Re: [PATCH v7 02/60] sparc/PCI: Use correct bus address to resource offset

From: Bjorn Helgaas
Date: Tue Oct 20 2015 - 12:46:07 EST


On Thu, Oct 08, 2015 at 02:38:21PM -0700, Yinghai Lu wrote:
> After we add 64bit mmio parsing, we got some "no compatible bridge window"
> warning on anther new model that support 64bit resource.
>
> It turns out that we can not use mem_space.start as 64bit mem space
> offset, aka mem_space.start != offset.
>
> Use child_phys_addr to calculate exact offset and recorder offset in
> pbm. Still assume all mem have same offset, otherwise panic early.
>
> After patch we get correct offset.
>
> /pci@305: PCI IO [io 0x2007e00000000-0x2007e0fffffff] offset 2007e00000000
> /pci@305: PCI MEM [mem 0x2000000100000-0x200007effffff] offset 2000000000000
> /pci@305: PCI MEM64 [mem 0x2000100000000-0x2000dffffffff] offset 2000000000000
> ...
> pci_sun4v f02ae7f8: PCI host bridge to bus 0000:00
> pci_bus 0000:00: root bus resource [io 0x2007e00000000-0x2007e0fffffff] (bus address [0x0000-0xfffffff])
> pci_bus 0000:00: root bus resource [mem 0x2000000100000-0x200007effffff] (bus address [0x00100000-0x7effffff])
> pci_bus 0000:00: root bus resource [mem 0x2000100000000-0x2000dffffffff] (bus address [0x100000000-0xdffffffff])
>
>
> -v2: to make is simple, do not add mem64_offset, and assume
> mem64_offset == mem_offset, otherwise would make
> pci_mmap_resource() path too complicated.
>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
> ---
> arch/sparc/kernel/pci.c | 14 +++++++-------
> arch/sparc/kernel/pci_common.c | 36 +++++++++++++++++++++++++++---------
> arch/sparc/kernel/pci_impl.h | 3 +++
> 3 files changed, 37 insertions(+), 16 deletions(-)
>
> diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
> index badf095..451792e 100644
> --- a/arch/sparc/kernel/pci.c
> +++ b/arch/sparc/kernel/pci.c
> @@ -654,12 +654,12 @@ struct pci_bus *pci_scan_one_pbm(struct pci_pbm_info *pbm,
> printk("PCI: Scanning PBM %s\n", node->full_name);
>
> pci_add_resource_offset(&resources, &pbm->io_space,
> - pbm->io_space.start);
> + pbm->io_offset);
> pci_add_resource_offset(&resources, &pbm->mem_space,
> - pbm->mem_space.start);
> + pbm->mem_offset);
> if (pbm->mem64_space.flags)
> pci_add_resource_offset(&resources, &pbm->mem64_space,
> - pbm->mem_space.start);
> + pbm->mem_offset);
> pbm->busn.start = pbm->pci_first_busno;
> pbm->busn.end = pbm->pci_last_busno;
> pbm->busn.flags = IORESOURCE_BUS;
> @@ -751,10 +751,10 @@ static int __pci_mmap_make_offset_bus(struct pci_dev *pdev, struct vm_area_struc
> return -EINVAL;
>
> if (mmap_state == pci_mmap_io) {
> - vma->vm_pgoff = (pbm->io_space.start +
> + vma->vm_pgoff = (pbm->io_offset +
> user_offset) >> PAGE_SHIFT;
> } else {
> - vma->vm_pgoff = (pbm->mem_space.start +
> + vma->vm_pgoff = (pbm->mem_offset +
> user_offset) >> PAGE_SHIFT;
> }
>
> @@ -981,9 +981,9 @@ void pci_resource_to_user(const struct pci_dev *pdev, int bar,
> unsigned long offset;
>
> if (rp->flags & IORESOURCE_IO)
> - offset = pbm->io_space.start;
> + offset = pbm->io_offset;
> else
> - offset = pbm->mem_space.start;
> + offset = pbm->mem_offset;
>
> *start = rp->start - offset;
> *end = rp->end - offset;
> diff --git a/arch/sparc/kernel/pci_common.c b/arch/sparc/kernel/pci_common.c
> index 33524c1..28e976a 100644
> --- a/arch/sparc/kernel/pci_common.c
> +++ b/arch/sparc/kernel/pci_common.c
> @@ -393,6 +393,7 @@ static void pci_register_iommu_region(struct pci_pbm_info *pbm)
> void pci_determine_mem_io_space(struct pci_pbm_info *pbm)
> {
> const struct linux_prom_pci_ranges *pbm_ranges;
> + resource_size_t mem64_offset = 0;
> int i, saw_mem, saw_io;
> int num_pbm_ranges;
>
> @@ -410,13 +411,16 @@ void pci_determine_mem_io_space(struct pci_pbm_info *pbm)
>
> for (i = 0; i < num_pbm_ranges; i++) {
> const struct linux_prom_pci_ranges *pr = &pbm_ranges[i];
> - unsigned long a, size;
> + unsigned long a, size, region_a;
> u32 parent_phys_hi, parent_phys_lo;
> + u32 child_phys_mid, child_phys_lo;
> u32 size_hi, size_lo;
> int type;
>
> parent_phys_hi = pr->parent_phys_hi;
> parent_phys_lo = pr->parent_phys_lo;
> + child_phys_mid = pr->child_phys_mid;
> + child_phys_lo = pr->child_phys_lo;
> if (tlb_type == hypervisor)
> parent_phys_hi &= 0x0fffffff;
>
> @@ -426,6 +430,8 @@ void pci_determine_mem_io_space(struct pci_pbm_info *pbm)
> type = (pr->child_phys_hi >> 24) & 0x3;
> a = (((unsigned long)parent_phys_hi << 32UL) |
> ((unsigned long)parent_phys_lo << 0UL));
> + region_a = (((unsigned long)child_phys_mid << 32UL) |
> + ((unsigned long)child_phys_lo << 0UL));
> size = (((unsigned long)size_hi << 32UL) |
> ((unsigned long)size_lo << 0UL));
>
> @@ -440,6 +446,7 @@ void pci_determine_mem_io_space(struct pci_pbm_info *pbm)
> pbm->io_space.start = a;
> pbm->io_space.end = a + size - 1UL;
> pbm->io_space.flags = IORESOURCE_IO;
> + pbm->io_offset = a - region_a;
> saw_io = 1;
> break;
>
> @@ -448,6 +455,7 @@ void pci_determine_mem_io_space(struct pci_pbm_info *pbm)
> pbm->mem_space.start = a;
> pbm->mem_space.end = a + size - 1UL;
> pbm->mem_space.flags = IORESOURCE_MEM;
> + pbm->mem_offset = a - region_a;
> saw_mem = 1;
> break;
>
> @@ -456,6 +464,7 @@ void pci_determine_mem_io_space(struct pci_pbm_info *pbm)
> pbm->mem64_space.start = a;
> pbm->mem64_space.end = a + size - 1UL;
> pbm->mem64_space.flags = IORESOURCE_MEM;
> + mem64_offset = a - region_a;
> saw_mem = 1;
> break;
>
> @@ -471,14 +480,23 @@ void pci_determine_mem_io_space(struct pci_pbm_info *pbm)
> prom_halt();
> }
>
> - printk("%s: PCI IO[%llx] MEM[%llx]",
> - pbm->name,
> - pbm->io_space.start,
> - pbm->mem_space.start);
> - if (pbm->mem64_space.flags)
> - printk(" MEM64[%llx]",
> - pbm->mem64_space.start);
> - printk("\n");
> + if (pbm->io_space.flags)
> + printk("%s: PCI IO %pR offset %llx\n",
> + pbm->name, &pbm->io_space, pbm->io_offset);
> + if (pbm->mem_space.flags)
> + printk("%s: PCI MEM %pR offset %llx\n",
> + pbm->name, &pbm->mem_space, pbm->mem_offset);
> + if (pbm->mem64_space.flags) {
> + if (pbm->mem_space.flags) {
> + if (mem64_offset != pbm->mem_offset)
> + panic("mem offset %llx != mem64 offset %llx\n",
> + pbm->mem_offset, mem64_offset);

Why do you panic rather than just handling the mem64 offset? As far
as I know, there's no PCI reason why the mem64 offset has to be the
same as the mem one.

> + } else
> + pbm->mem_offset = mem64_offset;
> +
> + printk("%s: PCI MEM64 %pR offset %llx\n",
> + pbm->name, &pbm->mem64_space, pbm->mem_offset);
> + }
>
> pbm->io_space.name = pbm->mem_space.name = pbm->name;
> pbm->mem64_space.name = pbm->name;
> diff --git a/arch/sparc/kernel/pci_impl.h b/arch/sparc/kernel/pci_impl.h
> index 37222ca..08b74af 100644
> --- a/arch/sparc/kernel/pci_impl.h
> +++ b/arch/sparc/kernel/pci_impl.h
> @@ -99,6 +99,9 @@ struct pci_pbm_info {
> struct resource mem_space;
> struct resource mem64_space;
> struct resource busn;
> + /* offset */
> + resource_size_t io_offset;
> + resource_size_t mem_offset;
>
> /* Base of PCI Config space, can be per-PBM or shared. */
> unsigned long config_space;
> --
> 1.8.4.5
>
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