From 4be518d838809e21354f32087aa9c26efc50b410 Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Tue, 16 Feb 2021 14:33:07 +1100 Subject: powerpc/iommu: Do not immediately panic when failed IOMMU table allocation Most platforms allocate IOMMU table structures (specifically it_map) at the boot time and when this fails - it is a valid reason for panic(). However the powernv platform allocates it_map after a device is returned to the host OS after being passed through and this happens long after the host OS booted. It is quite possible to trigger the it_map allocation panic() and kill the host even though it is not necessary - the host OS can still use the DMA bypass mode (requires a tiny fraction of it_map's memory) and even if that fails, the host OS is runnnable as it was without the device for which allocating it_map causes the panic. Instead of immediately crashing in a powernv/ioda2 system, this prints an error and continues. All other platforms still call panic(). Signed-off-by: Alexey Kardashevskiy Reviewed-by: David Gibson Reviewed-by: Leonardo Bras Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210216033307.69863-3-aik@ozlabs.ru --- arch/powerpc/kernel/iommu.c | 6 ++++-- arch/powerpc/platforms/cell/iommu.c | 3 ++- arch/powerpc/platforms/pasemi/iommu.c | 4 +++- arch/powerpc/platforms/powernv/pci-ioda.c | 15 ++++++++------- arch/powerpc/platforms/pseries/iommu.c | 10 +++++++--- arch/powerpc/sysdev/dart_iommu.c | 3 ++- 6 files changed, 26 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index 91d0ba7559a6..42e195aaf23a 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -727,8 +727,10 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid, sz = BITS_TO_LONGS(tbl->it_size) * sizeof(unsigned long); tbl->it_map = vzalloc_node(sz, nid); - if (!tbl->it_map) - panic("iommu_init_table: Can't allocate %ld bytes\n", sz); + if (!tbl->it_map) { + pr_err("%s: Can't allocate %ld bytes\n", __func__, sz); + return NULL; + } iommu_table_reserve_pages(tbl, res_start, res_end); diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c index 2124831cf57c..fa08699aedeb 100644 --- a/arch/powerpc/platforms/cell/iommu.c +++ b/arch/powerpc/platforms/cell/iommu.c @@ -486,7 +486,8 @@ cell_iommu_setup_window(struct cbe_iommu *iommu, struct device_node *np, window->table.it_size = size >> window->table.it_page_shift; window->table.it_ops = &cell_iommu_ops; - iommu_init_table(&window->table, iommu->nid, 0, 0); + if (!iommu_init_table(&window->table, iommu->nid, 0, 0)) + panic("Failed to initialize iommu table"); pr_debug("\tioid %d\n", window->ioid); pr_debug("\tblocksize %ld\n", window->table.it_blocksize); diff --git a/arch/powerpc/platforms/pasemi/iommu.c b/arch/powerpc/platforms/pasemi/iommu.c index b500a6e47e6b..5be7242fbd86 100644 --- a/arch/powerpc/platforms/pasemi/iommu.c +++ b/arch/powerpc/platforms/pasemi/iommu.c @@ -146,7 +146,9 @@ static void iommu_table_iobmap_setup(void) */ iommu_table_iobmap.it_blocksize = 4; iommu_table_iobmap.it_ops = &iommu_table_iobmap_ops; - iommu_init_table(&iommu_table_iobmap, 0, 0, 0); + if (!iommu_init_table(&iommu_table_iobmap, 0, 0, 0)) + panic("Failed to initialize iommu table"); + pr_debug(" <- %s\n", __func__); } diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index f0f901683a2f..66c3c3337334 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -1762,7 +1762,8 @@ found: tbl->it_ops = &pnv_ioda1_iommu_ops; pe->table_group.tce32_start = tbl->it_offset << tbl->it_page_shift; pe->table_group.tce32_size = tbl->it_size << tbl->it_page_shift; - iommu_init_table(tbl, phb->hose->node, 0, 0); + if (!iommu_init_table(tbl, phb->hose->node, 0, 0)) + panic("Failed to initialize iommu table"); pe->dma_setup_done = true; return; @@ -1930,16 +1931,16 @@ static long pnv_pci_ioda2_setup_default_config(struct pnv_ioda_pe *pe) res_start = pe->phb->ioda.m32_pci_base >> tbl->it_page_shift; res_end = min(window_size, SZ_4G) >> tbl->it_page_shift; } - iommu_init_table(tbl, pe->phb->hose->node, res_start, res_end); - rc = pnv_pci_ioda2_set_window(&pe->table_group, 0, tbl); + if (iommu_init_table(tbl, pe->phb->hose->node, res_start, res_end)) + rc = pnv_pci_ioda2_set_window(&pe->table_group, 0, tbl); + else + rc = -ENOMEM; if (rc) { - pe_err(pe, "Failed to configure 32-bit TCE table, err %ld\n", - rc); + pe_err(pe, "Failed to configure 32-bit TCE table, err %ld\n", rc); iommu_tce_table_put(tbl); - return rc; + tbl = NULL; /* This clears iommu_table_base below */ } - if (!pnv_iommu_bypass_disabled) pnv_pci_ioda2_set_bypass(pe, true); diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c index 5b3050ff0c55..0c55b991f665 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -638,7 +638,8 @@ static void pci_dma_bus_setup_pSeries(struct pci_bus *bus) iommu_table_setparms(pci->phb, dn, tbl); tbl->it_ops = &iommu_table_pseries_ops; - iommu_init_table(tbl, pci->phb->node, 0, 0); + if (!iommu_init_table(tbl, pci->phb->node, 0, 0)) + panic("Failed to initialize iommu table"); /* Divide the rest (1.75GB) among the children */ pci->phb->dma_window_size = 0x80000000ul; @@ -720,7 +721,8 @@ static void pci_dma_bus_setup_pSeriesLP(struct pci_bus *bus) iommu_table_setparms_lpar(ppci->phb, pdn, tbl, ppci->table_group, dma_window); tbl->it_ops = &iommu_table_lpar_multi_ops; - iommu_init_table(tbl, ppci->phb->node, 0, 0); + if (!iommu_init_table(tbl, ppci->phb->node, 0, 0)) + panic("Failed to initialize iommu table"); iommu_register_group(ppci->table_group, pci_domain_nr(bus), 0); pr_debug(" created table: %p\n", ppci->table_group); @@ -749,7 +751,9 @@ static void pci_dma_dev_setup_pSeries(struct pci_dev *dev) tbl = PCI_DN(dn)->table_group->tables[0]; iommu_table_setparms(phb, dn, tbl); tbl->it_ops = &iommu_table_pseries_ops; - iommu_init_table(tbl, phb->node, 0, 0); + if (!iommu_init_table(tbl, phb->node, 0, 0)) + panic("Failed to initialize iommu table"); + set_iommu_table_base(&dev->dev, tbl); return; } diff --git a/arch/powerpc/sysdev/dart_iommu.c b/arch/powerpc/sysdev/dart_iommu.c index 6b4a34b36d98..1d33b7a5ea83 100644 --- a/arch/powerpc/sysdev/dart_iommu.c +++ b/arch/powerpc/sysdev/dart_iommu.c @@ -344,7 +344,8 @@ static void iommu_table_dart_setup(void) iommu_table_dart.it_index = 0; iommu_table_dart.it_blocksize = 1; iommu_table_dart.it_ops = &iommu_dart_ops; - iommu_init_table(&iommu_table_dart, -1, 0, 0); + if (!iommu_init_table(&iommu_table_dart, -1, 0, 0)) + panic("Failed to initialize iommu table"); /* Reserve the last page of the DART to avoid possible prefetch * past the DART mapped area -- cgit v1.2.3