On Thu, Apr 14, 2016 at 01:36:33PM +1000, Alexey Kardashevskiy wrote:
>On 04/14/2016 09:54 AM, Gavin Shan wrote:
>>On Wed, Apr 13, 2016 at 06:29:42PM +1000, Alexey Kardashevskiy wrote:
>>>On 02/17/2016 02:43 PM, Gavin Shan wrote:
>>>>Currently, there is one macro (TCE32_TABLE_SIZE) representing the
>>>>TCE table size for one DMA32 segment. The constant representing
>>>>the DMA32 segment size (1 << 28) is still used in the code.
>>>>
>>>>This defines PNV_IODA1_DMA32_SEGSIZE representing one DMA32
>>>>segment size. the TCE table size can be calcualted when the page
>>>
>>>s/calcualted/calculated/
>>>
>>>
>>>>has fixed 4KB size. So all the related calculation depends on one
>>>>macro (PNV_IODA1_DMA32_SEGSIZE). No logical changes introduced.
>>>
>>>Please move PNV_IODA1_DMA32_SEGSIZE where TCE32_TABLE_SIZE was.
>>>
>>>
>>>>
>>>>Signed-off-by: Gavin Shan <gws...@linux.vnet.ibm.com>
>>>>---
>>>> arch/powerpc/platforms/powernv/pci-ioda.c | 30
>>>> +++++++++++++++++-------------
>>>> arch/powerpc/platforms/powernv/pci.h | 1 +
>>>> 2 files changed, 18 insertions(+), 13 deletions(-)
>>>>
>>>>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c
>>>>b/arch/powerpc/platforms/powernv/pci-ioda.c
>>>>index d18b95e..e60cff6 100644
>>>>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>>>>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>>>>@@ -48,9 +48,6 @@
>>>> #include "powernv.h"
>>>> #include "pci.h"
>>>>
>>>>-/* 256M DMA window, 4K TCE pages, 8 bytes TCE */
>>>>-#define TCE32_TABLE_SIZE ((0x10000000 / 0x1000) * 8)
>>>>-
>>>> #define POWERNV_IOMMU_DEFAULT_LEVELS 1
>>>> #define POWERNV_IOMMU_MAX_LEVELS 5
>>>>
>>>>@@ -2034,7 +2031,7 @@ static void pnv_pci_ioda1_setup_dma_pe(struct pnv_phb
>>>>*phb,
>>>>
>>>> struct page *tce_mem = NULL;
>>>> struct iommu_table *tbl;
>>>>- unsigned int i;
>>>>+ unsigned int tce32_segsz, i;
>>>
>>>
>>>PNV_IODA1_DMA32_SEGSIZE is a segment size in bytes. The name @tce32_segsz
>>>also suggests that it is a segment size in bytes (otherwise it would be
>>>tce32_seg_entries or something like this) but it is not, it is a number of
>>>TCE entries (arch/powerpc/kernel/iommu.c uses "entry" for these). And
>>>tce32_segsz never changes. So:
>>>
>>>const unsigned int entries = PNV_IODA1_DMA32_SEGSIZE >> (IOMMU_PAGE_SHIFT_4K
>>>- 3);
>>>
>>
>>Are you sure @tce32_segsz and equation you gave are for number of TCE entries,
>>not the size of meory required for the DMA32 segment TCE table?
>
>No, I am not :) "-3" makes it a table size in bytes, so it is rather tablesz
>then.
>
Ok. @tce32_segsz is the size of memory used for TCE entries for one segment
(256MB),
not a whole TCE table. So I think @tce32_segsz is better than @tablesz from the
perspective.
>
>>
>>>> int64_t rc;
>>>> void *addr;
>>>>
>>>>@@ -2054,29 +2051,34 @@ static void pnv_pci_ioda1_setup_dma_pe(struct
>>>>pnv_phb *phb,
>>>> /* Grab a 32-bit TCE table */
>>>> pe->tce32_seg = base;
>>>> pe_info(pe, " Setting up 32-bit TCE table at %08x..%08x\n",
>>>>- (base << 28), ((base + segs) << 28) - 1);
>>>>+ base * PNV_IODA1_DMA32_SEGSIZE,
>>>>+ (base + segs) * PNV_IODA1_DMA32_SEGSIZE - 1);
>>>>
>>>> /* XXX Currently, we allocate one big contiguous table for the
>>>> * TCEs. We only really need one chunk per 256M of TCE space
>>>> * (ie per segment) but that's an optimization for later, it
>>>> * requires some added smarts with our get/put_tce implementation
>>>>+ *
>>>>+ * Each TCE page is 4KB in size and each TCE entry occupies 8
>>>>+ * bytes
>>>> */
>>>>+ tce32_segsz = PNV_IODA1_DMA32_SEGSIZE >> (IOMMU_PAGE_SHIFT_4K - 3);
>>>
>>>> tce_mem = alloc_pages_node(phb->hose->node, GFP_KERNEL,
>>>>- get_order(TCE32_TABLE_SIZE * segs));
>>>>+ get_order(tce32_segsz * segs));
>>>> if (!tce_mem) {
>>>> pe_err(pe, " Failed to allocate a 32-bit TCE memory\n");
>>>> goto fail;
>>>> }
>>>> addr = page_address(tce_mem);
>>>>- memset(addr, 0, TCE32_TABLE_SIZE * segs);
>>>>+ memset(addr, 0, tce32_segsz * segs);
>>>>
>>>> /* Configure HW */
>>>> for (i = 0; i < segs; i++) {
>>>> rc = opal_pci_map_pe_dma_window(phb->opal_id,
>>>> pe->pe_number,
>>>> base + i, 1,
>>>>- __pa(addr) + TCE32_TABLE_SIZE * i,
>>>>- TCE32_TABLE_SIZE, 0x1000);
>>>>+ __pa(addr) + tce32_segsz * i,
>>>>+ tce32_segsz, 0x1000);
>>>
>>>
>>>As you started using IOMMU_PAGE_SHIFT_4K and you are also touching this piece
>>>of code -
>>>
>>>s/0x1000/IOMMU_PAGE_SHIFT_4K/
>>>
>>
>>Does 0x1000 is equal to IOMMU_PAGE_SHIFT_4K? I guess you probably suggested
>>to use IOMMU_PAGE_SIZE_4K instead?
>
>
>Ah, my bad, should have been IOMMU_PAGE_SIZE_4K. I'll pay more attention to
>the details, sorry.
>
No worries. Thanks for your review anyway.
>>
>>>> if (rc) {
>>>> pe_err(pe, " Failed to configure 32-bit TCE table,"
>>>> " err %ld\n", rc);
>>>>@@ -2085,8 +2087,9 @@ static void pnv_pci_ioda1_setup_dma_pe(struct pnv_phb
>>>>*phb,
>>>> }
>>>>
>>>> /* Setup linux iommu table */
>>>>- pnv_pci_setup_iommu_table(tbl, addr, TCE32_TABLE_SIZE * segs,
>>>>- base << 28, IOMMU_PAGE_SHIFT_4K);
>>>>+ pnv_pci_setup_iommu_table(tbl, addr, tce32_segsz * segs,
>>>>+ base * PNV_IODA1_DMA32_SEGSIZE,
>>>>+ IOMMU_PAGE_SHIFT_4K);
>>>>
>>>> /* OPAL variant of P7IOC SW invalidated TCEs */
>>>> if (phb->ioda.tce_inval_reg)
>>>>@@ -2116,7 +2119,7 @@ static void pnv_pci_ioda1_setup_dma_pe(struct pnv_phb
>>>>*phb,
>>>> if (pe->tce32_seg >= 0)
>>>> pe->tce32_seg = -1;
>>>> if (tce_mem)
>>>>- __free_pages(tce_mem, get_order(TCE32_TABLE_SIZE * segs));
>>>>+ __free_pages(tce_mem, get_order(tce32_segsz * segs));
>>>> if (tbl) {
>>>> pnv_pci_unlink_table_and_group(tbl, &pe->table_group);
>>>> iommu_free_table(tbl, "pnv");
>>>>@@ -3445,7 +3448,8 @@ static void __init pnv_pci_init_ioda_phb(struct
>>>>device_node *np,
>>>> mutex_init(&phb->ioda.pe_list_mutex);
>>>>
>>>> /* Calculate how many 32-bit TCE segments we have */
>>>>- phb->ioda.tce32_count = phb->ioda.m32_pci_base >> 28;
>>>>+ phb->ioda.tce32_count = phb->ioda.m32_pci_base /
>>>>+ PNV_IODA1_DMA32_SEGSIZE;
>>>>
>>>> #if 0 /* We should really do that ... */
>>>> rc = opal_pci_set_phb_mem_window(opal->phb_id,
>>>>diff --git a/arch/powerpc/platforms/powernv/pci.h
>>>>b/arch/powerpc/platforms/powernv/pci.h
>>>>index 00539ff..1d8e775 100644
>>>>--- a/arch/powerpc/platforms/powernv/pci.h
>>>>+++ b/arch/powerpc/platforms/powernv/pci.h
>>>>@@ -84,6 +84,7 @@ struct pnv_ioda_pe {
>>>>
>>>> #define PNV_IODA1_M64_NUM 16 /* Number of M64 BARs */
>>>> #define PNV_IODA1_M64_SEGS 8 /* Segments per M64 BAR */
>>>>+#define PNV_IODA1_DMA32_SEGSIZE 0x10000000
>>>>
>>>> #define PNV_PHB_FLAG_EEH (1 << 0)
>>>>
>>>>
>
>--
>Alexey
>
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