[PATCH v12 5/6] PCI: endpoint: pci-epf-vntb: Clean up

From: Frank Li
Date: Fri Oct 07 2022 - 15:14:10 EST

Remove unused field: epf_db_phy.
Remove __iomem before epf_db.
Change epf_db to u32* from void *
Remove duplicate check if (readl(ntb->epf_db + i * 4)).
Using sizeof(u32) instead of number 4 at all place.

Clean up sparse build warning:
Using epf_db[i] instead of readl() because epf_db is located in local
memory and allocated by dma_alloc_coherent(). Sparse build warning when
there are not __iomem at readl().
Added __iomem force type convert in vntb_epf_peer_spad_read\write() and
vntb_epf_spad_read\write(). This require strong order at read and write.

Replace pci_epc_mem_free_addr() with pci_epf_free_space() at error handle
path to match pci_epf_alloc_space().

Cleanup warning found by scripts/kernel-doc
Fix indentation of the struct epf_ntb_ctrl
Consolidate term
host, host1 to HOST
vhost, vHost, Vhost, VHOST2 to VHOST

Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
drivers/pci/endpoint/functions/pci-epf-vntb.c | 157 ++++++++++--------
1 file changed, 90 insertions(+), 67 deletions(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
index 1466dd1904175..acea753af29ed 100644
--- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
+++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
@@ -11,7 +11,7 @@
* Author: Kishon Vijay Abraham I <kishon@xxxxxx>
*/

-/**
+/*
* +------------+ +---------------------------------------+
* | | | |
* +------------+ | +--------------+
@@ -99,20 +99,20 @@ enum epf_ntb_bar {
* NTB Driver NTB Driver
*/
struct epf_ntb_ctrl {
- u32 command;
- u32 argument;
- u16 command_status;
- u16 link_status;
- u32 topology;
- u64 addr;
- u64 size;
- u32 num_mws;
- u32 reserved;
- u32 spad_offset;
- u32 spad_count;
- u32 db_entry_size;
- u32 db_data[MAX_DB_COUNT];
- u32 db_offset[MAX_DB_COUNT];
+ u32 command;
+ u32 argument;
+ u16 command_status;
+ u16 link_status;
+ u32 topology;
+ u64 addr;
+ u64 size;
+ u32 num_mws;
+ u32 reserved;
+ u32 spad_offset;
+ u32 spad_count;
+ u32 db_entry_size;
+ u32 db_data[MAX_DB_COUNT];
+ u32 db_offset[MAX_DB_COUNT];
} __packed;

struct epf_ntb {
@@ -136,8 +136,7 @@ struct epf_ntb {

struct epf_ntb_ctrl *reg;

- phys_addr_t epf_db_phy;
- void __iomem *epf_db;
+ u32 *epf_db;

phys_addr_t vpci_mw_phy[MAX_MW];
void __iomem *vpci_mw_addr[MAX_MW];
@@ -156,12 +155,14 @@ static struct pci_epf_header epf_ntb_header = {
};

/**
- * epf_ntb_link_up() - Raise link_up interrupt to Virtual Host
+ * epf_ntb_link_up() - Raise link_up interrupt to Virtual Host (VHOST)
* @ntb: NTB device that facilitates communication between HOST and VHOST
* @link_up: true or false indicating Link is UP or Down
*
* Once NTB function in HOST invoke ntb_link_enable(),
- * this NTB function driver will trigger a link event to vhost.
+ * this NTB function driver will trigger a link event to VHOST.
+ *
+ * Returns: Zero for success, or an error code in case of failure
*/
static int epf_ntb_link_up(struct epf_ntb *ntb, bool link_up)
{
@@ -175,9 +176,9 @@ static int epf_ntb_link_up(struct epf_ntb *ntb, bool link_up)
}

/**
- * epf_ntb_configure_mw() - Configure the Outbound Address Space for vhost
- * to access the memory window of host
- * @ntb: NTB device that facilitates communication between host and vhost
+ * epf_ntb_configure_mw() - Configure the Outbound Address Space for VHOST
+ * to access the memory window of HOST
+ * @ntb: NTB device that facilitates communication between HOST and VHOST
* @mw: Index of the memory window (either 0, 1, 2 or 3)
*
* EP Outbound Window
@@ -194,7 +195,9 @@ static int epf_ntb_link_up(struct epf_ntb *ntb, bool link_up)
* | | | |
* | | | |
* +--------+ +-----------+
- * VHost PCI EP
+ * VHOST PCI EP
+ *
+ * Returns: Zero for success, or an error code in case of failure
*/
static int epf_ntb_configure_mw(struct epf_ntb *ntb, u32 mw)
{
@@ -219,7 +222,7 @@ static int epf_ntb_configure_mw(struct epf_ntb *ntb, u32 mw)

/**
* epf_ntb_teardown_mw() - Teardown the configured OB ATU
- * @ntb: NTB device that facilitates communication between HOST and vHOST
+ * @ntb: NTB device that facilitates communication between HOST and VHOST
* @mw: Index of the memory window (either 0, 1, 2 or 3)
*
* Teardown the configured OB ATU configured in epf_ntb_configure_mw() using
@@ -234,12 +237,12 @@ static void epf_ntb_teardown_mw(struct epf_ntb *ntb, u32 mw)
}

/**
- * epf_ntb_cmd_handler() - Handle commands provided by the NTB Host
+ * epf_ntb_cmd_handler() - Handle commands provided by the NTB HOST
* @work: work_struct for the epf_ntb_epc
*
* Workqueue function that gets invoked for the two epf_ntb_epc
* periodically (once every 5ms) to see if it has received any commands
- * from NTB host. The host can send commands to configure doorbell or
+ * from NTB HOST. The HOST can send commands to configure doorbell or
* configure memory window or to update link status.
*/
static void epf_ntb_cmd_handler(struct work_struct *work)
@@ -254,12 +257,9 @@ static void epf_ntb_cmd_handler(struct work_struct *work)
ntb = container_of(work, struct epf_ntb, cmd_handler.work);

for (i = 1; i < ntb->db_count; i++) {
- if (readl(ntb->epf_db + i * 4)) {
- if (readl(ntb->epf_db + i * 4))
- ntb->db |= 1 << (i - 1);
-
+ if (ntb->epf_db[i]) {
ntb_db_event(&ntb->ntb, i);
- writel(0, ntb->epf_db + i * 4);
+ ntb->epf_db[i] = 0;
}
}

@@ -321,8 +321,8 @@ static void epf_ntb_cmd_handler(struct work_struct *work)

/**
* epf_ntb_config_sspad_bar_clear() - Clear Config + Self scratchpad BAR
- * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
- * address.
+ * @ntb: EPC associated with one of the HOST which holds peer's outbound
+ * address.
*
* Clear BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
* self scratchpad region (removes inbound ATU configuration). While BAR0 is
@@ -331,8 +331,10 @@ static void epf_ntb_cmd_handler(struct work_struct *work)
* used for self scratchpad from epf_ntb_bar[BAR_CONFIG].
*
* Please note the self scratchpad region and config region is combined to
- * a single region and mapped using the same BAR. Also note HOST2's peer
- * scratchpad is HOST1's self scratchpad.
+ * a single region and mapped using the same BAR. Also note VHOST's peer
+ * scratchpad is HOST's self scratchpad.
+ *
+ * Returns: void
*/
static void epf_ntb_config_sspad_bar_clear(struct epf_ntb *ntb)
{
@@ -347,13 +349,15 @@ static void epf_ntb_config_sspad_bar_clear(struct epf_ntb *ntb)

/**
* epf_ntb_config_sspad_bar_set() - Set Config + Self scratchpad BAR
- * @ntb: NTB device that facilitates communication between HOST and vHOST
+ * @ntb: NTB device that facilitates communication between HOST and VHOST
*
- * Map BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
+ * Map BAR0 of EP CONTROLLER which contains the VHOST's config and
* self scratchpad region.
*
* Please note the self scratchpad region and config region is combined to
* a single region and mapped using the same BAR.
+ *
+ * Returns: Zero for success, or an error code in case of failure
*/
static int epf_ntb_config_sspad_bar_set(struct epf_ntb *ntb)
{
@@ -380,7 +384,7 @@ static int epf_ntb_config_sspad_bar_set(struct epf_ntb *ntb)
/**
* epf_ntb_config_spad_bar_free() - Free the physical memory associated with
* config + scratchpad region
- * @ntb: NTB device that facilitates communication between HOST and vHOST
+ * @ntb: NTB device that facilitates communication between HOST and VHOST
*/
static void epf_ntb_config_spad_bar_free(struct epf_ntb *ntb)
{
@@ -393,11 +397,13 @@ static void epf_ntb_config_spad_bar_free(struct epf_ntb *ntb)
/**
* epf_ntb_config_spad_bar_alloc() - Allocate memory for config + scratchpad
* region
- * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @ntb: NTB device that facilitates communication between HOST and VHOST
*
* Allocate the Local Memory mentioned in the above diagram. The size of
* CONFIG REGION is sizeof(struct epf_ntb_ctrl) and size of SCRATCHPAD REGION
* is obtained from "spad-count" configfs entry.
+ *
+ * Returns: Zero for success, or an error code in case of failure
*/
static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb)
{
@@ -424,7 +430,7 @@ static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb)
spad_count = ntb->spad_count;

ctrl_size = sizeof(struct epf_ntb_ctrl);
- spad_size = 2 * spad_count * 4;
+ spad_size = 2 * spad_count * sizeof(u32);

if (!align) {
ctrl_size = roundup_pow_of_two(ctrl_size);
@@ -454,7 +460,7 @@ static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb)
ctrl->num_mws = ntb->num_mws;
ntb->spad_size = spad_size;

- ctrl->db_entry_size = 4;
+ ctrl->db_entry_size = sizeof(u32);

for (i = 0; i < ntb->db_count; i++) {
ntb->reg->db_data[i] = 1 + i;
@@ -465,11 +471,13 @@ static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb)
}

/**
- * epf_ntb_configure_interrupt() - Configure MSI/MSI-X capaiblity
- * @ntb: NTB device that facilitates communication between HOST and vHOST
+ * epf_ntb_configure_interrupt() - Configure MSI/MSI-X capability
+ * @ntb: NTB device that facilitates communication between HOST and VHOST
*
* Configure MSI/MSI-X capability for each interface with number of
* interrupts equal to "db_count" configfs entry.
+ *
+ * Returns: Zero for success, or an error code in case of failure
*/
static int epf_ntb_configure_interrupt(struct epf_ntb *ntb)
{
@@ -511,18 +519,22 @@ static int epf_ntb_configure_interrupt(struct epf_ntb *ntb)

/**
* epf_ntb_db_bar_init() - Configure Doorbell window BARs
- * @ntb: NTB device that facilitates communication between HOST and vHOST
+ * @ntb: NTB device that facilitates communication between HOST and VHOST
+ *
+ * Returns: Zero for success, or an error code in case of failure
*/
static int epf_ntb_db_bar_init(struct epf_ntb *ntb)
{
const struct pci_epc_features *epc_features;
- u32 align;
struct device *dev = &ntb->epf->dev;
- int ret;
struct pci_epf_bar *epf_bar;
- void __iomem *mw_addr;
enum pci_barno barno;
- size_t size = 4 * ntb->db_count;
+ void *mw_addr;
+ size_t size;
+ u32 align;
+ int ret;
+
+ size = sizeof(u32) * ntb->db_count;

epc_features = pci_epc_get_features(ntb->epf->epc,
ntb->epf->func_no,
@@ -557,14 +569,14 @@ static int epf_ntb_db_bar_init(struct epf_ntb *ntb)
return ret;

err_alloc_peer_mem:
- pci_epc_mem_free_addr(ntb->epf->epc, epf_bar->phys_addr, mw_addr, epf_bar->size);
+ pci_epf_free_space(ntb->epf, mw_addr, barno, 0);
return -1;
}

/**
* epf_ntb_db_bar_clear() - Clear doorbell BAR and free memory
* allocated in peer's outbound address space
- * @ntb: NTB device that facilitates communication between HOST and vHOST
+ * @ntb: NTB device that facilitates communication between HOST and VHOST
*/
static void epf_ntb_db_bar_clear(struct epf_ntb *ntb)
{
@@ -580,8 +592,9 @@ static void epf_ntb_db_bar_clear(struct epf_ntb *ntb)

/**
* epf_ntb_mw_bar_init() - Configure Memory window BARs
- * @ntb: NTB device that facilitates communication between HOST and vHOST
+ * @ntb: NTB device that facilitates communication between HOST and VHOST
*
+ * Returns: Zero for success, or an error code in case of failure
*/
static int epf_ntb_mw_bar_init(struct epf_ntb *ntb)
{
@@ -629,7 +642,7 @@ static int epf_ntb_mw_bar_init(struct epf_ntb *ntb)

/**
* epf_ntb_mw_bar_clear() - Clear Memory window BARs
- * @ntb: NTB device that facilitates communication between HOST and vHOST
+ * @ntb: NTB device that facilitates communication between HOST and VHOST
*/
static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb)
{
@@ -652,7 +665,7 @@ static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb)

/**
* epf_ntb_epc_destroy() - Cleanup NTB EPC interface
- * @ntb: NTB device that facilitates communication between HOST and vHOST
+ * @ntb: NTB device that facilitates communication between HOST and VHOST
*
* Wrapper for epf_ntb_epc_destroy_interface() to cleanup all the NTB interfaces
*/
@@ -665,7 +678,9 @@ static void epf_ntb_epc_destroy(struct epf_ntb *ntb)
/**
* epf_ntb_init_epc_bar() - Identify BARs to be used for each of the NTB
* constructs (scratchpad region, doorbell, memorywindow)
- * @ntb: NTB device that facilitates communication between HOST and vHOST
+ * @ntb: NTB device that facilitates communication between HOST and VHOST
+ *
+ * Returns: Zero for success, or an error code in case of failure
*/
static int epf_ntb_init_epc_bar(struct epf_ntb *ntb)
{
@@ -706,11 +721,13 @@ static int epf_ntb_init_epc_bar(struct epf_ntb *ntb)

/**
* epf_ntb_epc_init() - Initialize NTB interface
- * @ntb: NTB device that facilitates communication between HOST and vHOST2
+ * @ntb: NTB device that facilitates communication between HOST and VHOST
*
* Wrapper to initialize a particular EPC interface and start the workqueue
- * to check for commands from host. This function will write to the
+ * to check for commands from HOST. This function will write to the
* EP controller HW for configuring it.
+ *
+ * Returns: Zero for success, or an error code in case of failure
*/
static int epf_ntb_epc_init(struct epf_ntb *ntb)
{
@@ -777,7 +794,7 @@ static int epf_ntb_epc_init(struct epf_ntb *ntb)

/**
* epf_ntb_epc_cleanup() - Cleanup all NTB interfaces
- * @ntb: NTB device that facilitates communication between HOST1 and HOST2
+ * @ntb: NTB device that facilitates communication between HOST and VHOST
*
* Wrapper to cleanup all NTB interfaces.
*/
@@ -934,6 +951,8 @@ static const struct config_item_type ntb_group_type = {
*
* Add configfs directory specific to NTB. This directory will hold
* NTB specific properties like db_count, spad_count, num_mws etc.,
+ *
+ * Returns: Pointer to config_group
*/
static struct config_group *epf_ntb_add_cfs(struct pci_epf *epf,
struct config_group *group)
@@ -1084,11 +1103,11 @@ static int vntb_epf_link_enable(struct ntb_dev *ntb,
static u32 vntb_epf_spad_read(struct ntb_dev *ndev, int idx)
{
struct epf_ntb *ntb = ntb_ndev(ndev);
- int off = ntb->reg->spad_offset, ct = ntb->reg->spad_count * 4;
+ int off = ntb->reg->spad_offset, ct = ntb->reg->spad_count * sizeof(u32);
u32 val;
- void __iomem *base = ntb->reg;
+ void __iomem *base = (void __iomem *)ntb->reg;

- val = readl(base + off + ct + idx * 4);
+ val = readl(base + off + ct + idx * sizeof(u32));
return val;
}

@@ -1096,10 +1115,10 @@ static int vntb_epf_spad_write(struct ntb_dev *ndev, int idx, u32 val)
{
struct epf_ntb *ntb = ntb_ndev(ndev);
struct epf_ntb_ctrl *ctrl = ntb->reg;
- int off = ctrl->spad_offset, ct = ctrl->spad_count * 4;
- void __iomem *base = ntb->reg;
+ int off = ctrl->spad_offset, ct = ctrl->spad_count * sizeof(u32);
+ void __iomem *base = (void __iomem *)ntb->reg;

- writel(val, base + off + ct + idx * 4);
+ writel(val, base + off + ct + idx * sizeof(u32));
return 0;
}

@@ -1108,10 +1127,10 @@ static u32 vntb_epf_peer_spad_read(struct ntb_dev *ndev, int pidx, int idx)
struct epf_ntb *ntb = ntb_ndev(ndev);
struct epf_ntb_ctrl *ctrl = ntb->reg;
int off = ctrl->spad_offset;
- void __iomem *base = ntb->reg;
+ void __iomem *base = (void __iomem *)ntb->reg;
u32 val;

- val = readl(base + off + idx * 4);
+ val = readl(base + off + idx * sizeof(u32));
return val;
}

@@ -1120,9 +1139,9 @@ static int vntb_epf_peer_spad_write(struct ntb_dev *ndev, int pidx, int idx, u32
struct epf_ntb *ntb = ntb_ndev(ndev);
struct epf_ntb_ctrl *ctrl = ntb->reg;
int off = ctrl->spad_offset;
- void __iomem *base = ntb->reg;
+ void __iomem *base = (void __iomem *)ntb->reg;

- writel(val, base + off + idx * 4);
+ writel(val, base + off + idx * sizeof(u32));
return 0;
}

@@ -1275,6 +1294,8 @@ static struct pci_driver vntb_pci_driver = {
* Invoked when a primary interface or secondary interface is bound to EPC
* device. This function will succeed only when EPC is bound to both the
* interfaces.
+ *
+ * Returns: Zero for success, or an error code in case of failure
*/
static int epf_ntb_bind(struct pci_epf *epf)
{
@@ -1359,6 +1380,8 @@ static struct pci_epf_ops epf_ntb_ops = {
*
* Probe NTB function driver when endpoint function bus detects a NTB
* endpoint function.
+ *
+ * Returns: Zero for success, or an error code in case of failure
*/
static int epf_ntb_probe(struct pci_epf *epf)
{
--
2.35.1