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Subject: Re: [PATCH v5 07/11] powerpc/pseries/iommu: Reorganize
 iommu_table_setparms*() with new helper
To:     Leonardo Bras <leobras.c@gmail.com>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Alexey Kardashevskiy <aik@ozlabs.ru>,
        David Gibson <david@gibson.dropbear.id.au>,
        kernel test robot <lkp@intel.com>,
        Nicolin Chen <nicoleotsuka@gmail.com>
Cc:     linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
References: <20210716082755.428187-1-leobras.c@gmail.com>
 <20210716082755.428187-8-leobras.c@gmail.com>
From:   Frederic Barrat <fbarrat@linux.ibm.com>
Message-ID: <b1cdc216-31e3-a0ca-7b52-22cf4fa5579a@linux.ibm.com>
Date:   Tue, 20 Jul 2021 19:50:07 +0200
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On 16/07/2021 10:27, Leonardo Bras wrote:
> Add a new helper _iommu_table_setparms(), and use it in
> iommu_table_setparms() and iommu_table_setparms_lpar() to avoid duplicated
> code.
> 
> Also, setting tbl->it_ops was happening outsite iommu_table_setparms*(),
> so move it to the new helper. Since we need the iommu_table_ops to be
> declared before used, declare iommu_table_lpar_multi_ops and
> iommu_table_pseries_ops to before their respective iommu_table_setparms*().
> 
> Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
> ---


Looks good
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>


>   arch/powerpc/platforms/pseries/iommu.c | 72 ++++++++++++++------------
>   1 file changed, 38 insertions(+), 34 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
> index 7ca79a04fa52..108c3dcca686 100644
> --- a/arch/powerpc/platforms/pseries/iommu.c
> +++ b/arch/powerpc/platforms/pseries/iommu.c
> @@ -501,6 +501,24 @@ static int tce_setrange_multi_pSeriesLP_walk(unsigned long start_pfn,
>   	return tce_setrange_multi_pSeriesLP(start_pfn, num_pfn, arg);
>   }
>   
> +static void iommu_table_setparms_common(struct iommu_table *tbl, unsigned long busno,
> +					unsigned long liobn, unsigned long win_addr,
> +					unsigned long window_size, unsigned long page_shift,
> +					void *base, struct iommu_table_ops *table_ops)
> +{
> +	tbl->it_busno = busno;
> +	tbl->it_index = liobn;
> +	tbl->it_offset = win_addr >> page_shift;
> +	tbl->it_size = window_size >> page_shift;
> +	tbl->it_page_shift = page_shift;
> +	tbl->it_base = (unsigned long)base;
> +	tbl->it_blocksize = 16;
> +	tbl->it_type = TCE_PCI;
> +	tbl->it_ops = table_ops;
> +}
> +
> +struct iommu_table_ops iommu_table_pseries_ops;
> +
>   static void iommu_table_setparms(struct pci_controller *phb,
>   				 struct device_node *dn,
>   				 struct iommu_table *tbl)
> @@ -509,8 +527,13 @@ static void iommu_table_setparms(struct pci_controller *phb,
>   	const unsigned long *basep;
>   	const u32 *sizep;
>   
> -	node = phb->dn;
> +	/* Test if we are going over 2GB of DMA space */
> +	if (phb->dma_window_base_cur + phb->dma_window_size > SZ_2G) {
> +		udbg_printf("PCI_DMA: Unexpected number of IOAs under this PHB.\n");
> +		panic("PCI_DMA: Unexpected number of IOAs under this PHB.\n");
> +	}
>   
> +	node = phb->dn;
>   	basep = of_get_property(node, "linux,tce-base", NULL);
>   	sizep = of_get_property(node, "linux,tce-size", NULL);
>   	if (basep == NULL || sizep == NULL) {
> @@ -519,33 +542,18 @@ static void iommu_table_setparms(struct pci_controller *phb,
>   		return;
>   	}
>   
> -	tbl->it_base = (unsigned long)__va(*basep);
> +	iommu_table_setparms_common(tbl, phb->bus->number, 0, phb->dma_window_base_cur,
> +				    phb->dma_window_size, IOMMU_PAGE_SHIFT_4K,
> +				    __va(*basep), &iommu_table_pseries_ops);
>   
>   	if (!is_kdump_kernel())
>   		memset((void *)tbl->it_base, 0, *sizep);
>   
> -	tbl->it_busno = phb->bus->number;
> -	tbl->it_page_shift = IOMMU_PAGE_SHIFT_4K;
> -
> -	/* Units of tce entries */
> -	tbl->it_offset = phb->dma_window_base_cur >> tbl->it_page_shift;
> -
> -	/* Test if we are going over 2GB of DMA space */
> -	if (phb->dma_window_base_cur + phb->dma_window_size > 0x80000000ul) {
> -		udbg_printf("PCI_DMA: Unexpected number of IOAs under this PHB.\n");
> -		panic("PCI_DMA: Unexpected number of IOAs under this PHB.\n");
> -	}
> -
>   	phb->dma_window_base_cur += phb->dma_window_size;
> -
> -	/* Set the tce table size - measured in entries */
> -	tbl->it_size = phb->dma_window_size >> tbl->it_page_shift;
> -
> -	tbl->it_index = 0;
> -	tbl->it_blocksize = 16;
> -	tbl->it_type = TCE_PCI;
>   }
>   
> +struct iommu_table_ops iommu_table_lpar_multi_ops;
> +
>   /*
>    * iommu_table_setparms_lpar
>    *
> @@ -557,17 +565,13 @@ static void iommu_table_setparms_lpar(struct pci_controller *phb,
>   				      struct iommu_table_group *table_group,
>   				      const __be32 *dma_window)
>   {
> -	unsigned long offset, size;
> +	unsigned long offset, size, liobn;
>   
> -	of_parse_dma_window(dn, dma_window, &tbl->it_index, &offset, &size);
> +	of_parse_dma_window(dn, dma_window, &liobn, &offset, &size);
> +
> +	iommu_table_setparms_common(tbl, phb->bus->number, liobn, offset, size, IOMMU_PAGE_SHIFT_4K, NULL,
> +				    &iommu_table_lpar_multi_ops);
>   
> -	tbl->it_busno = phb->bus->number;
> -	tbl->it_page_shift = IOMMU_PAGE_SHIFT_4K;
> -	tbl->it_base   = 0;
> -	tbl->it_blocksize  = 16;
> -	tbl->it_type = TCE_PCI;
> -	tbl->it_offset = offset >> tbl->it_page_shift;
> -	tbl->it_size = size >> tbl->it_page_shift;
>   
>   	table_group->tce32_start = offset;
>   	table_group->tce32_size = size;
> @@ -647,7 +651,7 @@ static void pci_dma_bus_setup_pSeries(struct pci_bus *bus)
>   	tbl = pci->table_group->tables[0];
>   
>   	iommu_table_setparms(pci->phb, dn, tbl);
> -	tbl->it_ops = &iommu_table_pseries_ops;
> +
>   	if (!iommu_init_table(tbl, pci->phb->node, 0, 0))
>   		panic("Failed to initialize iommu table");
>   
> @@ -730,7 +734,7 @@ static void pci_dma_bus_setup_pSeriesLP(struct pci_bus *bus)
>   		tbl = ppci->table_group->tables[0];
>   		iommu_table_setparms_lpar(ppci->phb, pdn, tbl,
>   				ppci->table_group, dma_window);
> -		tbl->it_ops = &iommu_table_lpar_multi_ops;
> +
>   		if (!iommu_init_table(tbl, ppci->phb->node, 0, 0))
>   			panic("Failed to initialize iommu table");
>   		iommu_register_group(ppci->table_group,
> @@ -760,7 +764,7 @@ static void pci_dma_dev_setup_pSeries(struct pci_dev *dev)
>   		PCI_DN(dn)->table_group = iommu_pseries_alloc_group(phb->node);
>   		tbl = PCI_DN(dn)->table_group->tables[0];
>   		iommu_table_setparms(phb, dn, tbl);
> -		tbl->it_ops = &iommu_table_pseries_ops;
> +
>   		if (!iommu_init_table(tbl, phb->node, 0, 0))
>   			panic("Failed to initialize iommu table");
>   
> @@ -1443,7 +1447,7 @@ static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
>   		tbl = pci->table_group->tables[0];
>   		iommu_table_setparms_lpar(pci->phb, pdn, tbl,
>   				pci->table_group, dma_window);
> -		tbl->it_ops = &iommu_table_lpar_multi_ops;
> +
>   		iommu_init_table(tbl, pci->phb->node, 0, 0);
>   		iommu_register_group(pci->table_group,
>   				pci_domain_nr(pci->phb->bus), 0);
>