Re: [patch] PCI Cleanup

From: Matthew Dobson (colpatch@us.ibm.com)
Date: Tue Aug 13 2002 - 17:29:38 EST


Linus,
        I think I'm getting what you're aiming for here. See if this patch comes close
to what you're looking for.

        The basic idea is we get rid of the byte/word/dword functions and just put a
size arg in the generic calls. I put back the different struct pci_ops for
conf1 and conf2, so that drivers and other code could use either config option.
  I also fixed the macros in access.h so that it correctly calls the new functions.

Please *don't* apply this as it will break a bunch of stuff (just about all PCI
code ;)

Cheers!

-Matt

Linus Torvalds wrote:
> On 13 Aug 2002, Alan Cox wrote:
>
>>>OK, that IDE thing smacks of unmitigated evil to me, but if things are relying
>>>on it, we shouldn't change it.
>>
>>It wants to force its own conf1/conf2 over the BIOS even if BIOS is
>>preferred because some BIOSes dont honour the size requested and the
>>hardware has bugs.
>>
>>That to me says there may well be cleaner approaches.
>
>
> The thing I liked about the separate structures for function pointers for
> conf1/conf2 is that I could at least _see_ that the IDE driver might some
> day be changed to just do
>
> ..
> conf2_struct->pci_config_read_byte(..)
> ..
>
> even if (judging by past performance) this would never happen ;)
>
> This is why I'd like to continue with the notion of having a well-defined
> structure that contains all the pointers (and one default case). Now,
> shrinking those structures down to 2 entries instead of 6 sounds like a
> fine idea to me, but short-circuiting them internally sounds bad because
> it loses the ability to use the pci config space functions independently
> of each other.
>
> Linus
>
>

diff -Nur linux-2.5.31-vanilla/arch/i386/pci/direct.c linux-2.5.31-patched/arch/i386/pci/direct.c
--- linux-2.5.31-vanilla/arch/i386/pci/direct.c Sat Aug 10 18:41:23 2002
+++ linux-2.5.31-patched/arch/i386/pci/direct.c Tue Aug 13 15:22:03 2002
@@ -69,75 +69,23 @@
         return 0;
 }
 
-
 #undef PCI_CONF1_ADDRESS
 
-static int pci_conf1_read_config_byte(struct pci_dev *dev, int where, u8 *value)
+static int pci_conf1_read_size_indep(struct pci_dev *dev, int where, int size, u32 *value)
 {
- int result;
- u32 data;
-
- if (!value)
- return -EINVAL;
-
- result = pci_conf1_read(0, dev->bus->number, PCI_SLOT(dev->devfn),
- PCI_FUNC(dev->devfn), where, 1, &data);
-
- *value = (u8)data;
-
- return result;
-}
-
-static int pci_conf1_read_config_word(struct pci_dev *dev, int where, u16 *value)
-{
- int result;
- u32 data;
-
- if (!value)
- return -EINVAL;
-
- result = pci_conf1_read(0, dev->bus->number, PCI_SLOT(dev->devfn),
- PCI_FUNC(dev->devfn), where, 2, &data);
-
- *value = (u16)data;
-
- return result;
-}
-
-static int pci_conf1_read_config_dword(struct pci_dev *dev, int where, u32 *value)
-{
- if (!value)
- return -EINVAL;
-
         return pci_conf1_read(0, dev->bus->number, PCI_SLOT(dev->devfn),
- PCI_FUNC(dev->devfn), where, 4, value);
+ PCI_FUNC(dev->devfn), where, size, value);
 }
 
-static int pci_conf1_write_config_byte(struct pci_dev *dev, int where, u8 value)
+static int pci_conf1_write_size_indep(struct pci_dev *dev, int where, int size, u32 value)
 {
         return pci_conf1_write(0, dev->bus->number, PCI_SLOT(dev->devfn),
- PCI_FUNC(dev->devfn), where, 1, value);
-}
-
-static int pci_conf1_write_config_word(struct pci_dev *dev, int where, u16 value)
-{
- return pci_conf1_write(0, dev->bus->number, PCI_SLOT(dev->devfn),
- PCI_FUNC(dev->devfn), where, 2, value);
-}
-
-static int pci_conf1_write_config_dword(struct pci_dev *dev, int where, u32 value)
-{
- return pci_conf1_write(0, dev->bus->number, PCI_SLOT(dev->devfn),
- PCI_FUNC(dev->devfn), where, 4, value);
+ PCI_FUNC(dev->devfn), where, size, value);
 }
 
 static struct pci_ops pci_direct_conf1 = {
- pci_conf1_read_config_byte,
- pci_conf1_read_config_word,
- pci_conf1_read_config_dword,
- pci_conf1_write_config_byte,
- pci_conf1_write_config_word,
- pci_conf1_write_config_dword
+ pci_conf1_read_size_indep,
+ pci_conf1_write_size_indep
 };
 
 
@@ -217,57 +165,21 @@
 
 #undef PCI_CONF2_ADDRESS
 
-static int pci_conf2_read_config_byte(struct pci_dev *dev, int where, u8 *value)
-{
- int result;
- u32 data;
- result = pci_conf2_read(0, dev->bus->number, PCI_SLOT(dev->devfn),
- PCI_FUNC(dev->devfn), where, 1, &data);
- *value = (u8)data;
- return result;
-}
-
-static int pci_conf2_read_config_word(struct pci_dev *dev, int where, u16 *value)
-{
- int result;
- u32 data;
- result = pci_conf2_read(0, dev->bus->number, PCI_SLOT(dev->devfn),
- PCI_FUNC(dev->devfn), where, 2, &data);
- *value = (u16)data;
- return result;
-}
-
-static int pci_conf2_read_config_dword(struct pci_dev *dev, int where, u32 *value)
+static int pci_conf2_read_size_indep(struct pci_dev *dev, int where, int size, u32 *value)
 {
         return pci_conf2_read(0, dev->bus->number, PCI_SLOT(dev->devfn),
- PCI_FUNC(dev->devfn), where, 4, value);
-}
-
-static int pci_conf2_write_config_byte(struct pci_dev *dev, int where, u8 value)
-{
- return pci_conf2_write(0, dev->bus->number, PCI_SLOT(dev->devfn),
- PCI_FUNC(dev->devfn), where, 1, value);
+ PCI_FUNC(dev->devfn), where, size, value);
 }
 
-static int pci_conf2_write_config_word(struct pci_dev *dev, int where, u16 value)
+static int pci_conf2_write_size_indep(struct pci_dev *dev, int where, int size, u32 value)
 {
         return pci_conf2_write(0, dev->bus->number, PCI_SLOT(dev->devfn),
- PCI_FUNC(dev->devfn), where, 2, value);
-}
-
-static int pci_conf2_write_config_dword(struct pci_dev *dev, int where, u32 value)
-{
- return pci_conf2_write(0, dev->bus->number, PCI_SLOT(dev->devfn),
- PCI_FUNC(dev->devfn), where, 4, value);
+ PCI_FUNC(dev->devfn), where, size, value);
 }
 
 static struct pci_ops pci_direct_conf2 = {
- pci_conf2_read_config_byte,
- pci_conf2_read_config_word,
- pci_conf2_read_config_dword,
- pci_conf2_write_config_byte,
- pci_conf2_write_config_word,
- pci_conf2_write_config_dword
+ pci_conf2_read_size_indep,
+ pci_conf2_write_size_indep
 };
 
 
@@ -292,16 +204,16 @@
         bus.number = 0;
         dev.bus = &bus;
         for(dev.devfn=0; dev.devfn < 0x100; dev.devfn++)
- if ((!o->read_word(&dev, PCI_CLASS_DEVICE, &x) &&
+ if ((!o->read(&dev, PCI_CLASS_DEVICE, 2, &x) &&
                      (x == PCI_CLASS_BRIDGE_HOST || x == PCI_CLASS_DISPLAY_VGA)) ||
- (!o->read_word(&dev, PCI_VENDOR_ID, &x) &&
+ (!o->read(&dev, PCI_VENDOR_ID, 2, &x) &&
                      (x == PCI_VENDOR_ID_INTEL || x == PCI_VENDOR_ID_COMPAQ)))
                         return 1;
         DBG("PCI: Sanity check failed\n");
         return 0;
 }
 
-static struct pci_ops * __devinit pci_check_direct(void)
+static int __init pci_direct_init(void)
 {
         unsigned int tmp;
         unsigned long flags;
@@ -312,6 +224,8 @@
          * Check if configuration type 1 works.
          */
         if (pci_probe & PCI_PROBE_CONF1) {
+ pci_config_read = pci_conf1_read;
+ pci_config_write = pci_conf1_write;
                 outb (0x01, 0xCFB);
                 tmp = inl (0xCF8);
                 outl (0x80000000, 0xCF8);
@@ -321,8 +235,10 @@
                         local_irq_restore(flags);
                         printk(KERN_INFO "PCI: Using configuration type 1\n");
                         if (!request_region(0xCF8, 8, "PCI conf1"))
- return NULL;
- return &pci_direct_conf1;
+ pci_root_ops = NULL;
+ else
+ pci_root_ops = &pci_direct_conf1;
+ return 0;
                 }
                 outl (tmp, 0xCF8);
         }
@@ -331,6 +247,8 @@
          * Check if configuration type 2 works.
          */
         if (pci_probe & PCI_PROBE_CONF2) {
+ pci_config_read = pci_conf2_read;
+ pci_config_write = pci_conf2_write;
                 outb (0x00, 0xCFB);
                 outb (0x00, 0xCF8);
                 outb (0x00, 0xCFA);
@@ -339,28 +257,15 @@
                         local_irq_restore(flags);
                         printk(KERN_INFO "PCI: Using configuration type 2\n");
                         if (!request_region(0xCF8, 4, "PCI conf2"))
- return NULL;
- return &pci_direct_conf2;
+ pci_root_ops = NULL;
+ else
+ pci_root_ops = &pci_direct_conf2;
+ return 0;
                 }
         }
 
         local_irq_restore(flags);
- return NULL;
-}
-
-static int __init pci_direct_init(void)
-{
- if ((pci_probe & (PCI_PROBE_CONF1 | PCI_PROBE_CONF2))
- && (pci_root_ops = pci_check_direct())) {
- if (pci_root_ops == &pci_direct_conf1) {
- pci_config_read = pci_conf1_read;
- pci_config_write = pci_conf1_write;
- }
- else {
- pci_config_read = pci_conf2_read;
- pci_config_write = pci_conf2_write;
- }
- }
+ pci_root_ops = NULL;
         return 0;
 }
 
diff -Nur linux-2.5.31-vanilla/drivers/pci/access.c linux-2.5.31-patched/drivers/pci/access.c
--- linux-2.5.31-vanilla/drivers/pci/access.c Sat Aug 10 18:41:29 2002
+++ linux-2.5.31-patched/drivers/pci/access.c Tue Aug 13 15:09:56 2002
@@ -19,24 +19,38 @@
 #define PCI_word_BAD (pos & 1)
 #define PCI_dword_BAD (pos & 3)
 
-#define PCI_OP(rw,size,type) \
-int pci_##rw##_config_##size (struct pci_dev *dev, int pos, type value) \
+#define PCI_OP_READ(size,type,len) \
+int pci_read_config_##size (struct pci_dev *dev, int pos, type *value) \
 { \
         int res; \
         unsigned long flags; \
+ u32 data; \
         if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
         spin_lock_irqsave(&pci_lock, flags); \
- res = dev->bus->ops->rw##_##size(dev, pos, value); \
+ res = dev->bus->ops->read(dev, pos, len, &data); \
+ *value = (type)data; \
         spin_unlock_irqrestore(&pci_lock, flags); \
         return res; \
 }
 
-PCI_OP(read, byte, u8 *)
-PCI_OP(read, word, u16 *)
-PCI_OP(read, dword, u32 *)
-PCI_OP(write, byte, u8)
-PCI_OP(write, word, u16)
-PCI_OP(write, dword, u32)
+#define PCI_OP_WRITE(size,type,len) \
+int pci_write_config_##size (struct pci_dev *dev, int pos, type value) \
+{ \
+ int res; \
+ unsigned long flags; \
+ if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
+ spin_lock_irqsave(&pci_lock, flags); \
+ res = dev->bus->ops->write(dev, pos, len, value); \
+ spin_unlock_irqrestore(&pci_lock, flags); \
+ return res; \
+}
+
+PCI_OP_READ(byte, u8, 1)
+PCI_OP_READ(word, u16, 2)
+PCI_OP_READ(dword, u32, 4)
+PCI_OP_WRITE(byte, u8, 1)
+PCI_OP_WRITE(word, u16, 2)
+PCI_OP_WRITE(dword, u32, 4)
 
 EXPORT_SYMBOL(pci_read_config_byte);
 EXPORT_SYMBOL(pci_read_config_word);
diff -Nur linux-2.5.31-vanilla/include/linux/pci.h linux-2.5.31-patched/include/linux/pci.h
--- linux-2.5.31-vanilla/include/linux/pci.h Sat Aug 10 18:41:28 2002
+++ linux-2.5.31-patched/include/linux/pci.h Tue Aug 13 14:49:36 2002
@@ -456,12 +456,8 @@
 /* Low-level architecture-dependent routines */
 
 struct pci_ops {
- int (*read_byte)(struct pci_dev *, int where, u8 *val);
- int (*read_word)(struct pci_dev *, int where, u16 *val);
- int (*read_dword)(struct pci_dev *, int where, u32 *val);
- int (*write_byte)(struct pci_dev *, int where, u8 val);
- int (*write_word)(struct pci_dev *, int where, u16 val);
- int (*write_dword)(struct pci_dev *, int where, u32 val);
+ int (*read)(struct pci_dev *, int where, int size, u32 *val);
+ int (*write)(struct pci_dev *, int where, int size, u32 val);
 };
 
 struct pbus_set_ranges_data

-
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