[PATCH 6/25] msi: Implement helper functions read_msi_msg and write_msi_msg.

From: Eric W. Biederman
Date: Tue Jun 20 2006 - 18:33:03 EST


In support of this I also add a struct msi_msg that captures
the the two address and one data field ina typical msi message,
and I remember the pos and if the address is 64bit in
struct msi_desc.

This makes the code a little more readable and easier to maintain,
and paves the way to further simplfications.

Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
---
drivers/pci/msi.c | 195 +++++++++++++++++++++++++--------------------------
drivers/pci/msi.h | 9 +-
include/linux/pci.h | 6 ++
3 files changed, 104 insertions(+), 106 deletions(-)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index c1c93f0..e9db6c5 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -94,63 +94,100 @@ static void msi_set_mask_bit(unsigned in
}
}

-#ifdef CONFIG_SMP
-static void set_msi_affinity(unsigned int vector, cpumask_t cpu_mask)
+static void read_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
{
- struct msi_desc *entry;
- u32 address_hi, address_lo;
- unsigned int irq = vector;
- unsigned int dest_cpu = first_cpu(cpu_mask);
-
- entry = (struct msi_desc *)msi_desc[vector];
- if (!entry || !entry->dev)
- return;
+ switch(entry->msi_attrib.type) {
+ case PCI_CAP_ID_MSI:
+ {
+ struct pci_dev *dev = entry->dev;
+ int pos = entry->msi_attrib.pos;
+ u16 data;
+
+ pci_read_config_dword(dev, msi_lower_address_reg(pos),
+ &msg->address_lo);
+ if (entry->msi_attrib.is_64) {
+ pci_read_config_dword(dev, msi_upper_address_reg(pos),
+ &msg->address_hi);
+ pci_read_config_word(dev, msi_data_reg(pos, 1), &data);
+ } else {
+ msg->address_hi = 0;
+ pci_read_config_word(dev, msi_data_reg(pos, 1), &data);
+ }
+ msg->data = data;
+ break;
+ }
+ case PCI_CAP_ID_MSIX:
+ {
+ void __iomem *base;
+ base = entry->mask_base +
+ entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
+
+ msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
+ msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
+ msg->data = readl(base + PCI_MSIX_ENTRY_DATA_OFFSET);
+ break;
+ }
+ default:
+ BUG();
+ }
+}

+static void write_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
+{
switch (entry->msi_attrib.type) {
case PCI_CAP_ID_MSI:
{
- int pos = pci_find_capability(entry->dev, PCI_CAP_ID_MSI);
-
- if (!pos)
- return;
-
- pci_read_config_dword(entry->dev, msi_upper_address_reg(pos),
- &address_hi);
- pci_read_config_dword(entry->dev, msi_lower_address_reg(pos),
- &address_lo);
-
- msi_ops->target(vector, dest_cpu, &address_hi, &address_lo);
-
- pci_write_config_dword(entry->dev, msi_upper_address_reg(pos),
- address_hi);
- pci_write_config_dword(entry->dev, msi_lower_address_reg(pos),
- address_lo);
- set_native_irq_info(irq, cpu_mask);
+ struct pci_dev *dev = entry->dev;
+ int pos = entry->msi_attrib.pos;
+
+ pci_write_config_dword(dev, msi_lower_address_reg(pos),
+ msg->address_lo);
+ if (entry->msi_attrib.is_64) {
+ pci_write_config_dword(dev, msi_upper_address_reg(pos),
+ msg->address_hi);
+ pci_write_config_word(dev, msi_data_reg(pos, 1),
+ msg->data);
+ } else {
+ pci_write_config_word(dev, msi_data_reg(pos, 0),
+ msg->data);
+ }
break;
}
case PCI_CAP_ID_MSIX:
{
- int offset_hi =
- entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET;
- int offset_lo =
- entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET;
-
- address_hi = readl(entry->mask_base + offset_hi);
- address_lo = readl(entry->mask_base + offset_lo);
-
- msi_ops->target(vector, dest_cpu, &address_hi, &address_lo);
-
- writel(address_hi, entry->mask_base + offset_hi);
- writel(address_lo, entry->mask_base + offset_lo);
- set_native_irq_info(irq, cpu_mask);
+ void __iomem *base;
+ base = entry->mask_base +
+ entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
+
+ writel(msg->address_lo,
+ base + PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
+ writel(msg->address_hi,
+ base + PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
+ writel(msg->data, base + PCI_MSIX_ENTRY_DATA_OFFSET);
break;
}
default:
- break;
+ BUG();
}
}
+
+#ifdef CONFIG_SMP
+static void set_msi_affinity(unsigned int vector, cpumask_t cpu_mask)
+{
+ struct msi_desc *entry;
+ struct msi_msg msg;
+ unsigned int irq = vector;
+ unsigned int dest_cpu = first_cpu(cpu_mask);
+
+ entry = (struct msi_desc *)msi_desc[vector];
+ if (!entry || !entry->dev)
+ return;
+
+ read_msi_msg(entry, &msg);
+ msi_ops->target(vector, dest_cpu, &msg.address_hi, &msg.address_lo);
+ write_msi_msg(entry, &msg);
+ set_native_irq_info(irq, cpu_mask);
+}
#else
#define set_msi_affinity NULL
#endif /* CONFIG_SMP */
@@ -614,23 +651,10 @@ int pci_save_msix_state(struct pci_dev *

vector = head = dev->irq;
while (head != tail) {
- int j;
- void __iomem *base;
struct msi_desc *entry;

entry = msi_desc[vector];
- base = entry->mask_base;
- j = entry->msi_attrib.entry_nr;
-
- entry->address_lo_save =
- readl(base + j * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
- entry->address_hi_save =
- readl(base + j * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
- entry->data_save =
- readl(base + j * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_DATA_OFFSET);
+ read_msi_msg(entry, &entry->msg_save);

tail = msi_desc[vector]->link.tail;
vector = tail;
@@ -647,8 +671,6 @@ void pci_restore_msix_state(struct pci_d
u16 save;
int pos;
int vector, head, tail = 0;
- void __iomem *base;
- int j;
struct msi_desc *entry;
int temp;
struct pci_cap_saved_state *save_state;
@@ -671,18 +693,7 @@ void pci_restore_msix_state(struct pci_d
vector = head = dev->irq;
while (head != tail) {
entry = msi_desc[vector];
- base = entry->mask_base;
- j = entry->msi_attrib.entry_nr;
-
- writel(entry->address_lo_save,
- base + j * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
- writel(entry->address_hi_save,
- base + j * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
- writel(entry->data_save,
- base + j * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_DATA_OFFSET);
+ write_msi_msg(entry, &entry->msg_save);

tail = msi_desc[vector]->link.tail;
vector = tail;
@@ -697,29 +708,19 @@ #endif
static int msi_register_init(struct pci_dev *dev, struct msi_desc *entry)
{
int status;
- u32 address_hi;
- u32 address_lo;
- u32 data;
+ struct msi_msg msg;
int pos, vector = dev->irq;
u16 control;

- pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
+ pos = entry->msi_attrib.pos;
pci_read_config_word(dev, msi_control_reg(pos), &control);

/* Configure MSI capability structure */
- status = msi_ops->setup(dev, vector, &address_hi, &address_lo, &data);
+ status = msi_ops->setup(dev, vector, &msg.address_hi, &msg.address_lo, &msg.data);
if (status < 0)
return status;

- pci_write_config_dword(dev, msi_lower_address_reg(pos), address_lo);
- if (is_64bit_address(control)) {
- pci_write_config_dword(dev,
- msi_upper_address_reg(pos), address_hi);
- pci_write_config_word(dev,
- msi_data_reg(pos, 1), data);
- } else
- pci_write_config_word(dev,
- msi_data_reg(pos, 0), data);
+ write_msi_msg(entry, &msg);
if (entry->msi_attrib.maskbit) {
unsigned int maskbits, temp;
/* All MSIs are unmasked by default, Mask them all */
@@ -769,9 +770,11 @@ static int msi_capability_init(struct pc
entry->link.tail = vector;
entry->msi_attrib.type = PCI_CAP_ID_MSI;
entry->msi_attrib.state = 0; /* Mark it not active */
+ entry->msi_attrib.is_64 = is_64bit_address(control);
entry->msi_attrib.entry_nr = 0;
entry->msi_attrib.maskbit = is_mask_bit_support(control);
entry->msi_attrib.default_vector = dev->irq; /* Save IOAPIC IRQ */
+ entry->msi_attrib.pos = pos;
dev->irq = vector;
entry->dev = dev;
if (is_mask_bit_support(control)) {
@@ -809,9 +812,7 @@ static int msix_capability_init(struct p
struct msix_entry *entries, int nvec)
{
struct msi_desc *head = NULL, *tail = NULL, *entry = NULL;
- u32 address_hi;
- u32 address_lo;
- u32 data;
+ struct msi_msg msg;
int status;
int vector, pos, i, j, nr_entries, temp = 0;
unsigned long phys_addr;
@@ -848,9 +849,11 @@ static int msix_capability_init(struct p
entries[i].vector = vector;
entry->msi_attrib.type = PCI_CAP_ID_MSIX;
entry->msi_attrib.state = 0; /* Mark it not active */
+ entry->msi_attrib.is_64 = 1;
entry->msi_attrib.entry_nr = j;
entry->msi_attrib.maskbit = 1;
entry->msi_attrib.default_vector = dev->irq;
+ entry->msi_attrib.pos = pos;
entry->dev = dev;
entry->mask_base = base;
if (!head) {
@@ -869,21 +872,13 @@ static int msix_capability_init(struct p
irq_handler_init(PCI_CAP_ID_MSIX, vector, 1);
/* Configure MSI-X capability structure */
status = msi_ops->setup(dev, vector,
- &address_hi,
- &address_lo,
- &data);
+ &msg.address_hi,
+ &msg.address_lo,
+ &msg.data);
if (status < 0)
break;

- writel(address_lo,
- base + j * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
- writel(address_hi,
- base + j * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
- writel(data,
- base + j * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_DATA_OFFSET);
+ write_msi_msg(entry, &msg);
attach_msi_entry(entry, vector);
}
if (i != nvec) {
diff --git a/drivers/pci/msi.h b/drivers/pci/msi.h
index 9b31d4c..62f61b6 100644
--- a/drivers/pci/msi.h
+++ b/drivers/pci/msi.h
@@ -130,10 +130,10 @@ struct msi_desc {
__u8 type : 5; /* {0: unused, 5h:MSI, 11h:MSI-X} */
__u8 maskbit : 1; /* mask-pending bit supported ? */
__u8 state : 1; /* {0: free, 1: busy} */
- __u8 reserved: 1; /* reserved */
+ __u8 is_64 : 1; /* Address size: 0=32bit 1=64bit */
__u8 entry_nr; /* specific enabled entry */
__u8 default_vector; /* default pre-assigned vector */
- __u8 unused; /* formerly unused destination cpu*/
+ __u8 pos; /* Location of the msi capability */
}msi_attrib;

struct {
@@ -146,10 +146,7 @@ struct msi_desc {

#ifdef CONFIG_PM
/* PM save area for MSIX address/data */
-
- u32 address_hi_save;
- u32 address_lo_save;
- u32 data_save;
+ struct msi_msg msg_save;
#endif
};

diff --git a/include/linux/pci.h b/include/linux/pci.h
index e36e3d5..c7be27b 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -591,6 +591,12 @@ struct msix_entry {
u16 entry; /* driver uses to specify entry, OS writes */
};

+struct msi_msg {
+ u32 address_lo; /* low 32 bits of msi message address */
+ u32 address_hi; /* high 32 bits of msi message address */
+ u32 data; /* 16 bits of msi message data */
+};
+
#ifndef CONFIG_PCI_MSI
static inline void pci_scan_msi_device(struct pci_dev *dev) {}
static inline int pci_enable_msi(struct pci_dev *dev) {return -1;}
--
1.4.0.gc07e

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