From 70aaf61a9b8b86eb08da96344efd1c0f0925ee6e Mon Sep 17 00:00:00 2001 From: Logan Gunthorpe Date: Thu, 22 Aug 2019 10:10:11 -0600 Subject: PCI: Clean up resource_alignment parameter to not require static buffer 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. Link: https://lore.kernel.org/r/20190822161013.5481-2-logang@deltatee.com Signed-off-by: Logan Gunthorpe Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 41 +++++++++++++++++++++++------------------ 1 file changed, 23 insertions(+), 18 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 08dfb16bd084..fbfb64ba447d 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5932,8 +5932,7 @@ 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); /** @@ -5954,7 +5953,7 @@ 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; @@ -6120,21 +6119,25 @@ 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; } @@ -6275,8 +6278,7 @@ 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)) { @@ -6311,15 +6313,18 @@ 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; -- cgit