Messages in this thread | | | Date | Thu, 31 Aug 2023 14:43:53 +0200 | From | Robert Richter <> | Subject | Re: [PATCH v9 02/15] cxl/regs: Prepare for multiple users of register mappings |
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On 29.08.23 14:52:54, Jonathan Cameron wrote: > On Fri, 25 Aug 2023 18:31:58 -0500 > Terry Bowman <terry.bowman@amd.com> wrote: > > > From: Robert Richter <rrichter@amd.com> > > > > The function devm_cxl_iomap_block() is used to map register mappings > > of CXL component or device registers. A @dev is used to unmap the IO > > regions during device removal. > > > > Now, there are multiple devices using the register mappings. E.g. the > > RAS cap of the Component Registers is used by cxl_pci, the HDM cap > > used in cxl_mem. This could cause IO blocks not being freed and a > > subsequent reinitialization to fail if the same device is used for > > both. > > > > To prevent that, expand cxl_map_component_regs() to pass a @dev to be > > used with devm to IO unmap. This allows to pass the device that > > actually is creating and using the IO region. > > > > For symmetry also change the function i/f of cxl_map_device_regs(). > > > > Signed-off-by: Robert Richter <rrichter@amd.com> > > Signed-off-by: Terry Bowman <terry.bowman@amd.com> > > I'm not sure we should leave map->dev around after this change > as it's not obvious where it is valid to use and where it isn't. > > Perhaps we just need to pass the device into the few calls > that use it other than the ones you have here.
I have checked that and it turned out we would need to pass @dev through multiple functions (see cxl_setup_regs()). So I left it in as devm is a special case (mis)using it.
> > This patch itself looks fine to me.
I will take it as a Reviewed-by:?
Thanks,
-Robert
> > Jonathan > > > --- > > drivers/cxl/core/hdm.c | 3 ++- > > drivers/cxl/core/regs.c | 4 ++-- > > drivers/cxl/cxl.h | 2 ++ > > drivers/cxl/pci.c | 4 ++-- > > 4 files changed, 8 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c > > index 4449b34a80cc..17c8ba8c75e0 100644 > > --- a/drivers/cxl/core/hdm.c > > +++ b/drivers/cxl/core/hdm.c > > @@ -98,7 +98,8 @@ static int map_hdm_decoder_regs(struct cxl_port *port, void __iomem *crb, > > return -ENODEV; > > } > > > > - return cxl_map_component_regs(&map, regs, BIT(CXL_CM_CAP_CAP_ID_HDM)); > > + return cxl_map_component_regs(&map, &port->dev, regs, > > + BIT(CXL_CM_CAP_CAP_ID_HDM)); > > } > > > > static bool should_emulate_decoders(struct cxl_endpoint_dvsec_info *info) > > diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c > > index 6281127b3e9d..dfc3e272e7d8 100644 > > --- a/drivers/cxl/core/regs.c > > +++ b/drivers/cxl/core/regs.c > > @@ -201,10 +201,10 @@ void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr, > > } > > > > int cxl_map_component_regs(const struct cxl_register_map *map, > > + struct device *dev, > > struct cxl_component_regs *regs, > > unsigned long map_mask) > > { > > - struct device *dev = map->dev; > > struct mapinfo { > > const struct cxl_reg_map *rmap; > > void __iomem **addr; > > @@ -235,9 +235,9 @@ int cxl_map_component_regs(const struct cxl_register_map *map, > > EXPORT_SYMBOL_NS_GPL(cxl_map_component_regs, CXL); > > > > int cxl_map_device_regs(const struct cxl_register_map *map, > > + struct device *dev, > > struct cxl_device_regs *regs) > > { > > - struct device *dev = map->dev; > > resource_size_t phys_addr = map->resource; > > struct mapinfo { > > const struct cxl_reg_map *rmap; > > diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h > > index 76d92561af29..ec8ba9ebcf64 100644 > > --- a/drivers/cxl/cxl.h > > +++ b/drivers/cxl/cxl.h > > @@ -274,9 +274,11 @@ void cxl_probe_component_regs(struct device *dev, void __iomem *base, > > void cxl_probe_device_regs(struct device *dev, void __iomem *base, > > struct cxl_device_reg_map *map); > > int cxl_map_component_regs(const struct cxl_register_map *map, > > + struct device *dev, > > struct cxl_component_regs *regs, > > unsigned long map_mask); > > int cxl_map_device_regs(const struct cxl_register_map *map, > > + struct device *dev, > > struct cxl_device_regs *regs); > > int cxl_map_pmu_regs(struct pci_dev *pdev, struct cxl_pmu_regs *regs, > > struct cxl_register_map *map); > > diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c > > index 48f88d96029d..88ddcff8a0b2 100644 > > --- a/drivers/cxl/pci.c > > +++ b/drivers/cxl/pci.c > > @@ -827,7 +827,7 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) > > if (rc) > > return rc; > > > > - rc = cxl_map_device_regs(&map, &cxlds->regs.device_regs); > > + rc = cxl_map_device_regs(&map, cxlds->dev, &cxlds->regs.device_regs); > > if (rc) > > return rc; > > > > @@ -844,7 +844,7 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) > > > > cxlds->component_reg_phys = map.resource; > > > > - rc = cxl_map_component_regs(&map, &cxlds->regs.component, > > + rc = cxl_map_component_regs(&map, cxlds->dev, &cxlds->regs.component, > > BIT(CXL_CM_CAP_CAP_ID_RAS)); > > if (rc) > > dev_dbg(&pdev->dev, "Failed to map RAS capability.\n"); >
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