Since not all devices require a 32-bit MSI address, add support to the
PCIe host driver to allow setting the DMA mask to 64-bits. This allows
kernels to disable ZONE_DMA32 and bounce buffering (swiotlb) without
risking not being able to get a 32-bit address during DMA allocation.
Basically, in the slim chance that there are no 32-bit allocations
available, the current PCIe host driver will fail to allocate the
msi_msg page due to a DMA address overflow (seen in [1]). With this
patch, the PCIe driver can advertise 64-bit support via it's MSI
capabilities to hint to the PCIe host driver to set the DMA mask to
64-bits.
[1] https://lore.kernel.org/all/[email protected]/
Signed-off-by: Will McVicker <[email protected]>
---
drivers/pci/controller/dwc/pcie-designware-host.c | 14 ++++++++++++--
drivers/pci/controller/dwc/pcie-designware.c | 9 +++++++++
drivers/pci/controller/dwc/pcie-designware.h | 6 ++++++
3 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 0cfc3c098f13..630615719236 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -338,6 +338,8 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp)
struct platform_device *pdev = to_platform_device(dev);
int ret;
u32 ctrl, num_ctrls;
+ bool msi_64b = false;
+ u16 msi_capabilities;
for (ctrl = 0; ctrl < MAX_MSI_CTRLS; ctrl++)
pp->irq_mask[ctrl] = ~0;
@@ -375,9 +377,17 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp)
dw_chained_msi_isr, pp);
}
- ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
+ msi_capabilities = dw_pcie_msi_capabilities(pci);
+ if (msi_capabilities & PCI_MSI_FLAGS_ENABLE)
+ msi_64b = msi_capabilities & PCI_MSI_FLAGS_64BIT ? true : false;
+
+ dev_dbg(dev, "Setting MSI DMA mask to %s-bit.\n",
+ msi_64b ? "64" : "32");
+ ret = dma_set_mask_and_coherent(dev, msi_64b ?
+ DMA_BIT_MASK(64) : DMA_BIT_MASK(32));
if (ret)
- dev_warn(dev, "Failed to set DMA mask to 32-bit. Devices with only 32-bit MSI support may not work properly\n");
+ dev_warn(dev, "Failed to set DMA mask to %s-bit.\n",
+ msi_64b ? "64" : "32");
pp->msi_page = dma_alloc_coherent(dev, PAGE_SIZE, &pp->msi_data,
GFP_KERNEL);
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index c6725c519a47..8ed402307d7f 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -82,6 +82,15 @@ u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap)
}
EXPORT_SYMBOL_GPL(dw_pcie_find_capability);
+u16 dw_pcie_msi_capabilities(struct dw_pcie *pci)
+{
+ u8 offset;
+
+ offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
+ return dw_pcie_readw_dbi(pci, offset + PCI_MSI_FLAGS);
+}
+EXPORT_SYMBOL_GPL(dw_pcie_msi_capabilities);
+
static u16 dw_pcie_find_next_ext_capability(struct dw_pcie *pci, u16 start,
u8 cap)
{
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 09b887093a84..70a251c8f72b 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -432,6 +432,7 @@ void dw_pcie_host_deinit(struct dw_pcie_rp *pp);
int dw_pcie_allocate_domains(struct dw_pcie_rp *pp);
void __iomem *dw_pcie_own_conf_map_bus(struct pci_bus *bus, unsigned int devfn,
int where);
+u16 dw_pcie_msi_capabilities(struct dw_pcie *pci);
#else
static inline irqreturn_t dw_handle_msi_irq(struct dw_pcie_rp *pp)
{
@@ -462,6 +463,11 @@ static inline void __iomem *dw_pcie_own_conf_map_bus(struct pci_bus *bus,
{
return NULL;
}
+
+static inline u16 dw_pcie_msi_capabilities(struct dw_pcie *pci)
+{
+ return 0;
+}
#endif
#ifdef CONFIG_PCIE_DW_EP
--
2.37.1.559.g78731f0fdb-goog
Hi Will,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on helgaas-pci/next]
[also build test ERROR on linus/master next-20220810]
[cannot apply to v5.19]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Will-McVicker/PCI-dwc-Add-support-for-64-bit-MSI-target-addresses/20220810-020421
base: https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next
config: sparc-buildonly-randconfig-r004-20220810 (https://download.01.org/0day-ci/archive/20220811/[email protected]/config)
compiler: sparc-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/7a41faa4e02a0a8945f79e7af86d10e371b2fc12
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Will-McVicker/PCI-dwc-Add-support-for-64-bit-MSI-target-addresses/20220810-020421
git checkout 7a41faa4e02a0a8945f79e7af86d10e371b2fc12
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=sparc SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <[email protected]>
All errors (new ones prefixed by >>):
>> drivers/pci/controller/dwc/pcie-designware.c:85:5: error: redefinition of 'dw_pcie_msi_capabilities'
85 | u16 dw_pcie_msi_capabilities(struct dw_pcie *pci)
| ^~~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/pci/controller/dwc/pcie-designware.c:20:
drivers/pci/controller/dwc/pcie-designware.h:467:19: note: previous definition of 'dw_pcie_msi_capabilities' with type 'u16(struct dw_pcie *)' {aka 'short unsigned int(struct dw_pcie *)'}
467 | static inline u16 dw_pcie_msi_capabilities(struct dw_pcie *pci)
| ^~~~~~~~~~~~~~~~~~~~~~~~
vim +/dw_pcie_msi_capabilities +85 drivers/pci/controller/dwc/pcie-designware.c
84
> 85 u16 dw_pcie_msi_capabilities(struct dw_pcie *pci)
86 {
87 u8 offset;
88
89 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
90 return dw_pcie_readw_dbi(pci, offset + PCI_MSI_FLAGS);
91 }
92 EXPORT_SYMBOL_GPL(dw_pcie_msi_capabilities);
93
--
0-DAY CI Kernel Test Service
https://01.org/lkp
On Tue, Aug 09, 2022 at 06:00:50PM +0000, Will McVicker wrote:
> + bool msi_64b = false;
Spellt out bit here?
> + msi_capabilities = dw_pcie_msi_capabilities(pci);
> + if (msi_capabilities & PCI_MSI_FLAGS_ENABLE)
> + msi_64b = msi_capabilities & PCI_MSI_FLAGS_64BIT ? true : false;
No need for the tenary operator here:
msi_64bit = msi_capabilities & PCI_MSI_FLAGS_64BIT;
Hi Will,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on helgaas-pci/next]
[also build test ERROR on linus/master next-20220811]
[cannot apply to v5.19]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Will-McVicker/PCI-dwc-Add-support-for-64-bit-MSI-target-addresses/20220810-020421
base: https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next
config: powerpc-randconfig-c003-20220810 (https://download.01.org/0day-ci/archive/20220811/[email protected]/config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 5f1c7e2cc5a3c07cbc2412e851a7283c1841f520)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install powerpc cross compiling tool for clang build
# apt-get install binutils-powerpc-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/7a41faa4e02a0a8945f79e7af86d10e371b2fc12
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Will-McVicker/PCI-dwc-Add-support-for-64-bit-MSI-target-addresses/20220810-020421
git checkout 7a41faa4e02a0a8945f79e7af86d10e371b2fc12
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash drivers/pci/
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <[email protected]>
All errors (new ones prefixed by >>):
>> drivers/pci/controller/dwc/pcie-designware.c:85:5: error: redefinition of 'dw_pcie_msi_capabilities'
u16 dw_pcie_msi_capabilities(struct dw_pcie *pci)
^
drivers/pci/controller/dwc/pcie-designware.h:467:19: note: previous definition is here
static inline u16 dw_pcie_msi_capabilities(struct dw_pcie *pci)
^
1 error generated.
vim +/dw_pcie_msi_capabilities +85 drivers/pci/controller/dwc/pcie-designware.c
84
> 85 u16 dw_pcie_msi_capabilities(struct dw_pcie *pci)
86 {
87 u8 offset;
88
89 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
90 return dw_pcie_readw_dbi(pci, offset + PCI_MSI_FLAGS);
91 }
92 EXPORT_SYMBOL_GPL(dw_pcie_msi_capabilities);
93
--
0-DAY CI Kernel Test Service
https://01.org/lkp
On 08/11/2022, Christoph Hellwig wrote:
> On Tue, Aug 09, 2022 at 06:00:50PM +0000, Will McVicker wrote:
> > + bool msi_64b = false;
>
> Spellt out bit here?
>
> > + msi_capabilities = dw_pcie_msi_capabilities(pci);
> > + if (msi_capabilities & PCI_MSI_FLAGS_ENABLE)
> > + msi_64b = msi_capabilities & PCI_MSI_FLAGS_64BIT ? true : false;
>
> No need for the tenary operator here:
>
> msi_64bit = msi_capabilities & PCI_MSI_FLAGS_64BIT;
Thanks for the suggestions. I'll update in the next patchset.