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author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2017-01-30 18:11:56 +1100 |
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committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-01-31 13:54:17 +1100 |
commit | b3c711a9e19eb2b300132f1712ff3d5afb4b02dc (patch) | |
tree | bdef93ab202200f4fe5b827c90e8c94d3e7ef840 /arch/powerpc/kernel/isa-bridge.c | |
parent | 38e9d36bc149932964dcd25818c7f7283239592d (diff) | |
download | linux-b3c711a9e19eb2b300132f1712ff3d5afb4b02dc.tar.bz2 |
powerpc: Add support for non-PCI ISA bridges
The POWER9 chip supports an LPC bus that isn't hanging
off a PCI bus, so let's add support for that, mapping it
to the reserved space at ISA_IO_BASE
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/isa-bridge.c')
-rw-r--r-- | arch/powerpc/kernel/isa-bridge.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/isa-bridge.c b/arch/powerpc/kernel/isa-bridge.c index c898ff0cafec..bb6f8993412e 100644 --- a/arch/powerpc/kernel/isa-bridge.c +++ b/arch/powerpc/kernel/isa-bridge.c @@ -168,6 +168,97 @@ void __init isa_bridge_find_early(struct pci_controller *hose) } /** + * isa_bridge_find_early - Find and map the ISA IO space early before + * main PCI discovery. This is optionally called by + * the arch code when adding PCI PHBs to get early + * access to ISA IO ports + */ +void __init isa_bridge_init_non_pci(struct device_node *np) +{ + const __be32 *ranges, *pbasep = NULL; + int rlen, i, rs; + u32 na, ns, pna; + u64 cbase, pbase, size = 0; + + /* If we already have an ISA bridge, bail off */ + if (isa_bridge_devnode != NULL) + return; + + pna = of_n_addr_cells(np); + if (of_property_read_u32(np, "#address-cells", &na) || + of_property_read_u32(np, "#size-cells", &ns)) { + pr_warn("ISA: Non-PCI bridge %s is missing address format\n", + np->full_name); + return; + } + + /* Check it's a supported address format */ + if (na != 2 || ns != 1) { + pr_warn("ISA: Non-PCI bridge %s has unsupported address format\n", + np->full_name); + return; + } + rs = na + ns + pna; + + /* Grab the ranges property */ + ranges = of_get_property(np, "ranges", &rlen); + if (ranges == NULL || rlen < rs) { + pr_warn("ISA: Non-PCI bridge %s has absent or invalid ranges\n", + np->full_name); + return; + } + + /* Parse it. We are only looking for IO space */ + for (i = 0; (i + rs - 1) < rlen; i += rs) { + if (be32_to_cpup(ranges + i) != 1) + continue; + cbase = be32_to_cpup(ranges + i + 1); + size = of_read_number(ranges + i + na + pna, ns); + pbasep = ranges + i + na; + break; + } + + /* Got something ? */ + if (!size || !pbasep) { + pr_warn("ISA: Non-PCI bridge %s has no usable IO range\n", + np->full_name); + return; + } + + /* Align size and make sure it's cropped to 64K */ + size = PAGE_ALIGN(size); + if (size > 0x10000) + size = 0x10000; + + /* Map pbase */ + pbase = of_translate_address(np, pbasep); + if (pbase == OF_BAD_ADDR) { + pr_warn("ISA: Non-PCI bridge %s failed to translate IO base\n", + np->full_name); + return; + } + + /* We need page alignment */ + if ((cbase & ~PAGE_MASK) || (pbase & ~PAGE_MASK)) { + pr_warn("ISA: Non-PCI bridge %s has non aligned IO range\n", + np->full_name); + return; + } + + /* Got it */ + isa_bridge_devnode = np; + + /* Set the global ISA io base to indicate we have an ISA bridge + * and map it + */ + isa_io_base = ISA_IO_BASE; + __ioremap_at(pbase, (void *)ISA_IO_BASE, + size, pgprot_val(pgprot_noncached(__pgprot(0)))); + + pr_debug("ISA: Non-PCI bridge is %s\n", np->full_name); +} + +/** * isa_bridge_find_late - Find and map the ISA IO space upon discovery of * a new ISA bridge */ |