Re: [PATCH 2/5] powerpc: Map & release OpenCAPI LPC memory

[Frederic Barrat <fbarrat@linux.ibm.com>]

Le 17/09/2019 à 03:42, Alastair D'Silva a écrit :
> From: Alastair D'Silva <alastair@d-silva.org>
> 
> Map & release OpenCAPI LPC memory.
> 
> Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
> ---
>   arch/powerpc/include/asm/pnv-ocxl.h   |  2 ++
>   arch/powerpc/platforms/powernv/ocxl.c | 42 +++++++++++++++++++++++++++
>   2 files changed, 44 insertions(+)
> 
> diff --git a/arch/powerpc/include/asm/pnv-ocxl.h b/arch/powerpc/include/asm/pnv-ocxl.h
> index 7de82647e761..f8f8ffb48aa8 100644
> --- a/arch/powerpc/include/asm/pnv-ocxl.h
> +++ b/arch/powerpc/include/asm/pnv-ocxl.h
> @@ -32,5 +32,7 @@ extern int pnv_ocxl_spa_remove_pe_from_cache(void *platform_data, int pe_handle)
>   
>   extern int pnv_ocxl_alloc_xive_irq(u32 *irq, u64 *trigger_addr);
>   extern void pnv_ocxl_free_xive_irq(u32 irq);
> +extern u64 pnv_ocxl_platform_lpc_setup(struct pci_dev *pdev, u64 size);
> +extern void pnv_ocxl_platform_lpc_release(struct pci_dev *pdev);
>   
>   #endif /* _ASM_PNV_OCXL_H */
> diff --git a/arch/powerpc/platforms/powernv/ocxl.c b/arch/powerpc/platforms/powernv/ocxl.c
> index 8c65aacda9c8..81393728d6a3 100644
> --- a/arch/powerpc/platforms/powernv/ocxl.c
> +++ b/arch/powerpc/platforms/powernv/ocxl.c
> @@ -475,6 +475,48 @@ void pnv_ocxl_spa_release(void *platform_data)
>   }
>   EXPORT_SYMBOL_GPL(pnv_ocxl_spa_release);
>   
> +u64 pnv_ocxl_platform_lpc_setup(struct pci_dev *pdev, u64 size)
> +{
> +	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
> +	struct pnv_phb *phb = hose->private_data;
> +	struct pci_dn *pdn = pci_get_pdn(pdev);
> +	u32 bdfn = (pdn->busno << 8) | pdn->devfn;


We can spare a call to pci_get_pdn() with
bdfn = (pdev->bus->number << 8) | pdev->devfn;


> +	u64 base_addr = 0;
> +
> +	int rc = opal_npu_mem_alloc(phb->opal_id, bdfn, size, &base_addr);
> +
> +	WARN_ON(rc);

Instead of a WARN, we should catch the error and return a null address 
to the caller.

> +
> +	base_addr = be64_to_cpu(base_addr);
> +
> +	rc = check_hotplug_memory_addressable(base_addr, base_addr + size);


That code is missing?


> +	if (rc) {
> +		dev_warn(&pdev->dev,
> +			 "LPC memory range 0x%llx-0x%llx is not fully addressable",
> +			 base_addr, base_addr + size - 1);
> +		return 0;
> +	}
> +
> +
> +	return base_addr;
> +}
> +EXPORT_SYMBOL_GPL(pnv_ocxl_platform_lpc_setup);
> +
> +void pnv_ocxl_platform_lpc_release(struct pci_dev *pdev)
> +{
> +	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
> +	struct pnv_phb *phb = hose->private_data;
> +	struct pci_dn *pdn = pci_get_pdn(pdev);
> +	u32 bdfn;
> +	int rc;
> +
> +	bdfn = (pdn->busno << 8) | pdn->devfn;
> +	rc = opal_npu_mem_release(phb->opal_id, bdfn);
> +	WARN_ON(rc);


Same comments as above.

   Fred



> +}
> +EXPORT_SYMBOL_GPL(pnv_ocxl_platform_lpc_release);
> +
> +
>   int pnv_ocxl_spa_remove_pe_from_cache(void *platform_data, int pe_handle)
>   {
>   	struct spa_data *data = (struct spa_data *) platform_data;
>