[PATCH kernel v7 19/31] powerpc/powernv/ioda2: Introduce pnv_pci_ioda2_create_table/pnc_pci_free_table

From: Alexey Kardashevskiy
Date: Fri Mar 27 2015 - 11:02:39 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 enforce window size to be a power of two.

This is a pretty mechanical patch.

Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
---
arch/powerpc/platforms/powernv/pci-ioda.c | 85 +++++++++++++++++++++++--------
1 file changed, 63 insertions(+), 22 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index a1e0df9..908863a 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -24,7 +24,9 @@
#include <linux/msi.h>
#include <linux/memblock.h>
#include <linux/iommu.h>
+#include <linux/mmzone.h>

+#include <asm/mmzone.h>
#include <asm/sections.h>
#include <asm/io.h>
#include <asm/prom.h>
@@ -1337,6 +1339,58 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
__free_pages(tce_mem, get_order(TCE32_TABLE_SIZE * segs));
}

+static long pnv_pci_ioda2_create_table(struct pnv_ioda_pe *pe,
+ __u32 page_shift, __u64 window_size,
+ struct iommu_table *tbl)
+{
+ int nid = pe->phb->hose->node;
+ struct page *tce_mem = NULL;
+ void *addr;
+ unsigned long tce_table_size;
+ int64_t rc;
+ unsigned order;
+
+ if ((window_size > memory_hotplug_max()) || !is_power_of_2(window_size))
+ return -EINVAL;
+
+ tce_table_size = (window_size >> page_shift) * 8;
+ tce_table_size = max(0x1000UL, tce_table_size);
+
+ /* Allocate TCE table */
+ order = get_order(tce_table_size);
+
+ tce_mem = alloc_pages_node(nid, GFP_KERNEL, order);
+ if (!tce_mem) {
+ pr_err("Failed to allocate a TCE memory, order=%d\n", order);
+ rc = -ENOMEM;
+ 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,
+ page_shift);
+
+ tbl->it_ops = &pnv_ioda2_iommu_ops;
+
+ return 0;
+fail:
+ if (tce_mem)
+ __free_pages(tce_mem, get_order(tce_table_size));
+
+ return rc;
+}
+
+static void pnv_pci_free_table(struct iommu_table *tbl)
+{
+ if (!tbl->it_size)
+ return;
+
+ free_pages(tbl->it_base, get_order(tbl->it_size << 3));
+ memset(tbl, 0, sizeof(struct iommu_table));
+}
+
static void pnv_pci_ioda2_set_bypass(struct pnv_ioda_pe *pe, bool enable)
{
uint16_t window_id = (pe->pe_number << 1 ) + 1;
@@ -1409,11 +1463,9 @@ static struct iommu_table_group_ops pnv_pci_ioda2_ops = {
static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
struct pnv_ioda_pe *pe)
{
- struct page *tce_mem = NULL;
- void *addr;
const __be64 *swinvp;
- struct iommu_table *tbl;
- unsigned int tce_table_size, end;
+ unsigned int end;
+ struct iommu_table *tbl = &pe->table_group.tables[0];
int64_t rc;

/* We shouldn't already have a 32-bit DMA associated */
@@ -1422,30 +1474,20 @@ 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);

- /* 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");
- goto fail;
+ rc = pnv_pci_ioda2_create_table(pe, 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);
+ return;
}
- addr = page_address(tce_mem);
- memset(addr, 0, tce_table_size);

/* Setup iommu */
pe->table_group.tables[0].it_group = &pe->table_group;
-
- /* Setup linux iommu table */
- tbl = &pe->table_group.tables[0];
- 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);
#ifdef CONFIG_IOMMU_API
pe->table_group.ops = &pnv_pci_ioda2_ops;
@@ -1494,8 +1536,7 @@ 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));
+ pnv_pci_free_table(tbl);
}

static void pnv_ioda_setup_dma(struct pnv_phb *phb)
--
2.0.0

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