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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>
This commit is contained in:
Benjamin Herrenschmidt 2017-01-30 18:11:56 +11:00 committed by Michael Ellerman
parent 38e9d36bc1
commit b3c711a9e1
2 changed files with 92 additions and 0 deletions
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1
arch/powerpc/include/asm/isa-bridge.h
View File

@ -4,6 +4,7 @@
#ifdef CONFIG_PPC64
extern void isa_bridge_find_early(struct pci_controller *hose);
extern void isa_bridge_init_non_pci(struct device_node *np);
static inline int isa_vaddr_is_ioport(void __iomem *address)
{

91
arch/powerpc/kernel/isa-bridge.c
View File

@ -167,6 +167,97 @@ void __init isa_bridge_find_early(struct pci_controller *hose)
pr_debug("ISA bridge (early) is %s\n", np->full_name);
}
/**
* 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