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| author | Kishon Vijay Abraham I <kishon@ti.com> | 2019-03-25 15:09:39 +0530 |
|---|---|---|
| committer | Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> | 2019-04-15 13:24:02 +0100 |
| commit | 2a9a801620efac92885fc9cd53594c0b9aba87a4 (patch) | |
| tree | 7929d63f8828b13144f2ce30755497b74e520cb7 /drivers/pci/endpoint | |
| parent | fbb2de891cc4d69c0c80c4116cf870a99235cfe8 (diff) | |
| download | lwn-2a9a801620efac92885fc9cd53594c0b9aba87a4.tar.gz lwn-2a9a801620efac92885fc9cd53594c0b9aba87a4.zip | |
PCI: endpoint: Add support to specify alignment for buffers allocated to BARs
The address that is allocated using pci_epf_alloc_space() is
directly written to the target address of the Inbound Address
Translation unit (ie the HW component implementing inbound address
decoding) on endpoint controllers.
Designware IP [1] has a configuration parameter (CX_ATU_MIN_REGION_SIZE
[2]) which has 64KB as default value and the lower 16 bits of the Base,
Limit and Target registers of the Inbound ATU are fixed to zero. If the
programmed memory address is not aligned to 64 KB boundary this causes
memory corruption.
Modify pci_epf_alloc_space() API to take alignment size as argument in
order to allocate buffers to be mapped to BARs with an alignment that
suits the platform where they are used.
Add an 'align' parameter to epc_features which can be used by platform
drivers to specify the BAR allocation alignment requirements and use
this while invoking pci_epf_alloc_space().
[1] "I/O and MEM Match Modes" section in DesignWare Cores PCI Express
Controller Databook version 4.90a
[2] http://www.ti.com/lit/ug/spruid7c/spruid7c.pdf
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Diffstat (limited to 'drivers/pci/endpoint')
| -rw-r--r-- | drivers/pci/endpoint/functions/pci-epf-test.c | 5 | ||||
| -rw-r--r-- | drivers/pci/endpoint/pci-epf-core.c | 10 |
2 files changed, 11 insertions, 4 deletions
diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index d0b91da49bf4..c0786ca74312 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -438,7 +438,7 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf) epc_features = epf_test->epc_features; base = pci_epf_alloc_space(epf, sizeof(struct pci_epf_test_reg), - test_reg_bar); + test_reg_bar, epc_features->align); if (!base) { dev_err(dev, "Failed to allocated register space\n"); return -ENOMEM; @@ -453,7 +453,8 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf) if (!!(epc_features->reserved_bar & (1 << bar))) continue; - base = pci_epf_alloc_space(epf, bar_size[bar], bar); + base = pci_epf_alloc_space(epf, bar_size[bar], bar, + epc_features->align); if (!base) dev_err(dev, "Failed to allocate space for BAR%d\n", bar); diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c index 8bfdcd291196..fb1306de8f40 100644 --- a/drivers/pci/endpoint/pci-epf-core.c +++ b/drivers/pci/endpoint/pci-epf-core.c @@ -109,10 +109,12 @@ EXPORT_SYMBOL_GPL(pci_epf_free_space); * pci_epf_alloc_space() - allocate memory for the PCI EPF register space * @size: the size of the memory that has to be allocated * @bar: the BAR number corresponding to the allocated register space + * @align: alignment size for the allocation region * * Invoke to allocate memory for the PCI EPF register space. */ -void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar) +void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar, + size_t align) { void *space; struct device *dev = epf->epc->dev.parent; @@ -120,7 +122,11 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar) if (size < 128) size = 128; - size = roundup_pow_of_two(size); + + if (align) + size = ALIGN(size, align); + else + size = roundup_pow_of_two(size); space = dma_alloc_coherent(dev, size, &phys_addr, GFP_KERNEL); if (!space) { |