Hi Will and Rob
Thank you for your quick review comments.
On 7/16/2024 6:42 AM, Rob Herring wrote:
On Tue, Jul 16, 2024 at 09:58:12AM +0100, Will Deacon wrote:
On Mon, Jul 15, 2024 at 11:13:35AM -0700, Mayank Rana wrote:
Add usage of Synopsys Designware PCIe controller based MSI controller to
support MSI functionality with ECAM compliant Synopsys Designware PCIe
controller. To use this functionality add device compatible string as
"snps,dw-pcie-ecam-msi".
Signed-off-by: Mayank Rana <quic_mrana@xxxxxxxxxxx>
---
drivers/pci/controller/pci-host-generic.c | 92 ++++++++++++++++++++++++++++++-
1 file changed, 91 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/controller/pci-host-generic.c b/drivers/pci/controller/pci-host-generic.c
index c2c027f..457ae44 100644
--- a/drivers/pci/controller/pci-host-generic.c
+++ b/drivers/pci/controller/pci-host-generic.c
@@ -8,13 +8,73 @@
* Author: Will Deacon <will.deacon@xxxxxxx>
*/
-#include <linux/kernel.h>
#include <linux/init.h>
+#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/of_address.h>
#include <linux/pci-ecam.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
+#include "dwc/pcie-designware-msi.h"
+
+struct dw_ecam_pcie {
+ void __iomem *cfg;
+ struct dw_msi *msi;
+ struct pci_host_bridge *bridge;
+};
+
+static u32 dw_ecam_pcie_readl(void *p_data, u32 reg)
+{
+ struct dw_ecam_pcie *ecam_pcie = (struct dw_ecam_pcie *)p_data;
+
+ return readl(ecam_pcie->cfg + reg);
+}
+
+static void dw_ecam_pcie_writel(void *p_data, u32 reg, u32 val)
+{
+ struct dw_ecam_pcie *ecam_pcie = (struct dw_ecam_pcie *)p_data;
+
+ writel(val, ecam_pcie->cfg + reg);
+}
+
+static struct dw_ecam_pcie *dw_pcie_ecam_msi(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct dw_ecam_pcie *ecam_pcie;
+ struct dw_msi_ops *msi_ops;
+ u64 addr;
+
+ ecam_pcie = devm_kzalloc(dev, sizeof(*ecam_pcie), GFP_KERNEL);
+ if (!ecam_pcie)
+ return ERR_PTR(-ENOMEM);
+
+ if (of_property_read_reg(dev->of_node, 0, &addr, NULL) < 0) {
Using this function on MMIO addresses is wrong. It is an untranslated
address.
ok. do you prefer me to use of_address_to_resource() instead here ?
+ dev_err(dev, "Failed to get reg address\n");
+ return ERR_PTR(-ENODEV);
+ }
+
+ ecam_pcie->cfg = devm_ioremap(dev, addr, PAGE_SIZE);
+ if (ecam_pcie->cfg == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ msi_ops = devm_kzalloc(dev, sizeof(*msi_ops), GFP_KERNEL);
+ if (!msi_ops)
+ return ERR_PTR(-ENOMEM);
+
+ msi_ops->readl_msi = dw_ecam_pcie_readl;
+ msi_ops->writel_msi = dw_ecam_pcie_writel;
+ msi_ops->pp = ecam_pcie;
+ ecam_pcie->msi = dw_pcie_msi_host_init(pdev, msi_ops, 0);
+ if (IS_ERR(ecam_pcie->msi)) {
+ dev_err(dev, "dw_pcie_msi_host_init() failed\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ dw_pcie_msi_init(ecam_pcie->msi);
+ return ecam_pcie;
+}
Hmm. This looks like quite a lot of not-very-generic code to be adding
to pci-host-generic.c. The file is now, what, 50% designware logic?
Agreed.
I would suggest you add ECAM support to the DW/QCom driver reusing some
of the common ECAM support code.
I can try although there is very limited reusage of code with
pcie-qcom.c and pcie-designware-host.c except reusing MSI functionality.
That would make more new OPs within pcie-designware-host.c and
pcie-qcom.c just to perform few operation. As now MSI functionality is
available outside pcie core designware driver (although those changes
are under review), will you be ok to allow separate Qualcomm PCIe ECAM
driver as previously submitted RFC as
https://lore.kernel.org/all/d10199df-5fb3-407b-b404-a0a4d067341f@xxxxxxxxxxx/T/
I can modify above ECAM driver to call into PCIe designware module based
MSI ops as doing here and that would allow reusing of MSI functionality
at same time allowing separate driver for handling firmware VM based
implementation.
I suppose another option would be to define a node and driver which is
just the DW MSI controller. That might not work given the power domain
being added (which is not very generic either).
yes, I did consider this approach, and haven't used this due to concern
as you mentioned, and also that ask for modifying devicetree usage for
existing user of PCIe Designware controller based MSI controller.
Regards,
Mayank
