Signed-off-by: Dan Carpenter <[email protected]>
> ---
> v2: fix typo in commit message
> v3: Use ALIGN_DOWN() instead of ANDing with ~aligned_offset (this is a
> style improvement).
>
> 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)
> --
> 2.43.0
>

Reviewed-by: Niklas Cassel <[email protected]>

2024-01-22 20:24:35

by Niklas Cassel

[permalink] [raw]
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 <[email protected]>
> ---
> 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 <[email protected]>


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)

2024-01-22 20:31:47

by Niklas Cassel

[permalink] [raw]
Subject: Re: [PATCH v3 1/2] PCI: dwc: Fix a 64bit bug in dw_pcie_ep_raise_msix_irq()

On Mon, Jan 22, 2024 at 06:19:52PM +0300, 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.
>
> Fixes: 2217fffcd63f ("PCI: dwc: endpoint: Fix dw_pcie_ep_raise_msix_irq() alignment support")
> Signed-off-by: Dan Carpenter <[email protected]>
> ---
> v2: fix typo in commit message
> v3: Use ALIGN_DOWN() instead of ANDing with ~aligned_offset (this is a
> style improvement).
>
> 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)
> --
> 2.43.0
>

Oh.. I just got emails that the patch that this fixes has been backported,
so perhaps we should add:
Cc: [email protected]
as well...?


Kind regards,
Niklas