Refine mp_register_ioapic() to prepare for IOAPIC hotplug by:
1) change return value from void to int.
2) check for gsi range conflicts
3) check for IOAPIC physical address conflicts
4) enhance the way to allocate IOAPIC index
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/io_apic.h | 4 +-
arch/x86/kernel/apic/io_apic.c | 87 ++++++++++++++++++++++++++--------------
2 files changed, 58 insertions(+), 33 deletions(-)
diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index a666dcdeea67..8741c1ea33c3 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -188,8 +188,8 @@ extern int mp_find_ioapic_pin(int ioapic, u32 gsi);
extern u32 mp_pin_to_gsi(int ioapic, int pin);
extern int mp_map_gsi_to_irq(u32 gsi, unsigned int flags);
extern void mp_unmap_irq(int irq);
-extern void mp_register_ioapic(int id, u32 address, u32 gsi_base,
- struct ioapic_domain_cfg *cfg);
+extern int mp_register_ioapic(int id, u32 address, u32 gsi_base,
+ struct ioapic_domain_cfg *cfg);
extern int mp_irqdomain_map(struct irq_domain *domain, unsigned int virq,
irq_hw_number_t hwirq);
extern void mp_irqdomain_unmap(struct irq_domain *domain, unsigned int virq);
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 81f014891237..6fa5df9a8551 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -3827,20 +3827,6 @@ int mp_find_ioapic_pin(int ioapic, u32 gsi)
return gsi - gsi_cfg->gsi_base;
}
-static int bad_ioapic(unsigned long address)
-{
- if (nr_ioapics >= MAX_IO_APICS) {
- pr_warn("WARNING: Max # of I/O APICs (%d) exceeded (found %d), skipping\n",
- MAX_IO_APICS, nr_ioapics);
- return 1;
- }
- if (!address) {
- pr_warn("WARNING: Bogus (zero) I/O APIC address found in table, skipping!\n");
- return 1;
- }
- return 0;
-}
-
static int bad_ioapic_register(int idx)
{
union IO_APIC_reg_00 reg_00;
@@ -3860,29 +3846,51 @@ static int bad_ioapic_register(int idx)
return 0;
}
-void mp_register_ioapic(int id, u32 address, u32 gsi_base,
- struct ioapic_domain_cfg *cfg)
+static int find_free_ioapic_entry(void)
{
- int idx = 0;
- int entries;
+ return nr_ioapics;
+}
+
+/**
+ * mp_register_ioapic() - Register an IOAPIC device
+ * @id: hardware IOAPIC ID
+ * @address: physical address of IOAPIC register area
+ * @gsi_base: base of GSI associated with the IOAPIC
+ * @cfg: configuration information for the IOAPIC
+ */
+int mp_register_ioapic(int id, u32 address, u32 gsi_base,
+ struct ioapic_domain_cfg *cfg)
+{
+ u32 gsi_end;
+ int idx, ioapic, entries;
struct mp_ioapic_gsi *gsi_cfg;
- if (bad_ioapic(address))
- return;
+ if (!address) {
+ pr_warn("Bogus (zero) I/O APIC address found, skipping!\n");
+ return -EINVAL;
+ }
+ for_each_ioapic(ioapic)
+ if (ioapics[ioapic].mp_config.apicaddr == address) {
+ pr_warn("address 0x%x conflicts with IOAPIC%d\n",
+ address, ioapic);
+ return -EEXIST;
+ }
- idx = nr_ioapics;
+ idx = find_free_ioapic_entry();
+ if (idx >= MAX_IO_APICS) {
+ pr_warn("Max # of I/O APICs (%d) exceeded (found %d), skipping\n",
+ MAX_IO_APICS, idx);
+ return -ENOSPC;
+ }
ioapics[idx].mp_config.type = MP_IOAPIC;
ioapics[idx].mp_config.flags = MPC_APIC_USABLE;
ioapics[idx].mp_config.apicaddr = address;
- ioapics[idx].irqdomain = NULL;
- ioapics[idx].irqdomain_cfg = *cfg;
set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address);
-
if (bad_ioapic_register(idx)) {
clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
- return;
+ return -ENODEV;
}
ioapics[idx].mp_config.apicid = io_apic_unique_id(idx, id);
@@ -3893,24 +3901,41 @@ void mp_register_ioapic(int id, u32 address, u32 gsi_base,
* and to prevent reprogramming of IOAPIC pins (PCI GSIs).
*/
entries = io_apic_get_redir_entries(idx);
+ gsi_end = gsi_base + entries - 1;
+ for_each_ioapic(ioapic) {
+ gsi_cfg = mp_ioapic_gsi_routing(ioapic);
+ if ((gsi_base >= gsi_cfg->gsi_base &&
+ gsi_base <= gsi_cfg->gsi_end) ||
+ (gsi_end >= gsi_cfg->gsi_base &&
+ gsi_end <= gsi_cfg->gsi_end)) {
+ pr_warn("GSI range [%u-%u] for new IOAPIC conflicts with GSI[%u-%u]\n",
+ gsi_base, gsi_end,
+ gsi_cfg->gsi_base, gsi_cfg->gsi_end);
+ clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
+ return -ENOSPC;
+ }
+ }
gsi_cfg = mp_ioapic_gsi_routing(idx);
gsi_cfg->gsi_base = gsi_base;
- gsi_cfg->gsi_end = gsi_base + entries - 1;
+ gsi_cfg->gsi_end = gsi_end;
- /*
- * The number of IO-APIC IRQ registers (== #pins):
- */
- ioapics[idx].nr_registers = entries;
+ ioapics[idx].irqdomain = NULL;
+ ioapics[idx].irqdomain_cfg = *cfg;
if (gsi_cfg->gsi_end >= gsi_top)
gsi_top = gsi_cfg->gsi_end + 1;
+ if (nr_ioapics <= idx)
+ nr_ioapics = idx + 1;
+
+ /* Set nr_registers to mark entry present */
+ ioapics[idx].nr_registers = entries;
pr_info("IOAPIC[%d]: apic_id %d, version %d, address 0x%x, GSI %d-%d\n",
idx, mpc_ioapic_id(idx),
mpc_ioapic_ver(idx), mpc_ioapic_addr(idx),
gsi_cfg->gsi_base, gsi_cfg->gsi_end);
- nr_ioapics++;
+ return 0;
}
int mp_irqdomain_map(struct irq_domain *domain, unsigned int virq,
--
1.7.10.4
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