brcm80211: smac: avoid sprom endianess conversions for crc8 check

The data from the sprom consists of u16 values stored in little
endian notation over which a crc8 was determined. To validate this
the buffer needed to be converted for big-endian systems. Reading
the sprom data is now done per byte so conversion is only done
after a successful crc8 check.

Reviewed-by: Alwin Beukers <alwin@broadcom.com>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 30 insertions, 39 deletions

diff --git a/drivers/net/wireless/brcm80211/brcmsmac/srom.c b/drivers/net/wireless/brcm80211/brcmsmac/srom.c
index a884fe072dac..66aa0e772bb2 100644
--- a/drivers/net/wireless/brcm80211/brcmsmac/srom.c
+++ b/drivers/net/wireless/brcm80211/brcmsmac/srom.c
@@ -586,14 +586,13 @@ static const struct brcms_sromvar perpath_pci_sromvars[] = {
  * shared between devices. */
 static u8 brcms_srom_crc8_table[CRC8_TABLE_SIZE];
 
-static u16 __iomem *
+static u8 __iomem *
 srom_window_address(struct si_pub *sih, u8 __iomem *curmap)
 {
         if (sih->ccrev < 32)
-                return (u16 __iomem *)(curmap + PCI_BAR0_SPROM_OFFSET);
+                return curmap + PCI_BAR0_SPROM_OFFSET;
         if (sih->cccaps & CC_CAP_SROM)
-                return (u16 __iomem *)
-                       (curmap + PCI_16KB0_CCREGS_OFFSET + CC_SROM_OTP);
+                return curmap + PCI_16KB0_CCREGS_OFFSET + CC_SROM_OTP;
 
         return NULL;
 }
@@ -782,37 +781,34 @@ _initvars_srom_pci(u8 sromrev, u16 *srom, struct list_head *var_list)
  * Return 0 on success, nonzero on error.
  */
 static int
-sprom_read_pci(struct si_pub *sih, u16 __iomem *sprom, uint wordoff,
+sprom_read_pci(struct si_pub *sih, u8 __iomem *sprom, uint wordoff,
                u16 *buf, uint nwords, bool check_crc)
 {
         int err = 0;
         uint i;
+        u8 *bbuf = (u8 *)buf; /* byte buffer */
+        uint nbytes = nwords << 1;
 
-        /* read the sprom */
-        for (i = 0; i < nwords; i++)
-                buf[i] = R_REG(&sprom[wordoff + i]);
+        /* read the sprom in bytes */
+        for (i = 0; i < nbytes; i++)
+                bbuf[i] = readb(sprom+i);
 
-        if (check_crc) {
-
-                if (buf[0] == 0xffff)
-                        /*
-                         * The hardware thinks that an srom that starts with
-                         * 0xffff is blank, regardless of the rest of the
-                         * content, so declare it bad.
-                         */
-                        return -ENODATA;
-
-                /* fixup the endianness so crc8 will pass */
-                htol16_buf(buf, nwords * 2);
-                if (crc8(brcms_srom_crc8_table, (u8 *) buf, nwords * 2,
-                         CRC8_INIT_VALUE) !=
-                         CRC8_GOOD_VALUE(brcms_srom_crc8_table))
-                        /* DBG only pci always read srom4 first, then srom8/9 */
-                        err = -EIO;
+        if (buf[0] == 0xffff)
+                /*
+                 * The hardware thinks that an srom that starts with
+                 * 0xffff is blank, regardless of the rest of the
+                 * content, so declare it bad.
+                 */
+                return -ENODATA;
 
+        if (check_crc &&
+            crc8(brcms_srom_crc8_table, bbuf, nbytes, CRC8_INIT_VALUE) !=
+                 CRC8_GOOD_VALUE(brcms_srom_crc8_table))
+                err = -EIO;
+        else
                 /* now correct the endianness of the byte array */
-                ltoh16_buf(buf, nwords * 2);
-        }
+                ltoh16_buf(buf, nbytes);
+
         return err;
 }
 
@@ -859,7 +855,7 @@ static int otp_read_pci(struct si_pub *sih, u16 *buf, uint bufsz)
 static int initvars_srom_pci(struct si_pub *sih, void __iomem *curmap)
 {
         u16 *srom;
-        u16 __iomem *sromwindow;
+        u8 __iomem *sromwindow;
         u8 sromrev = 0;
         u32 sr;
         int err = 0;
@@ -875,18 +871,13 @@ static int initvars_srom_pci(struct si_pub *sih, void __iomem *curmap)
 
         crc8_populate_lsb(brcms_srom_crc8_table, SROM_CRC8_POLY);
         if (ai_is_sprom_available(sih)) {
-                err = sprom_read_pci(sih, sromwindow, 0, srom, SROM_WORDS,
-                                     true);
-
-                if ((sih->buscoretype == PCIE_CORE_ID && sih->buscorerev >= 6)
-                     || (sih->buscoretype == PCI_CORE_ID &&
-                         sih->buscorerev >= 0xe)) {
-                        err = sprom_read_pci(sih, sromwindow, 0, srom,
-                                             SROM4_WORDS, true);
+                err = sprom_read_pci(sih, sromwindow, 0, srom,
+                                     SROM4_WORDS, true);
+
+                if (err == 0)
+                        /* srom read and passed crc */
+                        /* top word of sprom contains version and crc8 */
                         sromrev = srom[SROM4_CRCREV] & 0xff;
-                } else {
-                        err = -EIO;
-                }
         } else {
                 /* Use OTP if SPROM not available */
                 err = otp_read_pci(sih, srom, SROM_MAX);