Re: [PATCH v3 03/27] powerpc: Map & release OpenCAPI LPC memory

[Alastair D'Silva]

On Tue, 2020-02-25 at 11:02 +0100, Frederic Barrat wrote:
> 
> Le 21/02/2020 Ã 04:26, Alastair D'Silva a Ãcrit :
> > From: Alastair D'Silva <alastair@xxxxxxxxxxx>
> > 
> > This patch adds platform support to map & release LPC memory.
> > 
> > Signed-off-by: Alastair D'Silva <alastair@xxxxxxxxxxx>
> > ---
> >   arch/powerpc/include/asm/pnv-ocxl.h   |  4 +++
> >   arch/powerpc/platforms/powernv/ocxl.c | 43
> > +++++++++++++++++++++++++++
> >   2 files changed, 47 insertions(+)
> > 
> > diff --git a/arch/powerpc/include/asm/pnv-ocxl.h
> > b/arch/powerpc/include/asm/pnv-ocxl.h
> > index 7de82647e761..0b2a6707e555 100644
> > --- a/arch/powerpc/include/asm/pnv-ocxl.h
> > +++ b/arch/powerpc/include/asm/pnv-ocxl.h
> > @@ -32,5 +32,9 @@ 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);
> > +#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
> > +u64 pnv_ocxl_platform_lpc_setup(struct pci_dev *pdev, u64 size);
> > +void pnv_ocxl_platform_lpc_release(struct pci_dev *pdev);
> > +#endif
> 
> This breaks the compilation of the ocxl driver if
> CONFIG_MEMORY_HOTPLUG=n
> 
> Those functions still make sense even without memory hotplug, for 
> example in the context of the implementation you had to access
> opencapi 
> LPC memory through mmap(). The #ifdef is really needed only around
> the 
> check_hotplug_memory_addressable() call.
> 
>    Fred

Hmm, we do still need sparsemem though. Let me think about his some
more.

> 
> 
> >   #endif /* _ASM_PNV_OCXL_H */
> > diff --git a/arch/powerpc/platforms/powernv/ocxl.c
> > b/arch/powerpc/platforms/powernv/ocxl.c
> > index 8c65aacda9c8..f2edbcc67361 100644
> > --- a/arch/powerpc/platforms/powernv/ocxl.c
> > +++ b/arch/powerpc/platforms/powernv/ocxl.c
> > @@ -475,6 +475,49 @@ void pnv_ocxl_spa_release(void *platform_data)
> >   }
> >   EXPORT_SYMBOL_GPL(pnv_ocxl_spa_release);
> >   
> > +#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
> > +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;
> > +	u32 bdfn = pci_dev_id(pdev);
> > +	__be64 base_addr_be64;
> > +	u64 base_addr;
> > +	int rc;
> > +
> > +	rc = opal_npu_mem_alloc(phb->opal_id, bdfn, size,
> > &base_addr_be64);
> > +	if (rc) {
> > +		dev_warn(&pdev->dev,
> > +			 "OPAL could not allocate LPC memory, rc=%d\n",
> > rc);
> > +		return 0;
> > +	}
> > +
> > +	base_addr = be64_to_cpu(base_addr_be64);
> > +
> > +	rc = check_hotplug_memory_addressable(base_addr >> PAGE_SHIFT,
> > +					      size >> PAGE_SHIFT);
> > +	if (rc)
> > +		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;
> > +	u32 bdfn = pci_dev_id(pdev);
> > +	int rc;
> > +
> > +	rc = opal_npu_mem_release(phb->opal_id, bdfn);
> > +	if (rc)
> > +		dev_warn(&pdev->dev,
> > +			 "OPAL reported rc=%d when releasing LPC
> > memory\n", rc);
> > +}
> > +EXPORT_SYMBOL_GPL(pnv_ocxl_platform_lpc_release);
> > +#endif
> > +
> >   int pnv_ocxl_spa_remove_pe_from_cache(void *platform_data, int
> > pe_handle)
> >   {
> >   	struct spa_data *data = (struct spa_data *) platform_data;
> > 
-- 
Alastair D'Silva
Open Source Developer
Linux Technology Centre, IBM Australia
mob: 0423 762 819