Re: [PATCH kernel v10 25/34] powerpc/powernv/ioda2: Introduce helpers to allocate TCE pages
From: Gavin Shan
Date: Thu May 14 2015 - 00:32:54 EST
On Tue, May 12, 2015 at 01:39:14AM +1000, Alexey Kardashevskiy wrote:
>This is a part of moving TCE table allocation into an iommu_ops
>callback to support multiple IOMMU groups per one VFIO container.
>
>This moves the code which allocates the actual TCE tables to helpers:
>pnv_pci_ioda2_table_alloc_pages() and pnv_pci_ioda2_table_free_pages().
>These do not allocate/free the iommu_table struct.
>
>This enforces window size to be a power of two.
>
>This should cause no behavioural change.
>
>Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
Reviewed-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
>---
>Changes:
>v10:
>* removed @table_group parameter from pnv_pci_create_table as it was not used
>* removed *tce_table_allocated from pnv_alloc_tce_table_pages()
>* pnv_pci_create_table/pnv_pci_free_table renamed to
>pnv_pci_ioda2_table_alloc_pages/pnv_pci_ioda2_table_free_pages and moved
>back to pci-ioda.c as these only allocate pages for IODA2 and there is
>no chance they will be reused for IODA1/P5IOC2
>* shortened subject line
>
>v9:
>* moved helpers to the common powernv pci.c file from pci-ioda.c
>* moved bits from pnv_pci_create_table() to pnv_alloc_tce_table_pages()
>---
> arch/powerpc/platforms/powernv/pci-ioda.c | 82 +++++++++++++++++++++++--------
> 1 file changed, 62 insertions(+), 20 deletions(-)
>
>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>index 9b80b74..7d98d83 100644
>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>@@ -49,6 +49,8 @@
> /* 256M DMA window, 4K TCE pages, 8 bytes TCE */
> #define TCE32_TABLE_SIZE ((0x10000000 / 0x1000) * 8)
>
>+static void pnv_pci_ioda2_table_free_pages(struct iommu_table *tbl);
>+
> static void pe_level_printk(const struct pnv_ioda_pe *pe, const char *level,
> const char *fmt, ...)
> {
>@@ -1313,8 +1315,8 @@ static void pnv_pci_ioda2_release_dma_pe(struct pci_dev *dev, struct pnv_ioda_pe
> iommu_group_put(pe->table_group.group);
> BUG_ON(pe->table_group.group);
> }
>+ pnv_pci_ioda2_table_free_pages(tbl);
> iommu_free_table(tbl, of_node_full_name(dev->dev.of_node));
>- free_pages(addr, get_order(TCE32_TABLE_SIZE));
> }
>
> static void pnv_ioda_release_vf_PE(struct pci_dev *pdev, u16 num_vfs)
>@@ -2034,13 +2036,62 @@ static struct iommu_table_group_ops pnv_pci_ioda2_ops = {
> };
> #endif
>
>-static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
>- struct pnv_ioda_pe *pe)
>+static __be64 *pnv_pci_ioda2_table_do_alloc_pages(int nid, unsigned shift)
> {
> struct page *tce_mem = NULL;
>+ __be64 *addr;
>+ unsigned order = max_t(unsigned, shift, PAGE_SHIFT) - PAGE_SHIFT;
>+
>+ tce_mem = alloc_pages_node(nid, GFP_KERNEL, order);
>+ if (!tce_mem) {
>+ pr_err("Failed to allocate a TCE memory, order=%d\n", order);
>+ return NULL;
>+ }
>+ addr = page_address(tce_mem);
>+ memset(addr, 0, 1UL << (order + PAGE_SHIFT));
>+
>+ return addr;
>+}
>+
>+static long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset,
>+ __u32 page_shift, __u64 window_size, struct iommu_table *tbl)
>+{
It seems that pci-ioda.c has the convention to have u32/u64, instead of
__u32/__u64.
Thanks,
Gavin
> void *addr;
>+ const unsigned window_shift = ilog2(window_size);
>+ unsigned entries_shift = window_shift - page_shift;
>+ unsigned table_shift = max_t(unsigned, entries_shift + 3, PAGE_SHIFT);
>+ const unsigned long tce_table_size = 1UL << table_shift;
>+
>+ if ((window_size > memory_hotplug_max()) || !is_power_of_2(window_size))
>+ return -EINVAL;
>+
>+ /* Allocate TCE table */
>+ addr = pnv_pci_ioda2_table_do_alloc_pages(nid, table_shift);
>+ if (!addr)
>+ return -ENOMEM;
>+
>+ /* Setup linux iommu table */
>+ pnv_pci_setup_iommu_table(tbl, addr, tce_table_size, bus_offset,
>+ page_shift);
>+
>+ pr_devel("Created TCE table: ws=%08llx ts=%lx @%08llx\n",
>+ window_size, tce_table_size, bus_offset);
>+
>+ return 0;
>+}
>+
>+static void pnv_pci_ioda2_table_free_pages(struct iommu_table *tbl)
>+{
>+ if (!tbl->it_size)
>+ return;
>+
>+ free_pages(tbl->it_base, get_order(tbl->it_size << 3));
>+}
>+
>+static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
>+ struct pnv_ioda_pe *pe)
>+{
> struct iommu_table *tbl;
>- unsigned int tce_table_size, end;
> int64_t rc;
>
> /* We shouldn't already have a 32-bit DMA associated */
>@@ -2059,24 +2110,16 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
>
> /* The PE will reserve all possible 32-bits space */
> pe->tce32_seg = 0;
>- end = (1 << ilog2(phb->ioda.m32_pci_base));
>- tce_table_size = (end / 0x1000) * 8;
> pe_info(pe, "Setting up 32-bit TCE table at 0..%08x\n",
>- end);
>+ phb->ioda.m32_pci_base);
>
>- /* Allocate TCE table */
>- tce_mem = alloc_pages_node(phb->hose->node, GFP_KERNEL,
>- get_order(tce_table_size));
>- if (!tce_mem) {
>- pe_err(pe, "Failed to allocate a 32-bit TCE memory\n");
>+ /* Setup linux iommu table */
>+ rc = pnv_pci_ioda2_table_alloc_pages(pe->phb->hose->node,
>+ 0, IOMMU_PAGE_SHIFT_4K, phb->ioda.m32_pci_base, tbl);
>+ if (rc) {
>+ pe_err(pe, "Failed to create 32-bit TCE table, err %ld", rc);
> goto fail;
> }
>- addr = page_address(tce_mem);
>- memset(addr, 0, tce_table_size);
>-
>- /* Setup linux iommu table */
>- pnv_pci_setup_iommu_table(tbl, addr, tce_table_size, 0,
>- IOMMU_PAGE_SHIFT_4K);
>
> tbl->it_ops = &pnv_ioda2_iommu_ops;
> iommu_init_table(tbl, phb->hose->node);
>@@ -2122,9 +2165,8 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
> fail:
> if (pe->tce32_seg >= 0)
> pe->tce32_seg = -1;
>- if (tce_mem)
>- __free_pages(tce_mem, get_order(tce_table_size));
> if (tbl) {
>+ pnv_pci_ioda2_table_free_pages(tbl);
> pnv_pci_unlink_table_and_group(tbl, &pe->table_group);
> iommu_free_table(tbl, "pnv");
> }
>--
>2.4.0.rc3.8.gfb3e7d5
>
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