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SubjectRe: [PATCH] firmware: xilinx: Use hash-table for api feature check
Date
Hi,

On 24. 11. 20 6:52, Rajan Vaja wrote:
> From: Amit Sunil Dhamne <amit.sunil.dhamne@xilinx.com>
>
> Currently array of fix length PM_API_MAX is used to cache
> the pm_api version (valid or invalid). However ATF based
> PM APIs values are much higher then PM_API_MAX.
> So to include ATF based PM APIs also, use hash-table to
> store the pm_api version status.
>
> Signed-off-by: Amit Sunil Dhamne <amit.sunil.dhamne@xilinx.com>
> Reported-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Ravi Patel <ravi.patel@xilinx.com>
> Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
> ---
> drivers/firmware/xilinx/zynqmp.c | 63 ++++++++++++++++++++++++++++--------
> include/linux/firmware/xlnx-zynqmp.h | 4 ---
> 2 files changed, 49 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/firmware/xilinx/zynqmp.c b/drivers/firmware/xilinx/zynqmp.c
> index efb8a66..349ab39 100644
> --- a/drivers/firmware/xilinx/zynqmp.c
> +++ b/drivers/firmware/xilinx/zynqmp.c
> @@ -20,12 +20,28 @@
> #include <linux/of_platform.h>
> #include <linux/slab.h>
> #include <linux/uaccess.h>
> +#include <linux/hashtable.h>
>
> #include <linux/firmware/xlnx-zynqmp.h>
> #include "zynqmp-debug.h"
>
> +/* Max HashMap Order for PM API feature check (1<<7 = 128) */
> +#define PM_API_FEATURE_CHECK_MAX_ORDER 7
> +
> static bool feature_check_enabled;
> -static u32 zynqmp_pm_features[PM_API_MAX];
> +DEFINE_HASHTABLE(pm_api_features_map, PM_API_FEATURE_CHECK_MAX_ORDER);
> +
> +/**
> + * struct pm_api_feature_data - PM API Feature data
> + * @pm_api_id: PM API Id, used as key to index into hashmap
> + * @feature_status: status of PM API feature: valid, invalid
> + * @hentry: hlist_node that hooks this entry into hashtable
> + */
> +struct pm_api_feature_data {
> + u32 pm_api_id;
> + int feature_status;
> + struct hlist_node hentry;
> +};
>
> static const struct mfd_cell firmware_devs[] = {
> {
> @@ -142,29 +158,37 @@ static int zynqmp_pm_feature(u32 api_id)
> int ret;
> u32 ret_payload[PAYLOAD_ARG_CNT];
> u64 smc_arg[2];
> + struct pm_api_feature_data *feature_data;
>
> if (!feature_check_enabled)
> return 0;
>
> - /* Return value if feature is already checked */
> - if (api_id > ARRAY_SIZE(zynqmp_pm_features))
> - return PM_FEATURE_INVALID;
> + /* Check for existing entry in hash table for given api */
> + hash_for_each_possible(pm_api_features_map, feature_data, hentry,
> + api_id) {
> + if (feature_data->pm_api_id == api_id)
> + return feature_data->feature_status;
> + }
>
> - if (zynqmp_pm_features[api_id] != PM_FEATURE_UNCHECKED)
> - return zynqmp_pm_features[api_id];
> + /* Add new entry if not present */
> + feature_data = kmalloc(sizeof(*feature_data), GFP_KERNEL);
> + if (!feature_data)
> + return -ENOMEM;
>
> + feature_data->pm_api_id = api_id;
> smc_arg[0] = PM_SIP_SVC | PM_FEATURE_CHECK;
> smc_arg[1] = api_id;
>
> ret = do_fw_call(smc_arg[0], smc_arg[1], 0, ret_payload);
> - if (ret) {
> - zynqmp_pm_features[api_id] = PM_FEATURE_INVALID;
> - return PM_FEATURE_INVALID;
> - }
> + if (ret)
> + ret = -EOPNOTSUPP;
> + else
> + ret = ret_payload[1];
>
> - zynqmp_pm_features[api_id] = ret_payload[1];
> + feature_data->feature_status = ret;
> + hash_add(pm_api_features_map, &feature_data->hentry, api_id);
>
> - return zynqmp_pm_features[api_id];
> + return ret;
> }
>
> /**
> @@ -200,9 +224,12 @@ int zynqmp_pm_invoke_fn(u32 pm_api_id, u32 arg0, u32 arg1,
> * Make sure to stay in x0 register
> */
> u64 smc_arg[4];
> + int ret;
>
> - if (zynqmp_pm_feature(pm_api_id) == PM_FEATURE_INVALID)
> - return -ENOTSUPP;
> + /* Check if feature is supported or not */
> + ret = zynqmp_pm_feature(pm_api_id);
> + if (ret < 0)
> + return ret;
>
> smc_arg[0] = PM_SIP_SVC | pm_api_id;
> smc_arg[1] = ((u64)arg1 << 32) | arg0;
> @@ -1252,9 +1279,17 @@ static int zynqmp_firmware_probe(struct platform_device *pdev)
>
> static int zynqmp_firmware_remove(struct platform_device *pdev)
> {
> + struct pm_api_feature_data *feature_data;
> + int i;
> +
> mfd_remove_devices(&pdev->dev);
> zynqmp_pm_api_debugfs_exit();
>
> + hash_for_each(pm_api_features_map, i, feature_data, hentry) {
> + hash_del(&feature_data->hentry);
> + kfree(feature_data);
> + }
> +
> return 0;
> }
>
> diff --git a/include/linux/firmware/xlnx-zynqmp.h b/include/linux/firmware/xlnx-zynqmp.h
> index 5968df8..41a1bab 100644
> --- a/include/linux/firmware/xlnx-zynqmp.h
> +++ b/include/linux/firmware/xlnx-zynqmp.h
> @@ -50,10 +50,6 @@
> #define ZYNQMP_PM_CAPABILITY_WAKEUP 0x4U
> #define ZYNQMP_PM_CAPABILITY_UNUSABLE 0x8U
>
> -/* Feature check status */
> -#define PM_FEATURE_INVALID -1
> -#define PM_FEATURE_UNCHECKED 0
> -
> /*
> * Firmware FPGA Manager flags
> * XILINX_ZYNQMP_PM_FPGA_FULL: FPGA full reconfiguration
>

Some lines should be added.

Cc: stable <stable@vger.kernel.org>
Fixes: f3217d6f2f7a ("firmware: xilinx: fix out-of-bounds access")

Tested-by: Michal Simek <michal.simek@xilinx.com>

Arnd: do you see any issue with this?
I found that your origin patch was taken by Greg and pushed to any
5.10-rc version which caused panic on Xilinx Versal. That's why I would
like to get this patch to v5.10 if possible.

Thanks,
Michal



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