On Thu, Sep 12, 2024 at 03:44:32PM +0300, Jani Nikula wrote:
> On Tue, 10 Sep 2024, Ville Syrjala <[email protected]> wrote:
> > From: Ville Syrjälä <[email protected]>
> >
> > Abstract away the nuts and bolts of the SPI vs. PCI ROM
> > stuff, and hide it all in soc/intel_rom.c so that the
> > VBT code doesn't have to care about this stuff.
> >
> > This leaves intel_bios.c with a single codepath that
> > can focus on the details related to the VBT layout.
> >
> > This should have no functional changes.
> 
> Neat! Some nitpicks inline, but overall,
> 
> Reviewed-by: Jani Nikula <[email protected]>
> 
> 
> >
> > Signed-off-by: Ville Syrjälä <[email protected]>
> > ---
> >  drivers/gpu/drm/i915/Makefile                 |   3 +-
> >  drivers/gpu/drm/i915/display/intel_bios.c     | 150 ++++------------
> >  drivers/gpu/drm/i915/soc/intel_rom.c          | 160 ++++++++++++++++++
> >  drivers/gpu/drm/i915/soc/intel_rom.h          |  25 +++
> >  drivers/gpu/drm/xe/Makefile                   |   3 +-
> >  .../xe/compat-i915-headers/soc/intel_rom.h    |   6 +
> >  6 files changed, 224 insertions(+), 123 deletions(-)
> >  create mode 100644 drivers/gpu/drm/i915/soc/intel_rom.c
> >  create mode 100644 drivers/gpu/drm/i915/soc/intel_rom.h
> >  create mode 100644 drivers/gpu/drm/xe/compat-i915-headers/soc/intel_rom.h
> >
> > diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> > index c63fa2133ccb..d14c8870aecb 100644
> > --- a/drivers/gpu/drm/i915/Makefile
> > +++ b/drivers/gpu/drm/i915/Makefile
> > @@ -51,7 +51,8 @@ i915-y += \
> >  i915-y += \
> >     soc/intel_dram.o \
> >     soc/intel_gmch.o \
> > -   soc/intel_pch.o
> > +   soc/intel_pch.o \
> > +   soc/intel_rom.o
> >  
> >  # core library code
> >  i915-y += \
> > diff --git a/drivers/gpu/drm/i915/display/intel_bios.c 
> > b/drivers/gpu/drm/i915/display/intel_bios.c
> > index 0b92b494117f..37d4b4ddfa95 100644
> > --- a/drivers/gpu/drm/i915/display/intel_bios.c
> > +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> > @@ -33,12 +33,12 @@
> >  #include <drm/drm_edid.h>
> >  #include <drm/drm_fixed.h>
> >  
> > +#include "soc/intel_rom.h"
> > +
> >  #include "i915_drv.h"
> > -#include "i915_reg.h"
> >  #include "intel_display.h"
> >  #include "intel_display_types.h"
> >  #include "intel_gmbus.h"
> > -#include "intel_uncore.h"
> >  
> >  #define _INTEL_BIOS_PRIVATE
> >  #include "intel_vbt_defs.h"
> > @@ -3055,150 +3055,58 @@ static struct vbt_header *firmware_get_vbt(struct 
> > intel_display *display,
> >     return vbt;
> >  }
> >  
> > -static u32 intel_spi_read32(struct intel_uncore *uncore, u32 offset)
> > +static struct vbt_header *oprom_get_vbt(struct intel_display *display,
> > +                                   struct intel_rom *rom,
> > +                                   size_t *size, const char *type)
> >  {
> > -   intel_uncore_write(uncore, PRIMARY_SPI_ADDRESS, offset);
> > +   struct vbt_header *vbt;
> > +   size_t vbt_size;
> > +   loff_t offset;
> >  
> > -   return intel_uncore_read(uncore, PRIMARY_SPI_TRIGGER);
> > -}
> > -
> > -static u16 intel_spi_read16(struct intel_uncore *uncore, u32 offset)
> > -{
> > -   return intel_spi_read32(uncore, offset) & 0xffff;
> > -}
> > -
> > -static struct vbt_header *spi_oprom_get_vbt(struct intel_display *display,
> > -                                       size_t *size)
> > -{
> > -   struct drm_i915_private *i915 = to_i915(display->drm);
> > -   u32 count, data, found, store = 0;
> > -   u32 static_region, oprom_offset;
> > -   u32 oprom_size = 0x200000;
> > -   u16 vbt_size;
> > -   u32 *vbt;
> > -
> > -   static_region = intel_uncore_read(&i915->uncore, SPI_STATIC_REGIONS);
> > -   static_region &= OPTIONROM_SPI_REGIONID_MASK;
> > -   intel_uncore_write(&i915->uncore, PRIMARY_SPI_REGIONID, static_region);
> > -
> > -   oprom_offset = intel_uncore_read(&i915->uncore, OROM_OFFSET);
> > -   oprom_offset &= OROM_OFFSET_MASK;
> > +   if (!rom)
> > +           return NULL;
> >  
> >     BUILD_BUG_ON(sizeof(vbt_signature) != sizeof(u32));
> >  
> > -   for (count = 0; count < oprom_size; count += 4) {
> > -           data = intel_spi_read32(&i915->uncore, oprom_offset + count);
> > -           if (data == *((const u32 *)vbt_signature)) {
> > -                   found = oprom_offset + count;
> > -                   break;
> > -           }
> > -   }
> > +   offset = intel_rom_find(rom, *(const u32 *)vbt_signature);
> > +   if (offset < 0)
> > +           goto err_free_rom;
> >  
> > -   if (count >= oprom_size)
> > -           goto err_not_found;
> > -
> > -   if (sizeof(struct vbt_header) > oprom_size - count) {
> > +   if (sizeof(struct vbt_header) > intel_rom_size(rom) - offset) {
> >             drm_dbg(display->drm, "VBT header incomplete\n");
> > -           goto err_not_found;
> > +           goto err_free_rom;
> >     }
> >  
> > -   /* Get VBT size and allocate space for the VBT */
> > -   vbt_size = intel_spi_read16(&i915->uncore,
> > -                               found + offsetof(struct vbt_header, 
> > vbt_size));
> > +   BUILD_BUG_ON(sizeof(vbt->vbt_size) != sizeof(u16));
> >  
> > -   if (vbt_size > oprom_size - count) {
> > -           drm_dbg(display->drm,
> > -                   "VBT incomplete (vbt_size overflows)\n");
> > -           goto err_not_found;
> > +   vbt_size = intel_rom_read16(rom, offset + offsetof(struct vbt_header, 
> > vbt_size));
> > +   if (vbt_size > intel_rom_size(rom) - offset) {
> > +           drm_dbg(display->drm, "VBT incomplete (vbt_size overflows)\n");
> > +           goto err_free_rom;
> >     }
> >  
> >     vbt = kzalloc(round_up(vbt_size, 4), GFP_KERNEL);
> >     if (!vbt)
> > -           goto err_not_found;
> > +           goto err_free_rom;
> >  
> > -   for (count = 0; count < vbt_size; count += 4)
> > -           *(vbt + store++) = intel_spi_read32(&i915->uncore, found + 
> > count);
> > +   intel_rom_read_block(rom, vbt, offset, vbt_size);
> >  
> >     if (!intel_bios_is_valid_vbt(display, vbt, vbt_size))
> >             goto err_free_vbt;
> >  
> > -   drm_dbg_kms(display->drm, "Found valid VBT in SPI flash\n");
> > +   drm_dbg_kms(display->drm, "Found valid VBT in %s\n", type);
> 
> There's some (pre-existing) drm_dbg vs. drm_dbg_kms discrepancy here.

I'll prepare a patch to clean that up.

> 
> >  
> >     if (size)
> >             *size = vbt_size;
> >  
> > +   intel_rom_free(rom);
> > +
> >     return (struct vbt_header *)vbt;
> 
> The cast is now unnecessary.

Ack.

> 
> >  
> >  err_free_vbt:
> >     kfree(vbt);
> > -err_not_found:
> > -   return NULL;
> > -}
> > -
> > -static struct vbt_header *oprom_get_vbt(struct intel_display *display,
> > -                                   size_t *sizep)
> > -{
> > -   struct pci_dev *pdev = to_pci_dev(display->drm->dev);
> > -   void __iomem *p = NULL, *oprom;
> > -   struct vbt_header *vbt;
> > -   u16 vbt_size;
> > -   size_t i, size;
> > -
> > -   oprom = pci_map_rom(pdev, &size);
> > -   if (!oprom)
> > -           return NULL;
> > -
> > -   BUILD_BUG_ON(sizeof(vbt_signature) != sizeof(u32));
> > -
> > -   /* Scour memory looking for the VBT signature. */
> > -   for (i = 0; i + 4 < size; i += 4) {
> > -           if (ioread32(oprom + i) != *((const u32 *)vbt_signature))
> > -                   continue;
> > -
> > -           p = oprom + i;
> > -           size -= i;
> > -           break;
> > -   }
> > -
> > -   if (!p)
> > -           goto err_unmap_oprom;
> > -
> > -   if (sizeof(struct vbt_header) > size) {
> > -           drm_dbg(display->drm, "VBT header incomplete\n");
> > -           goto err_unmap_oprom;
> > -   }
> > -
> > -   vbt_size = ioread16(p + offsetof(struct vbt_header, vbt_size));
> > -   if (vbt_size > size) {
> > -           drm_dbg(display->drm,
> > -                   "VBT incomplete (vbt_size overflows)\n");
> > -           goto err_unmap_oprom;
> > -   }
> > -
> > -   /* The rest will be validated by intel_bios_is_valid_vbt() */
> > -   vbt = kmalloc(round_up(vbt_size, 4), GFP_KERNEL);
> > -   if (!vbt)
> > -           goto err_unmap_oprom;
> > -
> > -   memcpy_fromio(vbt, p, vbt_size);
> > -
> > -   if (!intel_bios_is_valid_vbt(display, vbt, vbt_size))
> > -           goto err_free_vbt;
> > -
> > -   pci_unmap_rom(pdev, oprom);
> > -
> > -   if (sizep)
> > -           *sizep = vbt_size;
> > -
> > -   drm_dbg_kms(display->drm, "Found valid VBT in PCI ROM\n");
> > -
> > -   return vbt;
> > -
> > -err_free_vbt:
> > -   kfree(vbt);
> > -err_unmap_oprom:
> > -   pci_unmap_rom(pdev, oprom);
> > -
> > +err_free_rom:
> > +   intel_rom_free(rom);
> >     return NULL;
> >  }
> >  
> > @@ -3220,11 +3128,11 @@ static const struct vbt_header 
> > *intel_bios_get_vbt(struct intel_display *display
> >      */
> >     if (!vbt && IS_DGFX(i915))
> >             with_intel_runtime_pm(&i915->runtime_pm, wakeref)
> > -                   vbt = spi_oprom_get_vbt(display, sizep);
> > +                   vbt = oprom_get_vbt(display, intel_rom_spi(i915), 
> > sizep, "SPI flash");
> >  
> >     if (!vbt)
> >             with_intel_runtime_pm(&i915->runtime_pm, wakeref)
> > -                   vbt = oprom_get_vbt(display, sizep);
> > +                   vbt = oprom_get_vbt(display, intel_rom_pci(i915), 
> > sizep, "PCI ROM");
> >  
> >     return vbt;
> >  }
> > diff --git a/drivers/gpu/drm/i915/soc/intel_rom.c 
> > b/drivers/gpu/drm/i915/soc/intel_rom.c
> > new file mode 100644
> > index 000000000000..243d98cab8c3
> > --- /dev/null
> > +++ b/drivers/gpu/drm/i915/soc/intel_rom.c
> > @@ -0,0 +1,160 @@
> > +// SPDX-License-Identifier: MIT
> > +/*
> > + * Copyright © 2024 Intel Corporation
> > + */
> > +
> > +#include "i915_drv.h"
> > +#include "i915_reg.h"
> > +
> > +#include "intel_rom.h"
> > +#include "intel_uncore.h"
> > +
> > +struct intel_rom {
> > +   /* for PCI ROM */
> > +   struct pci_dev *pdev;
> > +   void __iomem *oprom;
> > +
> > +   /* for SPI */
> > +   struct intel_uncore *uncore;
> > +   loff_t offset;
> > +
> > +   size_t size;
> > +
> > +   u32 (*read32)(struct intel_rom *rom, loff_t offset);
> > +   u16 (*read16)(struct intel_rom *rom, loff_t offset);
> > +   void (*read_block)(struct intel_rom *rom, void *data, loff_t offset, 
> > size_t size);
> > +   void (*free)(struct intel_rom *rom);
> > +};
> > +
> > +static u32 spi_read32(struct intel_rom *rom, loff_t offset)
> > +{
> > +   intel_uncore_write(rom->uncore, PRIMARY_SPI_ADDRESS,
> > +                      rom->offset + offset);
> > +
> > +   return intel_uncore_read(rom->uncore, PRIMARY_SPI_TRIGGER);
> > +}
> > +
> > +static u16 spi_read16(struct intel_rom *rom, loff_t offset)
> > +{
> > +   return spi_read32(rom, offset) & 0xffff;
> > +}
> > +
> > +struct intel_rom *intel_rom_spi(struct drm_i915_private *i915)
> 
> Would be nice to get rid of struct drm_i915_private too, but then it
> needs pci_dev and uncore, and we'll need to abstract uncore too, so
> let's just roll with this as a concrete step forward.

Yeah, dunno what we'll do about that suff.

> 
> > +{
> > +   struct intel_rom *rom;
> > +   u32 static_region;
> > +
> > +   rom = kzalloc(sizeof(*rom), GFP_KERNEL);
> > +   if (!rom)
> > +           return NULL;
> > +
> > +   rom->uncore = &i915->uncore;
> > +
> > +   static_region = intel_uncore_read(rom->uncore, SPI_STATIC_REGIONS);
> > +   static_region &= OPTIONROM_SPI_REGIONID_MASK;
> > +   intel_uncore_write(rom->uncore, PRIMARY_SPI_REGIONID, static_region);
> > +
> > +   rom->offset = intel_uncore_read(rom->uncore, OROM_OFFSET) & 
> > OROM_OFFSET_MASK;
> > +
> > +   rom->size = 0x200000;
> > +
> > +   rom->read32 = spi_read32;
> > +   rom->read16 = spi_read16;
> > +
> > +   return rom;
> > +}
> > +
> > +static u32 pci_read32(struct intel_rom *rom, loff_t offset)
> > +{
> > +   return ioread32(rom->oprom + offset);
> > +}
> > +
> > +static u16 pci_read16(struct intel_rom *rom, loff_t offset)
> > +{
> > +   return ioread16(rom->oprom + offset);
> > +}
> > +
> > +static void pci_read_block(struct intel_rom *rom, void *data,
> > +                      loff_t offset, size_t size)
> > +{
> > +   memcpy_fromio(data, rom->oprom + offset, size);
> > +}
> > +
> > +static void pci_free(struct intel_rom *rom)
> > +{
> > +   pci_unmap_rom(rom->pdev, rom->oprom);
> > +}
> > +
> > +struct intel_rom *intel_rom_pci(struct drm_i915_private *i915)
> > +{
> > +   struct intel_rom *rom;
> > +
> > +   rom = kzalloc(sizeof(*rom), GFP_KERNEL);
> > +   if (!rom)
> > +           return NULL;
> > +
> > +   rom->pdev = to_pci_dev(i915->drm.dev);
> > +
> > +   rom->oprom = pci_map_rom(rom->pdev, &rom->size);
> > +   if (!rom->oprom) {
> > +           kfree(rom);
> > +           return NULL;
> > +   }
> > +
> > +   rom->read32 = pci_read32;
> > +   rom->read16 = pci_read16;
> > +   rom->read_block = pci_read_block;
> > +   rom->free = pci_free;
> > +
> > +   return rom;
> > +}
> > +
> > +u32 intel_rom_read32(struct intel_rom *rom, loff_t offset)
> > +{
> > +   return rom->read32(rom, offset);
> > +}
> > +
> > +u16 intel_rom_read16(struct intel_rom *rom, loff_t offset)
> > +{
> > +   return rom->read16(rom, offset);
> > +}
> > +
> > +void intel_rom_read_block(struct intel_rom *rom, void *data,
> > +                     loff_t offset, size_t size)
> > +{
> > +   u32 *ptr = data;
> > +   loff_t index;
> 
> Just nitpicking, but should this (and rom reads above) now sanity check
> offset+size against rom->size? IDK if it's worth it for such a simple
> thing. The caller is supposed to know what it's doing.

I considered that but decided to cut my losses before I
end up designing a whole new kernel subsystem.

> 
> > +
> > +   if (rom->read_block) {
> > +           rom->read_block(rom, data, offset, size);
> > +           return;
> > +   }
> > +
> > +   for (index = 0; index < size; index += 4)
> > +           *ptr++ = rom->read32(rom, offset + index);
> > +}
> > +
> > +loff_t intel_rom_find(struct intel_rom *rom, u32 needle)
> > +{
> > +   loff_t offset;
> > +
> > +   for (offset = 0; offset < rom->size; offset += 4) {
> > +           if (rom->read32(rom, offset) == needle)
> > +                   return offset;
> > +   }
> > +
> > +   return -ENOENT;
> > +}
> > +
> > +size_t intel_rom_size(struct intel_rom *rom)
> > +{
> > +   return rom->size;
> > +}
> > +
> > +void intel_rom_free(struct intel_rom *rom)
> > +{
> > +   if (rom && rom->free)
> > +           rom->free(rom);
> > +
> > +   kfree(rom);
> > +}
> > diff --git a/drivers/gpu/drm/i915/soc/intel_rom.h 
> > b/drivers/gpu/drm/i915/soc/intel_rom.h
> > new file mode 100644
> > index 000000000000..fb2979c8ef7f
> > --- /dev/null
> > +++ b/drivers/gpu/drm/i915/soc/intel_rom.h
> > @@ -0,0 +1,25 @@
> > +/* SPDX-License-Identifier: MIT */
> > +/*
> > + * Copyright © 2024 Intel Corporation
> > + */
> > +
> > +#ifndef __INTEL_ROM_H__
> > +#define __INTEL_ROM_H__
> > +
> > +#include <linux/types.h>
> > +
> > +struct drm_i915_private;
> > +struct intel_rom;
> > +
> > +struct intel_rom *intel_rom_spi(struct drm_i915_private *i915);
> > +struct intel_rom *intel_rom_pci(struct drm_i915_private *i915);
> > +
> > +u32 intel_rom_read32(struct intel_rom *rom, loff_t offset);
> > +u16 intel_rom_read16(struct intel_rom *rom, loff_t offset);
> > +void intel_rom_read_block(struct intel_rom *rom, void *data,
> > +                     loff_t offset, size_t size);
> > +loff_t intel_rom_find(struct intel_rom *rom, u32 needle);
> > +size_t intel_rom_size(struct intel_rom *rom);
> > +void intel_rom_free(struct intel_rom *rom);
> > +
> > +#endif /* __INTEL_ROM_H__ */
> > diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
> > index edfd812e0f41..dd1c0666e6bd 100644
> > --- a/drivers/gpu/drm/xe/Makefile
> > +++ b/drivers/gpu/drm/xe/Makefile
> > @@ -180,7 +180,8 @@ xe-$(CONFIG_DRM_XE_DISPLAY) += \
> >  # SOC code shared with i915
> >  xe-$(CONFIG_DRM_XE_DISPLAY) += \
> >     i915-soc/intel_dram.o \
> > -   i915-soc/intel_pch.o
> > +   i915-soc/intel_pch.o \
> > +   i915-soc/intel_rom.o
> >  
> >  # Display code shared with i915
> >  xe-$(CONFIG_DRM_XE_DISPLAY) += \
> > diff --git a/drivers/gpu/drm/xe/compat-i915-headers/soc/intel_rom.h 
> > b/drivers/gpu/drm/xe/compat-i915-headers/soc/intel_rom.h
> > new file mode 100644
> > index 000000000000..05cbfb697b2b
> > --- /dev/null
> > +++ b/drivers/gpu/drm/xe/compat-i915-headers/soc/intel_rom.h
> > @@ -0,0 +1,6 @@
> > +/* SPDX-License-Identifier: MIT */
> > +/*
> > + * Copyright © 2024 Intel Corporation
> > + */
> > +
> > +#include "../../../i915/soc/intel_rom.h"
> 
> -- 
> Jani Nikula, Intel

-- 
Ville Syrjälä
Intel

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