[PATCH v3 12/35] x86/msi: Provide msi message shadow structs

David Woodhouse
2020-10-24T21:36:46Z

From: Thomas Gleixner <tglx@linutronix.de>

Create shadow structs with named bitfields for msi_msg data, address_lo and
address_hi and use them in the MSI message composer.

Provide a function to retrieve the destination ID. This could be inline,
but that'd create a circular header dependency.

[dwmw2: fix bitfields not all to be a union]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
arch/x86/include/asm/msi.h | 49 +++++++++++++++++++++++++++++++++++++
arch/x86/kernel/apic/apic.c | 35 ++++++++++++++------------
2 files changed, 68 insertions(+), 16 deletions(-)

diff --git a/arch/x86/include/asm/msi.h b/arch/x86/include/asm/msi.h
index cd30013d15d3..322fd905da9c 100644
--- a/arch/x86/include/asm/msi.h
+++ b/arch/x86/include/asm/msi.h
@@ -9,4 +9,53 @@ typedef struct irq_alloc_info msi_alloc_info_t;
int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
msi_alloc_info_t *arg);

+/* Structs and defines for the X86 specific MSI message format */
+
+typedef struct x86_msi_data {
+ u32 vector : 8,
+ delivery_mode : 3,
+ dest_mode_logical : 1,
+ reserved : 2,
+ active_low : 1,
+ is_level : 1;
+
+ u32 dmar_subhandle;
+} __attribute__ ((packed)) arch_msi_msg_data_t;
+#define arch_msi_msg_data x86_msi_data
+
+typedef struct x86_msi_addr_lo {
+ union {
+ struct {
+ u32 reserved_0 : 2,
+ dest_mode_logical : 1,
+ redirect_hint : 1,
+ reserved_1 : 8,
+ destid_0_7 : 8,
+ base_address : 12;
+ };
+ struct {
+ u32 dmar_reserved_0 : 2,
+ dmar_index_15 : 1,
+ dmar_subhandle_valid : 1,
+ dmar_format : 1,
+ dmar_index_0_14 : 15,
+ dmar_base_address : 12;
+ };
+ };
+} __attribute__ ((packed)) arch_msi_msg_addr_lo_t;
+#define arch_msi_msg_addr_lo x86_msi_addr_lo
+
+#define X86_MSI_BASE_ADDRESS_LOW (0xfee00000 >> 20)
+
+typedef struct x86_msi_addr_hi {
+ u32 reserved : 8,
+ destid_8_31 : 24;
+} __attribute__ ((packed)) arch_msi_msg_addr_hi_t;
+#define arch_msi_msg_addr_hi x86_msi_addr_hi
+
+#define X86_MSI_BASE_ADDRESS_HIGH (0)
+
+struct msi_msg;
+u32 x86_msi_msg_get_destid(struct msi_msg *msg, bool extid);
+
#endif /* _ASM_X86_MSI_H */
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 4c15bf29ea2c..f7196ee0f005 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -50,7 +50,6 @@
#include <asm/io_apic.h>
#include <asm/desc.h>
#include <asm/hpet.h>
-#include <asm/msidef.h>
#include <asm/mtrr.h>
#include <asm/time.h>
#include <asm/smp.h>
@@ -2484,22 +2483,16 @@ int hard_smp_processor_id(void)
void __irq_msi_compose_msg(struct irq_cfg *cfg, struct msi_msg *msg,
bool dmar)
{
- msg->address_hi = MSI_ADDR_BASE_HI;
+ memset(msg, 0, sizeof(*msg));

- msg->address_lo =
- MSI_ADDR_BASE_LO |
- (apic->dest_mode_logical ?
- MSI_ADDR_DEST_MODE_LOGICAL :
- MSI_ADDR_DEST_MODE_PHYSICAL) |
- MSI_ADDR_REDIRECTION_CPU |
- MSI_ADDR_DEST_ID(cfg->dest_apicid);
+ msg->arch_addr_lo.base_address = X86_MSI_BASE_ADDRESS_LOW;
+ msg->arch_addr_lo.dest_mode_logical = apic->dest_mode_logical;
+ msg->arch_addr_lo.destid_0_7 = cfg->dest_apicid & 0xFF;

- msg->data =
- MSI_DATA_TRIGGER_EDGE |
- MSI_DATA_LEVEL_ASSERT |
- MSI_DATA_DELIVERY_FIXED |
- MSI_DATA_VECTOR(cfg->vector);
+ msg->arch_data.delivery_mode = APIC_DELIVERY_MODE_FIXED;
+ msg->arch_data.vector = cfg->vector;

+ msg->address_hi = X86_MSI_BASE_ADDRESS_HIGH;
/*
* Only the IOMMU itself can use the trick of putting destination
* APIC ID into the high bits of the address. Anything else would
@@ -2507,11 +2500,21 @@ void __irq_msi_compose_msg(struct irq_cfg *cfg, struct msi_msg *msg,
* address higher APIC IDs.
*/
if (dmar)
- msg->address_hi |= MSI_ADDR_EXT_DEST_ID(cfg->dest_apicid);
+ msg->arch_addr_hi.destid_8_31 = cfg->dest_apicid >> 8;
else
- WARN_ON_ONCE(MSI_ADDR_EXT_DEST_ID(cfg->dest_apicid));
+ WARN_ON_ONCE(cfg->dest_apicid > 0xFF);
}

+u32 x86_msi_msg_get_destid(struct msi_msg *msg, bool extid)
+{
+ u32 dest = msg->arch_addr_lo.destid_0_7;
+
+ if (extid)
+ dest |= msg->arch_addr_hi.destid_8_31 << 8;
+ return dest;
+}
+EXPORT_SYMBOL_GPL(x86_msi_msg_get_destid);
+
/*
* Override the generic EOI implementation with an optimized version.
* Only called during early boot when only one CPU is active and with