[PATCH v3 1/3] PCI: Introduce pcibios_ignore_alignment_request

Shawn Anastasio
2019-05-28T04:03:29Z

Introduce a new pcibios function pcibios_ignore_alignment_request
which allows the PCI core to defer to platform-specific code to
determine whether or not to ignore alignment requests for PCI resources.

The existing behavior is to simply ignore alignment requests when
PCI_PROBE_ONLY is set. This is behavior is maintained by the
default implementation of pcibios_ignore_alignment_request.

Signed-off-by: Shawn Anastasio <shawn@anastas.io>
---
drivers/pci/pci.c | 9 +++++++--
include/linux/pci.h | 1 +
2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 8abc843b1615..8207a09085d1 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5882,6 +5882,11 @@ resource_size_t __weak pcibios_default_alignment(void)
return 0;
}

+int __weak pcibios_ignore_alignment_request(void)
+{
+ return pci_has_flag(PCI_PROBE_ONLY);
+}
+
#define RESOURCE_ALIGNMENT_PARAM_SIZE COMMAND_LINE_SIZE
static char resource_alignment_param[RESOURCE_ALIGNMENT_PARAM_SIZE] = {0};
static DEFINE_SPINLOCK(resource_alignment_lock);
@@ -5906,9 +5911,9 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev,
p = resource_alignment_param;
if (!*p && !align)
goto out;
- if (pci_has_flag(PCI_PROBE_ONLY)) {
+ if (pcibios_ignore_alignment_request()) {
align = 0;
- pr_info_once("PCI: Ignoring requested alignments (PCI_PROBE_ONLY)\n");
+ pr_info_once("PCI: Ignoring requested alignments\n");
goto out;
}

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 4a5a84d7bdd4..47471dcdbaf9 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1990,6 +1990,7 @@ static inline void pcibios_penalize_isa_irq(int irq, int active) {}
int pcibios_alloc_irq(struct pci_dev *dev);
void pcibios_free_irq(struct pci_dev *dev);
resource_size_t pcibios_default_alignment(void);
+int pcibios_ignore_alignment_request(void);

#ifdef CONFIG_HIBERNATE_CALLBACKS
extern struct dev_pm_ops pcibios_pm_ops;
--
2.20.1