On 24.08.2021 16:20, Prabhakar Kushwaha wrote:
> Hi Heiner,
>
>> -----Original Message-----
>> From: Heiner Kallweit <hkallweit1@xxxxxxxxx>
>> Sent: Sunday, August 22, 2021 7:23 PM
>> To: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>; Ariel Elior <aelior@xxxxxxxxxxx>;
>> Sudarsana Reddy Kalluru <skalluru@xxxxxxxxxxx>; GR-everest-linux-l2 <GR-
>> everest-linux-l2@xxxxxxxxxxx>; Jakub Kicinski <kuba@xxxxxxxxxx>; David
>> Härdeman <david@xxxxxxxxxxx>
>> Cc: linux-pci@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx
>> Subject: [PATCH 05/12] bnx2x: Read VPD with pci_vpd_alloc()
>>
>> External Email
>>
>> ----------------------------------------------------------------------
>> Use pci_vpd_alloc() to dynamically allocate a properly sized buffer and
>> read the full VPD data into it.
>>
>> This simplifies the code, and we no longer have to make assumptions about
>> VPD size.
>>
>> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
>> ---
>> drivers/net/ethernet/broadcom/bnx2x/bnx2x.h | 1 -
>> .../net/ethernet/broadcom/bnx2x/bnx2x_main.c | 44 +++++--------------
>> 2 files changed, 10 insertions(+), 35 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
>> b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
>> index d04994840..e789430f4 100644
>> --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
>> +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
>> @@ -2407,7 +2407,6 @@ void bnx2x_igu_clear_sb_gen(struct bnx2x *bp, u8
>> func, u8 idu_sb_id,
>> #define ETH_MAX_RX_CLIENTS_E2 ETH_MAX_RX_CLIENTS_E1H
>> #endif
>>
>> -#define BNX2X_VPD_LEN 128
>> #define VENDOR_ID_LEN 4
>>
>> #define VF_ACQUIRE_THRESH 3
>> diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
>> b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
>> index 6d9813491..0466adf8d 100644
>> --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
>> +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
>> @@ -12189,50 +12189,29 @@ static int bnx2x_get_hwinfo(struct bnx2x *bp)
>>
>> static void bnx2x_read_fwinfo(struct bnx2x *bp)
>> {
>> - int cnt, i, block_end, rodi;
>> - char vpd_start[BNX2X_VPD_LEN+1];
>> + int i, block_end, rodi;
>> char str_id_reg[VENDOR_ID_LEN+1];
>> char str_id_cap[VENDOR_ID_LEN+1];
>> - char *vpd_data;
>> - char *vpd_extended_data = NULL;
>> - u8 len;
>> + unsigned int vpd_len;
>> + u8 *vpd_data, len;
>>
>> - cnt = pci_read_vpd(bp->pdev, 0, BNX2X_VPD_LEN, vpd_start);
>> memset(bp->fw_ver, 0, sizeof(bp->fw_ver));
>>
>> - if (cnt < BNX2X_VPD_LEN)
>> - goto out_not_found;
>> + vpd_data = pci_vpd_alloc(bp->pdev, &vpd_len);
>
> Definition of pci_vpd_alloc() is below as per repo "git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git" and branch wip/heiner-vpd-api
> void *pci_vpd_alloc(struct pci_dev *dev, unsigned int *size)
> {
> unsigned int len = dev->vpd.len;
> void *buf;
> --
> --
> if (size)
> *size = len;
> }
> Here is len is already part of pci_dev.
>
> So why cannot same be set in caller function i.e. vpd_len = pb->pdev->vpd.len
>
Internals of struct pci_vpd shouldn't be referenced outside PCI core.
Also you can't use vpd.len w/o checking vpd.cap.
pci_vpd_alloc() encapsulates these internals.
>
>> + if (IS_ERR(vpd_data))
>> + return;
>>
>> /* VPD RO tag should be first tag after identifier string, hence
>> * we should be able to find it in first BNX2X_VPD_LEN chars
>> */
>> - i = pci_vpd_find_tag(vpd_start, BNX2X_VPD_LEN,
>> PCI_VPD_LRDT_RO_DATA);
>> + i = pci_vpd_find_tag(vpd_data, vpd_len, PCI_VPD_LRDT_RO_DATA);
>> if (i < 0)
>> goto out_not_found;
>>
>> block_end = i + PCI_VPD_LRDT_TAG_SIZE +
>> - pci_vpd_lrdt_size(&vpd_start[i]);
>> -
>> + pci_vpd_lrdt_size(&vpd_data[i]);
>> i += PCI_VPD_LRDT_TAG_SIZE;
>>
>> - if (block_end > BNX2X_VPD_LEN) {
>> - vpd_extended_data = kmalloc(block_end, GFP_KERNEL);
>> - if (vpd_extended_data == NULL)
>> - goto out_not_found;
>> -
>> - /* read rest of vpd image into vpd_extended_data */
>> - memcpy(vpd_extended_data, vpd_start, BNX2X_VPD_LEN);
>> - cnt = pci_read_vpd(bp->pdev, BNX2X_VPD_LEN,
>> - block_end - BNX2X_VPD_LEN,
>> - vpd_extended_data + BNX2X_VPD_LEN);
>> - if (cnt < (block_end - BNX2X_VPD_LEN))
>> - goto out_not_found;
>> - vpd_data = vpd_extended_data;
>> - } else
>> - vpd_data = vpd_start;
>> -
>> - /* now vpd_data holds full vpd content in both cases */
>> -
>> rodi = pci_vpd_find_info_keyword(vpd_data, i, block_end,
>> PCI_VPD_RO_KEYWORD_MFR_ID);
>> if (rodi < 0)
>> @@ -12258,17 +12237,14 @@ static void bnx2x_read_fwinfo(struct bnx2x *bp)
>>
>> rodi += PCI_VPD_INFO_FLD_HDR_SIZE;
>>
>> - if (len < 32 && (len + rodi) <= BNX2X_VPD_LEN) {
>> + if (len < 32 && (len + rodi) <= vpd_len) {
>> memcpy(bp->fw_ver, &vpd_data[rodi], len);
>> bp->fw_ver[len] = ' ';
>> }
>> }
>> - kfree(vpd_extended_data);
>> - return;
>> }
>> out_not_found:
>> - kfree(vpd_extended_data);
>> - return;
>> + kfree(vpd_data);
>
> As vpd_data allocation done in PCI layer.
> It will be logical to also free vpd_data in PCI layer.
>
The idea is right, however a call like pci_vpd_free() would be a one-liner
calling kfree(), and I doubt it's really worth it.
> --pk
>
Heiner
