On Tue, Nov 19, 2024 at 04:01:05PM +0200, Alexander Usyskin wrote:
> Implement read(), erase() and write() functions.
> 
> CC: Lucas De Marchi <lucas.demar...@intel.com>
> CC: Rodrigo Vivi <rodrigo.v...@intel.com>
> Acked-by: Miquel Raynal <miquel.ray...@bootlin.com>
> Co-developed-by: Tomas Winkler <tom...@gmail.com>
> Signed-off-by: Tomas Winkler <tom...@gmail.com>
> Co-developed-by: Vitaly Lubart <lubvi...@gmail.com>
> Signed-off-by: Vitaly Lubart <lubvi...@gmail.com>
> Signed-off-by: Alexander Usyskin <alexander.usys...@intel.com>
> ---
>  drivers/mtd/devices/mtd-intel-dg.c | 197 +++++++++++++++++++++++++++++
>  1 file changed, 197 insertions(+)
> 
> diff --git a/drivers/mtd/devices/mtd-intel-dg.c 
> b/drivers/mtd/devices/mtd-intel-dg.c
> index 05e333771be0..915b9750ca62 100644
> --- a/drivers/mtd/devices/mtd-intel-dg.c
> +++ b/drivers/mtd/devices/mtd-intel-dg.c
> @@ -5,13 +5,16 @@
>  
>  #include <linux/bitfield.h>
>  #include <linux/bits.h>
> +#include <linux/delay.h>
>  #include <linux/device.h>
>  #include <linux/intel_dg_nvm_aux.h>
>  #include <linux/io.h>
> +#include <linux/io-64-nonatomic-lo-hi.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/string.h>
>  #include <linux/slab.h>
> +#include <linux/sizes.h>
>  #include <linux/types.h>
>  
>  struct intel_dg_nvm {
> @@ -91,6 +94,33 @@ static inline u32 idg_nvm_read32(struct intel_dg_nvm *nvm, 
> u32 address)
>       return ioread32(base + NVM_TRIGGER_REG);
>  }
>  
> +static inline u64 idg_nvm_read64(struct intel_dg_nvm *nvm, u32 address)
> +{
> +     void __iomem *base = nvm->base;
> +
> +     iowrite32(address, base + NVM_ADDRESS_REG);
> +
> +     return readq(base + NVM_TRIGGER_REG);
> +}
> +
> +static void idg_nvm_write32(struct intel_dg_nvm *nvm, u32 address, u32 data)
> +{
> +     void __iomem *base = nvm->base;
> +
> +     iowrite32(address, base + NVM_ADDRESS_REG);
> +
> +     iowrite32(data, base + NVM_TRIGGER_REG);
> +}
> +
> +static void idg_nvm_write64(struct intel_dg_nvm *nvm, u32 address, u64 data)
> +{
> +     void __iomem *base = nvm->base;
> +
> +     iowrite32(address, base + NVM_ADDRESS_REG);
> +
> +     writeq(data, base + NVM_TRIGGER_REG);
> +}
> +
>  static int idg_nvm_get_access_map(struct intel_dg_nvm *nvm, u32 *access_map)
>  {
>       u32 flmap1;
> @@ -147,6 +177,173 @@ static int idg_nvm_is_valid(struct intel_dg_nvm *nvm)
>       return 0;
>  }
>  
> +__maybe_unused
> +static unsigned int idg_nvm_get_region(const struct intel_dg_nvm *nvm, 
> loff_t from)
> +{
> +     unsigned int i;
> +
> +     for (i = 0; i < nvm->nregions; i++) {
> +             if ((nvm->regions[i].offset + nvm->regions[i].size - 1) > from 
> &&
> +                 nvm->regions[i].offset <= from &&
> +                 nvm->regions[i].size != 0)
> +                     break;
> +     }
> +
> +     return i;
> +}
> +
> +static ssize_t idg_nvm_rewrite_partial(struct intel_dg_nvm *nvm, loff_t to,
> +                                    loff_t offset, size_t len, const u32 
> *newdata)
> +{
> +     u32 data = idg_nvm_read32(nvm, to);
> +
> +     if (idg_nvm_error(nvm))
> +             return -EIO;
> +
> +     memcpy((u8 *)&data + offset, newdata, len);

I'm a bit concerned with the usage of len here without any check...

> +
> +     idg_nvm_write32(nvm, to, data);
> +     if (idg_nvm_error(nvm))
> +             return -EIO;
> +
> +     return len;
> +}
> +
> +__maybe_unused
> +static ssize_t idg_write(struct intel_dg_nvm *nvm, u8 region,
> +                      loff_t to, size_t len, const unsigned char *buf)
> +{
> +     size_t i;
> +     size_t len8;
> +     size_t len4;
> +     size_t to4;
> +     size_t to_shift;
> +     size_t len_s = len;
> +     ssize_t ret;
> +
> +     idg_nvm_set_region_id(nvm, region);
> +
> +     to4 = ALIGN_DOWN(to, sizeof(u32));
> +     to_shift = min(sizeof(u32) - ((size_t)to - to4), len);
> +     if (to - to4) {

As well the 'to'...

I was even trying to review all 3 patches together, 3, 4, and 5,
but there's too much indirection on those values and no checks
in any place...


> +             ret = idg_nvm_rewrite_partial(nvm, to4, to - to4, to_shift, 
> (uint32_t *)&buf[0]);
> +             if (ret < 0)
> +                     return ret;
> +
> +             buf += to_shift;
> +             to += to_shift;
> +             len_s -= to_shift;
> +     }
> +
> +     len8 = ALIGN_DOWN(len_s, sizeof(u64));
> +     for (i = 0; i < len8; i += sizeof(u64)) {
> +             u64 data;
> +
> +             memcpy(&data, &buf[i], sizeof(u64));
> +             idg_nvm_write64(nvm, to + i, data);
> +             if (idg_nvm_error(nvm))
> +                     return -EIO;
> +     }
> +
> +     len4 = len_s - len8;
> +     if (len4 >= sizeof(u32)) {
> +             u32 data;
> +
> +             memcpy(&data, &buf[i], sizeof(u32));
> +             idg_nvm_write32(nvm, to + i, data);
> +             if (idg_nvm_error(nvm))
> +                     return -EIO;
> +             i += sizeof(u32);
> +             len4 -= sizeof(u32);
> +     }
> +
> +     if (len4 > 0) {
> +             ret = idg_nvm_rewrite_partial(nvm, to + i, 0, len4, (uint32_t 
> *)&buf[i]);
> +             if (ret < 0)
> +                     return ret;
> +     }
> +
> +     return len;
> +}
> +
> +__maybe_unused
> +static ssize_t idg_read(struct intel_dg_nvm *nvm, u8 region,
> +                     loff_t from, size_t len, unsigned char *buf)
> +{
> +     size_t i;
> +     size_t len8;
> +     size_t len4;
> +     size_t from4;
> +     size_t from_shift;
> +     size_t len_s = len;
> +
> +     idg_nvm_set_region_id(nvm, region);
> +
> +     from4 = ALIGN_DOWN(from, sizeof(u32));
> +     from_shift = min(sizeof(u32) - ((size_t)from - from4), len);
> +
> +     if (from - from4) {
> +             u32 data = idg_nvm_read32(nvm, from4);
> +
> +             if (idg_nvm_error(nvm))
> +                     return -EIO;
> +             memcpy(&buf[0], (u8 *)&data + (from - from4), from_shift);
> +             len_s -= from_shift;
> +             buf += from_shift;
> +             from += from_shift;
> +     }
> +
> +     len8 = ALIGN_DOWN(len_s, sizeof(u64));
> +     for (i = 0; i < len8; i += sizeof(u64)) {
> +             u64 data = idg_nvm_read64(nvm, from + i);
> +
> +             if (idg_nvm_error(nvm))
> +                     return -EIO;
> +
> +             memcpy(&buf[i], &data, sizeof(data));
> +     }
> +
> +     len4 = len_s - len8;
> +     if (len4 >= sizeof(u32)) {
> +             u32 data = idg_nvm_read32(nvm, from + i);
> +
> +             if (idg_nvm_error(nvm))
> +                     return -EIO;
> +             memcpy(&buf[i], &data, sizeof(data));
> +             i += sizeof(u32);
> +             len4 -= sizeof(u32);
> +     }
> +
> +     if (len4 > 0) {
> +             u32 data = idg_nvm_read32(nvm, from + i);
> +
> +             if (idg_nvm_error(nvm))
> +                     return -EIO;
> +             memcpy(&buf[i], &data, len4);
> +     }
> +
> +     return len;
> +}
> +
> +__maybe_unused
> +static ssize_t
> +idg_erase(struct intel_dg_nvm *nvm, u8 region, loff_t from, u64 len, u64 
> *fail_addr)
> +{
> +     u64 i;
> +     const u32 block = 0x10;
> +     void __iomem *base = nvm->base;
> +
> +     for (i = 0; i < len; i += SZ_4K) {
> +             iowrite32(from + i, base + NVM_ADDRESS_REG);
> +             iowrite32(region << 24 | block, base + NVM_ERASE_REG);
> +             /* Since the writes are via sguint
> +              * we cannot do back to back erases.
> +              */
> +             msleep(50);
> +     }
> +     return len;
> +}
> +
>  static int intel_dg_nvm_init(struct intel_dg_nvm *nvm, struct device *device)
>  {
>       int ret;
> -- 
> 2.43.0
> 

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