Clean up the 'resource_alignment' parameter code to use kstrdup
in the initcall routine instead of a static buffer that wastes memory
regardless of whether the feature is used. This allows us to drop
'COMMAND_LINE_SIZE' bytes (typically 256-4096 depending on architecture)
of static data.
This is similar to what has been done for the 'disable_acs_redir'
parameter.
Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/pci/pci.c | 41 +++++++++++++++++++++++------------------
1 file changed, 23 insertions(+), 18 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 766f5779db92..bd7cdcfeb094 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5896,8 +5896,7 @@ resource_size_t __weak pcibios_default_alignment(void)
return 0;
}
-#define RESOURCE_ALIGNMENT_PARAM_SIZE COMMAND_LINE_SIZE
-static char resource_alignment_param[RESOURCE_ALIGNMENT_PARAM_SIZE] = {0};
+static char *resource_alignment_param;
static DEFINE_SPINLOCK(resource_alignment_lock);
/**
@@ -5918,7 +5917,7 @@ static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev,
spin_lock(&resource_alignment_lock);
p = resource_alignment_param;
- if (!*p && !align)
+ if (!p || !*p)
goto out;
if (pci_has_flag(PCI_PROBE_ONLY)) {
align = 0;
@@ -6084,21 +6083,25 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev)
static ssize_t pci_set_resource_alignment_param(const char *buf, size_t count)
{
- if (count > RESOURCE_ALIGNMENT_PARAM_SIZE - 1)
- count = RESOURCE_ALIGNMENT_PARAM_SIZE - 1;
spin_lock(&resource_alignment_lock);
- strncpy(resource_alignment_param, buf, count);
- resource_alignment_param[count] = '\0';
+
+ kfree(resource_alignment_param);
+ resource_alignment_param = kstrndup(buf, count, GFP_KERNEL);
+
spin_unlock(&resource_alignment_lock);
- return count;
+
+ return resource_alignment_param ? count : -ENOMEM;
}
static ssize_t pci_get_resource_alignment_param(char *buf, size_t size)
{
- size_t count;
+ size_t count = 0;
+
spin_lock(&resource_alignment_lock);
- count = snprintf(buf, size, "%s", resource_alignment_param);
+ if (resource_alignment_param)
+ count = snprintf(buf, size, "%s", resource_alignment_param);
spin_unlock(&resource_alignment_lock);
+
return count;
}
@@ -6238,8 +6241,7 @@ static int __init pci_setup(char *str)
} else if (!strncmp(str, "cbmemsize=", 10)) {
pci_cardbus_mem_size = memparse(str + 10, &str);
} else if (!strncmp(str, "resource_alignment=", 19)) {
- pci_set_resource_alignment_param(str + 19,
- strlen(str + 19));
+ resource_alignment_param = str + 19;
} else if (!strncmp(str, "ecrc=", 5)) {
pcie_ecrc_get_policy(str + 5);
} else if (!strncmp(str, "hpiosize=", 9)) {
@@ -6275,15 +6277,18 @@ static int __init pci_setup(char *str)
early_param("pci", pci_setup);
/*
- * 'disable_acs_redir_param' is initialized in pci_setup(), above, to point
- * to data in the __initdata section which will be freed after the init
- * sequence is complete. We can't allocate memory in pci_setup() because some
- * architectures do not have any memory allocation service available during
- * an early_param() call. So we allocate memory and copy the variable here
- * before the init section is freed.
+ * 'resource_alignment_param' and 'disable_acs_redir_param' are initialized
+ * in pci_setup(), above, to point to data in the __initdata section which
+ * will be freed after the init sequence is complete. We can't allocate memory
+ * in pci_setup() because some architectures do not have any memory allocation
+ * service available during an early_param() call. So we allocate memory and
+ * copy the variable here before the init section is freed.
+ *
*/
static int __init pci_realloc_setup_params(void)
{
+ resource_alignment_param = kstrdup(resource_alignment_param,
+ GFP_KERNEL);
disable_acs_redir_param = kstrdup(disable_acs_redir_param, GFP_KERNEL);
return 0;
--
2.20.1
