[PATCH kernel v10 25/34] powerpc/powernv/ioda2: Introduce helpers to allocate TCE pages

From: Alexey Kardashevskiy
Date: Mon May 11 2015 - 11:41:10 EST


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>
---
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)
+{
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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