On Thu, 2014-04-10 at 18:46 +0300, Michael S. Tsirkin wrote:
On Thu, Apr 10, 2014 at 04:29:41PM +0300, Marcel Apfelbaum wrote:
<I/O Base Register, I/O Limit Register> pair and <Prefetchable Memory Base Register, Prefetchable Memory Limit Register> pair are both optional. Do not reserve ranges if the above registers are not implemented.
Signed-off-by: Marcel Apfelbaum marcel.a@redhat.com
Reviewed-by: Michael S. Tsirkin mst@redhat.com
src/fw/pciinit.c | 9 ++------- src/hw/pci.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ src/hw/pci.h | 9 +++++++++ 3 files changed, 59 insertions(+), 7 deletions(-)
diff --git a/src/fw/pciinit.c b/src/fw/pciinit.c index 9b5d7ad..bbaecd6 100644 --- a/src/fw/pciinit.c +++ b/src/fw/pciinit.c @@ -26,13 +26,6 @@ #define PCI_BRIDGE_MEM_MIN (1<<21) // 2M == hugepage size #define PCI_BRIDGE_IO_MIN 0x1000 // mandated by pci bridge spec
-enum pci_region_type {
- PCI_REGION_TYPE_IO,
- PCI_REGION_TYPE_MEM,
- PCI_REGION_TYPE_PREFMEM,
- PCI_REGION_TYPE_COUNT,
-};
static const char *region_type_name[] = { [ PCI_REGION_TYPE_IO ] = "io", [ PCI_REGION_TYPE_MEM ] = "mem", @@ -681,6 +674,8 @@ static int pci_bios_check_devices(struct pci_bus *busses) for (type = 0; type < PCI_REGION_TYPE_COUNT; type++) { u64 align = (type == PCI_REGION_TYPE_IO) ? PCI_BRIDGE_IO_MIN : PCI_BRIDGE_MEM_MIN;
if (!pci_bridge_has_region(s->bus_dev, type))continue; if (pci_region_align(&s->r[type]) > align) align = pci_region_align(&s->r[type]); u64 sum = pci_region_sum(&s->r[type]);diff --git a/src/hw/pci.c b/src/hw/pci.c index 055353d..27e7b1c 100644 --- a/src/hw/pci.c +++ b/src/hw/pci.c @@ -243,6 +243,54 @@ u8 pci_find_capability(struct pci_device *pci, u8 cap_id) return 0; }
+static int pci_config_writableb(struct pci_device *pci, u32 addr, u8 test_val)
Don't like this name. pci_config_writable_byte or better see below.
+{
- u8 val;
- val = pci_config_readb(pci->bdf, addr);
- pci_config_writeb(pci->bdf, addr, test_val);
- if (!(pci_config_readb(pci->bdf, addr)))
return 0;This only works for readonly fields which return 0 on read. Maybe name should reflect this: how about pci_config_is_reserved() ?
No problem with that
There's no need to pass in test value either, it makes the interface fragile: passing e.g. 0x0 as value won't work.
Yes, the value would be the caller responsibility. But I think that a value like 0xF0 (explained below) will cover all we need.
- pci_config_writeb(pci->bdf, addr, val);
Practically that's overkill.
I have to restore prev settings. I do not see this as an overkill: a query should preserve the prev value. And is also not expensive, and it is made only by bridges, not a real issue from my point of view.
Just set base > limit and there won't be need to save and restore: range is disabled.
That would be possible, yes. But again, I don't want to change values in a query.
- return 1;
+}
+static int pci_config_writablew(struct pci_device *pci, u32 addr, u16 test_val) +{
- u16 val;
- val = pci_config_readw(pci->bdf, addr);
- pci_config_writew(pci->bdf, addr, test_val);
- if (!(pci_config_readw(pci->bdf, addr)))
return 0;- pci_config_writew(pci->bdf, addr, val);
- return 1;
+}
This one isn't needed at all.
I can use the byte function, yes, thanks, I'll drop it.
+int pci_bridge_has_region(struct pci_device *pci,
enum pci_region_type region_type)+{
- if (pci->class != PCI_CLASS_BRIDGE_PCI)
return 0;Do we really need this test here?
Better safe than sorry. If is not a bridge this will mess up pci device's configuration and the bug will be hard to find.
- switch (region_type) {
- case PCI_REGION_TYPE_IO:
return pci_config_writableb(pci, PCI_IO_BASE, 0xF0) &&pci_config_writableb(pci, PCI_IO_LIMIT, 0xF0);I think we should only test base. Testing limit like this might cause issues as bridge now claims some resources temporarily.
I can test only one, yes. The spec said that both should be 0, but going for one of them should be enough.
Also why 0xF0 and not 0xFF? Seems like a random value.
0xF0 is not random, the last 4 bits are *always* read only, this is why I don't test them. Any value starting from 0x10 will do. 0xFF it will still work, as the last 4 bits will be silently dropped, but why not follow the spec.
- case PCI_REGION_TYPE_PREFMEM:
return pci_config_writablew(pci, PCI_PREF_MEMORY_BASE, 0xFFF0) &&pci_config_writablew(pci, PCI_PREF_MEMORY_LIMIT, 0xFFF0);- case PCI_REGION_TYPE_MEM: /* fall through */
- default:
return 1;- }
- return 1;
+}
void pci_reboot(void)
[...]
- }
- return 1;
unreacheable code.
Right. Some compilation flags and automatic check tools might have a problem with that, this why I left it there. I can remove it, of course.
+}
Here's a simpler implementation.
int pci_bridge_has_region(struct pci_device *pci, enum pci_region_type region_type) { u8 base;
switch (region_type) { case PCI_REGION_TYPE_IO:base = PCI_IO_BASE; break; case PCI_REGION_TYPE_PREFMEM: base = PCI_PREF_MEMORY_BASE; break; default: /* Regular memory support is mandatory */ return 1; }
/* Check that base is writeable. Safe as this increases base so it * won't cause bridge to claim new resources.
Yes, but it can claim less. Why mess with the orig value for a query? I think a query should not modify a value, even if does not affect the system. It is hard to track this kind of changes, and restoring the value is not a big price to pay IMHO.
Thanks for the review, Marcel
*/ pci_config_writeb(pci->bdf, base, 0xFF); return !!pci_config_readb(pci->bdf, base);}
diff --git a/src/hw/pci.h b/src/hw/pci.h index e828225..0aaa84c 100644 --- a/src/hw/pci.h +++ b/src/hw/pci.h @@ -12,6 +12,13 @@ #define PCI_NUM_REGIONS 7 #define PCI_BRIDGE_NUM_REGIONS 2
+enum pci_region_type {
- PCI_REGION_TYPE_IO,
- PCI_REGION_TYPE_MEM,
- PCI_REGION_TYPE_PREFMEM,
- PCI_REGION_TYPE_COUNT,
+};
static inline u8 pci_bdf_to_bus(u16 bdf) { return bdf >> 8; } @@ -117,6 +124,8 @@ int pci_init_device(const struct pci_device_id *ids struct pci_device *pci_find_init_device(const struct pci_device_id *ids , void *arg); u8 pci_find_capability(struct pci_device *pci, u8 cap_id); +int pci_bridge_has_region(struct pci_device *pci,
enum pci_region_type region_type);void pci_reboot(void);
#endif
1.8.3.1