On Thu, Mar 10, 2016 at 04:47:04PM +1100, Alexey Kardashevskiy wrote: > On 03/03/2016 12:40 PM, David Gibson wrote: > >On Tue, Mar 01, 2016 at 08:10:27PM +1100, Alexey Kardashevskiy wrote: > >>We are going to have multiple DMA windows soon so let's start preparing. > >> > >>This adds a new helper to create a DMA window and makes use of it in > >>sPAPRPHBState::realize(). > >> > >>Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> > >>--- > >> hw/ppc/spapr_pci.c | 40 +++++++++++++++++++++++++++------------- > >> 1 file changed, 27 insertions(+), 13 deletions(-) > >> > >>diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c > >>index 3d1145e..248f20a 100644 > >>--- a/hw/ppc/spapr_pci.c > >>+++ b/hw/ppc/spapr_pci.c > >>@@ -803,6 +803,29 @@ static char *spapr_phb_get_loc_code(sPAPRPHBState > >>*sphb, PCIDevice *pdev) > >> return buf; > >> } > >> > >>+static int spapr_phb_dma_window_enable(sPAPRPHBState *sphb, > >>+ uint32_t liobn, uint32_t page_shift, > >>+ uint64_t window_addr, > >>+ uint64_t window_size) > >>+{ > >>+ sPAPRTCETable *tcet; > >>+ uint32_t nb_table = window_size >> page_shift; > >>+ > >>+ if (!nb_table) { > >>+ return -1; > >>+ } > > > >The caller shouldn't do this, so this probably makes more sense as an > >assert() than an error return. > > > @dma_win_size is a PHB property so the cli can set it to zero - where is it > supposed to fail? When DMA won't work? This will be not really obvious for > the user. Check dma_win_size==0 where we check mem_win_addr/...?
Ah.. good point. It could be checked in the caller, but it doesn't make a lot of sense to. > >>+ > >>+ tcet = spapr_tce_new_table(DEVICE(sphb), liobn, window_addr, > >>+ page_shift, nb_table, false); > >>+ if (!tcet) { > >>+ return -1; > >>+ } > > > >Since you're adding error reporting, you might as well make it via the > >error API instead of a return code. That way if we wasnt to add more > >detailed error API reporting to spapr_tce_new_table() in future, > >there's less to change. > > Well, the table allocation is the only real thing which may fail there and > spapr_phb_realize() does not pass Error to the callers ?? I'm not sure what you mean by that. > so > spapr_phb_dma_window_enable() would be the first one to propagate an error > and it just seems a bit over engineered. Should I still do that? Yes. You can argue it's overengineered, but better we move towards overengineered in a consistent way, than continue to use a mishmash of error codes and the error api. > > > >>+ > >>+ memory_region_add_subregion(&sphb->iommu_root, tcet->bus_offset, > >>+ spapr_tce_get_iommu(tcet)); > >>+ return 0; > >>+} > >>+ > >> /* Macros to operate with address in OF binding to PCI */ > >> #define b_x(x, p, l) (((x) & ((1<<(l))-1)) << (p)) > >> #define b_n(x) b_x((x), 31, 1) /* 0 if relocatable */ > >>@@ -1228,8 +1251,6 @@ static void spapr_phb_realize(DeviceState *dev, Error > >>**errp) > >> int i; > >> PCIBus *bus; > >> uint64_t msi_window_size = 4096; > >>- sPAPRTCETable *tcet; > >>- uint32_t nb_table; > >> > >> if (sphb->index != (uint32_t)-1) { > >> hwaddr windows_base; > >>@@ -1381,18 +1402,11 @@ static void spapr_phb_realize(DeviceState *dev, > >>Error **errp) > >> } > >> } > >> > >>- nb_table = sphb->dma_win_size >> SPAPR_TCE_PAGE_SHIFT; > >>- tcet = spapr_tce_new_table(DEVICE(sphb), sphb->dma_liobn, > >>- 0, SPAPR_TCE_PAGE_SHIFT, nb_table, false); > >>- if (!tcet) { > >>- error_setg(errp, "Unable to create TCE table for %s", > >>- sphb->dtbusname); > >>- return; > >>- } > >>- > >> /* Register default 32bit DMA window */ > >>- memory_region_add_subregion(&sphb->iommu_root, sphb->dma_win_addr, > >>- spapr_tce_get_iommu(tcet)); > >>+ if (spapr_phb_dma_window_enable(sphb, sphb->dma_liobn, > >>SPAPR_TCE_PAGE_SHIFT, > >>+ sphb->dma_win_addr, > >>sphb->dma_win_size)) { > >>+ error_setg(errp, "Unable to create TCE table for %s", > >>sphb->dtbusname); > >>+ } > >> > >> sphb->msi = g_hash_table_new_full(g_int_hash, g_int_equal, g_free, > >> g_free); > >> } > > > > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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