From 07c5ba912401b2ae3f13e3ce214158aec723c3fd Mon Sep 17 00:00:00 2001 From: Josh Collier Date: Thu, 11 Apr 2019 07:07:42 -0700 Subject: IB/hfi1: Add debugfs to control expansion ROM write protect Some kernels now enable CONFIG_IO_STRICT_DEVMEM which prevents multiple handles to PCI resource0. In order to continue to support expansion ROM updates while the driver is loaded, the driver must now provide an interface to control the expansion ROM write protection. This patch adds an exprom_wp debugfs interface that allows the hfi1_eprom user tool to disable the expansion ROM write protection by opening the file and writing a '1'. The write protection is released when writing a '0' or automatically re-enabled when the file handle is closed. The current implementation will only allow one handle to be opened at a time across all hfi1 devices. Reviewed-by: Dennis Dalessandro Signed-off-by: Josh Collier Signed-off-by: Dennis Dalessandro Signed-off-by: Jason Gunthorpe --- drivers/infiniband/hw/hfi1/debugfs.c | 74 ++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) (limited to 'drivers') diff --git a/drivers/infiniband/hw/hfi1/debugfs.c b/drivers/infiniband/hw/hfi1/debugfs.c index 057bb82c664f..15efb4a380b2 100644 --- a/drivers/infiniband/hw/hfi1/debugfs.c +++ b/drivers/infiniband/hw/hfi1/debugfs.c @@ -1080,6 +1080,77 @@ static int qsfp2_debugfs_release(struct inode *in, struct file *fp) return __qsfp_debugfs_release(in, fp, 1); } +#define EXPROM_WRITE_ENABLE BIT_ULL(14) + +static bool exprom_wp_disabled; + +static int exprom_wp_set(struct hfi1_devdata *dd, bool disable) +{ + u64 gpio_val = 0; + + if (disable) { + gpio_val = EXPROM_WRITE_ENABLE; + exprom_wp_disabled = true; + dd_dev_info(dd, "Disable Expansion ROM Write Protection\n"); + } else { + exprom_wp_disabled = false; + dd_dev_info(dd, "Enable Expansion ROM Write Protection\n"); + } + + write_csr(dd, ASIC_GPIO_OUT, gpio_val); + write_csr(dd, ASIC_GPIO_OE, gpio_val); + + return 0; +} + +static ssize_t exprom_wp_debugfs_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + return 0; +} + +static ssize_t exprom_wp_debugfs_write(struct file *file, + const char __user *buf, size_t count, + loff_t *ppos) +{ + struct hfi1_pportdata *ppd = private2ppd(file); + char cdata; + + if (count != 1) + return -EINVAL; + if (get_user(cdata, buf)) + return -EFAULT; + if (cdata == '0') + exprom_wp_set(ppd->dd, false); + else if (cdata == '1') + exprom_wp_set(ppd->dd, true); + else + return -EINVAL; + + return 1; +} + +static unsigned long exprom_in_use; + +static int exprom_wp_debugfs_open(struct inode *in, struct file *fp) +{ + if (test_and_set_bit(0, &exprom_in_use)) + return -EBUSY; + + return 0; +} + +static int exprom_wp_debugfs_release(struct inode *in, struct file *fp) +{ + struct hfi1_pportdata *ppd = private2ppd(fp); + + if (exprom_wp_disabled) + exprom_wp_set(ppd->dd, false); + clear_bit(0, &exprom_in_use); + + return 0; +} + #define DEBUGFS_OPS(nm, readroutine, writeroutine) \ { \ .name = nm, \ @@ -1119,6 +1190,9 @@ static const struct counter_info port_cntr_ops[] = { qsfp1_debugfs_open, qsfp1_debugfs_release), DEBUGFS_XOPS("qsfp2", qsfp2_debugfs_read, qsfp2_debugfs_write, qsfp2_debugfs_open, qsfp2_debugfs_release), + DEBUGFS_XOPS("exprom_wp", exprom_wp_debugfs_read, + exprom_wp_debugfs_write, exprom_wp_debugfs_open, + exprom_wp_debugfs_release), DEBUGFS_OPS("asic_flags", asic_flags_read, asic_flags_write), DEBUGFS_OPS("dc8051_memory", dc8051_memory_read, NULL), DEBUGFS_OPS("lcb", debugfs_lcb_read, debugfs_lcb_write), -- cgit v1.2.3