This adds multi-level TCE tables support to pnv_pci_ioda2_create_table()
and pnv_pci_ioda2_free_table() callbacks.

Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
 arch/powerpc/include/asm/iommu.h          |   4 +
 arch/powerpc/platforms/powernv/pci-ioda.c | 125 +++++++++++++++++++++++-------
 arch/powerpc/platforms/powernv/pci.c      |  19 +++++
 3 files changed, 122 insertions(+), 26 deletions(-)

diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index cc26eca..283f70f 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -85,6 +85,8 @@ struct iommu_pool {
 struct iommu_table {
        unsigned long  it_busno;     /* Bus number this table belongs to */
        unsigned long  it_size;      /* Size of iommu table in entries */
+       unsigned long  it_indirect_levels;
+       unsigned long  it_level_size;
        unsigned long  it_offset;    /* Offset into global table */
        unsigned long  it_base;      /* mapped address of tce table */
        unsigned long  it_index;     /* which iommu table this is */
@@ -133,6 +135,8 @@ extern struct iommu_table *iommu_init_table(struct 
iommu_table * tbl,
 
 #define POWERPC_IOMMU_MAX_TABLES       1
 
+#define POWERPC_IOMMU_DEFAULT_LEVELS   1
+
 struct powerpc_iommu;
 
 struct powerpc_iommu_ops {
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c 
b/arch/powerpc/platforms/powernv/pci-ioda.c
index 1f725d4..f542819 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1295,16 +1295,79 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb 
*phb,
                __free_pages(tce_mem, get_order(TCE32_TABLE_SIZE * segs));
 }
 
+static void pnv_free_tce_table(unsigned long addr, unsigned size,
+               unsigned level)
+{
+       addr &= ~(TCE_PCI_READ | TCE_PCI_WRITE);
+
+       if (level) {
+               long i;
+               u64 *tmp = (u64 *) addr;
+
+               for (i = 0; i < size; ++i) {
+                       unsigned long hpa = be64_to_cpu(tmp[i]);
+
+                       if (!(hpa & (TCE_PCI_READ | TCE_PCI_WRITE)))
+                               continue;
+
+                       pnv_free_tce_table((unsigned long) __va(hpa),
+                                       size, level - 1);
+               }
+       }
+
+       free_pages(addr, get_order(size << 3));
+}
+
+static __be64 *pnv_alloc_tce_table(int nid,
+               unsigned shift, unsigned levels, unsigned long *left)
+{
+       struct page *tce_mem = NULL;
+       __be64 *addr, *tmp;
+       unsigned order = max_t(unsigned, shift, PAGE_SHIFT) - PAGE_SHIFT;
+       unsigned long chunk = 1UL << shift, i;
+
+       tce_mem = alloc_pages_node(nid, GFP_KERNEL, order);
+       if (!tce_mem) {
+               pr_err("Failed to allocate a TCE memory\n");
+               return NULL;
+       }
+
+       if (!*left)
+               return NULL;
+
+       addr = page_address(tce_mem);
+       memset(addr, 0, chunk);
+
+       --levels;
+       if (!levels) {
+               /* This is last level, actual TCEs */
+               *left -= min(*left, chunk);
+               return addr;
+       }
+
+       for (i = 0; i < (chunk >> 3); ++i) {
+               /* We allocated required TCEs, mark the rest "page fault" */
+               if (!*left) {
+                       addr[i] = cpu_to_be64(0);
+                       continue;
+               }
+
+               tmp = pnv_alloc_tce_table(nid, shift, levels, left);
+               addr[i] = cpu_to_be64(__pa(tmp) |
+                               TCE_PCI_READ | TCE_PCI_WRITE);
+       }
+
+       return addr;
+}
+
 static long pnv_pci_ioda2_create_table(struct pnv_ioda_pe *pe,
-               __u32 page_shift, __u32 window_shift,
+               __u32 page_shift, __u32 window_shift, __u32 levels,
                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;
+       unsigned long tce_table_size, left;
+       unsigned shift;
 
        if ((page_shift != 12) && (page_shift != 16) && (page_shift != 24))
                return -EINVAL;
@@ -1312,20 +1375,27 @@ static long pnv_pci_ioda2_create_table(struct 
pnv_ioda_pe *pe,
        if ((1ULL << window_shift) > memory_hotplug_max())
                return -EINVAL;
 
+       if (!levels || (levels > 5))
+               return -EINVAL;
+
        tce_table_size = (1ULL << (window_shift - page_shift)) * 8;
        tce_table_size = max(0x1000UL, tce_table_size);
 
        /* Allocate TCE table */
-       order = get_order(tce_table_size);
+#define ROUND_UP(x, n) (((x) + (n) - 1u) & ~((n) - 1u))
+       shift = ROUND_UP(window_shift - page_shift, levels) / levels;
+       shift += 3;
+       shift = max_t(unsigned, shift, IOMMU_PAGE_SHIFT_4K);
+       pr_info("Creating TCE table %08llx, %d levels, TCE table size = %lx\n",
+                       1ULL << window_shift, levels, 1UL << 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);
-               rc = -ENOMEM;
-               goto fail;
-       }
-       addr = page_address(tce_mem);
-       memset(addr, 0, tce_table_size);
+       tbl->it_level_size = 1ULL << (shift - 3);
+       left = tce_table_size;
+       addr = pnv_alloc_tce_table(nid, shift, levels, &left);
+       if (!addr)
+               return -ENOMEM;
+
+       tbl->it_indirect_levels = levels - 1;
 
        /* Setup linux iommu table */
        pnv_pci_setup_iommu_table(tbl, addr, tce_table_size, 0,
@@ -1335,20 +1405,18 @@ static long pnv_pci_ioda2_create_table(struct 
pnv_ioda_pe *pe,
        iommu_init_table(tbl, nid);
 
        return 0;
-fail:
-       if (tce_mem)
-               __free_pages(tce_mem, get_order(tce_table_size));
-
-       return rc;
 }
 
 static void pnv_pci_ioda2_free_table(struct iommu_table *tbl)
 {
+       const unsigned size = tbl->it_indirect_levels ?
+                       tbl->it_level_size : tbl->it_size;
+
        if (!tbl->it_size)
                return;
 
-       free_pages(tbl->it_base, get_order(tbl->it_size << 3));
-       memset(tbl, 0, sizeof(struct iommu_table));
+       pnv_free_tce_table(tbl->it_base, size, tbl->it_indirect_levels);
+       iommu_reset_table(tbl, "ioda2");
 }
 
 static long pnv_pci_ioda2_set_window(struct pnv_ioda_pe *pe,
@@ -1357,12 +1425,15 @@ static long pnv_pci_ioda2_set_window(struct pnv_ioda_pe 
*pe,
        struct pnv_phb *phb = pe->phb;
        const __be64 *swinvp;
        int64_t rc;
+       const unsigned size = tbl->it_indirect_levels ?
+                       tbl->it_level_size : tbl->it_size;
        const __u64 start_addr = tbl->it_offset << tbl->it_page_shift;
        const __u64 win_size = tbl->it_size << tbl->it_page_shift;
 
-       pe_info(pe, "Setting up window at %llx..%llx pagesize=0x%x 
tablesize=0x%lx\n",
+       pe_info(pe, "Setting up window at %llx..%llx pagesize=0x%x 
tablesize=0x%lx levels=%d levelsize=%x\n",
                        start_addr, start_addr + win_size - 1,
-                       1UL << tbl->it_page_shift, tbl->it_size << 3);
+                       1UL << tbl->it_page_shift, tbl->it_size,
+                       tbl->it_indirect_levels + 1, tbl->it_level_size);
 
        pe->iommu.tables[0] = *tbl;
        tbl = &pe->iommu.tables[0];
@@ -1373,8 +1444,9 @@ static long pnv_pci_ioda2_set_window(struct pnv_ioda_pe 
*pe,
         * shifted by 1 bit for 32-bits DMA space.
         */
        rc = opal_pci_map_pe_dma_window(phb->opal_id, pe->pe_number,
-                       pe->pe_number << 1, 1, __pa(tbl->it_base),
-                       tbl->it_size << 3, 1ULL << tbl->it_page_shift);
+                       pe->pe_number << 1, tbl->it_indirect_levels + 1,
+                       __pa(tbl->it_base),
+                       size << 3, 1ULL << tbl->it_page_shift);
        if (rc) {
                pe_err(pe, "Failed to configure TCE table, err %ld\n", rc);
                goto fail;
@@ -1488,7 +1560,8 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb 
*phb,
                end);
 
        rc = pnv_pci_ioda2_create_table(pe, IOMMU_PAGE_SHIFT_4K,
-                       ilog2(phb->ioda.m32_pci_base), tbl);
+                       ilog2(phb->ioda.m32_pci_base),
+                       POWERPC_IOMMU_DEFAULT_LEVELS, tbl);
        if (rc) {
                pe_err(pe, "Failed to create 32-bit TCE table, err %ld", rc);
                return;
diff --git a/arch/powerpc/platforms/powernv/pci.c 
b/arch/powerpc/platforms/powernv/pci.c
index cf8206b..e98495a 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -605,6 +605,25 @@ static unsigned long pnv_dmadir_to_flags(enum 
dma_data_direction direction)
 static __be64 *pnv_tce(struct iommu_table *tbl, long index)
 {
        __be64 *tmp = ((__be64 *)tbl->it_base);
+       int  level = tbl->it_indirect_levels;
+       const long shift = ilog2(tbl->it_level_size);
+       unsigned long mask = (tbl->it_level_size - 1) << (level * shift);
+
+       if (index >= tbl->it_size)
+               return NULL;
+
+       while (level) {
+               int n = (index & mask) >> (level * shift);
+               unsigned long tce = be64_to_cpu(tmp[n]);
+
+               if (!(tce & (TCE_PCI_READ | TCE_PCI_WRITE)))
+                       return NULL;
+
+               tmp = __va(tce & ~(TCE_PCI_READ | TCE_PCI_WRITE));
+               index &= ~mask;
+               mask >>= shift;
+               --level;
+       }
 
        return tmp + index;
 }
-- 
2.0.0

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