[PATCH] Use pci_generic_prep_mwi on ia64

Matthew Wilcox
2006-10-07T03:40:14Z

The pci_generic_prep_mwi() code does everything that pcibios_prep_mwi()
does on ia64. All we need to do is be sure that pci_cache_line_size
is set appropriately, and we can delete pcibios_prep_mwi().

Using SMP_CACHE_BYTES as the default was wrong on uniprocessor machines
as it is only 8 bytes. The default in the generic code of L1_CACHE_BYTES
is at least as good.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>

diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c
index b30be7c..4f77472 100644
--- a/arch/ia64/pci/pci.c
+++ b/arch/ia64/pci/pci.c
@@ -738,75 +738,44 @@ int ia64_pci_legacy_write(struct pci_bus
return ret;
}

+/* It's defined in drivers/pci/pci.c */
+extern u8 pci_cache_line_size;
+
/**
- * pci_cacheline_size - determine cacheline size for PCI devices
- * @dev: void
+ * set_pci_cacheline_size - determine cacheline size for PCI devices
*
* We want to use the line-size of the outer-most cache. We assume
* that this line-size is the same for all CPUs.
*
* Code mostly taken from arch/ia64/kernel/palinfo.c:cache_info().
- *
- * RETURNS: An appropriate -ERRNO error value on eror, or zero for success.
*/
-static unsigned long
-pci_cacheline_size (void)
+static void __init set_pci_cacheline_size(void)
{
u64 levels, unique_caches;
s64 status;
pal_cache_config_info_t cci;
- static u8 cacheline_size;
-
- if (cacheline_size)
- return cacheline_size;

status = ia64_pal_cache_summary(&levels, &unique_caches);
if (status != 0) {
- printk(KERN_ERR "%s: ia64_pal_cache_summary() failed (status=%ld)\n",
- __FUNCTION__, status);
- return SMP_CACHE_BYTES;
+ printk(KERN_ERR "%s: ia64_pal_cache_summary() failed "
+ "(status=%ld)\n", __FUNCTION__, status);
+ return;
}

- status = ia64_pal_cache_config_info(levels - 1, /* cache_type (data_or_unified)= */ 2,
- &cci);
+ status = ia64_pal_cache_config_info(levels - 1,
+ /* cache_type (data_or_unified)= */ 2, &cci);
if (status != 0) {
- printk(KERN_ERR "%s: ia64_pal_cache_config_info() failed (status=%ld)\n",
- __FUNCTION__, status);
- return SMP_CACHE_BYTES;
+ printk(KERN_ERR "%s: ia64_pal_cache_config_info() failed "
+ "(status=%ld)\n", __FUNCTION__, status);
+ return;
}
- cacheline_size = 1 << cci.pcci_line_size;
- return cacheline_size;
+ pci_cache_line_size = (1 << cci.pcci_line_size) / 4;
}

-/**
- * pcibios_prep_mwi - helper function for drivers/pci/pci.c:pci_set_mwi()
- * @dev: the PCI device for which MWI is enabled
- *
- * For ia64, we can get the cacheline sizes from PAL.
- *
- * RETURNS: An appropriate -ERRNO error value on eror, or zero for success.
- */
-int
-pcibios_prep_mwi (struct pci_dev *dev)
-{
- unsigned long desired_linesize, current_linesize;
- int rc = 0;
- u8 pci_linesize;
-
- desired_linesize = pci_cacheline_size();
-
- pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &pci_linesize);
- current_linesize = 4 * pci_linesize;
- if (desired_linesize != current_linesize) {
- printk(KERN_WARNING "PCI: slot %s has incorrect PCI cache line size of %lu bytes,",
- pci_name(dev), current_linesize);
- if (current_linesize > desired_linesize) {
- printk(" expected %lu bytes instead\n", desired_linesize);
- rc = -EINVAL;
- } else {
- printk(" correcting to %lu\n", desired_linesize);
- pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, desired_linesize / 4);
- }
- }
- return rc;
+static int __init pcibios_init(void)
+{
+ set_pci_cacheline_size();
+ return 0;
}
+
+subsys_initcall(pcibios_init);
diff --git a/include/asm-ia64/pci.h b/include/asm-ia64/pci.h
index ef616fd..825eb7d 100644
--- a/include/asm-ia64/pci.h
+++ b/include/asm-ia64/pci.h
@@ -26,16 +26,18 @@ void pcibios_config_init(void);
struct pci_dev;

/*
- * PCI_DMA_BUS_IS_PHYS should be set to 1 if there is _necessarily_ a direct correspondence
- * between device bus addresses and CPU physical addresses. Platforms with a hardware I/O
- * MMU _must_ turn this off to suppress the bounce buffer handling code in the block and
- * network device layers. Platforms with separate bus address spaces _must_ turn this off
- * and provide a device DMA mapping implementation that takes care of the necessary
+ * PCI_DMA_BUS_IS_PHYS should be set to 1 if there is _necessarily_ a direct
+ * correspondence between device bus addresses and CPU physical addresses.
+ * Platforms with a hardware I/O MMU _must_ turn this off to suppress the
+ * bounce buffer handling code in the block and network device layers.
+ * Platforms with separate bus address spaces _must_ turn this off and provide
+ * a device DMA mapping implementation that takes care of the necessary
* address translation.
*
- * For now, the ia64 platforms which may have separate/multiple bus address spaces all
- * have I/O MMUs which support the merging of physically discontiguous buffers, so we can
- * use that as the sole factor to determine the setting of PCI_DMA_BUS_IS_PHYS.
+ * For now, the ia64 platforms which may have separate/multiple bus address
+ * spaces all have I/O MMUs which support the merging of physically
+ * discontiguous buffers, so we can use that as the sole factor to determine
+ * the setting of PCI_DMA_BUS_IS_PHYS.
*/
extern unsigned long ia64_max_iommu_merge_mask;
#define PCI_DMA_BUS_IS_PHYS (ia64_max_iommu_merge_mask = ~0UL)
@@ -52,9 +54,6 @@ pcibios_penalize_isa_irq (int irq, int a
/* We don't do dynamic PCI IRQ allocation */
}

-#define HAVE_ARCH_PCI_MWI 1
-extern int pcibios_prep_mwi (struct pci_dev *);
-
#include <asm-generic/pci-dma-compat.h>

/* pci_unmap_{single,page} is not a nop, thus... */