From dcb58a40caeb77b937d7930eafc5bd22373a754e Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Tue, 12 May 2015 15:41:32 +0300 Subject: [PATCH] drm/i915: constify validate_vbt in VBT parsing MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Make input and output of validate_vbt const, and fix the fallout. We shouldn't modify the VBT, so make the compiler help us here. v2: use pointer arithmetics on void* to simplify (Ville) Signed-off-by: Jani Nikula Reviewed-by: Ville Syrjälä Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_bios.c | 49 ++++++++++++++++--------------- 1 file changed, 25 insertions(+), 24 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c index 5876e7cb132d..cbd16c01959a 100644 --- a/drivers/gpu/drm/i915/intel_bios.c +++ b/drivers/gpu/drm/i915/intel_bios.c @@ -205,7 +205,7 @@ get_lvds_fp_timing(const struct bdb_header *bdb, /* Try to find integrated panel data */ static void parse_lfp_panel_data(struct drm_i915_private *dev_priv, - struct bdb_header *bdb) + const struct bdb_header *bdb) { const struct bdb_lvds_options *lvds_options; const struct bdb_lvds_lfp_data *lvds_lfp_data; @@ -311,7 +311,8 @@ parse_lfp_panel_data(struct drm_i915_private *dev_priv, } static void -parse_lfp_backlight(struct drm_i915_private *dev_priv, struct bdb_header *bdb) +parse_lfp_backlight(struct drm_i915_private *dev_priv, + const struct bdb_header *bdb) { const struct bdb_lfp_backlight_data *backlight_data; const struct bdb_lfp_backlight_data_entry *entry; @@ -349,7 +350,7 @@ parse_lfp_backlight(struct drm_i915_private *dev_priv, struct bdb_header *bdb) /* Try to find sdvo panel data */ static void parse_sdvo_panel_data(struct drm_i915_private *dev_priv, - struct bdb_header *bdb) + const struct bdb_header *bdb) { const struct lvds_dvo_timing *dvo_timing; struct drm_display_mode *panel_fixed_mode; @@ -403,7 +404,7 @@ static int intel_bios_ssc_frequency(struct drm_device *dev, static void parse_general_features(struct drm_i915_private *dev_priv, - struct bdb_header *bdb) + const struct bdb_header *bdb) { struct drm_device *dev = dev_priv->dev; const struct bdb_general_features *general; @@ -429,7 +430,7 @@ parse_general_features(struct drm_i915_private *dev_priv, static void parse_general_definitions(struct drm_i915_private *dev_priv, - struct bdb_header *bdb) + const struct bdb_header *bdb) { const struct bdb_general_definitions *general; @@ -456,7 +457,7 @@ child_device_ptr(const struct bdb_general_definitions *p_defs, int i) static void parse_sdvo_device_mapping(struct drm_i915_private *dev_priv, - struct bdb_header *bdb) + const struct bdb_header *bdb) { struct sdvo_device_mapping *p_mapping; const struct bdb_general_definitions *p_defs; @@ -546,7 +547,7 @@ parse_sdvo_device_mapping(struct drm_i915_private *dev_priv, static void parse_driver_features(struct drm_i915_private *dev_priv, - struct bdb_header *bdb) + const struct bdb_header *bdb) { const struct bdb_driver_features *driver; @@ -572,7 +573,7 @@ parse_driver_features(struct drm_i915_private *dev_priv, } static void -parse_edp(struct drm_i915_private *dev_priv, struct bdb_header *bdb) +parse_edp(struct drm_i915_private *dev_priv, const struct bdb_header *bdb) { const struct bdb_edp *edp; const struct edp_power_seq *edp_pps; @@ -684,7 +685,7 @@ parse_edp(struct drm_i915_private *dev_priv, struct bdb_header *bdb) } static void -parse_psr(struct drm_i915_private *dev_priv, struct bdb_header *bdb) +parse_psr(struct drm_i915_private *dev_priv, const struct bdb_header *bdb) { const struct bdb_psr *psr; const struct psr_table *psr_table; @@ -795,7 +796,7 @@ static u8 *goto_next_sequence(u8 *data, int *size) } static void -parse_mipi(struct drm_i915_private *dev_priv, struct bdb_header *bdb) +parse_mipi(struct drm_i915_private *dev_priv, const struct bdb_header *bdb) { const struct bdb_mipi_config *start; const struct bdb_mipi_sequence *sequence; @@ -946,7 +947,7 @@ err: } static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port, - struct bdb_header *bdb) + const struct bdb_header *bdb) { union child_device_config *it, *child = NULL; struct ddi_vbt_port_info *info = &dev_priv->vbt.ddi_port_info[port]; @@ -1048,7 +1049,7 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port, } static void parse_ddi_ports(struct drm_i915_private *dev_priv, - struct bdb_header *bdb) + const struct bdb_header *bdb) { struct drm_device *dev = dev_priv->dev; enum port port; @@ -1068,7 +1069,7 @@ static void parse_ddi_ports(struct drm_i915_private *dev_priv, static void parse_device_mapping(struct drm_i915_private *dev_priv, - struct bdb_header *bdb) + const struct bdb_header *bdb) { const struct bdb_general_definitions *p_defs; const union child_device_config *p_child; @@ -1198,19 +1199,20 @@ static const struct dmi_system_id intel_no_opregion_vbt[] = { { } }; -static struct bdb_header *validate_vbt(char *base, size_t size, - struct vbt_header *vbt, - const char *source) +static const struct bdb_header *validate_vbt(const void *base, size_t size, + const void *_vbt, + const char *source) { + const struct vbt_header *vbt = _vbt; size_t offset; - struct bdb_header *bdb; + const struct bdb_header *bdb; if (vbt == NULL) { DRM_DEBUG_DRIVER("VBT signature missing\n"); return NULL; } - offset = (char *)vbt - base; + offset = _vbt - base; if (offset + sizeof(struct vbt_header) > size) { DRM_DEBUG_DRIVER("VBT header incomplete\n"); return NULL; @@ -1227,7 +1229,7 @@ static struct bdb_header *validate_vbt(char *base, size_t size, return NULL; } - bdb = (struct bdb_header *)(base + offset); + bdb = base + offset; if (offset + bdb->bdb_size > size) { DRM_DEBUG_DRIVER("BDB incomplete\n"); return NULL; @@ -1252,7 +1254,7 @@ intel_parse_bios(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; struct pci_dev *pdev = dev->pdev; - struct bdb_header *bdb = NULL; + const struct bdb_header *bdb = NULL; u8 __iomem *bios = NULL; if (HAS_PCH_NOP(dev)) @@ -1262,9 +1264,8 @@ intel_parse_bios(struct drm_device *dev) /* XXX Should this validation be moved to intel_opregion.c? */ if (!dmi_check_system(intel_no_opregion_vbt) && dev_priv->opregion.vbt) - bdb = validate_vbt((char *)dev_priv->opregion.header, OPREGION_SIZE, - (struct vbt_header *)dev_priv->opregion.vbt, - "OpRegion"); + bdb = validate_vbt(dev_priv->opregion.header, OPREGION_SIZE, + dev_priv->opregion.vbt, "OpRegion"); if (bdb == NULL) { size_t i, size; @@ -1277,7 +1278,7 @@ intel_parse_bios(struct drm_device *dev) for (i = 0; i + 4 < size; i++) { if (memcmp(bios + i, "$VBT", 4) == 0) { bdb = validate_vbt(bios, size, - (struct vbt_header *)(bios + i), + bios + i, "PCI ROM"); break; } -- 2.20.1